Circulatory System

Question 1

structure and functions of arteries/arterioles

Answer 1

thick muscular elastic walls
supply the necessary elements to the bodys organs

Question 2

structure and functions of capillaries

Answer 2

tiny blood vessels have thin walls. Oxygen and nutrients from the blood can move through the walls and get into organs and tissues. The capillaries also take waste products away from your tissues. Capillaries are where oxygen and nutrients are exchanged for carbon dioxide and waste.

Question 3

structure and function of pre capillary sphincters

Answer 3

rings of smooth muscle
help to direct blood flow into capillaries

Question 4

structure and function of veins/venules

Answer 4

thin walls, wide lumen
blood to the heart at a low pressure, deoxygenated blood

Question 5

pocket valves

Answer 5

little muscle doors
prevent back flow of blood

Question 6

whats plasma

Answer 6

the fluid part of the body (mainly water) that surrounds blood cells and transports them

Question 7

whats haemoglobin

Answer 7

an iron containing pigment found in red blood cells, which combines with oxygen to form oxyhemoglobin

Question 8

whats myoglobin

Answer 8

its an iron containing muscle pigment in slow twitch muscle fibres which has a higher affinity for oxygen than haemoglobin. it stores oxygen in muscle fibres which can be used quickly when exercise begins.

Question 9

whats mitochondria

Answer 9

often referred to as the powerhouse of the cells as respiration and energy production occur there.

Question 10

mechanism of venous return

Answer 10

Contraction of the skeletal muscles surrounding veins increases the pressure within the veins, pushing open the proximal valve and forcing blood toward the heart. For example, when calf muscles contract during exercise, blood is forced toward the heart, thus increasing venous return.

Question 11

what is the Bohr shift

Answer 11

describes the movement of the oxygen dissociation curve to the right of normal. This occurs due to increased levels of carbon dioxide, such as when a person increases their exercise level, which causes an increased concentration of carbonic acid to be formed.

Question 12

why does the Bohr shift occur

Answer 12

increase in carbon dioxide
decrease in PH(blood more acidic)
blood temp increases

Question 13

what happens during the Bohr shift

Answer 13

increase in heomoglobin dissociation due to increase in co2 etc

Question 14

whats the effect of the Bohr shift

Answer 14

has an affect on oxygen delivery to the muscles as there is an increase in resaturation of myoglobin.
The aim of myoglobin is to deposit oxygen and keep full saturation this then helps us with exercise as oxygen can be diffused into the muscles faster.

Question 15

what is the skeletal muscle pump

Answer 15

when muscles contract and relax meaning they change shape and press on nearby veins to make a pumping effect. This squeezes blood towards the heart

Question 16

what is the respiratory system

Answer 16

when muscles contract and relax during breathing in or out, pressure change in the thoracic(chest) and abdominal(stomach) cavities. these changes in pressure press on nearby veins and assist blood return to the heart

Question 17

what mechanisms aid with venous return

Answer 17

• skeletal muscle pump
• respiratory pump
• pocket valves
• gravity

Question 18

what is venous return

Answer 18

the return of blood to the right side of the heart via the vena cava

Question 19

what is pulmonary circulation

Answer 19

deoxygenated blood moving from the heart to the lungs and oxygenated blood moving back to the heart

Question 20

what is systemic circulation

Answer 20

oxygenated blood moving from heart to the body and then the return of deoxygenated blood from the body to the heart

Question 21

flow chart showing the order of the key blood vessels

Answer 21

heart - arteries - arterioles - capillaries - venues - vein - heart

Question 22

what is the definition of blood pressure

Answer 22

the force exerted by the blood against the blood vessel wall

Question 23

what is systolic pressure

Answer 23

the pressure in the arteries when ventricles are contracting

Question 24

what is diastolic pressure

Answer 24

the pressure in the arteries when the ventricles are relaxing

Question 25

what happens to blood pressure during aerobic activity

Answer 25

systolic pressure will increase but diastolic pressure will remain relatively constant

Question 26

what happens to blood pressure during anaerobic activity

Answer 26

the skeletal muscle pump is working harder causing an increase in venous return which causes and increase in both systolic and diastolic blood pressure

Question 27

whats the largest artery in the body called

Answer 27

the aorta

Question 28

what the largest vein in the body called

Answer 28

the vena cava

Question 29

how would a cool run help venous return

Answer 29

a Coll down helps to keep the skeletal muscle pump and respiratory pump working which prevents blood pooing

Question 30

whats blood pooling

Answer 30

when blood stays in veins and is not sent back to the heart properly

Question 31

how does blood redistribution occur

Answer 31

through vasoconstriction and vasodilation which is controlled by the pre capillary sphincters

Question 32

whats vasoconstriction

Answer 32

the narrowing of the blood vessels to reduce blood flow into the capillaries

Question 33

whats vasodilation

Answer 33

the widening of blood vessels to increase the flow of blood into the capillaries

Question 34

what is oxyhemoglobin dissociation

Answer 34

when oxygen is released from oxyhemoglobin

Question 35

what is atria-venous oxygen difference

Answer 35

the difference between the oxygen carried by the blood in arteries and veins. it also represents the amount of oxygen delivered to working tissue in the capillary system

Question 36

what has a higher affinity for oxygen haemoglobin or myoglobin

Answer 36

myoglobin

Question 37

whats starlings law

Answer 37

the greater venous return, the greater stroke volume is