Cardiovascular Flashcards

Question

(a-v) O2 difference

Answer 1

arterial venous oxygen difference oxygen extracted across a capillary bed per volume of blood. Rest – 5 ml O2 per 100 ml of blood; Maximal exercise – 16 ml O2 per 100 ml of blood

Answer 2

Rate of oxygen utilized by body to support aerobic metabolism Cardiac output multiplied by (a-v) O2 difference Rest – 3.5 ml O2/kg/min; Maximal Exercise – 57 mlO2/kg/min

Answer 3

4 chambers muscular organ pumps blood through blood vessels of heart larger in physically active adults. atria: receiving chambers of heart ventricles: large pumping chambers of heart coronary vessels: supply blood to heart wall top chambers of heart are atria, bottom are ventricles

Answer 4

Heart, trachea, esophagus and associated structure from a midline partition

Answer 5

heart surrounded by its own cavity emergency procedure that maintains blood flow in the body if a person's heart stops

Answer 6

pumps blood into pulmonary trunk smaller pulmonary circ major chambers eject blood into arteries and force it to flow through circ system artia open HO ventricle

Answer 7

Reservoirs, where blood returning from veins collect before it enters the ventricles. receives blood from superior vena cava, inferior VC, the corono sinus

Answer 8

pumps blood into aorta thicker wall generates greater bp: moves through systemic circ. left and right ventricle pump same volume of blood.

Answer 9

atrium and ventricles make up the chambers of heart allow blood to flow from atria to ventricles without going back When ventricles relax, higher pressure in atria forces the AV valves to open, and blood flows atria --> ventricles when ventricles contract blood flows toward the atria and causes AV valves to close. valves do not make sounds when they open

Answer 10

Between right atrium and right ventricle

Answer 11

abnormal heart sounds usually because of favity heart sounds

Answer 12

Opening of valve is narrowed

Answer 13

a heart valve that doesn't close completely. valves leak and allow blood to flow in reverse direction

Answer 14

Closing AV valves (between atria and ventricles), lower pitch, occurs at beginning of ventricle systole, occurs between 1st and 2nd heart beat.

Answer 15

closing semilunar valves (between ventricles and arteries) beginning of ventricular diastole between 1st and 2nd heart sound and next beat

Answer 16

both atria contract at the same time both ventricles contract at the same time 1) Superior and inferior cava -- right atrium(before end of ventricular relaxation, right atrium contracts)-- tricuspid valve--> 2) Right ventricle(relaxed)-> 3)pulmonary trunk(follows ventricular contraction)--> 4) pulmonary arteries-- lung tissue(pulmonary circulation)--> 5) Pulmonary veins --> 6)Left atrium -- Bicuspid valve--> 7)Left ventricle-- Aortic semilunar valve--> 8)Aorta--Coronary arteries--Heart tissue(coronary circulation)--Coronary sinus Cardiac veins,--Body tissue (systemic circulation)--> 1)

Answer 17

Supply blood to wall of the heart. originate from base of aorta. blood flowing gives = 70% of in O2

Answer 18

drain blood from cardiac muscles. pathways nearly parallel to coronary arteries. most drain blood in coronary sinus.

Answer 19

Similar to skeletal muscle arrangement of myofilaments in striations, myosin and actin interaction to produce force. Unlike skeletal muscle the fibers (cells) are anatomically interconnected; Intercalated disks bind cells together and gap junctions allow cytoplasm to electrically connect together. functional syncytium.- (contract in unison), imp. for ejection of blood. When one fiber contracts, all fibers contract. The fibers of the atria are electrically separated from the fibers of the ventricles Atrial cells contract together -- help fill up ventricles. valve closes. ventricular cells contract together Gap junction -- allow AP to transmit quickly -- allow syncytium

Answer 20

1)epicardium (outer) - thin 2)myocardium (middle) - thick 3) endocardium (inner) - simple squamous. - allows blood to move easily through heart.

Answer 21

autorhythmic cells spontaneously fire action potentials. Depolarizations of autorhythmic cells then spread rapidly to adjacent contractile cells through gap junctions. Auto rhythmic cells spontaneously fire action potentials Depolarization then spreads through gap junctions Producing action potentials in contractile cells

Answer 22

gap junctions are implied in this. muscle contractions only occur when a muscle has been stimulated. atrial contraction and then ventricle. no electrical signal. 1)heart at rest - chambers relaxed. 2)Atria stimulated - as APs spread across the atrial wall and toward the ventricles 3)Atria contract - pushing blood into ventricles to fill up before ventricle contraction. 4)ventricles stimulated - as AP spread across ventricular wall from apex to base. 5)Ventricles contract - push blood into great arteries.

Answer 23

can contract without neural stimulations all cells of conduction system can produce spontaneous AP. contraction of ventricle depends on this. AP pass slow through AV node to give atria time to fill. AP carried by purkinge fibers from bundle branches to ventricle walls. 1. SA node 2. AV node 3. AV bundle 4. purkinje fibers

Answer 24

Has an increase Ca2+ channels so can produce fast AP -- Na+ and Ca2+ channels open and close rhythmic rate. hearts pacemaker initiates contraction of heart. AP originates here -- if other place it is an ectopic beate -- which can cause fibrillation.

Answer 25

Can initiate AP if SA node cant just much slower. AP spreads slowly and into -- allows for atria to complete contraction before AP is delivered to ventricles

Answer 26

APs pass here and toward apex has two branches- Right and left bundle branches

Answer 27

pass to apex and of heart and extend to cardiac muscle of ventricle walls. electricle signal starts to reach ventricles for ejection.

Answer 28

Spread from one cell to adjacent cells through gap junctions at intercalated disk. slow depolarization prolongs AP 200-500 ms while skeletal are 2ms Cardiac muscle has plateau phase due to calcium channels remaining open after depolarization phase. rapid repolarization Outward rush of K+ ions balanced by in rush of Ca++ ions. - Ca2+ channels remain open during depolarization. Ca++ - for actin and myosin, slow diffusion prolongs. AP Prolonged refractory period allows relaxation of cells and is essential for filling of heart before next contraction and results in rhythmic aspect of heart rate. - plateau. Prevents tetanic contractions. ensures a rhythm of contraction and relaxation. relaxation implied for filling atria and ventricles. AP pass slow through AV node to give atria time to fill AP carried by purkinje fibers from bundles branches to ventricle wall

Answer 29

assessing electrical activity of heart. Can measure electrical currents produced by APs through the heart. record of mechanical events and not a direct measurement. force of contraction or blood pressure cannot be determined. Valuable in detecting cardiac abnormalities.

Answer 30

Depolarization of atria

Answer 31

depolarization of ventricles, comes before ventricle contraction.

Answer 32

repolarization of ventricle before ventricular relaxation

Answer 33

contraction of atria

Answer 34

Contraction of ventricle represents lengths of time required for ventricular depolarization and repolarization

Answer 35

Heart rate in excess of 100 beats per minute (pbm) Elevated body temperature, excessive sympathetic stimulation, toxic conditions.

Answer 36

Heart rate less than 60 bpm Increased stroke volume in athletes, excessive vagus nerve stimulation, nonfunctional SA node, carotid sinus syndrome.

Answer 37

Heart rate varies as much as 5% during respiratory cycle and up 30 % during deep sleep cause not always known; occasionally caused by ischemia, inflammation or cardiac failure.

Answer 38

Sudden increase in heart rate to 150-250 pbm for a few seconds or even several hours; P waves perced every QRS complex; P wave is inverted and superimposed on T wave. Excessive sympathetic stimulation, abnormally elevated permeability of cardiac muscle to Ca2+

Answer 39

As many as 300 P waves/min and 125 QRS complexes/min; resulting in two or three P waves (atrial contractions) for every QRS complex (ventricular contraction) Ectopic beats in atria

Answer 40

No P waves, normal QRS and T waves, irregular timing; ventricles are constantly stimulated by atria; reduced ventricle filling; increased chance of fibrillation ectopic beats in atria

Answer 41

frequently causes fibrillation Often associated with damage to AV node or ventricular muscle

Answer 42

right and left sides of heart can be viewed as two separate pump. With primer pump (atrium) and power pump (ventricles) --because they produce major force that allows blood to flow through pulmonary and systemic circulation. Refers to repetitive pumping process that starts with cardic contraction and ends with beginning of next contraction. blood moves from increase pressure to decrease pressure The heart is completely relaxed Blood flows to ventricles till = 70% max volume. atria and ventricles are relaxed. 1. the heart is completely relaxed 2. atrial systole 3. ventricular systole 4. ventricular systole continues 5. ventricular diastole

Answer 43

Relaxation of two atria.

Answer 44

atria and ventricles are relaxed blood returning to heart first enters atria semilunar valves closed AV valves opened therefore blood flows to ventricles till around 70% max volume

Answer 45

contraction of two atria forcing additional blood flow into ventricles to complete their filling. semilunar valves closes AV valves open

Answer 46

Pushes blood towards atria causing AV valves to close as pressure in ventricles increase contraction of two ventricles AV valves closed semilunar valves closed

Answer 47

ventricle pressure > pulm trunk and aorta semilunar valves are forced open and blood is ejected into pulm trunk and aorta. semilunar valves opened AV valves closed

Answer 48

As diastole continues pressure declines in ventricles until atrial pressures > ventricles then AV valve open and blood flows from atria into relaxed ventricles and they begin to fill again to prevent blood from flowing back to ventricles. ventricles pressure < aorta and pulm trunk relaxation of two ventricles semilunar valves closed AV valves closed

Answer 49

results from hearts normal functional characteristics and does not depend on neural or hormonal regulation Preload: degree which ventricular walls are stretched at the end of diastole venous return us the amount of blood that returns to heart. Afterload: pressure against which the ventricles must pump blood.

Answer 50

Automatic system influences heart pump and CO by altering HR and SV involves neural and hormonal control sympathetic. and parasympathetic reflexes includes chemical and nervous regulation.

Answer 51

blood flow highly regulated, so cells receive adequate nutrients and so waste products are removed Carry blood from heart to tissues and back Exchange nutrients, waste products and gases. - based on [] gradients Transport substances - hormones, enzymes, nutrients waste products molecules for coagulation -- absorbed by digestive system. Regulate blood pressure along with heart -- keeps flow going Directs blood flow to the tissues to maintain homeostasis - divert blood flow to where its needed. Pulmonary -- blood transport from right ventricle through lungs and back to left atrium systemic vessels -- blood from left ventricle through all parts of body and back to right atrium.

Answer 52

find right after heart thickest wall Ie/ pulmonary trunk and aorta very elastic -- expand and recoil

Answer 53

carry blood toward heart deoxygenated blood thinner and less elastic blood can pool constriction for blood flow back to heart, Ie/during exercise

Answer 54

deformation of valve blood pools

Answer 55

collect blood from veins and deliver to large veins

Answer 56

Can contract and relax smaller= increase resistance regulate blood flow to different regions medium size and small thick wall compared to diameter

Answer 57

Tunica adventitia--dence connective tissue tunica media -- middle layer tunica intima -- inner most layer. made of simple squamous epithelial cells. Diameter slightly larger than capillaries capillaries -- blood flow is more slow. exchange for substances like O2, nutrients an CO2 thinner walls

Answer 58

exchange of nutrients, waste products and dissolved gases through diffusion Low vessel diameter, high total cross-sectional area and low velocity at capillaries supports efficient diffusion. Moderate pressure important for fluid exchange blood flows from arteries to capillaries. blood flow regulated by precapillary sphincters thing walled single epithelium high cross section slow velocity

Answer 59

osmosis moves fluid into capillary blood pressure forces fluid out of capillary blood has great osmotic pressure because of its large [ ] of plasma proteins

Answer 60

results from disruption of normal balance of fluid exchange Inflammation - capillaries increase permeability to proteins, draw fluid into interstitial space. Ie/ in injury and infection.

Answer 61

Maximal value -- contraction of ventricles 120/80 systolic, diastolic

Answer 62

minimal value -- relaxation of ventricles

Answer 63

difference between systolic and diastolic pressures gets smaller from aorta --> capillaries measure at artery because high pressure point Pressure decreases as we move through circulatory system due to resistance to flow from vessels.

Answer 64

Blood away from heart blood oxygenated large and elastic branch into smaller arteries blood pressure cuff inflated until brachial artery is completely blocked

Answer 65

Achieved by periodic relaxation and contraction of precapillary sphincters.

Answer 66

Peripheral blood vessels continually in partially constricted state.

Answer 67

Stimulus; Increased CO2, and decreased pH or decreased O2, and nutrients such as glucose, amino acids and fatty acids, due to increased metabolism. Decreased CO2, and increased pH or increased O2, and nutrients, such as glucose, amino acids, and fatty acids. Response: Relaxation of precapillary sphincters and subsequent increase in blood flow through capillaries. contraction of prcapillary sphincters and subsequent decrease in blood flow through capillaries.

Answer 68

Primary controlled Stimulus; Increased physical activity or increased sympathetic activity. Increased body temperature detected by neurons of hypothalamus. Decreased body temperature detected by neurons of hypothalamus. Decrease in skin temperature below a critical value. anger or embarrassment. Response; Constriction of blood vessels in skin and viscera dilation of blood vessels in skin Constriction of blood vessels in skin dilation of blood vessels in skin (protects skin from extreme cold) Dilation of blood vessels in skin of face and upper thorax

Answer 69

reinforces increased activity of sympathetic division Stimulus; Increased physical activity and increased sympathetic activity, causing release of epinephrine and small amounts of norepinephrine from adrenal medulla Response; Constriction of blood vessels in skin and viscera, dilation of blood vessels in skeletal and cardiac muscle.

Answer 70

Stimulus; Increased metabolic activity of tissues over a long period, as occurs in athletes who train regularly. Decreased metabolic activity of tissues over a long period, as occurs during periods of reduced physical activity. Response; Increased number of capillaries Decrease number of capillaries

Answer 71

At rest ~20% of the systemic blood flow goes to the skeletal muscles During maximal exercise ~88% of the cardiac output can be diverted to the working skeletal muscles. Full body vasoconstriction Sympathetic NS Active muscle vasodilation Decreased O2 Increased CO2 Decreased pH NAP = CO X PR --> (cardiac output). (peripheral resistance) NAP =HR x SV x PR

Answer 72

Baroreceptors are stimulated. APs are sent along nerve fibers to medula at increased frequency. Promps Cc to increase PNS stimulation and decrease SNS of heart. Result: HR and SV decrease, cause BP to decrease.

Answer 73

Refex is mechanism of the nervous system. plays important role in regulating heart function. Keeps HR and SV within normal ranges. located in internal carotid arteries, located in carotid sinuses and aortic arch. changes peripheral resistance Stretch receptors that monitor BP result in changes in the stretch in the walls of these blood vessels and changes in the frequency of APs that are transmitted along nerve fibers from the stretch receptors to medulla oblangate

Answer 74

In medulla oblangate receives and integrates AP from the barorecptors. controls AP frequency in sympathetic nerve fibers that extend from brain and spinal cord to heart. also influences sympathetic stimulation of adrenal gland.

Answer 75

Less stimulation occurs in baroreceptor lower frequency of ADD is sent to medulla of brain and triggers response in cc cc increases SNS stimulation, decreases PNS HR and SV increase, causing Bp to increase if drop in BP is larger, sympathetic stimulation of adrnal medulla also increases epinephrine and noepinephrine secreted by adrnal medulla increases HR and SV causing BP to increase towards its normal range.

Answer 76

sensitive to changes in PH and CO2 levels.