blood vessels

Question 1

3 types of blood vessels

Answer 1

arteries
capillaires
veins

Question 2

arteries function

Answer 2

carries (oxygenated) blood away from the heart to the body tissues and cells through the systemic circuit for transport of nutrients and oxygen

Question 3

arteries structure

Answer 3

tunica externa- made of fibrous connective tissue
tunica media- made of elastic fibres and smooth muscle cells
tunica intima- made of squamous endothelium cells, attached to a layer of thin connective tissue

Question 4

arteria tunica externa function

Answer 4

- structural support
-protection

Question 5

ateria tunica media functions

Answer 5

• maintain blood pressure
• regulate blood flow

Question 6

adaptions of the smooth muscle cells for transport/ blood flow

Answer 6

vascoconstriction and vascodilation
vascoconstriction- narrows lumen diameter which decreases blood volume but increases blood pressure
vascodilation- dilates the artery lumen, increases blood volume but decreases blood pressure

essential for healthy circulation and proper functioning of the heart to decrease risk of cardiovascular diseases

• maintains blood flow

Question 7

adaptations of elastic tissue for transport/ blood flow

Answer 7

• distention and recoiling of the artery wall helps maintain high pressure and a steady flow
• walls stretching helps accomodate high volume of blood being pumped from the heart
• wall recoiling pushes the blood forward

Question 8

veins structure

Answer 8

tunica externa- thin fibrous connective tissue with more collagen

tunica media- thin layer of very little smooth muscle and elastic fibres

tunica intima- layer of squamous endothelium

Question 9

veins function

Answer 9

carries deoxygenated blood back to the heart from every body tissue in systemic circuit

Question 10

veins adaption to function

dont describe yet

Answer 10

large lumen
thin walls
valves
presence of only smooth muscle
endothelium

Question 11

the importance of valves

Answer 11

prevent backflow of blood, due to the blood being under low pressure
- supports unidirectional flow

Question 12

what helps the blood flow back up to the heart

Answer 12

• gravity
• valves
• vascoconstriction of smooth muscle helps push the blood upwards due to pressure changes
• squamous endothelium reduces friction , so the blood travels smoother

Question 13

what are the function of cappilaries

Answer 13

• exchange molecules
• deliver nutrients
• dispose of waste

to and from metaboliclly active tissue

Question 14

what is the structure of the capillaries

Answer 14

1 cell thick layer of squamous endothelium

Question 15

how are capillaries adapted to their function in the circulatory system (5)

Answer 15

large surface area- a large amount of capilaries surrounding each tissue, increases the surface contact of cells to the tissue and increases rate of diffusion

thin 1 cell thick walls- short diffusion distance as material doesnt need to travel a long distance, inreases rate of diffusion

small lumen- red blood cells squeeze through so this also reduces diffusion distance

steep concentration gradient- capillaries quick exchange maintains a steep concentration gradient that creates a continous flow of blood and therefore exchange

the large amount of capillaries- reduces resistance to blood flow which increases the amount of blood traveling to each tissue - increasing rate of diffusion