Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

BDS1 > Histology of blood vessels > Flashcards

Histology of blood vessels Flashcards

1
Q

What are the components of the blood vascular system?

A 
elastic arteries
muscular arteries
arterioles
capillaries
postcapillary and collecting venules
muscular venules
muscular veins
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the three layers of blood vessels?

A

Tunica intima
Tunica media
Tunica adventitia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What does the tunica intima consist of?

A

lining of simple squamous endothelial cells supported by a thick layer of connective tissue
bounded by the internal elastic lamina

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What does the tunica media consist of?

A

smooth muscle cells
some collagen and a variable amount of elastin
may be an external elastic lamina

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What does the tunica adventitia consist of?

A

supporting layer of dense, fibroelastic connective tissue

may contain vasa vasorum and nerves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are elastic arteries?

A

major distribution vessels closest to the heart

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Examples of elastic arteries

A

aorta, brachiocephalic, carotid, subclavian and pulmonary

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

how do elastic arteries function?

A

elastic wall expands to receive blood expelled from the heart during systole
smooth muscle contracts
elastic recoil helps maintain blood pressure during diastole

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the tunica intima of elastic arteries like?

A

single layer of squamous endothelial cells
subendothelial collagenous connective tissue rich in elastin
contains fibroblasts and smooth muscle like cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the tunica media of elastic arteries like?

A

concentric fenestrated sheets of elastin separated by collagen and smooth muscle cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the tunica adventitia of elastic arteries like?

A

collagenous connective tissue

contains vasa vasorum and a plexus of autonomic nerves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Structure of muscular arteries

A

thin tunica intima
tunica media almost entirely made of circumferential smooth muscle cells
Elastin reduced to an internal elastic lamina and sometimes less distinctive EEL

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

function of tunica intima in muscular arteries

A

withstand pressure

vary lumen diam to regulate flow - smooth uscles do not contract to assist blood flow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

how can pressure that can be sustained by artery be measured

A

proportional to wall thickness / dia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what is the structure of an arteriole like

A

tunica intima is thin and may contain IEL
tunica media less than 6 layer of smooth muscle cells
insignificant tunica adventitia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what is the main factor in regulation of blood flow

A

control of flow through arterioles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what happens if you halve the diameter of an arteriole

A

resistance increases by 16 fold

this is as viscous resistance to flow is inversely proportional to radius^4

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

size of capillaries

A

vary from 3-4 um to 30-40 um, less than 1 mm in length

19
Q

what are large diam capillaries called

A

sinusoids

found in liver, spleen, bone marrow and some endocrine glands

20
Q

what do capillaries consist of?

A

single layer of endothelial cells

21
Q

what are the 3 types of capillaries?

A

continuous
fenestrated
discontinuous

22
Q

what are the properties of continuous capillaries?

A

tube of endothelial cells resting on a thin basal lamina
no tunica I , M OR A
adjacent endothelial cells are linked by tight junctions (permeability barriers)
embraced by pericytes

23
Q

what does permeability to substances that pass through continuous capillaries rely on?

A

tightness of tight junctions between endothelial cells
very tight - blood brain barrier
less tight in most other places

24
Q

what is the importance of pericytes that surround continuous capillaries?

A

important in the stabilisation and survival of endothelial cells

25
Q

where are fenestrated capillaries found?

A

sites where there is rapid movement of macromolecules in/out of bloodstream
e.g. small intestine, kidney

26
Q

what is the structure of fenestrated capillaries?

A

luminal and basal plasma membranes of endothelial cells come together to form round windows which are around 80nm
fenestrations usually closed by a diaphragm
basal lamina continuous across fenestrations
pericytes usually absent

27
Q

where are discontinuous capillaries found?

A

found in sinusoids of liver and spleen

28
Q

structure of discontinuous capillaries

A

large gaps between endothelial cells
basal lamina also discontinuous
allows free passage of large macromolecules or even RBCs

29
Q

what is micro-circulation?

A

part of circ system concerned with the exchange of gases, fluids, nutrients and waste products

30
Q

where does microcirculation occur?

A

mainly in capillaries and all active cells ,must lie within 150um of a capillary

31
Q

where do capillaries drain into?

A

post capillary venules, collecting venules and muscular venules

32
Q

how is blood flow into capillaries controlled?

A

by arterioles and pre capillary sphincters
metarterioles are transitional vessels with a discontinuous layer of smooth muscle cells that regulate flow into the capillary
arteriovenous shunts provide direct connections between arterial and venous systems - can bypass capillaries

33
Q

how does venous drainage occur?

A

several capillaries unite to form post-capillary venules
main site for entry and exit of WBCs
post capillary venules until to form collecting venules - more pericytes
collecting venules drain into muscular venules (1-2 layers of smooth muscle cells)

34
Q

what are veins formed from?

A

union of muscular venules

35
Q

what is the structure of the vein?

A

recognisable tunica I,M,A
TI - little more than endothelium
TM- 2 layers of smooth muscle cells or more
TA- broadest layer
wall much thinner than artery of similar diam

36
Q

how does blood return from capillaries to the heart

A

veins - low pressure collecting system

  • blood flow is passive
  • assisted by -ve pressure within chest during inspiration
  • return from limbs aided by muscular contraction and compression of veins
  • backflow prevented by valves
37
Q

where are valves present?

A

in veins of above 2mm dia

38
Q

functions of endothelial cells

A

permeability barrier
synthesise components of basal lamina
synthesise materials that promote blood clotting on injury
synthesise molecules that prevent inappropriate clotting
secrete vasoactive factors that promote or inhibit vasodilation
produce inflamm mediators
produce some growth factors

39
Q

How does fluid enter the lymphatic system?

A

due to hydrostatic pressyre at the arterial end of blood capillaries, water, electrolytes and some proteins leak into extracellular space (TF)
fluid drains into lymphatic vessels and then back into the blood vascular system

40
Q

where are lymphatic vessels found?

A

all tissues except - CNS, cartilage, bone, bone marrow, placenta, cornea and teeth

41
Q

properties of lymphatic vessels

A

have extremely flattened endothelial cells, basic basal lamina and lack of pericytes
no RBCs
backflow prevented by delicate semi lunar valves

42
Q

what is angiogenesis?

A

formation of new blood vessels from pre existing capillaries

43
Q

how do new blood vessels form - angiogenesis?

A

begins as capillary sprout
involves migration and proliferation of endothelial cells, their assembly into tubes and recruitment of smooth muscle cells, pericytes and fibroblasts from arteries and veins

44
Q

Why might be a benefit of inhibition of angiogenesis?

A

attractive option for new anti cancer drugs as it is induced by tumour cells
this will reduce chances of metastasis
at the moment not successful as it is not isolated and angiogenesis of other blood vessels not in tumours is being prevented

BDS1 (21 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions