final

Question 1

primary reproductive organs

Answer 1

ovaries

Question 2

accessory reproductive organs

Answer 2

uterine tubes, uterus, vagina, external genitalia, mammary glands

Question 3

gametes are made using

Answer 3

mitotic division

Question 4

what is the site of oocyte production

Answer 4

ovarian follicles

Question 5

what is the site of sex hormone release

Answer 5

ovarian follicles (estrogen and progesterone)

Question 6

mature follicle forms from

Answer 6

secondary follicle

Question 7

mature follicle components

Answer 7

• secondary oocyte surrounded by zona pellucida
• then corona radiata
• antrum

Question 8

when ovulation occurs corona radiata goes

Answer 8

with the egg as it goes into uterine tube so in order to fertilize the egg it has to make it through both of these layers (corona radiata, zona pellucida) to reach the egg

Question 9

what cells are sources of estrogen?

Answer 9

granulosa cells

Question 10

what part of the mature follicle gets bigger during follicular development

Answer 10

fluid-filled antrum

Question 11

how often is a mature follicle formed

Answer 11

one per month

Question 12

division of mature follicle

Answer 12

divides mitoticly and divides into secondary oocyte with 23 chromosomes, it begins but stops in metaphase

doesn’t occur unless oocyte is fertilized

Question 13

corpus luteum formation

Answer 13

remanants of follicle
after mature follicle ruptures and oocyte expelled

Question 14

corpus luteum secretes

Answer 14

sex hormones progesterone and estrogen to stimulate buildup of uterine lining (endometrium) and prepare uterus for possible implantation of fertilized oocyte

Question 15

what structure releases GnRH

Answer 15

hypothalamus

Question 16

GnRH release stimulates release of

Answer 16

FSH and LH

Question 17

FSH and LH play a major role in

Answer 17

events in ovarian cycle

Question 18

phases of ovarian cycle

Answer 18

• follicular phase (days 1-13)
• ovulation (day 14)
• luteal phase (days 15-38)

Question 19

ovulation

Answer 19

• release of secondary oocyte from mature follicle
• occurs on day 14 of 28 day cycle
• antrum increases in size and swells with increased fluid
• expands until ovarian surface thins, eventually rupturing and expelling secondary oocyte

Question 20

ovulation is induced with increased

Answer 20

LH secretion

Question 21

order of oocyte release on ovaries

Answer 21

• infundibulum (has to catch oocyte, contains fimbriae)
• ampulla (where fertilization occurs)
• isthmus
• uterine part

Question 22

uterine wall is mostly

Answer 22

smooth muscle
contains
- endometrium
- myometrium
- perimetrium (thin connective tissue covering on outside)
from deep to superficial

Question 23

uterine cycle

Answer 23

changes in endometrial lining

Question 24

uterine cycle is influenced by

Answer 24

estrogen and progesterone - secreted by follicle and then corpus luteum

Question 25

uterine cycle phases

Answer 25

menstrual phase (1-5) proliferative phase (6-14) secretory phase (15-28)

Question 26

menstrual phase

Answer 26

1-5 sloughing off of functional layer lasts through period of menstrual bleeding

Question 27

proliferative phase

Answer 27

days 6-14 development of new functional layer of endometrium overlaps time of follicle growth and ovarian estrogen secretion

Question 28

secretory phase

Answer 28

days 15-28 increased progesterone secretion from corpus luteum results in increased vascularization and uterine gland development

Question 29

estrogen secretion happens in

Answer 29

proliferative phase of uterine cycle

Question 30

progesterone secretion happens in

Answer 30

secretory phase of uterine cycle

Question 31

if fertilization doesn't occur in secretory phase

Answer 31

- corpus luteum degenerates - drop in levels of progesterone (causing functional layer to slough off)

Question 32

levels of hormones during follicular phase of ovarian cycle

Answer 32

high FSH and estrogen levels low LH and progesterone

Question 33

mammary glands

Answer 33

exocrine glands divided into lobes and then into lobules composed of alveoli

Question 34

lactiferous ducts

Answer 34

bring materials to the nipple

Question 35

breast milk release

Answer 35

- occurs in response to internal and external stimuli - starts to produce after giving birth

Question 36

prolactin

Answer 36

produced in anterior pituitary gland stimulates milk production, with increase mammary gland forms more and larger alveoli

Question 37

oxytocin

Answer 37

produced by hypothalamus and released from posterior pituitary gland responsible for milk ejection

Question 38

primary male reproductive organs

Answer 38

testes

Question 39

accessory reproductive organs of male reproductive system

Answer 39

ducts and tubules lead from testes to penis male accessory glands penis

Question 40

epididymis

Answer 40

responsible for storage of sperm

Question 41

where are gametes produced in MRS

Answer 41

inside seminiferous tubules

Question 42

internal components of testes are organized into

Answer 42

lobules divided by septum

Question 43

components of seminiferous tubules

Answer 43

within tubule lumen of seminiferous tubules sperm or germ cells are found seminiferous tubules are making haploid gametes so meiosis is going to start dividing toward lumen sperm within lumen spermatids line the lumen spermatagonia on outside border of seminiferous tubule

Question 44

sustentacular cells

Answer 44

provide strength to germ cells, support them, provide nutritional support, and influence rate of sperm cell production

Question 45

maturation of sperm cells

Answer 45

spermatogonia (2n) - primary spermatocyte - secondary spermatocyte - spermatids - spermatogonia (sperm) (n)

Question 46

hormone regulation on spermatogenesis and androgen production

Answer 46

1. GnRH stimulates anterior pituitary gland to secrete FSH and LH 2. LH stimulates interstitial cells to secrete testosterone, FSH stimulates sustentacular cells to secrete androgen-binding protein (ABP) 3. Testosterone stimulates spermatogenesis but inhibits GnRH secretion and reduces the anterior pituitary glands sensitivity to GnRH 4. Rising sperm count levels causes sustentacular cells to secrete inhibin, further inhibiting FSH secretion 5. testosterone stimulates libido and development of secondary sex characteristics

Question 47

androgen binding protein keeps

Answer 47

testosterone levels high in testes

Question 48

seminal fluid

Answer 48

- alkaline secretion need to neutralize vaginal acidity - gives nutrients to sperm traveling in female reproductive tract - produced by accessory glands a) seminal vesicles b) prostate gland c) bulbourethral glands

Question 49

semen

Answer 49

- formed from seminal fluid and sperm - called ejaculate when released during intercourse - contain 200-500 million spermatozoa - transit time from seminiferous tubules to ejaculate is about 2 weeks

Question 50

puberty

Answer 50

- period in adolescence where reproductive organs become fully functional - external sex characteristics become more prominent

Question 51

timing of puberty affected by

Answer 51

genetics, health, environmental factors

Question 52

puberty initiation

Answer 52

1. hypothalamus secretes GnRH 2. stimulates anterior pituitary gland to secrete FSH and LH 3. sex hormone levels increase starting the process of gamete and sexual maturation

Question 53

menarche

Answer 53

about 2 years after first signs of puberty first period

Question 54

gender differences of puberty

Answer 54

girls 2 years prior to boys 8-12 for girls 9-14 for boys

Question 55

racial differences of puberty

Answer 55

african american girls about 1 year earlier than caucasions onset of puberty has decreased with better nutrition and health care

Question 56

precocious puberty

Answer 56

- signs of puberty developing much earlier than normal - may be without known cause - may be due to pituitary or gonad tumor

Question 57

perimenopause

Answer 57

time near menopause irregular or skipped periods

Question 58

menopause

Answer 58

women stop monthly menstrual cycles for a year 45-55 - atrophy of reproductive organs and breasts with reduced hormones - decrease vaginal wall thickness - hot flashes - thinning hair - increased risk of osteoporosis and heart disease - sometimes treated with hormone replacement therapy

Question 59

fertilization

Answer 59

- 2 gametes fuse to form diploid cell (containing genetic material from both parents) - restores diploid number of chromosomes - determines sex of organism - initiates cleavage

Question 60

oocyte viable for how long after ovulation

Answer 60

24 hrs

Question 61

sperm remains viable for

Answer 61

3-4 days

Question 62

corona radiata penetration

Answer 62

1st phase of fertilization of mature oocyte when sperm reaches secondary oocyte, it is initially prevented by corona radiata and zona pellucida sperm can push through these layers

Question 63

zona pellucide penetration

Answer 63

Acrosome reaction: - release of digestive enzymes from acrosomes - allows sperm to penetrate zona pellucida After penetration of secondary oocyte: - immediate hardening of zona pellucida - prevents other sperm from entering this layer - ensures only one sperm fertilizes the oocyte

Question 64

labor

Answer 64

physical expulsion of fetus and placenta from uterus usually 38 weeks

Question 65

increased levels of estrogen during labor

Answer 65

- increases myometrium sensitivity - stimulate production of oxytocin receptors on uterine myometrium

Question 66

contractions become more intense and more frequent with increasing

Answer 66

estrogen and oxytocin

Question 67

premature labor

Answer 67

prior to 38 wks undesirable because infant body systems are not fully develop (especially lungs, insufficient surfactant)

Question 68

initiation of true labor (uterine contractions)

Answer 68

1. mothers hypothalamus secretes increasing levels of oxytocin 2. fetus's hypothalamus also secreting oxytocin - combined maternal and fetal oxytocin initiates true labor

Question 69

both fetal and maternal release of oxytocin stimulate placenta to secrete

Answer 69

prostaglandins - help stimulate uterine muscle contraction and soften and dilate the cervix

Question 70

true labor is a

Answer 70

positive feedback mechanism

Question 71

positive feedback mechanism of true labor

Answer 71

1. oxytocin is released from mother and fetus hypothalamus 2. stimulates uterus to contract and placenta to make prostaglandins 3. prostaglandings stimulate more frequent and intense contractions of uterus 4. uterine contractions cause fetal head to push against cervix, causing it to stretch and dilate 5. dilating cervix initiates nerve signals to hypothalamus which causes more oxytocin release from mother and fetus

Question 72

blood

Answer 72

- regenerated CT - moves gases nutrients, wastes, and hormones - transported through CV system

Question 73

arteries

Answer 73

transport blood away from heart

Question 74

veins

Answer 74

transport blood toward heart

Question 75

capillaries

Answer 75

allow exchange between blood and body tissues

Question 76

components of blood

Answer 76

formed elements and plasma

Question 77

formed elements of blood

Answer 77

erythrocytes (RBCs) leuokocytes (white blood cells) platelets (thrombocytes)

Question 78

erythrocytes function in blood

Answer 78

transports respiratory gases in the blood

Question 79

leukocytes function in the blood

Answer 79

defend against pathogens

Question 80

platelets function in the blood

Answer 80

form clots to prevent blood loss

Question 81

plasma of blood

Answer 81

fluid portion of blood contains plasma proteins and dissolved solutes

Question 82

functions of blood

Answer 82

- transportation - protection - regulation of body conditions (maintaining homeostasis)

Question 83

blood helps transport...

Answer 83

formed elements, dissolved molecules, and ions - carries oxygen to and from carbon dioxide to the lungs - transports nutrients, hormones, heat, and waste products

Question 84

leukocytes, plasma proteins, and other molecules (of immune system) protect against

Answer 84

pathogens

Question 85

platelets and plasma proteins within blood protect against

Answer 85

blood loss

Question 86

blood and body temperature

Answer 86

blood absorbs heat from body cells (especially muscle) heat is released at skin blood vessels

Question 87

blood and pH

Answer 87

blood absorbs acid and base from body cells blood contains chemical buffers (e.g., bicarbonate, proteins)

Question 88

blood and fluid balance

Answer 88

water is added to blood from GI tract water is lost through urine, skin, and respiration fluid is constantly being exchanged between blood and interstitial fluid - blood contains proteins and ions helping maintain osmotic balance

Question 89

oxygen-rich blood is

Answer 89

bright red

Question 90

oxygen poor blood is

Answer 90

dark red

Question 91

volume of blood in body

Answer 91

about 5 L males have slightly more than females

Question 92

viscosity of blood

Answer 92

blood is thicker than water (4-5x) depends on amount of dissolved and suspended substances

Question 93

viscosity increases if

Answer 93

erythrocyte number increases amount of fluid decreases

Question 94

plasma concentration of solutes (e.g., proteins, ions) within blood

Answer 94

typically .09% determines direction of osmosis across capillary walls

Question 95

temperature of blood

Answer 95

1 degree high than measured body temperature

Question 96

pH of blood

Answer 96

between 7.35 and 7.45 crucial for normal plasma protein shape

Question 97

percentages of blood

Answer 97

Plasma: - 55% of whole blood - contains water, proteins, and other solutes Buffy Coat: - <1% of whole blood - contains platelets and leukocytes Erythrocytes: - 44% of whole blood - contains erythrocytes

Question 98

what type of fluid is plasma

Answer 98

extracellular fluid has higher protein concentration to interstitial fluid

Question 99

blood is a

Answer 99

colloid mixture contains dispersed proteins

Question 100

plasma proteins examples

Answer 100

albumin globulins fibrinogen other clotting proteins, enzymes, and some hormones

Question 101

most plasma proteins are produced in

Answer 101

the liver some may be produced by leukocytes or other organs

Question 102

colloid osmotic pressure

Answer 102

prevents loss of fluid from blood as it moves through capillaries - helps maintain blood volume and blood pressure

Question 103

colloid osmotic pressure can be

Answer 103

decreased with certain diseases resulting in fluid loss from blood and tissue swelling - liver disease - kidney diseases

Question 104

albumins

Answer 104

most abundant exert greatest colloid osmotic pressure act as transport proteins for some lipids, hormones, and ions

Question 105

globulins

Answer 105

- second largest group - smaller alpha-globulins and larger beta-globulins that transport water insoluble molecules, hormones, metals, ions - gamma-globulins (immunoglobulins or antibodies) - body defense

Question 106

fibrinogen

Answer 106

- 4% of plasma proteins - blood clot formation

Question 107

serum

Answer 107

plasma with clotting proteins removed

Question 108

hemopoiesis

Answer 108

production of formed elements

Question 109

where does hemopoiesis occur

Answer 109

red bone marrow of certain bones

Question 110

hemocytoblasts

Answer 110

stem cells/pluriopotent - can differentiate into many types of cells produces myeloid and lymphoid line

Question 111

myeloid line

Answer 111

forms erythrocytes, all leukocytes except lymphocytes, and megakaryocytes (platelet producing cells)

Question 112

lymphoid line

Answer 112

only produce lymphocytes

Question 113

erythrocytes are formed by

Answer 113

erythropoiesis

Question 114

platelets are formed by

Answer 114

thrombopoiesis

Question 115

leukocytes are formed by

Answer 115

leukopoesis

Question 116

platelet formation

Answer 116

megakaryocytes line blood vessels where appendages on megakaryocytes fall into called proplatelets as blood pushes through proplaets break off forming platelets within blood

Question 117

erythrocytes

Answer 117

- contain hemoglobin - biconcave disc structure - contain spectrin for support and flexibility - can stack and line up in single file (roleau) - transport oxygen and CO2 between tissues and lungs

Question 118

hemoglobin

Answer 118

red pigmented protein - oxygenated when maximally loaded with oxygen - termed deoxygenated when some oxygen is lost - composed of 4 globin proteins with 2 alpha chains and 2 beta chains each containing a heme group with iron in its center

Question 119

makeup of hemoglobin

Answer 119

oxygen binds to iron in center of hemoglobin, so each hemoglobin can bind to 4 oxygen molecule

Question 120

oxygen binds to iron

Answer 120

binding is weak rapid attachment in lungs and rapid detachment in body tissues

Question 121

carbon dioxide binds to globin protein

Answer 121

binding is weak attachment in body tissue and detachment in lungs

Question 122

EPO regulation of erythrocyte production

Answer 122

1. decreased blood oxygen levels 2. kidney detects decreased blood O2 3. kidney cells release EPO into blood 4. EPO stimulates red bone marrow to increase the rate of production of erythrocytes 5. increased numbers of erythrocytes enter the circulation, during which time the lungs oxygenate erythrocytes and blood O2 levels increase 6. increased O2 levels are detected by kidney, stopping EPO release (negative feedback)

Question 123

erythrocyte recycling

Answer 123

1. eryhtrocytes form in red bone marrow 2. they circulate in blood for about 120 days 3. aged erythrocytes are phagocytized by macrophages in the liver and spleen. the three components of hemoglobin are separated (globin, heme, iron) 4. each of separated coponents of hemoglobin have different fate - globin proteins: broken down into amino acids and enter the blood (potential use to make new erythrocytes) - iron: small amounts of iron are lost in sweat, urine, and feces daily; also lost during injury or mestruation - heme: converted to biliverdin then bilirubin which is transported to liver by albumin and released as bile into small intestine. then bilirubin is converted to urobilinogen in small intestine (some urobilinogen absorbed back into blood and converted into urobilin and excreted in urine, most continues in large intense and is converted into stercobilin and expelled in feces)

Question 124

type A

Answer 124

surface antigen A anti B antibodies

Question 125

type B

Answer 125

surface antigen B anti A antibodies

Question 126

type AB

Answer 126

surface antigens A and B no anti A or anti B

Question 127

type O

Answer 127

no surface antigens anti A and anti B

Question 128

Rh blood type

Answer 128

presence or absence of Rh factor (antigen D) deterines if blood is + or - antibodies to Rh are not usually there (only appear after Rh exposure to Rh+ blood)

Question 129

agglutination in transfusion reaction

Answer 129

if patient is type B and is given type A blood... - anti A antibodies in plasma will attach to type A erythrocytes and cause a clumping of erythrocytes creating a blockage in small vessels

Question 130

leukocytes

Answer 130

defend against pathogen motile and flexible - most not in blood but in tissues

Question 131

leukocytes have ability to perform

Answer 131

diapedesis and chemotaxis

Question 132

diapedesis

Answer 132

process of squeezing through blood vessel wall

Question 133

chemotaxis

Answer 133

attraction of leukocytes to chemical at an infection site

Question 134

neutrophils

Answer 134

phagocytize pathogens most abundant leukocyte

Question 135

eospinophils

Answer 135

phagocytize antigen-antibody complexes and allergens present in cases of parasitic infection

Question 136

basophils

Answer 136

release histamines (vasodilator increasing capillary permeability) and heparin (anticoagulant)

Question 137

granulocytes

Answer 137

neutrophils basophils eosinophils

Question 138

agranulocytes

Answer 138

lymphocytes monocytes

Question 139

lymphocytes

Answer 139

coordinate immune cell acitivty attack pathogens and abnormal infected cells produce antibodies

Question 140

monocytes

Answer 140

exit blood vessels and become macrophages phagocytize pathogens

Question 141

Most abundant to least abundant leukocytes

Answer 141

neutrophils lymphocytes monocytes eosinophils basophils

Question 142

platelets are stored in

Answer 142

spleen

Question 143

circulation of platelets

Answer 143

circulate for 8-10 days and then broken down and recycled

Question 144

platelets play a major role in

Answer 144

blood clotting

Question 145

hemostasis

Answer 145

stoppage of bleeding

Question 146

phases of hemostasis

Answer 146

vascular spasm platelet plug formation coagulation phase

Question 147

hemostasis steps

Answer 147

1. Vascular spasm - blood vessel constricts to limit blood escaping 2. Platelet plug formation - platelets arrive at site of injury and stick to exposed collagen fibers 3. Coagulation - coagulation cascade converts inactive proteins to active forms, leading to production of fibrin strands of a blood clot

Question 148

vascular spasm

Answer 148

- 1st phase - lasts from few to many minutes - greater vasoconstriction with greater vessel damage

Question 149

platelet plug formation

Answer 149

when blood vessel is damaged collagen fibers are exposed causing platelets to stick to collagen with help of von Willebrand factor where they develop long processes allowing for better adhesion where platelets continue to aggregate there

Question 150

when blood vessel is uninjured platelet activation is

Answer 150

inhibited as a result of prostacyclin which repels platelets and causes endothelial cells and platelets to make cAMP which inhibits platelet activation

Question 151

platelet activation

Answer 151

platelets cytosol degranulates and releases chemicals causing - prolonged vascular spasms - attraction of other platelets - coagulation stimulation - reparation of blood vessels

Question 152

platelet plug is formed typically within

Answer 152

1 minute prevented from getting to large by prostacyclin

Question 153

serotonin and thromboxane A2 causes

Answer 153

prolonged vascular spasms in platelet activation

Question 154

adenosine triphosphate (ADP) and thromboxane causes

Answer 154

attraction of other platelets and facilitate their degranulation (positive feedback)

Question 155

procoagulants stimulate

Answer 155

coagulation

Question 156

mitosis stimulating substances trigger

Answer 156

repair of blood vessel

Question 157

coagulation

Answer 157

blood clotting network of fibrin (insoluble protein that comes from fibrinogen) forms a mesh that traps erythrocytes, leukocytes, platelets, and plasma proteins to form a clot

Question 158

subsances involved in coagulation

Answer 158

- calcium, clotting factors, vitamin K

Question 159

clotting factors

Answer 159

most inactive enzymes most produced in liver within hepatocytes

Question 160

vitamin K

Answer 160

fat soluble coenzyme required for synthesiss of clotting factors II, VII, IX, X

Question 161

intrinsic coagulation pathway

Answer 161

initiated by damage to inside of blood vessel

Question 162

extrinsic coagulation pathway

Answer 162

initiated by damage to tissue outside of vessel

Question 163

clot elimination includes

Answer 163

clot retraction and fibrinolysis

Question 164

clot retraction

Answer 164

actinomyosin (protein with platelets) contracts and squeezes serum out of developing clot making it smaller

Question 165

fibrinolysis

Answer 165

degradation of fibrin strands by plasmin begins within 2 days after clot formation occurs slowly over a number of days

Question 166

four chambers of the heart

Answer 166

left atrium and right atrium left ventricles and right ventricles

Question 167

left atrium and right atrium are superior chambers that

Answer 167

receive blood and send it to ventricles

Question 168

left ventricle and right ventricles are inferior chambers that pump blood

Answer 168

away

Question 169

left side of the heart has

Answer 169

oxygenated blood

Question 170

right side of the heart has

Answer 170

deoxygenated blood

Question 171

right side

Answer 171

receives deoxygenated blood from body and pumps it to the lungs

Question 172

left side

Answer 172

receives oxygenated blood from the lungs and pumps it into the body

Question 173

atrioventricular valves are between

Answer 173

atria and ventricles

Question 174

semilunar valves are between

Answer 174

ventricle and an arteriole trunk pulmonary semilunar valve and aortic semilunar valve

Question 175

right AV is sometimes called

Answer 175

tricuspid

Question 176

left AV valve sometimes called

Answer 176

bicuspid mitral

Question 177

flow of blood through heart and lungs

Answer 177

1. deoxygenated blood enters the atrium through IVC and SVC 2. blood within right atrium enters right ventricle through right atrioventricular valve (tricuspid) 3. blood enters ventricle is pumped through pulmonary semilunar valve into the lungs 4. deoxygenated blood enters lungs where it flows through capillaries and becomes oxygenated and enters back into the heart in the left atrium 5. blood within left atrium is pumped into ventricles via left atrioventricular valve (mitral, bicuspid) 6. blood within ventricles is then pumped out via the aortic semilunar valve throughout the body where further gas exchange occurs as blood is delievered to body systems and deoxygenated blood is then brought back to the heart

Question 178

pericardium

Answer 178

refers to 3 layers of the heart

Question 179

outer layer of heart

Answer 179

fibrous periardium

Question 180

serous pericardium

Answer 180

contains visceral and parietal layer containing with pericardial cavity with serous fluid

Question 181

layers of the heart wall (from deep to superficial

Answer 181

epicardium myocardium endocardium

Question 182

ventricles have thicker walls than

Answer 182

atria

Question 183

left ventricle has thicker wall than

Answer 183

right ventricle left ventricle must generate higher pressure to force blood through systemic circulation; right just pumps to nearby lungs

Question 184

cardiac muscle contains

Answer 184

striated muscle due to arrangement of contractile proteins and overlapping nature of thin and thick filaments

Question 185

sarcolemma

Answer 185

plasma membrane containing openings called T-tubules which are infolds of plasma membrane

Question 186

cardiac muscle contains intercellular junctions that include

Answer 186

desmosomes gap junctions

Question 187

desmosomes

Answer 187

proteins that serve to connect two adjacent cells become embedded in cell membrane

Question 188

gap junctions

Answer 188

proteins with opening in center that functionally pass ions through

Question 189

gap junctions are important in

Answer 189

contraction and activation of muscle stimulate electrical current needed for contraction

Question 190

storage site for Ca2+

Answer 190

sarcoplasmic T tubules

Question 191

cardiac muscle contains

Answer 191

intercalated discs

Question 192

metabolism of cardiac muscle

Answer 192

high demand for energy - extensive blood supply - numerous mitochondria - myoglobin and creatine kinase

Question 193

creatine + ATP ---->

Answer 193

CK -- creatine phosphate + ADP

Question 194

cardiac muscle is able to use

Answer 194

different kinds of fuel molecules like: fatty acids, glucose, lactic acid, amino acids, and ketone bodies

Question 195

cardiac muscle metabolism relies mostly on

Answer 195

aerobic metabolism which makes it susceptible to failure when oxygen is low

Question 196

fibrous skeleton is made up of

Answer 196

dense irregular connective tissue

Question 197

fibrous skeleton provides

Answer 197

structural support at boundary of atria and ventricles that froms fibrous rings to anchor valves

Question 198

the fibrous skeleton acts as an

Answer 198

electrical insulator preventing ventricles from contracting at same time as atria

Question 199

coronary circulation delivers blood to

Answer 199

heart wall - coronary arteries transport oxygenated blood to heart wall - coronary veins transport deoxygenated blood away from heart wall toward right atrium

Question 200

conduction system

Answer 200

initiations and conducts electrical events to ensure proper timing of contractions

Question 201

conduction system contains specialized cardiac

Answer 201

muscle cells that have action potentials but do not contract

Question 202

conduction system activity is influenced by

Answer 202

autonomic nervous system

Question 203

components of conduction system

Answer 203

SA node AV node AV bundle (bundle of His) R and L bundle branches Purkinje fibers

Question 204

SA node

Answer 204

pacemaker tissue in posterior wall of atrium that starts generating action potential

Question 205

what part of the brain contains the cardiac center

Answer 205

medulla oblongata

Question 206

the cardiac center of the medulla contains

Answer 206

1. cardioacceleratory 2. cardioinhibitory centers

Question 207

the cardiac center of medulla receives signals from

Answer 207

baroreceptors and chemoreceptors in CV system

Question 208

the cardiac center sends signals via

Answer 208

sympathetic and parasympathetic pathways

Question 209

the cardiac center ______ cardiac activity

Answer 209

modifies - influences rate and force of hearts contractions

Question 210

what influences the rate and force of heart contractions

Answer 210

cardiac center

Question 211

what kind of nerve innervation decreases heart rate

Answer 211

parasympathetic

Question 212

what kind of nerve innervation increases heart rate and force of contraction

Answer 212

sympathetic

Question 213

steps of heart contraction

Answer 213

Conduction system 1. initiation - SA node generates action potential 2. spread of action potential - action potential is propagated throughout the atria and the conduction system Cardiac Muscle Cell 1. action potential - action potential is propagated across the sarcolemma of cardiac muscle cells 2. thin filaments slide past thick filaments and sarcomeres shorten within cardiac muscle cells

Question 214

RMP of nodal cells

Answer 214

-60mV

Question 215

the sodium concentration is great inside or outside of a nodal cell

Answer 215

greater concentration of Na+ outside of cell

Question 216

SA Node Cellular Activity

Answer 216

1. RMP @ -60mV 2. increase (depolarization) 3. MP reaches threshold (-40mV) - repolarization 4. when cell becomes negative enough ation potential is generated

Question 217

pacemaker potential

Answer 217

time it takes for SA node to go from -40mV to threshold voltage

Question 218

steps of SA node generating action potential

Answer 218

1. Reaching threshold - slow voltage gated Na+ channels open - inflow of Na+ changes membrane potential from -60mV to -40mV 2. Depolarization - fast voltage gated Ca2+ channels open. inflow of Ca2+ changes membrane potential from -40mV to just above 0mV 3. Repolarization - fast voltage gated Ca2+ close. voltage gated K+ channels open allowing K+ outflow. MP returns to -60mV and K+ channels close

Question 219

RMP of cardiac muscle cell

Answer 219

-90mV

Question 220

at RMP of cardiac muscle cell, all Na+ is

Answer 220

closed so concentration gradient for ions remains table so ions aren't moving through creating action potential

Question 221

electrical events of cardiac muscle cell

Answer 221

1. Depolarization - starts @ - 90mV and rapidly reaches +30mV 2. Plateau - almost no change during period of time 3. Repolarization

Question 222

why do cardiac muscle cells have a plateau

Answer 222

helps ensure heart is beating synchronously with all of its components so if stimulated, nothing will happen

Question 223

steps of cardiac muscle cells

Answer 223

1. Depolarization - fast voltage gated Na+ channels open and Na+ flows into cell reversing polarity from -90mV to +30mV. Channels then close 2. Plateau - voltage gated K+ channels open and K+ flow out of cardiac muscle cells. slow voltage gated Ca2+ channels open and Ca2+ moves into the cell with no electrical change and depolarized state is maintained 3. Repolarization - voltage gated Ca2+ channels close, voltage gated K+ channels remain open and K+ moves out of cardiac muscle cell, and polarity is reversed from +30mV to -90mV

Question 224

electrocardiogram (ECG/EKG)

Answer 224

- skin electrodes detect electrical signals of cardiac muscle cells - common diagnostic tools

Question 225

P wave

Answer 225

atrial depolarization

Question 226

QRS complex

Answer 226

ventricular depolarization

Question 227

during QRS complex the atria are

Answer 227

repolarizing

Question 228

T wave

Answer 228

ventricular repolarization

Question 229

P-Q segment

Answer 229

atrial cells' plateau (atria are contracting)

Question 230

S-T segment

Answer 230

ventricular plateau (ventricles contracting

Question 231

P-R interval

Answer 231

time from beginning of P wave to beginning of QRS from atrial depolarization to beginning of ventricular depolarization

Question 232

P-R interval represents the time to transmit

Answer 232

action potential through entire conduction system

Question 233

Q-T interval

Answer 233

time from beginning of QRS to end of T wave reflects time of ventricular depolarization and repolarization

Question 234

the length of Q-T interval depends upon

Answer 234

heart rate

Question 235

cardiac cycle

Answer 235

all events in heart from the start of one beat to the start of the next

Question 236

the cardiac cycle includes both

Answer 236

systole (contraction) and diastole (relaxation)

Question 237

relationship of contraction and pressure

Answer 237

contraction increases pressure relaxation decreases it

Question 238

blood moves ____ its pressure gradient

Answer 238

down (high to low)

Question 239

valves ensure that

Answer 239

flow of blood is forward (closure of valves prevents backflow)

Question 240

what is the most important driving force of cardiac cycle

Answer 240

ventricular activity

Question 241

ventricular contraction raises

Answer 241

ventricular pressure AV valves pushed closed, semilunar valves pushed open and blood pushed out

Question 242

ventricular relaxation lowers

Answer 242

ventricular pressure semilunar valves closed AV valves open (no pressure pushing them closed)

Question 243

phases of cardiac cycle

Answer 243

1. atrial contraction and ventricular filling 2. isovolumetric contraction 3. ventricular ejection 4. isovolumetric relaxation 5. atrial relaxation and ventricular filling

Question 244

atrial contraction and ventricular filling

Answer 244

- atria contract, ventricle relax - ventricular pressure is LESS than atrial and arterial pressure - AV valves open, semilunar valves closed

Question 245

isovolumetric contraction

Answer 245

- atria relax, ventricles closed - ventricular pressure is greater than atrial pressure but less than arterial trunk pressure - AV valves and semilunar valves closed

Question 246

ventricular ejection

Answer 246

- atria relax, ventricles contract - ventricular pressure is GREATER than both atrial pressure and arterial trunk pressure - AV valves closed, semilunar valve open

Question 247

isovolumetric relaxation

Answer 247

- atria and ventricles are relaxed - ventricular pressure is greater than atrial pressure but less than arterial pressure - both valves closed

Question 248

atrial relaxation and ventricular filling

Answer 248

- atria relax, ventricles relax - ventricular pressure is less than BOTH arterial and atrial pressure - AV valves open, semilunar valves closed

Question 249

cardiac output

Answer 249

amount of blood pumped by *single* ventricle in one *minute*

Question 250

cardiac output is a measure of

Answer 250

effectiveness of CV system

Question 251

CO increases in

Answer 251

healthy individuals during exercise

Question 252

formula for cardiac output (CO)

Answer 252

heart rate (BPM) x stroke volume (SV) = cardiac output (CO)

Question 253

patient HR 75 BPM, stroke volume is 70ml/beat. what is CO

Answer 253

75 beats/min x 70 ml/beat = 5250 ml/min = 5.25 L/min

Question 254

stroke volume

Answer 254

amount of blood ejected in one beat from one ventricle

Question 255

what influences stroke volume

Answer 255

venous return inotropic agents afterload

Question 256

venous return

Answer 256

volume of blood returned to the heart

Question 257

venous return is directly related to

Answer 257

stroke volume

Question 258

venous return determines amount of

Answer 258

ventricular blood prior to contraction (EDV)

Question 259

volume of blood determines

Answer 259

preload (pressure stretching heart wall before shortening)

Question 260

Frank-Starling law (Starling's Law)

Answer 260

as EDV increases, the greater stretch of heart wall, results in more optimal overlap of thick and thin filaments

Question 261

starling's law suggests that the heart

Answer 261

contracts more forcefully when filled with more blood so SV increases

Question 262

what factors increase venous return

Answer 262

increased venous pressure increased time to fill

Question 263

venous pressure increases during

Answer 263

exercise as muscles squeeze veins

Question 264

slower heart rates impact on venous return

Answer 264

time available to fill increases with slower heart rate (high-caliber athletes with strong hearts)

Question 265

steps of venous return

Answer 265

1. increased venous return (occurs with greater venous pressure or slower heart rate 2. increases stretch of heart wall (preload) which results in greater overlap of thick and thin filaments within sarcomeres of myocardium 3. additional crossbridges form and ventricles contract with greater force 4. stroke volume increases

Question 266

inotropic agents effect on stroke volume

Answer 266

1. positive inotropic agents 2. increased Ca2+ levels in sarcoplasm results in greater binding of Ca2+ to troponin of thin filaments within sarcomeres of myocardium 3. additional crossbridges form, and ventricles contract with greater force 4. stroke volume increases

Question 267

inotropic agents

Answer 267

substances that act on the myocardium to alter contractility

Question 268

positive inotropic agents

Answer 268

e.g., stimulation by sympathetic nervous system

Question 269

venous returns ____ stroke volume

Answer 269

increases SV

Question 270

inotropic agents _____ stroke volume

Answer 270

positive inotropic agents increases SV

Question 271

afterload

Answer 271

resistance in arteries to ejection of blood

Question 272

afterloads effect on stroke volume

Answer 272

1. artherosclerosis, deposition of plaque on inner lining of arteries is typically only a factor as we age 2. arteries become more narrow in diameter 3. increases the resistance to pump blood into arteries 4. stroke volume decreases

Question 273

chronotropic agenets

Answer 273

alter SA node and AV node activity

Question 274

positive chronotropic agents increase or decrease cardiac output

Answer 274

increase by increasing heart rate

Question 275

negative chronotropic agents increase or decrease cardiac output

Answer 275

decrease cardiac output by decreasing heart rate

Question 276

increase in heart rate increases or decreases CO

Answer 276

increases

Question 277

decrease in heart rate increases or decreases CO

Answer 277

decreases

Question 278

venous return is directly correlated with

Answer 278

stroke volume

Question 279

increase venous return and increase inotropic agents effect on CO

Answer 279

increase SV which increases CO

Question 280

afterloads effect on CO

Answer 280

increase in afterload would decrease SV causing a decreased in CO decrease in afterload would increase SV causing an increase in CO

Question 281

inotropic agents alter

Answer 281

Ca2+ levels in sarcoplasm

Question 282

foramen ovale

Answer 282

structure in fetal heart that transports deoxygenated blood from right atrium to left atrium where it becomes oxygenated

Question 283

ductus arteriosus

Answer 283

connection in fetal heart that connects aorta and pulmonary trunk

Question 284

arteries

Answer 284

convey blood from heart to capillaries

Question 285

capillaries

Answer 285

microscopic porous blood vessels exchange substances between blood and tissues

Question 286

veins

Answer 286

transport blood from capillaries to heart

Question 287

walls of arteries and veins from deep to superficial

Answer 287

tunica intima tunica media tunica externa

Question 288

what blood vessel contains valves

Answer 288

veins

Question 289

branching of arteries

Answer 289

branch into smaller vessels extending from the heart where they decrease in lumen diameter, decrease in elastic fibers, and increase in amount of smooth muscle

Question 290

3 types of arteries

Answer 290

elastic muscular arterioles

Question 291

capillary characteristics

Answer 291

small vessels connecting arterioles to venuoles average length = 1mm deiamter = 8-10 micrometers thin wall and small diameter make it optimal for exchange between blood and tissue fluid

Question 292

three types of capillaries

Answer 292

continuous fenestrated sinusoid

Question 293

continuous capillaries

Answer 293

endothelial cells form a continuous lining with tight junctions

Question 294

tight junctions

Answer 294

connect cells but don't form a complete seal found within continuous capillaries

Question 295

tight junctions contain

Answer 295

intracellular clefts which are gaps between endothelial cells of capillary wall allow smaller particles to pass through, and blocks large particles

Question 296

continuous capillaries are most commonly found in

Answer 296

muscle, skin, lungs, and CNS

Question 297

fenestrated capillaries

Answer 297

endothelial cells form a continuous lining but cells have fenestrations

Question 298

fenestrations allow for

Answer 298

movement of smaller plasma proteins

Question 299

where are fenestrated capillaries found

Answer 299

intestinal capillaries absorbing nutrients kidney capillaries filtering blood to form urine

Question 300

sinusoids (discontinuous capillaries)

Answer 300

endothelial cells form an incomplete lining with large pore gaps basement membrane is incomplete or absent openings allow for transport of large substances (formed elements, large proteins)

Question 301

where are sinusoids found

Answer 301

bone marrow, spleen, liver, and some endocrine glands

Question 302

venuoles

Answer 302

smallest veins companion vessels with arterioles merge to form veins

Question 303

smallest venuoles are

Answer 303

postcapillary venuoles

Question 304

largest venuoles have

Answer 304

all 3 tunics

Question 305

small and medium-sized veins are companion vessels with

Answer 305

muscular arteries

Question 306

largest veins travel with

Answer 306

elastic arteries

Question 307

most veins have numerous

Answer 307

valves preventing blood from pooling in limbs to ensure blood flow toward heart

Question 308

valves are made of

Answer 308

tunica intima and elastic and collagen fibers similar to heart's semilunar valves

Question 309

pulmonary arteries transport

Answer 309

deoxygenated blood to heart

Question 310

systemic arteries transport

Answer 310

oxygenated blood away from heart

Question 311

elastic arteries

Answer 311

stretch to accomodate the pulses of blood ejected from heart and recoil to propel blood through the arteries

Question 312

muscular arteries

Answer 312

regulate distribution of blood through vasoconstriction and vasodilation

Question 313

arterioles

Answer 313

regulate blood distribution through vasoconstriction and vasodilation

Question 314

precapillary sphincters regulate

Answer 314

blood flow through capillary beds when sphincter contracts, it closes off blood flow when relaxed, it allows blood to pass through

Question 315

large veins serve as

Answer 315

a blood resovior (at rest - 55% total blood)

Question 316

small/medium veins

Answer 316

receive blood from venuoles; blood drains into small/medium veins and then into large veins

Question 317

venules

Answer 317

receive blood from capillaries

Question 318

valves in veins prevent

Answer 318

backflow of blood

Question 319

bulk flow

Answer 319

fluid flows down presentation gradient large amounts of fluids and dissolved substances move

Question 320

movement direction of bulk flow depends on

Answer 320

net pressure of opposing forces (hydrostatic vs colloid osmotic)

Question 321

filtration

Answer 321

fluid moves out of blood - fluid and small solutes easily flow through capillary openings (intercellular clefts; fenestrations)

Question 322

filtration occurs on what end of capillary

Answer 322

arterial

Question 323

reabsorption

Answer 323

fluid moves back into blood

Question 324

reabsorption occurs at what end of capillary

Answer 324

venous end

Question 325

colloid osmotic pressure

Answer 325

the pull on water due to the presence of protein solutes

Question 326

hydrostatic pressure

Answer 326

force exerted by fluid

Question 327

blood hydrostatic pressure (HPb)

Answer 327

force exerted per unit area by blood vessel on wall promotes filtration from capillary

Question 328

blood colloid osmotic pressure (COPb)

Answer 328

draws fluid into blood due to blood proteins (e.g., albumins) promotes reabsorption (opposes dominant hydrostatic pressure) clinically called oncotic pressure

Question 329

on arterial end of blood capillary...

Answer 329

- blood hydrostatic pressure is > than osmotic pressure - net pressure moves from blood into interstitial fluid - filtration

Question 330

on venous end of capillary

Answer 330

- osmotic pressure is > than blood hydrostatic pressure - net pressure move from interstitial fluid back into blood - reabsorption

Question 331

formula for NFP on arterial end

Answer 331

net hydrostatic pressure - net colloid osmotic pressure = net filtration pressure (NFP)

Question 332

NFP on arterial end

Answer 332

14 mmHg

Question 333

NFP on venous end

Answer 333

-5 mmHg

Question 334

blood pressure

Answer 334

force of blood against vessel wall

Question 335

blood pressure gradient

Answer 335

change in pressure from one end of vessel to other - propels blood through vessels

Question 336

pressure is highest in

Answer 336

arteries and lowest in veins

Question 337

arterial blood pressure

Answer 337

blood flow in arteries pulses with cardiac cycle

Question 338

systolic pressure

Answer 338

occurs when ventricles contract (systole) recorded as upper number of blood pressure ratio highest pressure generated in arteries (they are stretched)

Question 339

diastolic pressure

Answer 339

occurs when ventricles relax (diastole) lower number of BP ratio

Question 340

pulse pressure

Answer 340

pressure in arteries added by heart contraction

Question 341

pulse pressure formula

Answer 341

difference between systolic and diastolic BP BP = 120/80 PP= 120-80= 40mmHg

Question 342

pulse pressure allows for palpitation of

Answer 342

throbbing pulse in elastic and muscular arteries

Question 343

what influences pulse pressure

Answer 343

elasticity and recoil of arteries - tends to decline with age and disease

Question 344

blood pressure gradient in systemic circulation

Answer 344

systemic gradient is difference between pressure in arteries near heart and inferior vena cava - mean BP in arteries = 93 mmHg - blood pressure in vena cava 0 - BP gradient = 0 mmHg

Question 345

increasing BP gradient is the

Answer 345

driving force to move blood through vasculature

Question 346

increasing BP graident increases

Answer 346

total blood flow and cardiac output

Question 347

resistance

Answer 347

friction that blood encounters

Question 348

resistance is due to

Answer 348

contact between blood and vessel wall

Question 349

peripheral resistance

Answer 349

resistance of blood in blood vessels

Question 350

resistance is affected by

Answer 350

- viscosity - vessel length - lumen size

Question 351

total BF equation

Answer 351

total blood flow = pressure gradient (established by heart)/resistance (experienced by blood as it moves through the vessels)

Question 352

factors the increase blood flow

Answer 352

increased cardiac output less resistance ( vasodilation, reduction in blood vessel length, or decrease in viscosity) steeper pressure gradient

Question 353

factors that decrease total blood flow

Answer 353

decreased cardiac output greater resistance (vasoconstriction, increase in vessel length, or increase in blood viscosity)

Question 354

skeletal muscle pump

Answer 354

venous side of blood vessels struggle to bring blood back to the heart and needs assistance to be propelled upwards when muscles contract, it compresses venous walls and blood is going to go in both direction with one way valves having blood be forced upwards

Question 355

respiratory pump aids in

Answer 355

increasing venous pressure and propelling it to the heart

Question 356

inspiration increases blood flow to

Answer 356

thoracic veins

Question 357

expiration increases blood flow into

Answer 357

heart and abdominal veins

Question 358

during inspiration there is more pressure in

Answer 358

intra-abdominal pressure than intrathoracic pressure causing blood flow up toward thoracic veins

Question 359

during expiration there is more pressure in

Answer 359

intrathoracic pressure than intra-abdominal pressure inferior vena cava is released of compression and blood flows into heart and abdominal veins

Question 360

blood pressure must be kept high enough to

Answer 360

maintain tissue perfusion but not so high that it damages blood vessels

Question 361

BP depends on

Answer 361

- cardiac output - resistance - blood volume *regulated by nervous and endocrine systems*

Question 362

autonomic reflexes regulate BP only

Answer 362

short-term involves nuclei in medulla oblongata quickly adjust cardiac output, resistance, or both

Question 363

autonomic reflexes meet

Answer 363

momentary pressure needs (standing up from supine position)

Question 364

cardiovascular center of medulla contains

Answer 364

2 autonomic nuclei: cardiac center and vasomotor center

Question 365

cardiac center influences

Answer 365

BP by influencing cardiac output

Question 366

vasomotor center influences BP by

Answer 366

influencing vessel diameter (vessel constriction influences resistance)

Question 367

baroreceptors

Answer 367

nerve endings that respond to stretch of vessel wall

Question 368

barorecptors firing rate changes with

Answer 368

BP changes

Question 369

where are baroreceptors found

Answer 369

tunica externa of aortic arch and carotid sinuses

Question 370

aortic arch baroreceptors transmit signals to

Answer 370

cardiovascular center through vagus nerve (CN X) - important in regulating systemic BP

Question 371

carotid sinuses transmit nerve signals to

Answer 371

CV center via glossopharyngeal nerve (CN IX) - monitor BP in head, neck (vessels that serve the brain) - more sensitive to blood pressure changes than aortic arch receptors

Question 372

autonomic reflexes for BP are

Answer 372

baroreceptor reflexes

Question 373

baroreceptor reflexes are initiated by

Answer 373

decrease or increase in BP

Question 374

if blood pressure decreases vessel stretch..

Answer 374

declines and baroreceptors firing rate decreases - this activates the cardioacceleratory center to stimulate sympathetic pathways to increase CO - it inhibits cardoinhibatory center to minimize parasympathetic activity - it activates the vasomotor center to stimualte the sympathetic pathways to increase vasoconstriction; parasympathetic stimulation inhibited - the increase in cardiac output and resistance raises BP

Question 375

if BP increases

Answer 375

- vessel is stretch and baroreceptor firing rate increases - cardioacceleratory center sends less signals along sympathetic pathways - stimulates cardioinhibatory center to activate parasympathetic pathways to SA and AV nodes - it causes vasomotor center to send fewer signals along the sympathetic pathways to blood vessels (vasodilation); parasympathetic output enhanced - decrease in cardiac output and resistance lowers BP

Question 376

baroreceptor reflexes are best for

Answer 376

quick changes in BP but are inneffective for long term BP regulation

Question 377

chemoreceptor reflexes

Answer 377

influence BP stimulation of chemoreceptors brings about negative feedback reflexes to return blood chemistry to normal - responses in respiratory and CV systems

Question 378

main peripheral chemorecptors are in

Answer 378

aortic and carotid bodies

Question 379

aortic and carotid bodies send input to

Answer 379

cardiovascular center

Question 380

aortic bodies send signals via

Answer 380

vagus nerve

Question 381

carotid bodies send signals via

Answer 381

glossopharyngeal nerve

Question 382

what stimulates chemoreceptors

Answer 382

- high carbon dioxide - low pH - low oxygen

Question 383

chemoreceptor firing stimulate

Answer 383

vasomotor center which - increases nerve signals along sympathetic pathways to vessels - shifts blood from venous resovoirs to increase venous return - raises BP and increases blood flow (including pulmonary) - allows for increased respiratory gas exchange in lungs

Question 384

hormones also regulate

Answer 384

BP

Question 385

epinephrine and norepinephrine work with

Answer 385

sympathetic nervous system

Question 386

hormones with effect on BP

Answer 386

angiotensin II ADH aldosterone ANP - influence BP through resistance, blood volume or both

Question 387

renin angiotensin system

Answer 387

1. kidney receptors detect low BP or are stimulated by sympathetic division; renin is released 2. renin converts angiotensinogen that is produced by liver into angiotensin I 3. ACE converts angiotensin I into angiotensin II 4. angiotensin II increased BP by - vasoconstriction - stimulating thirst center - decreasing urine formation

Question 388

aldosterone helps maintain

Answer 388

blood volume and pressure

Question 389

release of aldosterone is triggered by

Answer 389

several stimuli inclduing angiotensin II

Question 390

aldosterone increases absorption of

Answer 390

sodium ions and water in kidneys - decreases urine output

Question 391

ADH helps maintain and elevate

Answer 391

BP

Question 392

ADH is released from

Answer 392

posterior pituitary gland

Question 393

release of ADH is triggered by

Answer 393

nerve signals from hypothalamus stimulated by increased blood concentration or angiotensin II

Question 394

ADH effects

Answer 394

increased water reabsorption in kidney (less fluid loss, maintaining blood volume) stimulates thirst center to increase fluid intake (raising blood volume) in large amounts, causes vasoconstriction (increasing resistance and pressure)

Question 395

ADH is sometimes termed

Answer 395

vasopressin

Question 396

ANP decreases

Answer 396

BP

Question 396

what stimulated ANP release

Answer 396

stretch of atrial heart wall from high blood volume

Question 397

ANP effect on vessel diameter

Answer 397

causes vasodilation decreasing resistance

Question 398

ANP effect on urine output

Answer 398

increases urine output decreasing blood volume

Question 399

mechanisms of BP homeostasis

Answer 399

cardiac output resistance blood volume

Question 400

cardiac output, resistance, and blood volume are directly related to

Answer 400

blood pressure; increase in any of these will raise BP

Question 401

heart rate effect on cardiac output and BP

Answer 401

increased heart rate increases cardiac output and BP decreased heart rate decreases cardiac output and BP

Question 402

stroke volume effect on cardiac output and BP

Answer 402

increase SV increases CO and BP decreases SV decreases CO and BP

Question 403

vasocontriction narrows vessel and forces blood through narrower lumen causing

Answer 403

increase in resistance and BP

Question 404

vasodilation widens vessel and forces blood through wider lumen causing

Answer 404

decrease resistance and BP

Question 405

the longer the vessel..

Answer 405

the larger resistance which raises BP

Question 406

shorter vessels ...

Answer 406

decreases resistance which lowers BP

Question 407

increased blood viscosity increases

Answer 407

peripheral resistance and BP

Question 408

decreased blood viscosity decreases

Answer 408

peripheral resistance and BP

Question 409

fluid intake _____ blood volume and BP

Answer 409

increases

Question 410

fluid output _____ blood volume and blood pressure

Answer 410

decreases

Question 411

function of lymphatic system

Answer 411

transport and house lymphocytes and other immune cells return excess fluid in body tissues to blood to maintain blood volume

Question 412

lymph

Answer 412

fluid transported within lymph vessels

Question 413

components of lymph

Answer 413

water dissolved solutes small amounts of protein - sometimes cell debris, pathogens, or cancer cells

Question 414

anchoring filament

Answer 414

components of lymphatic capillary that anchors and stabilizes the position of the capillary and prevents walls from collapsing

Question 415

thoracic duct

Answer 415

drains everywhere except upper right side

Question 416

right lymphatic duct

Answer 416

drains right arm, right side of chest, and right side of head and neck

Question 417

primary lymphatic stuctures

Answer 417

red bone marrow thymus

Question 418

primary lymphatic structures are involved in

Answer 418

formation and maturation of lymphocytes

Question 419

secondary lymphatic structures do not

Answer 419

form lymphocytes but house them and other immune cells

Question 420

site of immune response initiation

Answer 420

secondary lymphatic structures

Question 421

secondary lymphatic structures include

Answer 421

lymph nodes, spleen, tonsils, and lymphatic nodules MALT

Question 422

red bone marrow

Answer 422

located between trabeculae of spongy bone site of hemopoiesis; production of blood's formed elements (includes production of T-lymphocytes and B-lymphocytes

Question 423

t lymphocytes migrate to

Answer 423

the thymus to complete maturation

Question 424

the thymus grows until

Answer 424

puberty, then regresses

Question 425

cortex of thymus contains

Answer 425

immature T-lymphocytes

Question 426

medulla of thymus contains

Answer 426

mature T-lymphocytes

Question 427

lymph nodes

Answer 427

filter lymph and remove unwanted substances occur in cluster

Question 428

cervical lymph nodes

Answer 428

receive lymph from head and neck

Question 429

axillary lymph nodes

Answer 429

receive lymph from breast, axilla, and arms

Question 430

inguinal lymph nodes

Answer 430

receive lymph from legs and pelvis

Question 431

afferent lymphatic vessels

Answer 431

bring lymph to node

Question 432

an efferent vessel

Answer 432

drains a lymph node (located @ hilum)

Question 433

components of lymph node

Answer 433

cortex medulla afferent vessels efferent vessels hilum

Question 434

lymph is monitored for

Answer 434

presence of foreign material

Question 435

macrophages remove

Answer 435

foreign debris from lymph

Question 436

lymphocytes may initiate

Answer 436

immune resopnse proliferative in germinal centers cause enlarged nodes that can be felt in neck

Question 437

spleen

Answer 437

largest lymphatic organ contains white and red pulp

Question 438

white pulp

Answer 438

clusters of T and B lymphocytes and macrophages around central artery

Question 439

red pulp

Answer 439

contains erythrocytes, platelets, macrophages, and B lymphocytes

Question 440

red pulp is the storage site for

Answer 440

erythrocytes and platelets

Question 441

spleen monitors

Answer 441

blood not lymph

Question 442

white pulp monitors lymph for

Answer 442

foreign materials and bacteria

Question 443

macrophages lining sinusoids of red pulp..

Answer 443

remove particles, phagocytize bacteria, debris, defective erythrocytes, and platelets

Question 444

summary functions of spleen

Answer 444

- remove foreign particles - clear defective erythrocytes and platelets - store erythrocytes and platelets

Question 445

in first 5months of fetal life, spleen makes

Answer 445

blood cells can be reactivated under certain conditions (extra medullary hemopoeisis) - hematological disorders

Question 446

tonsils

Answer 446

immune surveillance of inhaled and ingested substances

Question 447

tonsillar crypts

Answer 447

invaginations that trap material

Question 448

pharyngel tonsils

Answer 448

in nasopharynx called adenoids when enlarged

Question 449

palatine tonsils

Answer 449

in oral cavity

Question 450

lingual tonsils

Answer 450

along posterior 1/3 of tongue

Question 451

malt

Answer 451

located in GI, respiratory, genital, and urinary tracts helps defend against foreign substances

Question 452

the immune system protect us from

Answer 452

infectious agents and harmful substances composed of cellular and molecular structures that function together to provide immunity

Question 453

types of immunity differ based on

Answer 453

- cells involved - specificity of cell response - mechanisms of eliminating harmful substances - amount of time for response

Question 454

innate immunity

Answer 454

immediate response to wide array of substances

Question 455

adaptive immunity

Answer 455

delayed response to specific antigens

Question 456

characteristics of innate immunity

Answer 456

- responds non specifically to range of substances

Question 457

first line of denfense in innate immunity

Answer 457

skin and mucosal membranes

Question 458

second line of defense in innate immunity

Answer 458

internal processes like - activation of neutrophils, macrophages, dendritic cells, eosinophils, basophils, mast cells, and NK cells - chemicals such as interferon and complement - inflammation and fever

Question 459

phagocytic cells include

Answer 459

- neutrophil - macrophages - dendritic cells

Question 460

basophils and mast cells

Answer 460

- proinflammatory chemical-secreting cells - releases histamine, heparin, and aicosanoids

Question 461

NK cells

Answer 461

apoptosis initiating cells releases perforin and granzymes

Question 462

eosinophils

Answer 462

parasite destroying cells release cytotoxic chemicals

Question 463

interferon

Answer 463

synthesizes enzymes that interfere with viral replication result in apoptosis

Question 464

complement

Answer 464

group of over 30 plasma proteins that are synthesized by liver, continuously released in inactive form

Question 465

activation of complement

Answer 465

occurs by enzyme cascade

Question 466

complement activation follows

Answer 466

pathogen entry

Question 467

classical pathway (complement activation)

Answer 467

antibody attaches to foreign substance and then complement binds to antibody

Question 468

alternative pathways for complement activation

Answer 468

- binds to polysaccharides of bacterial or fungal cell wall

Question 469

opsonization

Answer 469

complement protein (opsonin) binds to pathogen and enhances likelihood of phagocytosis or pathogenic cell

Question 470

inflammation is enhnaced by

Answer 470

complement as it activates mast cells and basophils and attract neutrophils and macrophages

Question 471

cytolosis

Answer 471

complement triggers destruction of target cell complement proteins form membrane attack complex (MAC) that creates channel in target cell's membrane (fluid enters causing lysis)

Question 472

elimination of immune complexes

Answer 472

complement link antigen-antibody complexes to erythrocytes where cells are moved to liver and spleen where complexes are stripped off

Question 473

complement is what kind of imunity

Answer 473

nonspecific innate immunity

Question 474

inflammation

Answer 474

an immediate response to ward off unwanted substances - local nonspecific respsonse of vascularized tissue to injury, part of innate immunity

Question 475

steps of inflammation

Answer 475

1. Release of inflammatory and chemotacic factors - mast cells - basophils 2. vascular changes include - vasodilation of arterioles - increase capillary permeability - display of CAMs 3. recruitment of immune cells - margination - diapedesis - chemotaxis 4. delivery of plasma proteins

Question 476

cardinal signs of inflammation

Answer 476

- redness (increased blood flow) - heat ( increased blood flow and increased metabolic activity within the area) - swelling (increase in fluid loss from capillaries) - pain (stimulation of pain receptors) - loss of function

Question 477

duration of acute inflmmation

Answer 477

8-10 days

Question 478

fever (pyrexia)

Answer 478

abnormal temperature elevation 1 degree or more from normal results from release of pyrogens from immune cells or infectious agents

Question 479

events of fever

Answer 479

- pyrogens circulate through blood and target hypothalamus - in response, hypothalamus releases prostaglandin E2 - hypothalamus raises temperature set point leading to fever

Question 480

benfits of fever

Answer 480

- inhibits reproduction of bacteria and viruses - promotes interferon activity - increases activity of adaptive immunity - accelerate tissue reapair - increase CAMs on endothelium of capillaries in lymph nodes - recommended to leave low fever untreated

Question 481

adaptive immunity involves

Answer 481

specific lymphocyte responses to an antigen

Question 482

immune response consists of

Answer 482

lymphocytes and their products

Question 483

adaptive immunity is considered

Answer 483

3rd line of defnese

Question 484

branches of adaptive immunity

Answer 484

cell mediated immunity involves T-lymphocytes humoral immunity involving B-lymphocytes, plasma cells, and antibodies

Question 485

cell-mediated immunity

Answer 485

t lymphocytes (effective against APC) produces cytotoxic T-lymphocytes and helper T-lymphocytes destroy cells through apoptosis

Question 486

humoral immunity

Answer 486

B-lymphocytes plasma cells produce antibodies

Question 487

pathogens are detected by

Answer 487

lymphocytes because they contain antigens

Question 488

antigen

Answer 488

substance that binds a t-lymphocyte or antibody examples: - protein capside of virus - cell wall of bacteria or fungi - bacterial toxins - abnormal proteins or tumor agents

Question 489

antigens are usually

Answer 489

large proteins or polysaccharide

Question 490

antigenic determinant

Answer 490

also known as epitope - specific site on antigen recognized by immune system - each has different shape - pathogenic organisms can have multiple determinants

Question 491

immunogen

Answer 491

antigen that induces immune response

Question 492

immunogenicity

Answer 492

ability to trigger responses increases with antigen's degree of foreignness, size, complexity, or quanitity

Question 493

haptens

Answer 493

small foreign molecules that induce immune response when attached to carrier molecule in host e.g., poison ivy

Question 494

what accounts for hypersensitivity reactions

Answer 494

haptens e.g., drugs like penicillin

Question 495

B-lymphocytes make

Answer 495

direct contact with antigen

Question 496

T-lymphocytes have

Answer 496

antigen presented by some other cells

Question 497

coreceptors on helper T lymphocytes

Answer 497

CD4

Question 498

coreceptors on cytotoxic T lymphocytes

Answer 498

CD8

Question 499

B lymphocytes contain receptors that

Answer 499

directly attach to specific antigen

Question 500

cytotoxic t-lymphocytes release

Answer 500

chemicals that destroy other cells

Question 501

helper T- lymphocytes

Answer 501

assist in cell mediated, humoral, and innate immunity (activate NK cells and macrophages)

Question 502

other types of t-lymphocytes

Answer 502

memory T-cells and regulatory T-cells

Question 503

antigen presentation

Answer 503

cells display antigen on plasma membrane so T cells can recognize it

Question 504

two categories of cells present antigens

Answer 504

-all nucleated cells of body - antigen presenting cells (APC): dendritic cells, macrophages, and B lymphocytes

Question 505

antigen presentation requires

Answer 505

attachment of antigen to major histocompatibility complex (MHC) - group of transmembrane proteins

Question 506

CD4 interacts specifically with

Answer 506

MHC class II molecules

Question 507

CD8 interacts specifically with

Answer 507

MHC class I molecules

Question 508

main events in life events of lymphocytes

Answer 508

1. formation and maturation - occurs in primarily lymphatic structures (red bone marrow and thymus) - becomes able to recognize one specific antigen 2. activation of lymphocytes - in secondary lymphatic structures they are exposed to antigen and become activated - replicated to form identical lymphocytes 3. effector response: action of lymphocytes to eliminate antigen - T-lymphocytes migrate to site of infection - B lymphocytes stay in secondary lymphatic structure (as plasma cells)

Question 509

plasma cells that stay in secondary lymphatic structures

Answer 509

- synthesize and release large quantities of antibodies - antibodies are transported to infection site through blood and lymph

Question 510

activation of lymphocytes

Answer 510

- secondary lymphatic structures house B and T lymphocytes - site of activation and proliferation of these cells

Question 511

effector response of lymphocytes

Answer 511

- interaction of T lymphocytes and antibodies to eliminate foreign antigens at site of infection

Question 512

antigen challenge

Answer 512

first encounter between antigen and lymphocytes

Question 513

antigen challenge usually occurs in

Answer 513

secondary lymphatic structures -antigen in blood taken to spleen -antigen penetrating skin transported to lymph node - antigen from respiratory, GI, urogenital tracts, in tonsils or MALT

Question 514

clonal selection

Answer 514

forming clones in response to an antigen - all formed cells have same TCR or BCR that matches specific antigens

Question 515

activation of cytotoxic T lymphocytes

Answer 515

1. First Signal: CD8 binds with MHC class I molecule of infected cell; TCR interacts with antigen within MHC class I molecule 2. Second Signal: IL-2 released from activated helper T-lymphocytes activates cytotoxic T lymphocytes *activated cytotoxic T-lymphocytes differentiate to form clone of activated and memory cytotoxic T-lymphocytes

Question 516

activation of helper T-lymphocytes

Answer 516

1. First Signal: - CD4 binds with MHC class II molecule of APC; TCR interacts with antigen within MHC class II molecule 2. Second Signal: - other signal receptors interact and helper T-lymphocyte releases IL-2 which binds with helper T lymphocytes *activated helper T cells proliferate and differentiate to form a clone of activated and memory helper T cells*

Question 517

activation of B lymphocytes

Answer 517

1. First Signal: - free antigen binds to BCR; B-lymphocytes engulf and present antigen to activated helper T-lymphocyte 2. Second Signal: - IL-4 released from activated helper T cells stimulate B-lymphocyte 3. activated B lymphocytes proliferate and differentiate into clone of plasma cells and memory B lymphocytes

Question 518

effector response

Answer 518

mechanism used by lymphocytes to help eliminate antigen

Question 519

helper T-lymphocyte effector response

Answer 519

- releases IL-2, IL-4, and other other cytokines - help activate B-lymphocytes - activate cytotoxic T-lymphocytes with cytokines - regulate cells of adaptive and innate immunity

Question 520

cytotoxic T-lymphocyte effector response

Answer 520

destroy unhealthy cells by apoptosis releases perforin and granzyme to induce apoptosis

Question 521

plasma cells (differentiated B-lymphocytes)

Answer 521

produce antibodies

Question 522

most activated B lymphocytes become

Answer 522

plasma cells

Question 523

plasma cells synthesize and release

Answer 523

antibodies

Question 524

plasma cells remain in

Answer 524

the lymph nodes

Question 525

plasma cells produce

Answer 525

millions of antibodies during 5-day life span they circulate in lymph until encountering an antigen

Question 526

antibody titer

Answer 526

circualting blood concentration of antibody against a specific antigen - measures immune response

Question 527

antibodies

Answer 527

immunoglobin proteins produced against a particular agent

Question 528

antibodies tag

Answer 528

pathogens for destruction by immune cells

Question 529

antibody structure

Answer 529

- 4 polypeptide bounds together - 2 light chains and 2 heavy chains

Question 530

disulfide bonds in antibodies allows for

Answer 530

linkage between polypeptides

Question 531

variable regions

Answer 531

gives antibody specificty on antigen binding site unique to specific antibody

Question 532

constant region

Answer 532

area among bottom 75% of antibody structure that remains constant

Question 533

Fc region

Answer 533

fragmented constant

Question 534

binding of antigen-binding site of a antibody with antigen causes

Answer 534

- neutralization - agglutination - precipitation

Question 535

exposed Fc region portion following antigen binding by antibody promotes

Answer 535

- complement fixation - opsonization - activation of NK cells

Question 536

neutralization

Answer 536

antibody covers biologically active portion of microbe or toxin and neutralizes the organisms ability to be pathogenic

Question 537

agglutination

Answer 537

antibody cross-links bacteria forming a clump making it easier for organism to be phagocytized

Question 538

precipiatation

Answer 538

antibody-crosslink circulating particles forming insoluble antigen-antibody complexes and precipetate them out of solution

Question 539

complement fixation

Answer 539

Fc region of antibody binds to complement proteins; complement activated

Question 540

opsonization

Answer 540

Fc region of antibody binds to receptors of phagocytic cells, triggering phagocytosis

Question 541

activation of NK cells

Answer 541

Fc region of antibody binds to an NK cell triggering release of cytotoxic chemicals

Question 542

IgG

Answer 542

major class 75-85% most versatile - capable of all Ab actions

Question 543

IgM

Answer 543

pentamer best at agglutination

Question 544

IgA

Answer 544

dimer areas exposed to environment (mucosal membranes, tonsils) best at neutralization

Question 545

IgD

Answer 545

activates B cells (BCR)

Question 546

IgE

Answer 546

allergy and parasitism degranulation of basophils and mast cells; chemotacic for eosinophils

Question 547

effector response: cell mediated immunity

Answer 547

1. activated helper T lymphocytes release cytokines to stimulate activity of B cells and cytotoxic T cells, and regulate cells of innate immunity 2. activated cytotoxic T cells release cytotoxic molecules (perforin and granzymes) causing apoptosis fo foreign or abnormal cells

Question 548

effector response: humoral immunity

Answer 548

1. Fab region of antibody binds to antigen causing several consquences including neutralization of microbial cells, agglutination of cells, and precipitation of particles 2. Fc region of antibody serves as point of interaction with several structures including complement activation, bidning of phagocytic cells to cause phagocytosis of unwanted substances, and binding of NK cells to induce apoptosis of unwanted cell

Question 549

memory results from

Answer 549

formation of long-lived army of lymphocytes upon immune activation

Question 550

adaptive immunity activation requirs

Answer 550

contact between lymphocyte and antigen (lag time btwn first exposure of host and direct contact with lymphocyte)

Question 551

activation of adaptive immunity leads to

Answer 551

formation of many memory cells against specific antigen

Question 552

with subsequent antigen exposure

Answer 552

- many memory cells make contact with antigen more rapidly producing powerful secondary response (pathogen is typically eliminated before disease symptoms develop)

Question 553

what is the most effective way to develop memory

Answer 553

vaccines

Question 554

antibody titer in primary and secondary response

Answer 554

Primary: lag phase long IgM increase then high IgG then lowers Secondary: lag phase shorter immediate high IgG lower levels of IgM

Question 555

active immunity

Answer 555

production of memory cells due to contact with antigen

Question 556

branches of active immunity

Answer 556

naturally acquired- direct exposure to antigen artificially acquired- vaccine

Question 557

passive immunity

Answer 557

no production of memory cells, antibodies from another person or animal

Question 558

passive immunity branches

Answer 558

naturally acquired - transfer from mother to child across placenta or breast milk artificially acquired - transfer of serum containing antibody from another person or animal

Question 559

acute hypersensitivity

Answer 559

- allergy - overreaction of immune system to noninfectious substance, allergen

Question 560

autoimmune disorders

Answer 560

immune system is lacking tolerance for specific self-antigen which initiates response as if cells were foreign due to cross reactivity, altered self-antigens or entering areas of immune privledge

Question 561

cross reactivity

Answer 561

pathogen is so structurally similar, immune system doesn't recognize that it is self e.g., rheumatic heart disease

Question 562

altered self-antigen

Answer 562

something alters makeup of shape or makeup of antigen (either random mutation or from infection) causing cell to become foreign e.g., type 1 diabetes

Question 563

areas of immune privledge

Answer 563

some areas are not involved in immune response ovaries, testes, etc.

Question 564

aqcuired immunodeficiency syndrome

Answer 564

life threatening illness that results from human immunodeficiency virus - destrys helper T cells - resides in body fluids - transmitted through intercourse, needle sharing, breastfeedings, placenta

Question 565

HIV become AIDS when

Answer 565

helper T cells drop below a certain levels

Question 566

HIV tests look for

Answer 566

HIV antibodies in blood

Question 567

AIDS patients have many

Answer 567

CNS complications and are prey to opportunistic infections

Question 568

functions of GI tract

Answer 568

- ingestion - motility - secretions - digestion - absorption - elimination

Question 569

ingestion

Answer 569

introduction of solid and liquid nutrients into oral cavity first step in process of digesting and absorbing nutrients

Question 570

motility

Answer 570

voluntary and involuntary muscle contractions mixing and moving material through GI tract

Question 571

secretion

Answer 571

process of producing and releasing fluid products facilitating digestion e.g., digestive enzymes, acid, bile

Question 572

digestion

Answer 572

breakdown of ingested food into smaller structures mechanical and chemical

Question 573

mechanical digestion

Answer 573

materially physically broken down by chewing and mixing

Question 574

chemical digestion

Answer 574

involves specific enzyme to break chemical bonds change large complex molecules into smaller molecules

Question 575

absorption

Answer 575

transport of digested molecules, electrolytes, vitmains, water move from GI tract into blood or lymph

Question 576

elimination

Answer 576

expulsion of indigestible coponents that are not absorbed

Question 577

accessory digestive organs

Answer 577

teeth tongue salivary glands liver gallbladder pancreas

Question 578

GI tract or alimentery canal

Answer 578

where food actually passes through - oral cavity - pharynx - esophagous - stomach - small intestine - large intestine - anal canal

Question 579

tunics (deep to superfifical)

Answer 579

mucosa submucosa muscularis serosa

Question 580

enteric nervous system

Answer 580

- submucosal plexus and myenteric plexus - baroreceptors and chemoreceptors detect changes in tract wall (stretch) and chemical makeup of lumen content - sensory and motor neurons

Question 581

inner circular muscle layer thickened at several points to form

Answer 581

sphincter which closes off lumen and controls movement of material into next section of GI tract

Question 582

motility involves

Answer 582

peristalsis and mixing

Question 583

peristalsis

Answer 583

involves wave of contraction that moves bolus along propels food

Question 584

mixing

Answer 584

not designed to propel food but initiate mixing with secretions in both directions

Question 585

peristalsis and mixing both

Answer 585

occur at same time in different areas of GI tract

Question 586

oral cavity and salivary glands

Answer 586

- where mechanical digestion begins - saliva secreted from salivary glands in response to food - contains salivary amylase, enzyme initiating digestion of starch - mixed with ingested materials to form bolus

Question 587

pharynx

Answer 587

- bolus moved here where swallowing occurs - mucus secreted here to facilitate swallowing

Question 588

esophagous

Answer 588

bolus transported from pharynx to esophagous into stomach lubricated by mucus secretions

Question 589

stomach

Answer 589

bolus is mixed with gastric secertions by smooth muscle contractions secretions produced by epithelial cells of stomach chyme formed from mixing

Question 590

duodenum

Answer 590

part of upper GI tract

Question 591

vestibule

Answer 591

region behind lip and in front of teeth

Question 592

hard palate

Answer 592

bone covered by mucous membrane

Question 593

soft palate

Answer 593

located posteriorly and is a soft tissue that forms uvula where it ends

Question 594

tongue

Answer 594

skeletal muscle under voluntary control

Question 595

saliva

Answer 595

- mostly produced during mealtime - 99.5% water and mixture of solutes - salivary amylase, lysozyme, mucin added

Question 596

saliva function

Answer 596

- moistens ingested food to help become bolus - initiates chemical breakdown of starch (chemical digestion) - food molecules dissolved here so taste receptors stimulated - cleanses oral cavity structures - antibacterial subtances inhibit bacterial growth (lysozyme, antibodies)

Question 597

salivary glands

Answer 597

parotid salivary gland (attaches to roof of mouth) sublingual salivary glands ( attaches below tongue) submandibular salivary duct

Question 598

mechanical digestion

Answer 598

mastication

Question 599

mastication

Answer 599

chewing mechanically reducles bulk to facilitate swallowing requires coordinated activies of teeth, jaw, lips, tongue, cheeks

Question 600

chewing increases

Answer 600

- surface area to facilitate exposure to digestive enzymes - salivation

Question 601

mastication is controlled by

Answer 601

nuclei in medulla and pons mastication center^

Question 602

phases of swallowing

Answer 602

1. voluntary phase 2. pharyngeal phase 3. esophageal phase

Question 603

voluntary phase

Answer 603

bolus of food is pushed by tongue against hard palata and then moves toward oropharynx

Question 604

pharyngeal phase

Answer 604

involuntary as bolus moves through oropharynx, soft palata and uvula close off nasopharynx and the larynx elevates so the epiglottis closes over laryngeal opening

Question 605

esophageal phase

Answer 605

involuntary peristaltic contractions of esophageal muscle push bolus toward stomach acidity from esophageal phase in stomach can impact esophagus

Question 606

stomach performs

Answer 606

mechanical and chemical digestion

Question 607

where does the digestion of fat and protein begin

Answer 607

within stomach

Question 608

how long do ingested materials spend in stomach

Answer 608

2-6 hrs

Question 609

stomach serves as

Answer 609

"holding bag" for controlled release of partially digesting material (chyme) into small intestine (where most digestion and absorption occur)

Question 610

absorption of nutrients in stomach is

Answer 610

limited to small ,nonpolar substances

Question 611

gastric folds

Answer 611

rugae that allow for expansion of stomach which will happen as food enters

Question 612

pyloric sphincrer

Answer 612

where stomach and duodenum meet controls release of food content into small intestine

Question 613

stomach wall is composed of 3 layers

Answer 613

mucosa submucosa muscularis serosa

Question 614

mucosa of stomach

Answer 614

contains simple columnar epithelium with invaginations called gastric pits

Question 615

gastric pits

Answer 615

lined with secretory cells collectively called gastric gland

Question 616

what is responsible for absorption in mucosa of stomach

Answer 616

limina propria

Question 617

muscularis mucosae

Answer 617

contraction stimulates secretion from gastric glands

Question 618

muscularis of stomach

Answer 618

oblique layer circular layer longitudonal layer

Question 619

layers of stomach wall deep to superficial

Answer 619

1. oblique 2. circular 3. longitudonal

Question 620

gastric secretions

Answer 620

- produced by 5 types of secretory cells - 4 produce gastric juice, fifth secretes hormones

Question 621

surface mucus cells

Answer 621

- line stomach lumen and extend into gastric pits - secrete alkaline product containing mucin - mucous layer helps prevent ulceration of stomach lining (protect from enzymes and high acidity)

Question 622

mucous neck cells

Answer 622

immediately deep to base of gastric pit interspresed among parietal cells produce acid mucin help maintain acidic conditions

Question 623

both kinds of mucous cells help

Answer 623

protect the stomach lining from abrasion and injury

Question 624

parietal cells

Answer 624

intrinsic factor: required for absorption of vitamin B12 in ileum (necessary for production of erythrocytes) hydrochloric acid: responsible for low pH in stomach (1.5-2.5)

Question 625

hydrochloric acid functions

Answer 625

- converts inactive enzyme pepsinogen into active pepsin - denatures proteins, facilitating chemical digestion - kills most microorganisms entering stomach - helps breakdown plant cell walls and animal CT

Question 626

chief cells

Answer 626

- most numerous secretory cells within gastric glands - produce and secrete packets of zymogen granules that primarily contain pepsinogen, inactive precursor of pepsin

Question 627

pepsinogen activated by

Answer 627

HCl and other active pepsin molecules

Question 628

pepsin chemically digests

Answer 628

denatured proteins into oligopeptides

Question 629

chief cells produce

Answer 629

gastric lipase, playing limited role in fat digestion (10-15% of ingested fat)

Question 630

G cells

Answer 630

enteroendocrine cells that are widely distributed in gastric glands secretes gastrin

Question 631

gastrin stimulates

Answer 631

stomach secretions and motility

Question 632

what activates pepsinogen

Answer 632

HCl

Question 633

gastric mixing and emptying

Answer 633

Mixing 1. contraction of smooth muscle in stomach wall mix bolus with gastric secretions to form chyme 2. peristaltic waves result in pressure gradients that move stomach contents toward the pyloric region Emptying 3. Pressure gradient increases force in pylorus against pyloric sphincter 4. pyloric sphincter open, and small volume of chyme enters the duodenum 5. pyloric sphincter closes and retropulsion occurs

Question 634

small intestine

Answer 634

small bowel ingested nutrients reside here at least 12 hrs absorbs most nutrients and large percentage of water and electrolytes absorbs vitamins

Question 635

what is absorbed in small intestine

Answer 635

- most nutrients - water - electrolytes - vitamins

Question 636

segments of small intestine

Answer 636

duodenum jejunum ileum

Question 637

duodenum

Answer 637

- originates at pyloric sphincter - C shape around head of pancreas - continuous with jejunum at duodenojejunal flexure - most retroperitoneal

Question 638

the duedenum recieves

Answer 638

accessory gland secretions from liver, gallbladder, pancreas, and chyme from stomach

Question 639

jejunum

Answer 639

primary region for chemical digestion and nutrient absorption intraperitoneal and suspended by mesentery

Question 640

ileum

Answer 640

distal end terminates at ileocecal valve (sphincter controlling entry of materials into large intestine) intraperitoneal and suspended by mesentary continues absorption of digested materials

Question 641

small intestine layers

Answer 641

contains mucosa with circular folds submucosa muscularis and serosa

Question 642

mucosa of small intestine

Answer 642

shape in circular folds folds contain villi that extends towards lumen of intestine called intestinal villi

Question 643

circular folds increase

Answer 643

surface area available for absorption

Question 644

single intesntial villi

Answer 644

contains mucosa and submucosa

Question 645

intestinal villi contain

Answer 645

- simple columnar epithelial cells with microvilli) - goblet cells - unicellular gland cell - enteroendocrine cells

Question 646

simple columnar epithelial cells with microvilli function

Answer 646

absorbs nutrients

Question 647

microvilli on columnar cells of small intestine make a

Answer 647

brush border

Question 648

goblet cells

Answer 648

produce mucin

Question 649

unicellular gland cell

Answer 649

synthesizes eneteropeptidase

Question 650

enteroendocrine cell

Answer 650

secretes hormones

Question 651

large intestine

Answer 651

absorbs water and electrolytes from remaining digested material absorbs vitamins B and K produced by bacteria watery chyme compacted into feces stores feces until eliminated through defecation

Question 652

right colic flexure

Answer 652

bend of colon on right sight from ascending to transverse

Question 653

left colic flexure

Answer 653

bend of colon on left side from transverse to descending colon

Question 654

sigmoid flexure

Answer 654

bend of colon on bottom left from descending to signmoid

Question 655

mesocolon

Answer 655

mesentary attachments (CT holding things in place)

Question 656

liver

Answer 656

largest internal organ covered by CT capsule and layer of visceral peritoneum production of bile is main function in digestion

Question 657

bile

Answer 657

secreted by liver contains water, HCO3-, bile pigments, cholesterol, bile salts, lecithin, and mucin

Question 658

bile salts and lecithin help

Answer 658

mechanically digest lipids

Question 659

gallbladder

Answer 659

saclike organ attached to inferior surface. of liver stores, concentrates, and releases bile produced in liver

Question 660

cystic duct

Answer 660

connects gallbladder to common bile duct

Question 661

sphincter valve/hepatopancreatic sphincter

Answer 661

controls flow of bile into and out of gallbladder

Question 662

pancreas

Answer 662

endocrine function: secretes insulin and glucagon exocrine function: produces pancreatic juice to assit with digestive activies

Question 663

pancreas regions

Answer 663

head body and tail

Question 664

alpha cells of pancreas secrete

Answer 664

glucagon

Question 665

beta cells of pancreatic islet secretes

Answer 665

insulin

Question 666

acinar cells of pancreatic acinus secrete

Answer 666

-amylase - lipase - proteases - neucleases

Question 667

duct cells of pancreatic acinus secrete

Answer 667

bicarbonate ions

Question 668

pancreatic juice

Answer 668

formed from secretion of acinar cells and pancreatic duct cells alkaline fluid

Question 669

pancreatic juice is made of

Answer 669

mostly water, HCO3-, digestive enzymes - pancreatic amylase to digest starch - pancreatic lipase to digest triglycerides - inactive proteases that digest proteins when activated - nucleases for digestion of nucleic acids

Question 670

gastrin is secreted by

Answer 670

G cells in stomach

Question 671

gastrin is stimulated for release when

Answer 671

bolus is in stomach (especially if contains proteins)

Question 672

targets of gastrin

Answer 672

- parietal cells: stimulates secretion of hydrochloric acid - chief cells: stimulates releases of pepsinogen - pyloric sphincter: stimulates contraction

Question 673

cholecystokinin (CCK) is secreted by

Answer 673

enteroendocrine cells of small intestine stimulated for release when chyme containing amino acids and fatty acids enter small intestine

Question 674

primary target and effects of CCK

Answer 674

- inhibits stomach motility and gastric secretion - stimulates release of bile - stimulates release of enzyme-rich pancreatic juice - causes relxation of hepatopancreatic sphincter

Question 675

secretin is secreted by

Answer 675

enteroendocrine cells of small intestine primarily with increase in acidity of chyme entering small intestine

Question 676

primary targets and effects of secretin

Answer 676

- inhibits gastric secertions and stomach motility - stimulates secretion of alkaline solution from pancreatic ducts - stimulates secretion of alkaline solution

Question 677

carbohydrate digestion in small intestine

Answer 677

1. pancreatic amylase is produced by pancreas and secreted into small intestine 2. pancreatic amylase continues digestion of starch that began in oral cavity by salivary amylase 3. brush border enzymes complete the breakdown of starch to individual glucose molecules and are responsible for digestion of disaccharides

Question 678

protein digestion in small intestine

Answer 678

1. proteolytic enzymes are released from pancreas 2. enteropeptidase activates trypsinogeen to trypsin; trypsin then activates other proteolytic enzymes 3. activated pancreatic proteolytic enzymes (chymotrypsin and carboxypeptidase) break proteins into epeptides and aminoacids 4. brush border peptidases break peptides into single amino acids to be absorbed through epithelial cells into blood

Question 679

lipid digestion and absorption in small intesine

Answer 679

1. bile silts released from liver and gall bladder emulsify lipid droplets to form micelles 2. pancreatic lipase functions within micelles to digest each triglyceride into a monoglyceride and two free fatty acids 3. monoglycerides and three fatty acids enter an epithelial cell, while bile salts remain in intestinal lumen to be reabsorbed and recycled 4. triglyceride molecules are reassembled within epithelial cells. lipids are then wrapped with protein to form chylomicrons which are then packaged within secretory vesicles and then exocytosed from cells and absorbed into lacteals