the cardiovascular system

Question 1

what does the pulmonary circuit do

Answer 1

carries deoxygenated blood to the lungs and oxygenated blood back to the heart

Question 2

what does the systemic circuit do

Answer 2

carries oxygenated blood to the body tissues and deoxygenated blood back to the heart

Question 3

what is diastole

Answer 3

the relaxation phase of the heart

Question 4

what is systole

Answer 4

the contraction phase of the heart

Question 5

what does the SA node do

Answer 5

it initiates the heartbeat

Question 6

what is stroke volume determined by

Answer 6

venous return- if more blood enters the heart, more blood will be pumped out

Question 7

ejection fraction

Answer 7

the % of blood pumped out of the left ventricle, per beat.

Question 8

what are pocket valves

Answer 8

one way valves that prevent the back flow of blood/ one direction flow

Question 9

what is muscle pump

Answer 9

veins situated between skeletal muscles which help squeeze blood back to the heart when they contract and relax

Question 10

what is the respiratory pump

Answer 10

during exercise, breathing increases deeper in the thorax and abdomen

Question 11

smooth muscle

Answer 11

thin layer of smooth muscle helps squeeze blood back towards the heart

Question 12

gravity

Answer 12

blood from upper body is aided in its return by gravity

Question 13

what is frank starling law

Answer 13

when SV increases in response to an increase in the volume of blood filling in the left ventricle

Question 14

what is cardiac output

Answer 14

the amount/volume of blood pumped out of the left ventricle per minute

Question 15

examples of cardiac responses to exercise:changes in HR

Answer 15

HR increases (how much by is depending on the intensity of the exercise)
HR increases in direct proportion to exercise intensity

Question 16

where is the cardiac control centre located

Answer 16

medulla oblongata (brain stem)

Question 17

what controls the CCC

Answer 17

the autonomic nervous system- it is an involuntary nervous system

Question 18

what are the three main influences of the ANS

Answer 18

intrinsic control
hormonal control
neural control

Question 19

what do chemoreceptors do

Answer 19

informs the brain if CO2 levels increase, O2 levels decrease or if PH levels rise

Question 20

what do proprioceptors do

Answer 20

detects if movement has been increased or decreased

Question 21

what do baroreceptors do

Answer 21

dectect if blood flow and blood pressure increases or decreases

Question 22

what does the sympathetic nervous system do

Answer 22

increases HR
sends a signal via the accelerator nerve to the SA nerve to increase HR

Question 23

what does the parasympathetic nervous system do

Answer 23

decreases HR
sends a signal via the vagus nerve to the SA node to decrease HR

Question 24

which part of the autonomic nervous system is in control of HR when a person is at rest

Answer 24

the parasympathetic nervous system

Question 25

what hormone is released when the PNS is keeping the HR down

Answer 25

acetylcholine

Question 26

what are the two layers of blood

Answer 26

45% cells 55% plasma

Question 27

how many layers thick are arteries

Answer 27

3 layers thick

Question 28

what are arteries

Answer 28

blood vessels that carry blood away from the heart via the aorta

Question 29

how do arteries control blood flow

Answer 29

they vasodilate and vasoconstrict

Question 30

what type of blood do arteries carry

Answer 30

they usually carry highly oxygenated blood, with the exception of the pulmonary artery

Question 31

how do arteries/arterioles change shape and regulate blood flow

Answer 31

they have a layer of smooth muscle

Question 32

what do precapillary sphincters do

Answer 32

they vasodilate and vasocontrict

Question 33

what are capillaries

Answer 33

they are the smallest and thinnest blood vessels in the body

Question 34

what do capillaries do

Answer 34

they transport the oxygen rich red blood cells through them allowing oxygen to diffuse into the muscles and carbon dioxide out

Question 35

how many layers thick is a capillary

Answer 35

1 thin layer wall (allows for the movement of oxygen and carbon dioxide between the capillaries and blood to be made easier)

Question 36

what do veins do

Answer 36

carry deoxygenated blood back to the heart

Question 37

how many layers thick are veins

Answer 37

3 layers thick

Question 38

what type of blood do veins carry

Answer 38

mostly carry deoxygenated blood, with the exception of the pulmonary vein

Question 39

where do veins carry blood towards

Answer 39

the heart

Question 39

what is vascular shunting

Answer 39

blood is diverted to the working muscles and away from the non-essential organs

Question 39

what is vasodilation

Answer 39

smooth muscle relaxes to make the inside of the arterioles wider

Question 40

what is vasocontriction

Answer 40

smooth muscle contracts to make the inside of the arterioles narrower

Question 41

what are precapillary sphincters

Answer 41

rings of muscle at the junction between the arterioles and capillaries

Question 42

what do precapillary sphincters do

Answer 42

they can effectively 'open' or 'close' the capillaries leading to the muscles or organs

Question 43

what happens to O2 during exercise

Answer 43

it diffuses into the capillaries that are supplying muscle with oxygen

Question 44

what stores O2 in the muscle

Answer 44

myoglobin as it has a high affinity for O2

Question 45

where does aerobic respiration take place within the muscle

Answer 45

the mitochondria

Question 46

what is myoglobin

Answer 46

a protien that stores O2 in the muscle

Question 47

how much CO2 is transported around the body in the blood as hydrogen carbonate

Answer 47

70%

Question 48

why is carbon dioxide produced

Answer 48

it is produced by the muscles as a waste product that diffuses into the blood stream

Question 49

what is cardiac drift

Answer 49

the upward drift of heart rate over time, coupled with a progressive decline in stroke volume and the continued maintenance of cardiac output

Question 50

what effects cardiac drift

Answer 50

an increase in core temperature and body water losses