concept 3b part 1 Flashcards
anatomy of respiratory system
nasal cavity pharynx larynx trachea bronchi lungs (left and right) horizontal fissure oblique fissure
nares
external part of the nose
air enters respiratory tract here
then passes thought the nasal cavity where it is filtered thought mucous membranes and nasal hairs (vibrissae)
nose and mouth
serve important functions in breathing by removing dirt and particulate matter from the air and warming and humidifying it before it reaches lungs
pharynx
resides behind the nasal cavity at the back of the mouth
common pathway for air destined for the lungs and food destined for the esophagus
air passes here from the nasal cavity
larynx
lies below the pharynx
only a pathway for air
opening (glottis) is covered by the epiglottis during swallowing to keep food out of larynx
contains 2 vocal cords that move using skeletal muscle and cartilage
air passes from the larynx into the trachea
trachea
cartilaginous tube that connects the pharynx to the bronchi
contain ciliated epithelial cells to catch material that has made it past the mucous membranes in the nose and mouth
bronchi
tubelike passages for air that connect the trachea to the bronchioles
in the lungs the bronchi continue to divide into smaller structures known as bronchioles, which continue to divide until they end at the alveoli
alveoli
basic functional unit of the lung
time sac specialized for passive gas exchange b/w lungs and blood
coated with surfactant, detergent that lowers surface tension and prevents the alveolus from collapsing on itself
pleurae
membrane that surround each lung
forms a closed sac against which the lung expands
surface adjacent to the lung is the visceral pleura
the outer part is the parietal pleura
diaphragm
most important muscle in the lung
thin muscular strict that divides the thoracic (chest) cavity from the abdominal cavity
under somatic control, breathing itself is under autonomic control
intrapleural space
fluid filled potential space b/w the parietal and visceral pleura that lubricates that 2 pleural surfaces and allows for a pressure differential b/w the intracellular space and the lungs
thoracic cavity during inhalation
use diaphragm and external intercostal muscles to expand the thoracic cavity by contracting
diaphragm flattens and chest wall expands outward, the intrathoracic volume increases
increase in volume leads to decrease in intracellular pressure
lungs during inhalation
gas in lungs is initially at atmospheric pressure, higher than pressure in intracellular space
lungs expand into the intracellular space, pressure in lungs will drop
air is then sucked into lungs from environment
referred to as negative-pressure breathing
negative-pressure breathing
mechanism of inhalation into the lungs
driving force is lower (relatively negative) pressure in the intracellular space compared with the lungs
thoracic cavity during exhalation
relaxation of external intercostal muscles will reverse process of inhalation
diaphragm and external intercostals relax, the chest cavity decreases in volume
intracellular pressure increases, it is now higher pressure than in the lungs so air is pushed out
can be assisted by contraction of internal intercostal muscles and abdominal muscles
inhalation
air flow into the lungs, breathing in
increase volume of chest cavity
contract diaphragm and external intercostals
active process
exhalation
air flow out of the lungs, breathing out
decrease volume of chest cavity
relax diaphragm and external intercostals
contract internal intercostals and abdominal muscles to pull rib cage down
does not have to be an active process
spirometer
instrument used to measure lung capacities and volumes
cannot measure the amount of air remaining in the lung after complete exhalation (residual volume) but provides a number of measure useful in medicine
commonly tested lung volumes
total lung capacity (TLC) residual volume (RV) vital capacity (VC) tidal volume (TV) expiratory reserve volume (ERV) inspiratory reserve volume (IRV)
total lung capacity (TLC)
the maximum volume of air in the lungs when one inhales completely
usually around 6 to 7 liters
residual volume (RV)
the minimum volume of air in the lungs when one exhales completely
vital capacity (VC)
the difference b/w the minimum and maximum volume of air in the lungs
VC=TLC-RV
tital volume (TV)
the volume of air inhaled or exhaled in a normal breath
expiratory reserve volume (ERV)
the volume of additional air that can be forcibly exhaled after a normal exhalation
inspiratory reserve volume (IRV)
the volume of additional air that can be forcibly inhaled after a normal inhalation
ventilation centers
groups of neurons in the medusa oblongata that regulate respiration
contain chemoreceptors that are sensitive to carbon dioxide concentration
as partial pressure of CO2 rises in blood, the respiratory rate will increase so more CO2 is exhaled
functions of the respiratory system
gas exchange
thermoregulation
immune function
control of pH
gas exchange
primary function of lungs
each alveolus is surrounded by capillaries
capillaries bring deoxygenated blood from pulmonary arteries
walls of alveoli are one cell think and facilitate diffusion of CO2 from blood into lungs and oxygen into blood
oxygenated blood returns to left atrium of heart via pulmonary veins
pulmonary circulation
arteries and veins that circulate b/w the lungs and the heart
arteries originate from the right ventricle and carry deoxygenated blood to the lungs
veins carry oxygenated blood from the lungs to the left atrium of the heart
driving force of gas exchange
pressure differential of the gases
O2 in the alveoli flows dow its partial pressure gradient from the alveoli into the pulmonary capillaries
CO2 in the capillaries flows down its partial pressure gradient from the capillaries into the alveoli for expiration
thermoregulation
regulation of body temperature
heat-transfer of thermal energy-is regulated thought the body surfaced by vasodilation and vasoconstriction
vasodilation, capillaries expand, more blood can pass through, larger amount of thermal energy is dissipated
vasoconstriction, capillaries contract, less blood passes, conserving thermal energy
immune function in nasal cavity
first line of defense in the nasal cavity small hairs (vibrissae) that help trap potentially infectious particles contain lysozyme, able to attack the peptidoglycan walls of grampositve bacteria
immune function of internal airways
lined with mucus
which traps particulate matter and larger invaders
cilia then propel the mucus up the respiratory tract to the oral cavity, where it is expelled or swallowed–> mechanism called mucociliary escalator
immune function of lungs
lungs and alveoli contain numerous immune cells, including macrophages
mucosal surfaces contain IgA antibodies to protect against pathogens
mast cells have preformed antibodies on their surfaces, when substance attaches to antibody it releases inflammatory chemicals into surround area to promote immune response
macrophages
engulf and digest pathogens and signal to the rest of the immune system that there is an invader
control of pH
pH balance though the bicarbonate buffer system
as respiratory rate increases, more CO2 is blown off
this will push equation to the left
respiratory rate decreases, CO2 is retained, shifting buffer equation to the right producing more hydrogen ions and bicarbonate ions, lower pH
bicarbonate buffer system
CO2(g)+H2O(l)H2CO3(aq)H+(aq)+HCO3-(aq)
how disturbances in pH may affect respiration
cardiovascular system
consists of hear, blood vessels, and blood
heart acts as pump, circulating blood through the vasculature
vasculature consists of arteries, capillaries, and veins
blood is returned to the right side of the heart then pumped to the lungs to be reoxygenated
oxygenated blood returns to left side of heart then pumped to rest of the body
the heart
4 chambered structure composed of cardiac muscle
pump of the cardiovascular system
supports 2 circulations in series
right side accepts deoxygenated blood from body and pumps to lungs
left side accepts oxygenated blood from the lungs and pumps to the body
pulmonary circulation
right side of the heart receives deoxygenated blood from the body
pumped out of the heart and moved to the lungs by the pulmonary arteries (deoxygenated)
it is oxygenated and moved to the left side of the heart via the pulmonary veins
systemic circulation
left side of the heart receives oxygenated blood from the pulmonary veins
it is pumped out of the heart via the aorta to circulate to the rest of the body
atria
thin-walled structure where blood is pumped into the heart
right and left atrium
receives blood from the vena cava (deoxygenated blood entering right atrium) or the pulmonary veins (oxygenated blood entering left atrium)
ventricles
artia contract to push blood into the ventricles
once filled with blood they contract and send blood to the lungs or systemic circulations
thick wall of cardiac muscle to ensure strong contraction to pump blood far distances
atrioventricular valves
the atria are separated from the ventricles by these valves
LAB RAT
Left Atrium=Bicuspid valve (2 leaflets)
Right Atrium=Tricuspid valve (3 leaflets)
semilunar valves
separate the ventricles from the vasculature
valve allow the pump to create the pressure within the ventricles necessary to propel blood forward in circulation
prevent back flow of blood
Right ventricle=Pulmonary valve (3 leaflets)
Left ventricle=Aortic valve (3 leaflets)
electric conduction
contraction originates in electical impules generated by 4 electrically excitable structures 1 sinoatrial (SA) nodes, 2 atrioventricular (AV) node, bundle of His (AV bundle), and 3 the Purkinje fibers
SA node
where impulse initiation occurs
generates 60-100 signals per minute w/out neural input
small collection of cells in the wall of right atrium
as depolarization wave spreads from SA node, causes both atria to contract simultaneously
atrial systole
atrial contraction, initiated by SA node
results in an increase in atrial pressure that forces more blood into the ventricles
most blood moves from ratio to ventricles based on ventricular relaxation, it is passive
this additional blood from systole is called atrial kick, accounts for 5-30% of cardiac output
AV node
sits at the junction of the atria and ventricles
signal is delayed here to allow the ventricles to fill completely before they contract
signal then travels down the bundle of His and to the Purkinje fibers
bundle of His
embedded in the inter ventricular septum (wall)
has branches
carries the electrical signal from the AV node to the Purkinje fibers
Purkinje fibers
fibers located in the ventricular muscle
distribute signal through the muscle which stimulates ventricular contraction pushing blood into circulation
intercalated discs
connects muscle cells
contain many gap junctions directly connecting the cytoplasm of adjacent cells
this allows for coordinated ventricular contraction
myogenic activity of cardiac muscle
it can contract without any neural input
the SA node will generate about 60-100 beats per minute even if all innervation is cut
neural input is needed to speed up and slow down the rate of contraction but not generating
systole
ventricular contraction and AV valves close
blood is pumped our of the ventricles
diastole
heart is relaxed
semilunar valves are closed
blood from the atria fills the ventricles
ventricle pressure decreases
cardiac output
total blood volume pumped by the ventricle in a minute
ventricles (pumps) are in series so the volumes of blood passing through each side must be the same
product of heart rate (beats/min) and stroke volume (vol. of blood pumped/min)
CO=HR*SV
atrioventricular valves close
valve connecting atrium and ventricle tricupsid and bicuspid ventricular pressure increases atrial pressure maintains ventricular vol increases slightly (atrial kick)
semilunar valves open
valves from ventricles to vasculature
pulmonary and aortic
ventricular pressure increases slightly then decreases greatly
ventricular volume decreases (pump blood)
atrial pressure maintains
atrioventricular valves open
ventricular and atrial pressure drop slightly
then atrial pressure increases, this allows blood to flow passively into the ventricles (bc atria has greater pressure than ventricle)
vasculature
parts of cardiovascular system that transports blood through the body
3 major vessels: arteries, veins, and capillaries
all vessels lined with endothelial cells
arteries
carry blood away from the heart
largest is the aorta
divided into the coronary, common carotid, and renal arteries
arteries branch into arterioles which lead to capillaries
veins
capillaries join to venules
venues join to form veins
veins empty blood into the heart via the superior and inferior vena cava
atrioventricular valves close
valve connecting atrium and ventricle tricupsid and bicuspid ventricular pressure increases atrial pressure maintains ventricular vol increases slightly (atrial kick)
semilunar valves open
valves from ventricles to vasculature
pulmonary and aortic
ventricular pressure increases slightly then decreases greatly
ventricular volume decreases (pump blood)
atrial pressure maintains
atrioventricular valves open
ventricular and atrial pressure drop slightly
then atrial pressure increases, this allows blood to flow passively into the ventricles (bc atria has greater pressure than ventricle)
vasculature
parts of cardiovascular system that transports blood through the body
3 major vessels: arteries, veins, and capillaries
all vessels lined with endothelial cells
arteries
carry blood away from the heart
largest is the aorta
divided into the coronary, common carotid, and renal arteries
arteries branch into arterioles which lead to capillaries
veins
capillaries join to venules
venues join to form veins
veins empty blood into the heart via the superior and inferior vena cava
endothelial cells
specialized cells that line blood vessels
help maintain vessels by releasing chemicals that aid vasodilation and vasoconstriction
allow white blood cells to pass thought the vessel wall and not tissues during inflammatory response
release chemicals when damaged necessary for formation of blood clots
arteries
carry blood away from the heart
largest is the aorta
divided into the coronary, common carotid, and renal arteries
arteries branch into arterioles which lead to capillaries
structure of arteries
highly muscular and elastic
this creates resistance to the flow of blood
after filled with blood the elastic recoil from their walls maintains high pressure and forces blood forward
capillaries
single endothelial cell layer
thin walls allow easy diffusion of gases, nutrients, and wastes
interface for communication of circulatory system and tissues
allows endocrine signals to arrive at tissues from hormones in the blood
structure of veins
thin-walled and inelastic vessels that carry blood to the heart
able to stretch to accommodate large blood volumes
contain valves that prevent back flow
veins also have high pressure in the extremities that force blood up toward the heart
portal systems
systems where blood will pass through 2 capillary beds in series before returning to the heart
these systems are different bc in most cases blood will pass through only one capillary bed before returning to the heart
3 types: hepatic, hypophyseal, and renal
hepatic portal system
blood leaving capillary beds in the wall of the gut passes through the hepatic portal vein before reaching the capillary beds in the liver
capillaries in gut–> capillaries in liver
via hepatic portal vein
hypophyseal portal system
blood leaving capillary beds in the hypothalamus travels to a capillary bed in the anterior pituitary to allow paracrine secretion of releasing hormones
capillaries in hypothalamus–> capillaries in anterior pituitary
renal portal system
blood leaving the glomerulus travels through an efferent arteriole before surround the nephron in a capillary network called the vasa recta
blood composition
55% liquid and 45% cells
plasma is the liquid portion of blood, aqueous mixture of nutrients, salts, respiratory gases, hormones, and blood proteins
cells have 3 categories: erythrocytes, leukocytes, and platelets
cells formed from hematopoietic stem cells originating in the bone marrow
water in plasma
acts as a solvent for carrying other substances
plasma salts
sodium, potassium, calcium, magnesium, chloride, bicarbonate
act as osmotic balance, pH buffering, regulation of membrane potential
plasma proteins
albumin–> osmotic balance, pH buffering
fibrinogen–> clotting
immunoglobulins–> defense (antibodies)
erythrocyte
red blood cell specialized cell designed for oxygen transport contains hemoglobin 3.6 to 6 mill per cubic mm of blood help to transport carbon dioxide
structure of erythrocytes
biconcave, indented on both sides
shape assists in traveling through capillaries
increases surface area, allows for greater gas exchange
nuclei, mitochondria, and membrane-bound organelles are lost during maturation, this makes space for hemoglobin
do not carry out oxidative phosphorylation to generate ATP, rely entirely on glycolysis for production of ATP
unable to divide bc they lack nuclei, live for 120 days in blood stream before phagocytize and recycled for parts by liver and spleen
hemoglobin
iron-containing protein found in red blood cells
bind O2 and transport it throughout the body
can bind 4 molecules of O2
each red blood cell contains about 250 million molecules of hemoglobin, so each RBC can carry ~1 billion molecules of O2
hematocrit
measurement of home much of a blood sample consists of red blood cells
expressed as a percent
complete blood count
measures the quantity of each cell type in blood
for RBC 2 measures are hemoglobin and hematocrit
normal hemoglobin is b/w 13.5 and 17.5 for males and 12.0 and 16.0 for females
normal hematocrit is b/w 41 and 53% for males and 36 and 46% for females
leukocytes
white blood cells
production of antibodies and defense against infection
make up less than 1% of blood volume, about 4500-11000 per microliter of blood
can increase under certain conditions, like infection
part of the immune system
2 classes: granulocytes and agranulocytes
total of 5 types of cells divided into these classes
types of leukocytes
neutrophiles eosinophils basophils monocytes lymphocytes
granulocytes
neutrophiles, eosinophils, basophils
contain cytoplamsic granules visible by microscopy
granules contain compounds that are toxic to invading microbes
contents can be released thought exocytosis
involved in inflammatory reactions, allergies, pus formation, and destruction of bacteria and parasites
agranuloctyes
lymphocytes and monocytes
do not contain granules
lymphocytes
important in specific immune response, body’s target fight against particular pathogens
som act as primary responders, others maintain long-term memory bank of pathogen recognition
help body learn from experience and prepare to mount a fast response upon repeated exposure to pathogens
lymphocyte maturation
takes place in 1 of 3 locations: spleen, lymph nodes, or thymus
spleen or lymph node maturation results in B-cells responsible for antibody generation
thymus maturation results in T-cells which kill virally infected cells and activate other immune cells
monocytes
phagocytize foreign matter such as bacteria
most organs contain these
once they leave the bloodstream to enter organ they are called macrophages
thrombocytes
platelets
thrombocytes
platelets
cell fragments or shards released from cells in bone marrow known as megakaryocytes
assist in blood clotting
present in high concentration, 150000-400000 per microliter of blood
hematopoiesis
the production of blood cells and platelets
triggered by a number of hormones, growth factors, and cytokines
most notable is erythropoietin and thrombopoietin
erythropoietin
secreted by the kidneys
stimulates mainly red blood cell development
thrombopoietin
secreted by the liver and kidney
stimulates mainly platelet development
antigen
substance that binds to an antibody
may be foreign or a self-antigen
proteins on the surface of RBC
any specific target to which the immune system can react
2 major families: ABO antigens and Rh factor
ABO antigens
comprised of 3 alleles for blood type class of RBC cell-surface proteins A and B alleles are codominant, so a person may express one, both or none of the antigens alleles can be expressed as I(A), I(B), and i or A, B, and O
A blood type
genotypes: AA or AO A antigens produced anti-B antibodies produced can donate to A and AB can receive from A or O
B blood type
genotypes: BB or BO B antigens produced anti-A antibodies produced can donate to B or AB can receive from B or O
ABO antigens
comprised of 3 alleles for blood type class of RBC cell-surface proteins A and B alleles are codominant, so a person may express one, both or none of the antigens alleles can be expressed as I(A), I(B), and i or A, B, and O A and B are codominant and O is recessive
AB blood type
genotype: AB A and B antigens produced no antibodies produced can donate to AB only is a universal recipient, can receive from A, B, AB, or O
O blood type
genotype: OO no antigens produced anti-A and anti-B antibodies produced universal donor, can donate to A, B, AB, and O can receive from O only
Rh factor
a surface protein expressed on RBC
antigen on RBC
the presence or absence of which is indicated by + or - in blood type notation
may also be called the D allele
Rh+ follows autosomal dominant inheritance
Rh factor in pregnancy
when an Rh- woman is pregnant with and Rh+ fetus woman will become sensitized to Rh factor and will being making antibodies against it, not a problem for first child
in subsequent pregnancies in which fetus is Rh+ will present a problem bc maternal anti-Rh can cross placenta and attack fetal blood cells
resulting in hemolysis of fetal cells and condition known as erythroblastosis fetalis
today medicine is used to prevent this condition
blood pressure
ratio of systolic (ventricular contraction) to diastolic (ventricular relaxation) pressure
largest drop occurs in arterioles bc capillaries are thin-walled and unable to withstand pressure of material side
normal pressure is 90/60 and 120/80
measured with a sphygmomanometer
arteriole and capillaries act like resistors in circuit
blood pressure regulation
regulate using baroreceptors in walls of vasculature
when BP is too low they stimulate sympathetic NS causing vasoconstriction, increasing BP
hypertension
high blood pressure
sympathetic impulses could decrease, permitting relaxation
in the heart atrial cells secrete atrial natriuretic peptide (ANP)
human body has many different waits to raise blood pressure but few ways to lower it
atrial natriuretic peptide (ANP)
secreted by atrial cells
aids in loss of salt within the nephron, acting as diuretic with loss of fluid
fairly weak diuretic, some fluid is lost but not enough to counter the effects of high-salt diet on BP
oxygen in blood
measured by partial pressure, normal PP is 70-100 mmHg, inconvenient to measure
oxygen saturation is measured using finger probe usually around 97%
oxygen saturation
the percentage of hemoglobin molecules carrying oxygen
binding of oxygen occurs at the heme group’s central iron atom
binding and releasing of oxygen is an oxidation-reduction reaction
oxygen diffusion in lungs
oxygen diffused into alveolar capillaries
as first oxygen binds to heme group it induced a conformational shift in shape of hemoglobin
shift increased affinity for oxygen making it easier for subsequence molecules of oxygen to bind to remaining heme groups
oxyhemoglobin dissociation curve
blood is 100% saturated in the lungs
blood is 80% saturated in tissues during rest
blood is 30% saturated in tissues during exercise
carbon dioxide
primary waste produce of cellular respiration
majority of CO2 exists in the blood as bicarbonate ion HCO3-
as CO2 enters blood it encounters carbonic anhydrase which catalyzes the combination reaction b/w CO2 and water to form carbonic acid (H2CO3)
carbonic acid is weak acid and dissociated into a proton and a bicarbonate anion
Bohr effect
changes in the affinity of hemoglobin for oxygen caused by changes in the environment
when pH is low, increased conc. of H+, the oxyhemoglobin dissociation curve shifts right, indicating decreased affinity of hemoglobin for oxygen and more efficient off-loading of oxygen from hemoglobin
exercise on oxyhemoglobin curve
causes a right shift of oxyhemoglobin curve Exercise is the Right thing to do increase PaCO2 increase [H+] (decreased pH) increased temperature
fetal hemoglobin
left shift of the oxyhemoglobin curve
fetal hemglobin has higher affinity for oxygen than adult hemoglobin
left shift may occur due to decreased PaCO2, decreased [H+], increased pH, decreased temp
carbohydrates and amino acids in blood
absorbed into the capillaries of small intestine
enter systemic circulation via hepatic portal system
fats in blood
absorbed into lacteals in small intestine
bypassing hepatic portal circulation to eneter systemic circulation via the thoracic duct
once in bloodstream they are packaged in lipoproteins
wastes in blood
CO2, ammonia, urea
enter bloodstream by traveling down their concentration gradients from tissues to the capillaries
blood travels to kidney where waste products are filtered or secreted for elimination form body
hormones in blood
enter circulation in or near the gan where hormone is produced
usually occurs by exocytosis allowing secretion of hormone into bloodstream to travel to target tissue
hydrostatic pressure
the force per unit area that the blood exerts against the vessel walls
generated by the contraction of the heart and the elasticity of arteries
pushes fluid out of the bloodstream and into the interstitial thought the capillary walls
osmotic pressure
the “sucking” pressure generated by solutes as they attempt to draw water into the blood stream
most is attributable to plasma proteins, called oncotic pressure
Starling forces
balance of hydrostatic and osmotic pressure
essential for waiting the proper fluid volumes and solute concentrations inside and outside the vasculature
edema
accumulation of excess fluid in the interstitial
clots
composed of both coagulation factors (proteins) and platelets
prevent or minimize blood loss
thrombus
blood vessel damage
when damaged it exposed connective tissue which contains collagen and protein called tissue factors
when platelets come in contact with collagen it sense injury and release their contents to begin to aggregate or column together
coagulation factors are secreted by the liver sense tissue favor and initiate cascade of coagulation
endpoint of cascade activates prothrombin to form thrombin and thromboplastin
thrombin converts fibrinogen to fibrin that forms small fibers that aggregate into woven structure that captures RBC and platelets forming stable clot
clot is eventually broken down by plasmin generated from plasminogen
