Blood Vessels Flashcards
1
Q
3 layers of blood vessel walls
A
- Tunica interna
- Tunica media
- Tunica externa/adventitia
2
Q
Tunica interna
- structure
- one function
- structural difference in larger arteries
A
- Endothelium –> simple squamous epithelial layer
- Secretes endothelins (hormones) = interact w smooth muscle (constrictive or dilatory effects)
- Have an internal elastic membrane next to BM
3
Q
Tunica media
- structure x2
- one function
A
- Concentric smooth muscle cells
- Varying amounts of elastic fibres –> in laminae (concentric)
- Vasoconstriction –> to increase BP
4
Q
Tunica externa/adventita
- structure
- one function
- its blood supply
A
- Longitudinally orientated connective tissue (primarily collagen)
- Holds vessel together
- By vasa vasorum
5
Q
Vascular tree
A
Heart –> elastic artery –> muscle artery –> arterioles –> capillaries –> venules –> medium veins –> large veins –> heart
6
Q
Elastic arteries
- structure
- function
A
- Thick wall w lots of elastic tissue
- Expand during systole & relax during diastole –> elastic recoil
7
Q
Muscular arteries
- structure
- function
A
- Thick layer of circular muscle in tunic media
- Controls distribution of blood to regions through construction & relaxation
8
Q
Metarterioles
- structure x2
A
- Same diameter as capillary
- Smooth muscle in walls
9
Q
Atheroma
- what
- consequences
A
- Plaques in arteries
- May form a thrombus (blood clot) –> vascular occlusion
10
Q
Capillaries
- structure x2
- form…
A
- Simple squamous epithelium
- BM splits to enclose pericytes
- Capillary beds
11
Q
What regulates blood flow in capillary beds
A
Pre-capillary sphincter
12
Q
Function of pericytes in capillaries
A
Look after endothelial cells
13
Q
3 types of capillary
A
- Continuous
- Fenestrated
- Sinusoid
14
Q
Continuous capillaries
- structure x2
A
- Tight junctions between cells
- Vesicles for transportation
Most common
15
Q
Fenestrated capillaries
- structure x2
A
- Circular fenestrae/pores
- Larger molecules can cross
16
Q
Sinusoid capillaries
- structure
- location
A
- Bigger gaps
- In v specialised areas, so much less common
17
Q
Venules
- % of blood at rest
- structure x2
A
- 60-70%
- Thin walls
- Valves
18
Q
Artery vs vein x3
A
- Vein nearly always bigger (wider lumen)
- Vein = thinner wall
- Vein collapses, artery retains round same as more smooth muscle
19
Q
3 vessels out of the top of the aorta
A
- Brachiocephalic trunk
- Left common carotid artery
- Left subclavian artery
20
Q
What does the brachiocephalic trunk split into? x2
A
- Right subclavian
- Right common carotid
21
Q
How do the common carotid arteries split?
A
Into the internal left/right & the common
22
Q
How do the subclavian arteries split?
A
Into the vertebral
23
Q
What blood vessels supply the head & neck?
A
Common & internal carotid
24
Q
What blood vessels supply the brain?
A
Vertebral arteries provide a co-lateral supply
25
Names of the subclavian artery as it goes down the upper limb x3
- Subclavian
- Axillary
- Brachial
26
How does the brachial artery split?
Into radial & ulnar artery
27
Anastomoses
- what
- function
- example
- When one vessel plugs into another
- Co-lateral supply that allows for flow beyond a joint if a vessel gets occluded during movement
- e.g. superficial & deep palmar arches
28
Superficial & deep palmar arches
- what
- where
- Anastomoses
| - Arches in hand formed from radial & ulnar arteries
29
- Descending from the aorta, it becomes....
- Descending thoracic aorta becomes common iliac artery
30
What do trunk arteries supply?
Segmental blood supply to abdominal & thoracic wall
31
How does the common iliac artery split?
Into left and right common iliac artery
32
How do the left and right common iliac arteries split?
| - & what do they supply
- Internal iliac --> supplies pelvis
| - External iliac --> continues into lower limb
33
What does the external iliac artery become?
The femoral artery
34
Femoral artery
- where does it lie
- lies alongside...
- becomes...
- Femoral triangle
- Femoral vein & nerve (vein --> artery --> nerve)
- Popliteal artery
35
Main blood supply to the thich
= Profunda femoris (deep femoral artery)
36
Sequence of thoracic arteries
- Aorta
- Descending thoracic aorta
- Common iliac artery
- -> splits left & right
- -> splits internal & external
37
Sequence of upper limb arteries
- External becomes the femoral artery
| - Becomes the popliteal
38
Sequence of lower limb arteries
- Poplital
- Splits --> anterior tibial & tibio-peroneal trunk
- Tibio-peroneal trunk splits --> peroneal & posterior tibial
39
Lower limb veins
| - 2 types
- Deep
| - Superficial
40
Lower limb - deep veins
- location
- naming them
- Accompany limb arteries
| - Share names of the arteries
41
Lower limb - superficial veins
- location
- function
- examples x2
- More superficial
- Communicate w deeper veins via perforating veins
- Great Saphenous Vein
- Small Saphenous Vein
42
How is blood pooling avoided in the lower limb veins? x3
- Venous muscular pump
- Veins run through muscles --> muscles contract --> blood forced up
- Valves prevent backflow
43
Superficial upper limb veins
- Medial side
- Lateral side
- Meeting point
- Basilic vine
- Cephalic vein
- Antecubital fossa (joined by medical cubital vein)
44
Abdominal veins
- e.g. vein mirroring common iliac artery
- converge upon...
- Common iliac vein
| - Inferior vena cava
45
Inferior vena cava location x2
- Runs up right side
| - Behind liver into heart
46
Venule equivalent of internal & external carotid arteries
- & what they drain into
- Internal & external jugular veins
| - Brachiocephalic veins
47
Azygous vein
- location
- what drains into it
- what it drains into
- Along vertebral column (between IVC & SVC)
- Veins in posterior thoracic wall (e.g. intercostal veins)
- SVC
48
GI veins
- why different from other body systems
- via...
- Nutrients are absorbed - so transported straight to liver (not all the way around the system)
- Hepatic Portal Vein
49
What are vasa vasorum?
'Vessels of the vessel'
| - Smaller vessels branch into the outer part of the media of larger vessels
50
Internal elastic lamina
- where
- structure
- function
- End of tunica intima
- Layer of fenestrated elastic tissue
- Takes full force of systolic output
51
Artefacts in histology of aorta
```
Radial spokes (folds, crinkles in aorta)
- Due to elastic fibres
```
52
Difference in structure between elastic & muscular arteries
- Tunica media: muscular = mainly muscle fibres vs elastic
53
Arterioles
- structure x2
- function x2
- Thick wall, narrow lumen
- Prominent layers of smooth muscle but not a clear adventitia
- Resistance to cardiac output
- Controls blood distribution (vasoconstriction & dilation)
54
Venules
- structure
- function
- Thinner wall = very permeable
| - More permeable than capillaries --> site of fluid formation (e.g. exudate)
55
Arteriole vs venule x3
Venule =
- Normally bigger
- Larger lumen
- Less smooth muscle
56
In what vessel is there the biggest pressure drop?
Arterioles
