VASCULAR SYSTEM

Question 1

what is the vascular system made up of

Answer 1

Blood and blood vessels

Question 2

what is blood made up of

Answer 2

45 % cells
- red blood cells (transports O2)
- white blood cells (immune system)
- platelets (blood clotting)
55% plasma

Question 3

what is plasma made up of

Answer 3

92% water
7% proteins
electrolytes
nutrients
hormones
waste products
gases

Question 4

what is the role of blood

Answer 4

transportation - oxygen, glucose, lipids, amino acids, vitamins, hormones
regulation - temperature, pH
protection - immune system
homeostasis - thermoregulation

Question 5

name the blood vessels

Answer 5

arteries
arterioles
capillaries
venules
veins

Question 6

what are the characteristics and their functions of the arteries

Answer 6

thick walls - to withstand high pressure
elastic walls - allows for stretching (maintaining blood pressure)
smooth muscle - can vaso constrict/dilate to control blood flow
narrow lumen - maintains high blood pressure
no valves - high pressure maintains blood flow in 1 direction

Question 7

what is the mains roles of the arteries

Answer 7

transport oxygenated blood to tissues
maintain blood pressure
distribution of blood - e.g. to the working muscles during exercise
tissue oxygenation

Question 8

what are the characteristics of the arterioles

Answer 8

smaller than arterioles
smooth muscle
less elastic
narrow lumen
no valves

Question 9

what are the roles of arterioles

Answer 9

regulate blood flow
control blood pressure
direct blood to capillaries
redistribute blood during exercise

Question 10

what are the characteristics of the capillaries

Answer 10

small and thin
large surface area
narrow lumen
permeable walls
no valves or muscle

Question 11

what is the role of capillaries

Answer 11

exchange of substances
- O2 and CO2
- nutrients
- waste products
- support working muscles during exercise
- link arterioles to venules
- regulate temperature

Question 12

what are the characteristics of venules

Answer 12

capillaries>venules>veins
thin walls
less smooth muscle
no valves

Question 13

what is the role of venules

Answer 13

collect deoxygenated blood
transport waste products
regulate blood flow to veins
facilitate recovery post exercise

Question 14

what is the characteristics of veins

Answer 14

thin walls
larger lumen
valves
less elastic
surrounded by skeletal muscle

Question 15

what is the role of veins

Answer 15

return deoxygenated blood to the heart
contain blood reservoirs
air venous return
prevent backflow
facilitate recovery

Question 16

why are veins the only blood vessels with valves

Answer 16

they have the lowest pressure so they need help getting the deoxygenated blood back to the heart.
the valves only allow blood to flow in 1 direction and prevent backflow

Question 17

what is vascular shunt

Answer 17

the redistribution of blood during exercise.
at rest:
80% of blood goes to the ‘non essential organs’ (stomach, kidney, liver)
20% of the blood to the ‘‘working muscles’’
during exercise:
20% of blood goes to the non essential organs (stomach, kidney, liver)
80% of blood now goes to the working muscles

Question 18

how does the redistribution of blood happen

Answer 18

by vasoconstriction, vasodilation and widening, narrowing of pre-capillary sphincters

Question 19

EXAM Q:
how does the redistribution of blood during exercise happen

Answer 19

-vasodilation (widening of blood vessels) of the arteries/arterioles towards the working muscles occurs, in order to meet the higher oxygen demand.
-vasoconstriction (narrowing of the blood vessels) of the arteries/arterioles towards the non essential organs occurs at they don’t demand as much oxygen during exercise.
-the precapillary sphincters (small rings of smooth muscle located at the entrance of capillary beds, either constrict (towards non essential organs) or dilate (towards the working muscles), in order to allow more blood to where it needs to be.

Question 20

How does vascular shunting change blood flow?

Answer 20

at rest, 80% of blood goes to the non essential organs (kidneys, liver, stomach), to carry out normal bodily functions e.g. digestion, and 20% goes to the ‘working’ muscles. once exercise starts, this changes to 80% to the working muscles and 20% to the non essential organs. this is due to the higher oxygen demand at the working muscles, this happens via vasodilation, vasoconstriction and the narrowing and widening of pre-capillary sphincters.

Question 21

what is the importance of vascular shunting

Answer 21

• increases supply of o2 to working muscles
• removes waste products - co2
• gets more blood to skin - thermoregulation
• gest more blood back to the heart