Exam 4

Question 1

Heart

Answer 1

four-chambered organ that provides the drive for blood flow

11 oz. for average male
9 oz. for average female

Question 2

Myocardium

Answer 2

heart muscle, myocardial fibers interconnect in latticework fashion to allow the heart to function as a unit

Question 3

Stroke Volume

Answer 3

amount of blood being eject every time the heart beats

70 mL at rest

Question 4

Cardiac Output

Answer 4

Stroke Volume x Heart Rate

5L = 70mL x 72

can change based off training or presence of disease

Question 5

right side of the heart

Answer 5

receives blood returning from body

pumps blood to lungs for aeration through pulmonary circulation

deoxygenated

Question 6

left side of the heart

Answer 6

receives oxygenated blood from lungs

pumps blood into thick-walled muscular aorta for distribution via systemic circulation

Question 7

upper portion of heart

Answer 7

atrium

Question 8

lower portion of heart

Answer 8

ventricles

Question 9

atrioventricular valves (tricuspid)

Answer 9

provides one-way blood flow from the right atrium to right ventricle

Question 10

atrioventricular valves (bicuspid/mitral)

Answer 10

provides one-way blood flow from left atrium to left ventricle

Question 11

semilunar valves

Answer 11

located in arterial wall just outside heart; prevents blood from flowing back into the heart between contractions

Question 12

13 steps of blood flow through the heart

Answer 12

1. body
2. inferior/superior vena cava
3. right atrium
4. tricuspid valve
5. right ventricle
6. pulmonary arteries
7. lungs
8. pulmonary veins
9. left atrium
10. mitral/bicuspid valve
11. left ventricle
12. aortic valve
13. out to body

Question 13

myocardial contraction

Answer 13

atrial chambers serve as “primer pumps” to receive and store blood during ventricular contraction

simultaneous contraction of both atria forces remaining blood into ventricles

almost immediately after atrial contraction, ventricles contract and propel blood into arterial system

Question 14

systole

Answer 14

contraction phase

blood is pumped out of chamber

Question 15

diastole

Answer 15

relaxation phase

blood fills chamber

Question 16

Autorhythmaticity

Answer 16

ability of cardiac muscle tissue to initiate impulse for contraction at regular intervals

Question 17

Sinoatrial node

Answer 17

pacemaker of cardiac contraction made up of specialized nervous tissue; initiates atrial contraction/systole

Question 18

Atrioventricular node

Answer 18

delays impulse by 1/10 of second, allowing atria to contract before ventricles

Question 19

Purkinje fibers

Answer 19

rapidly spreads impulse to contract ventricles in a synchronized manner

Question 20

EKG (P wave)

Answer 20

atria contraction/depolarization

following P wave, pause due to AV node

Question 21

EKG (QRS complex)

Answer 21

ventricular contraction/depolarization (atrial relaxation/repolarization occurs during this time but is obscured by ventricular activity)

Question 22

EKG (T wave)

Answer 22

ventricular relaxation/repolarization

Question 23

parasympathetic system

Answer 23

hyperpolarizes SA Node

Question 24

sympathetic system

Answer 24

increases heart rate and stroke volume

Question 25

arterial system

Answer 25

high-pressure tubing that propels oxygen-rich blood to tissues layers of connective tissue and smooth muscle no gaseous exchange occurs between arterial blood and surrounding tissues

Question 26

metarterioles

Answer 26

arterioles branch and form smaller less muscular vessels end in microscopically small blood vessels called capillaries that contain 6% of total blood volume

Question 27

precapillary sphincter

Answer 27

consists of a ring of smooth muscle encircling the capillary at its origin and controls its diameter constriction and relaxation provide a means for blood flow regulation within a specific tissue to meet metabolic requirements

Question 28

Two factors trigger precapillary sphincter relaxation to open more capillaries

Answer 28

Driving force of increased local BP plus intrinsic neural control Local metabolites produced in exercise

Question 29

Ejection fraction (EF)

Answer 29

ratio of available blood to pumped blood EF = SV/EDV (end-diastolic volume)*100

Question 30

endurance training

Answer 30

can increase EDV, increasing SV & decreasing HR can also increase plasma volume, which may increase ventricle filling and force of contraction by Frank-Starling SV may increase because of increased ventricular contractility, ESV may decrease

Question 31

moderately trained or untrained people

Answer 31

SV increases with exercise intensity up to 40% to 50% of peak oxygen consumption

Question 32

Frank-Starling Mechanism

Answer 32

increased venous return stretches or “preloads” the ventricle, causing reactionary increase in contractile force of ventricle. This results in lower ESV

Question 33

blood pressure in aorta increasing/high

Answer 33

If blood pressure in aorta increases, SV decreases If blood pressure in an artery is high, EF into that artery can decrease. To overcome high blood pressure and increase EF, heart would have to work harder; if blood pressure is too high (hypertension), heart may not be able to supply sufficient oxygen, causing ischemia

Question 34

Blood pressure

Answer 34

Cardiac output × Total peripheral resistance (TPR)

Question 35

blood pressure mediation

Answer 35

Force of blood against arterial walls during cardiac cycle Peripheral vessels do not permit blood to“run off” into arterial system as rapidly as it ejects from heart Aorta “stores” some ejected blood, which creates pressure within the entire arterial system Arterial blood pressure reflects the combined effects of arterial blood flow per minute and resistance to flow in peripheral vasculature

Question 36

hypertension central mediation

Answer 36

via sympathetic hyperactivity more Epi/Norep, more Angiotensin II

Question 37

hypertension peripheral mediation

Answer 37

via damage to the endothelial wall structural alterations - collagen vs. elastin peptide release - reduced NO, too much Endothelin (ET-1)

Question 38

Angiotensin II

Answer 38

hypertensive hormone, increases blood volume, big vasoconstrictor, increases blood pressure exercise can help decrease the amount of angiotensin II we produce

Question 39

venoconstriction

Answer 39

constriction of veins via sympathetic stimulation veins contain 65% of blood volume, storage reservoirs/capacitance blood vessels

Question 40

Muscle Pump

Answer 40

rhythmic muscle contractions propelling blood to heart through one-way valves of veins (prevents backflow and ensures that blood moves towards heart when pumped)

Question 41

respiratory pump

Answer 41

changes in intrathoracic and intraabdominal pressure during expiration & inspiration, forcing blood in those cavities to flow toward heart

Question 42

varicose veins

Answer 42

Valves within a vein fail to maintain one-way blood flow; blood gathers in vein so they become excessively distended and painful Usually occurs in surface veins of lower extremities People with varicose veins should avoid static, straining-type exercises like resistance training Exercise does not prevent varicose veins, but regular exercise can minimize discomfort and complications

Question 43

3 components of blood

Answer 43

plasma (55% of whole blood volume) buffy coat (eukocytes and platelets less than 1%) erthrocytes (45% of whole blood volume)

Question 44

plasma

Answer 44

55% - 60% of total blood volume may decrease in volume as much as 10% during intense physical activity can increase as much as 10% at rest because of adaptations to training or acclimatization to hot, humid environments

Question 45

platelets

Answer 45

important for blood clotting contribute to heart attack, stroke, plaque build up

Question 46

red blood cells

Answer 46

transport oxygen via hemoglobin produced in bone marrow of long bones 4 month lifespan nuclei removed when produce, can't repair themselves

Question 47

EPO

Answer 47

Erythropoietin produced by kidneys and stimulates RBC in long bones hypoxic environment helps to produce more EPO

Question 48

blood supply of myocardium

Answer 48

coronary artery branches off aorta & supplies blood to heart (oxygenated) blood pressure is highest in aorta coronary artery branches into right & left sides

Question 49

anastomosis

Answer 49

intercommunication between 2 arteries ensuring blood flow to area even if one artery is blocked

Question 50

oxygen delivery to tissue

Answer 50

blood flow increases during exercise for delivery (oxygen, glucose, triglyceride) and removal (carbon dioxide)

Question 51

oxygen delivery depends on...

Answer 51

amount of oxygen tissue takes out of blood flowing by it

Question 52

fick equation

Answer 52

oxygen delivery = blood flow x a-vO2 diff VO2 = oxygen consumption Cardiac output (Q) = blood flow VO2 = Q × a-vO2 diff

Question 53

control of vasoconstriction and vasodilation

Answer 53

Release of norepinephrine by sympathetic nerves causes vasoconstriction of peripheral blood vessels Release of epinephrine by sympathetic nerves can cause both vasoconstriction and vasodilation

Question 54

autoregulation

Answer 54

changes in skeletal muscle during exercise that stimulate smooth muscle chemoreceptros in precapillary sphincters & increase vasodilation

Question 55

O2 kinetic chain during exercise

Answer 55

Respiratory (up-take) Central Circulation (transport) Peripheral Extraction (use)

Question 56

maximal oxygen uptake

Answer 56

the maximal amount of oxygen that can be consumed during dynamic exercise while breathing ambient air at sea level (VO2max, maximal aerobic power, functional aerobic power)

Question 57

rate limiting factor

Answer 57

physiological process when at its maximal level of function sets an upper limit (functionally) for entire oxygen kinetic chain sets the limits of performance

Question 58

central (Q)

Answer 58

heart rate x stroke volume: central research has demonstrated a 20% increase in SV

Question 59

physiological adaptations (SV)

Answer 59

Increased internal left ventricular volume and mass Reduced cardiac and arterial stiffness Increased diastolic filling time Improved intrinsic cardiac contractile function Increased plasma volume Increased red blood cell volume

Question 60

peripheral response (arteriovenous O2 difference)

Answer 60

amount of oxygen extracted by tissue measurement of bodys skeletal muscle ability to extract and utilize oxygen rest = 5ml/dl max exercise = 16-18 ml/dl

Question 61

physiological adaptations (A-VO2 diff)

Answer 61

Increased muscle-capillary density Increased mitochondrial density Increased hemoglobin Ultimately equates to a rightward shift in oxyhemaglobin dissociation curve

Question 62

detraining

Answer 62

occurs rapidly when a person terminates participation on regular physical activity only 1-2 weeks of detraining reduces both metabolic & exercise capacity, many training improvements fully lost within several weeks

Question 63

The relationship between blood volumes and pressure. How might an increased pressure in one of the chambers alter the blood flow dynamics?

Answer 63

As blood enters ventricle, pressure increases, more forceful contraction. During diastole, if pressure is increased, blood cannot enter the chamber as efficiently.

Question 64

Contraction and blood volumes.

Answer 64

stroke volume is enhanced with exercise, end-diastolic volume is enhanced, we have more to pump so we can pump more out.

Question 65

heart rate (mitochondria)

Answer 65

Grow the total number of mitochondria and mitochondria become larger = enhanced oxidative processes = enhanced O2 kinetic chain

Question 66

How might exercise alter the blood flow and pressure relationships?

Answer 66

Endurance training increases EDV, increasing SV, decreasing HR

Question 67

How might exercise improve hypertension?

Answer 67

Exercise diminishes angiotensin II helping to decrease hypertension.