Circulatory system

Question 1

Large elastic artery function

Answer 1

conducting

Question 2

Location of large elastic artery

Answer 2

closest to heart

Question 3

Tunica intima structure of LEA

Answer 3

endothelial cells w thin subendothelium of CT and discontinuous elastic laminae

Question 4

Tunica Media structure LEA

Answer 4

4-70 fenestrated elastic membranes w smooth muscle cells and collagen btwn lamella

Question 5

Thickest part of elastic artery?

Answer 5

Tunica media

Question 6

Tunica Adentitia LEA

Answer 6

thin CT layer containing lymphatics, nerves and vasa vasorum

Question 7

Distributing artery

Answer 7

Medium muscular artery

Question 8

function MMA

Answer 8

distribute blood to sub-regions of body

Question 9

T.intima MMA

Answer 9

endothelium, subendo and thick elastic lamina

Question 10

T.Media MMA

Answer 10

~40 layers smooth muscle connected by gap junctions

Question 11

gap junction in TM MMA allow

Answer 11

coordinated contraction

Question 12

T.Adentitia MMA

Answer 12

thin CT layer containing minor vasa vasorum, lymphatics and nerve fibres

Question 13

Arterioles function

Answer 13

microcirculation. carry blood to metarterioles

Question 14

structure arterioles

Answer 14

diameter less than 0.1mm
3 layers smooth muscle cells
no internal elastic lamina

Question 15

metarterioles function

Answer 15

supply capillary beds

Question 16

structure metarterioles

Answer 16

precapillary sphincters- intermediate rings of smooth muscle control blood flow

Question 17

Veins structure

Answer 17

larger diameter and thinner wall. more CT less elastic and muscle fibres

Question 18

small/medium veins structural features

Answer 18

well developed TA, thin TM and TI

Question 19

large veins structural features

Answer 19

diameter over 10mm, thicker TI. well developed longitudinal smooth muscle

Question 20

Venules function

Answer 20

continuous with postcapillary venules, unite to form a vein

Question 21

Venules structure

Answer 21

endothelium assoc with pericytes, form thin wall.
diameter up to 1mm.
contains valves

Question 22

pericytes

Answer 22

thin smooth muscle cells

Question 23

postcapillary venules function

Answer 23

receive blood from capillary beds, empties into venules.
surrounding tissue drains in due to lower pressure than cap and venules
site of wbc migration due to permeability

Question 24

structure postcap venules

Answer 24

endothelial lining assoc w pericytes

diameter 10-30 micrometres

Question 25

capillary structure

Answer 25

one layer endothelium and basement membrane. | short diff pathway

Question 26

3 types of capillary

Answer 26

continuous, fenestrated, sinusoid

Question 27

continuous capillary

Answer 27

complete lining, diffusion water, small and lipid soluble molecules specialised in cns and thymus

Question 28

fenestrated capillary

Answer 28

pores in endothelium, rapid water and larger solutes exchange

Question 29

sinusoid capillary

Answer 29

gaps btwn adj endothelial cells. free transfer of water and large plasma proteins phagocytes monitor gaps.

Question 30

arteriorvenous anastomosis

Answer 30

connection btwn two blood vessels.

Question 31

Tunica intima characteristics

Answer 31

inner layer. encompasses endothelial lining in arteries only- stretch and recoil to cop with changes in pressure

Question 32

why does TI encompass endo lining

Answer 32

reduce friction

Question 33

endothelium characteristics

Answer 33

internal walls of bv | reduce friction, continuous with artery/vein endothelium

Question 34

function of endothelium

Answer 34

release vasoactive substances affecting vascular tone, blood pressure and blood flow. vasodilation/constriction maintain vascular homeostasis

Question 35

vasodilators released by endo

Answer 35

nitric oxide- released by mechanical stress

Question 36

vasoconstrictors released by endo

Answer 36

endothelin

Question 37

Tunica Media characteristics

Answer 37

smooth muscle and loose CT CT- elastic fibres in artery, collagen in vein encircles endothelium, lines lumen of bv binds to inner and outer layers

Question 38

artery TM contains

Answer 38

external elastic membrane seperating TM from TE

Question 39

Tunica Externa characteristics

Answer 39

contains collagen, elastic fibres, vaso vasorum | in veins- cont smooth muscle cells

Question 40

function of TE

Answer 40

anchors vessel to adj tissues

Question 41

3 types of artery

Answer 41

1. elastic/ conducting 2. muscular 3. arterioles

Question 42

function elastic artery

Answer 42

conduct, maintain pressure

Question 43

function muscular artery

Answer 43

less recoil, distribute

Question 44

function arterioles

Answer 44

regulate pressure

Question 45

venous valves made of

Answer 45

TI folds

Question 46

function of valves

Answer 46

prevent backflow

Question 47

skeletal muscle pump

Answer 47

muscles create constriction on veins of muscles => valves open superior to contracting muscle, valves close inferior to contracting muscle