Histology of heart and blood vessels

Question 1

layers of blood vessels

Answer 1

tunica intima, tunica media, tunica externa/adventitia

Question 2

what are endocardium and tunica intima made up of

Answer 2

simple squamous epithelium and connective tissue and BM

Question 3

what are myocardium and tunica media made up of

Answer 3

muscle and elastic tissue

Question 4

what are epicardium and tunica externa made up of

Answer 4

fibrous connective tissue

Question 5

what does endocardium do

Answer 5

forms valves

Question 6

what does myocardium contain

Answer 6

striated muscle, lots of mitochondria, rich capillary bed, myocytes connected to intercalated disc

Question 7

intercalated discs

Answer 7

anchoring structures containing gap junctions

Question 8

functional syncytium

Answer 8

action potential travels through all cells connected together and cells function as a unit

Question 9

myocardium is arranged in a spiral around a

Answer 9

dense connective cardiac fibrous skeleton

Question 10

what does epicardium contain

Answer 10

main branches of coronary arteries, may be fatty

Question 11

arteries

Answer 11

thick muscle wall, smaller and rounded, thin adventitia

Question 12

vein

Answer 12

thin muscle wall, large flattened, thick adventitial, contains valves to prevent back flow

Question 13

types of arteries

Answer 13

elastic (large conducting), muscular (distributing arteries), arterioles (terminal branches)

Question 14

elastic arteries examples

Answer 14

aorta, common carotid, pulmonary

Question 15

muscular arteries examples

Answer 15

coronary arteries, radial, femoral

Question 16

arterioles

Answer 16

terminal branches which supply blood to capillary beds

Question 17

elastic arteries histology

Answer 17

pressure recevoir, stretched during systole, during diastole heart relaxes and then pressure falls, the artery recoils thereby maintaining pressure on the blood, elastic fibres are secreted by smooth muscle cells, recoil and stretchability is due to presence of extensive amounts of elastic fibres in T media in the form of layers= laminae

Question 18

muscular arteries histology

Answer 18

controls distribution of blood to regions, thick T media has smooth muscle cells, no elastic laminae between muscle cells in T media, Elastic fibres are concentrated in 2 well defined sheets called internal elastic lamina (IEL) just under epithelium and the thin external outer elastic lamina (OEL) between T media and T adventitia

Question 19

arterioles histology

Answer 19

smaller muscular arteries gradually change histologically to become arterioles, only 1-2 layers of smooth muscle in T media, no IEL or EEL, no T adventitia, rich sympathetic nerve innervation, control blood flow to capillary beds, control blood pressure

Question 20

capillaries structure

Answer 20

very thin T intima, no T media, no T adventitia, pericytes, low BP

Question 21

pericytes

Answer 21

incomplete layer of cells surrounding a capillary and have contractile properties which control blood flow

Question 22

3 types of capillaries

Answer 22

continuous, fenestrated, discontinuous/sinusoids

Question 23

continuous capillary

Answer 23

can control what is exchanged, material must pass through cell or between cell, selective transport mechanisms, eg in muscle

Question 24

fenestrated capillary

Answer 24

have fenestrations (pores), diaphragms filter molecules by MW and or charge eg endocrine glands, kidney renal corpuscle

Question 25

discontinuous capillary

Answer 25

gaps between endothelial cells and basement membrane, allow free passage of fluid and cells, eg liver spleen bone marrow

Question 26

sinusoids

Answer 26

large diameter discontinuous capillaries, found where large amount of exchange takes place, T intima contains phagocytic cells eg liver

Question 27

arteriovenous AV shunts

Answer 27

bypasses capillary beds eg skin for thermoregulation, s

Question 28

veins and venules structure of layers

Answer 28

T intima, T media, T adventitia- all thin

Question 29

what forms valves

Answer 29

folds of the tunica intima

Question 30

superficial veins

Answer 30

thick walled and no surrounding support

Question 31

deep veins

Answer 31

thin walled, surrounding support from deep fascia and muscles, superficial veins drain into deep veins, DVT

Question 32

lymphatic system does what

Answer 32

drains tissue fluid lose from blood capillaries into the systemic venous system. valves direct flow

Question 33

lymph capillaries

Answer 33

blind ended capillaries, lined by very thin endothelium, anchoring filaments, no red blood cells in lumen

Question 34

anchoring filaments

Answer 34

fine collagenous filaments link endothelial cell to surrounding tissue keeping lumen open

Question 35

blood vessels are organs because

Answer 35

they receive nerve supply, blood supply (vasa vasorum) and lymphatics in T adventitia