ANAT: Vasculature

Question 1

functions of the CV system

Answer 1

• gas exchange (resp system)
• fluid balance (urinary system)
• immune response
• temp and pressure regulation

Question 2

types of arteries (large to small)

Answer 2

• large: elastic arteries
• medium: muscular arteries
• arterioles
• metarterioles
• capillaries - continuous, fenestrated, sinusoidal

Question 3

types of veins

Answer 3

• large veins
• medium veins
• small veins (venules)

Question 4

type of flow in elastic and muscular arteries

Answer 4

• pulsatile flow (high pressure)
• therefore can detect pulse

Question 5

type of blood flow in veins and venules

Answer 5

• continuous/smooth flow (low pressure)
• therefore can’t detect pulse

Question 6

3 layers of a blood vessel

Answer 6

• tunica intima = simple squamous endothelium to prevent sticking of RBCs
• tunica media = muscular and/or elastic to alter rate of blood flow & size of lumen
• tunica adventitia or externa = elastic layer fibres and small blood vessels (vasa vasorum)

Question 7

structure of elastic arteries

Answer 7

• tunica intima: endothelium
• thick tunica media w/ smooth muscle and elastic fibres
• tunica adventitia w/ vasa vasorum
• closer to heart

Question 8

structure of muscular arteries

Answer 8

• tunica intima: endothelium
• mainly smooth muscle in tunica media
• internal and external elastic lamina
• vaso vasorum in tunica adventitia
• further from heart

Question 9

structure of arterioles

Answer 9

• tunica intima
• tunica media: few layers of smooth muscle and elaastic fibres
• thinner tunica adventitia

Question 10

structure of capillaries

Answer 10

• only simple squamous endothelium (tunica intima) = no tunica media/adventitia
• may have pericytes around basement membrane to help w/ contraction

Question 11

3 types of capillaries

Answer 11

• continuous: endothelial cells joined by tight junctions > particles have to diffuse through endothelial cells to get into lumen
• fenestrated: ‘windows’ across endothelium > some particle movement
• sinusoidal: larger gaps b/n endothelial cells + basement membrane > large compounds and some cells can move across

Question 12

metarterioles

Answer 12

• arterioles w/ smooth muscle sphincters which can close to redirect blood flow
• located where arterioles meet capillaries

Question 13

anastomosis

Answer 13

• provide alternative pathways for blood flow
• often located in places of extensive movement e.g. skeletal muscles

Question 14

structure of post capillary venules

Answer 14

• very similar to capillaries

Question 15

structure of venules

Answer 15

• tunica intima (endothelium)
• tunica media: smooth muscle
• thin tunica adventitia

Question 16

structure of medium + large veins

Answer 16

• tunica intima: endothelium
• tunica media: some smooth muscle
• tunica adventitia: connective tissue + collagen, vasa vasorum (blood supply to veins)
• valves to ensure unidirectional flow to heart

Question 17

role of lymphatic capillaries

Answer 17

• drain excess tissue fluid from capillaries > transport to immune system for filtration
• transported back to CV system (veins)
• slower flow than CV system

Question 18

structural features of lymphatic capillaries

Answer 18

• overlapping endothelial cells > mini valves
• incomplete basal lamina > larger molecules can enter capillaries from tissue fluid
• endothelial cells anchored to tissue by elastic fibres
• larger lymphatic vessels have valves > unidirectional flow

Question 19

where is lymph not found

Answer 19

• teeth
• bone marrow
• CNS

Question 20

which arteries do not transport oxygenated blood?

Answer 20

• pulmonary and umbilical