cardiorespiratory sys. and gas exchange

Question 1

2 systems function..

Answer 1

1) provide oxygen and nutrients to the body under various changes
2) clearing metabolic by-product from muscle

Question 2

blood structure

Answer 2

plasma 55%, leukocytes & platelets 1%, erythrocytes 45%;

Ph 7.4

Question 3

reason for blood PH changes

Answer 3

exercise, stress, deases

Question 4

physiological tolerance for changes in PH of arterial blood and muscle

Answer 4

6. 9 - 7.5;

6. 63 - 7.1

Question 5

ph is regulated by

Answer 5

bicarbonate, ventilation and kidney function

Question 6

oxygen presents in the blood in 2 forms

Answer 6

dissolved in blood (0.3ml/100ml) and carried via hemoglobin

Question 7

hemoglobin

Answer 7

iron-containing protein within the red blood cells that can bind 1-4 oxygen molecules.

Question 8

1 gr hemoglobin can carry …ml of oxygen

Answer 8

1.39ml

Question 9

healthy blood hemoglobin capacity

Answer 9

15gr per 100 ml = 20.8ml oxygen/ 100ml

Question 10

healthy (non-anemic) adult blood volume

Answer 10

5L or 7% of the body weight

Question 11

oxygen-hemoglobin dissociation curve

Answer 11

the curve is S-shaped/ sigmoidal.
As O2 partial pressure increases hemoglobin affinity for Os increases and plateaus at O2 pressure 60mmHg and 90% hemoglobin saturation. O2 of 100mmHg = 98% hemoglobin saturation

Question 12

the partial pressure is

Answer 12

pressure exerted by one gas in a mixture of gasses and calculated as the product of total pressure of a gas mixture and % of concentration of the specific gas.
example: atmospheric pressure=760 mmHg; O2 concentration=20.93%; O2 partial pressure= 760 x 20.93/100=159mmHg

Question 13

factors influencing O2-hemoglobin curve

Answer 13

1) decrease in body t shifts the curve to the left
2) increase - to the right
arterial blood acidity: acidic or low pH - to the right;high pH (alkalosis) - to the left.
3) exercise - higher body t - O2 is released at a higher partial pressure so to be used by muscles

Question 14

cardiac morphology

Answer 14

• mononucleated cardiac muscle
• 4 chambers (right/left atrium and ventricle)
• is under involuntary neural control
• SA= sinoatrial node or pacemaker of the heart

Question 15

SA function

Answer 15

generates the electrical impulse (at speed 0.08m/s) - to the both atrium - to the AV node (atrioventricular) impulse slows down; - to the left and right bundle branches into the Purkinje system - ventricular contraction. The total impulse time - 0.2 s

Question 16

the Purkinje system is

Answer 16

a series of fibers that surround ventricles which then stimulate ventricular contraction.

Question 17

venous blood route

Answer 17

right atrium (superior &inferior vena cava) - right ventricle - lung (via pulmonary artery) - gas exchange (load with O2 and remove metabolic by-products).

Question 18

superior/ inferior vena cava fuction

Answer 18

superior returns blood from head and upper extremities

inferior - trunk, lower extremities

Question 19

arterial blood route

Answer 19

left atrium (via pulmonary vein) - left ventricle - through the body via aorta - organs, tissues via vasculature

Question 20

central and peripheral circulation

Answer 20

heart and lungs = arterial system; the rest of the body = venous system.

Question 21

ECG (electrocardiogram)

Answer 21

detects electrical impulses of the heart by the surface electrodes (10-12 places on the chest) and presented as distinct pattern.
Is taken in a clinical setting to examine the heart under stress.

Question 22

ECG components

Answer 22

1) P-wave (represents atrial depolarization on SA-AV way)
2) QRS (ventricular depolarization on AV-Purkinje way)
3) T-way (electrical recovery/repolarization of the ventricles)
Note: atrial repolization can’t be seen as it takes place during QRS complex.

Question 23

blood circulation system is composed of

Answer 23

• arteries (carry blood from heart to the tissues and organs)
• veins (carry blood from the tissues and organs back to the heart)
• the pulmonary veins (carry oxygenated blood from the lungs to the heart)

Question 24

artery and vein blood pressure

Answer 24

arteries: for the systematic circulation it’s high (100mmHg in the aorta and 60mmHg in the arterioles)
veins; very low; due to this veins have one-way valves and smooth muscle bands that continue moving venous blood toward the heart as we move and contract muscles in our extremities.

Question 25

total peripheral resistance

Answer 25

the resistance of the entire systemic circulation.

Question 26

relation b/n the vessel dilation and constriction and peripheral resistacne

Answer 26

dilation - decrease; constriction - increase

Question 27

factors influencing the vessel dilation and constriction

Answer 27

type of exercise;
sympathetic nervous system stimulation;
local muscle tissue metabolism;
environmental stressors (heat,cold..)

Question 28

influence of the exercise on the blood circulation

Answer 28

sympathetic nervous system stimulates arteries vasodilation, therefore increases blood floor to the working muscles. Blood is redistributed from other organs to the muscles used for the particular exercise.

Question 29

cardiac cycle

Answer 29

events that occur from the one heartbeat to the start of another

Question 30

cardiac cycle is composed of ..

Answer 30

1) diastole - period of relaxation

2) systole - period of contraction

Question 31

diastole phase allows for the heart to

Answer 31

fill with blood

Question 32

SBP (systolic blood pressure) is

Answer 32

pressure exerted against the arterial walls as blood is forcefully ejected during ventricular contraction (systole)

Question 33

BP and HR measurements are used for..

Answer 33

describing the work of the heart and can provide and indirect estimation of the myocardial oxygen uptake

Question 34

rate-pressure product (RPP) or double product is

Answer 34

estimate of the heart work

RPP=SBPxHR

Question 35

DBP (diastolic blood pressure) is

Answer 35

pressure exerted against the arterial walls when no blood is being forcefully ejected through the vessels (diastole)

Question 36

DBP indicates

Answer 36

peripheral resistance or vascular stiffness; tend to decrease with vasodilation and increase with vasoconstriction.

Question 37

mean arterial pressure (MAP) is

Answer 37

the mean/average arterial pressure during a single cardiac cycle:
MAP = DBP + (0.333 x (SBP-DBP))

Question 38

MAP norma

Answer 38

greater than 60 mmHg is enough to sustain the organs of the average person. MAP is NORMALLY between 70 to 110 mmHg[7]
If the MAP falls below this number for an appreciable time, vital organs will not get enough Oxygen perfusion, and will become hypoxic, a condition CALLED ischemia.

Question 39

cardiac output (Q) is

Answer 39

the amount of blood pumped by the heart in 1 minute an dis represented by the formula: Q=SV x HR = (EDV-ESV) x HR

Question 40

SV (stroke volume) is

Answer 40

amount of blood ejected per heartbeat

SV=EDV - ESV

Question 41

EDV

ESV

Answer 41

end-diastolic volume - volume of blood in ventricles following filling.
end-systolic volume- volume of the blood in ventricles after contraction

Question 42

The Frank-Starling principle suggests … based on…

Answer 42

…the more the left ventricle stretched the more forceful the contraction and thus the greater volume of blood leaving the ventricle.
…length-tension relationship

Question 43

EDV factors

Answer 43

heart volume ; venous return of blood

Question 44

blood distribution at rest…

at exercise…

Answer 44

….internal organs 20-25%; muscles - 15-20%; kidneys 20%; brain 15%; heart 4-5%; skin 4-5%; bone 3-5%
… muscle 70-80%; skin 5-20%; heart 4-5%; internal organs 3-5%; brain 3-4%; kidneys 2-4%; bone 0.5 -1%