Blood Vessels and Lymphatics Flashcards
1
Q
Layers of blood vessels?
A
- tunica interna/intima
- tunica media
- tunica externa/adventitia
2
Q
Tunica interna/intima?
A
endothelium + connective tissue
- simple squamous epithelium
- entire vascular system including lining of heart chambers
- endothelium releases endothelins which constricts smooth muscle within walls of vessels to increase blood pressure
- basement membrane binds endothelium to connective tissue
- in large arteries - thick layer of elastic fibres known as internal elastic membrane at the boundary of tunica media - provides structure and stretch
3
Q
Tunica media?
A
muscle + connective tissue
- concentric layers of smooth muscle cells
- varying amounts of elastic fibres that support muscle cells
- thickest layer in arteries
- vasoconstriction - contraction of circular muscles
- vasodilation - relaxation of circular muscles
4
Q
Tunica externa/adventitia?
A
thick layer of connective tissue
- sheath of longitudinally orientated connective tissue
- mainly collagen I fibres
- thickest layer in veins - may be thicker than media in some arteries
5
Q
Order of vascular tree?
A
- elastic arteries
- muscular arteries
- arterioles
- capillaries
- venules
- medium veins
- large veins
6
Q
Elastic (large) arteries?
A
- conducting
- elastic
- expand during systsole
- elastic recoil during diastole drives blood onwards
7
Q
Muscular arteries?
A
- thick layer of circular smooth muscle in tunica media
- control distribution of blood, regulate blood flow by contraction/relaxation
- can increase in diameter
- contract to prevent haemorrhage
8
Q
Arch of aorta branches?
A
> brachiocephalic trunk - right common carotid artery - right subclavian artery
left common carotid artery
left subclavian artery
(lateral/inferior to arch - ascending and descending (thoracic) aorta)
9
Q
Upper limb arteries? (5)
A
- subclavian
- axillary
- brachial
- radial
- ulnar
10
Q
Anastomosis?
A
connection between two blood vessels
- needed for compromising positions of joints - found at all joints
11
Q
Arterial anastomosis of the hand?
A
deep and superficial palmar arches - derived from radial and ulnar arteries
- ensures supply to hand and fingers in any position of the upper limb
12
Q
Large arteries of the trunk? (3)
A
- descending thoracic aorta
- abdominal aorta
- common iliac artery
13
Q
Lower limb arteries? above knee
A
- femoral (common, deep and superficial)
- popliteal
14
Q
Lower limb arteries? below knee
A
- anterior tibial
- tibio-peroneal (tibio-fubular) trunk
- peroneal (fibular)
- posterior tibial
15
Q
Position of the femoral artery?
A
in the groin
- vein medially
- femoral nerves lateral
16
Q
Branching arteries getting smaller?
A
- arterioles (smaller than 0.5mm)
- metarterioles (same diameter as capillaries but with a layer of smooth muscle cells)
- capillaries - tube of endothelium only - no smooth muscle
17
Q
Capillaries?
A
- endothelial cells and basal lamina
- form networks - capillaries beds
- exchange of gases, nutrients, hormones via active transport, passive transport
- no smooth muscle
- only small contraction in pericytes - enclosed by basal lamina
18
Q
What regulates blood flow in capillaries?
A
pre-capilary sphincter
19
Q
Venules?
A
- smallest veins
- thin media - only a few smooth muscle fibres
- leukocytes can pass through walls into surrounding tissues
- one way blood flow - valves - covered in endothelium
20
Q
Compare veins to arteries?
A
- veins always look bigger
- artery small lumen thicker wall
- vein flat, artery round
21
Q
Relation of veins and arteries to each other?
A
large arteries - separate veins alongside
smaller arteries - venue comitantes around them - pulsation of artery helps venous return to heart (radial, anterior tibial)
22
Q
What is thrombosis?
A
- blood clot
- caused by plaques of atheroma forming within arteries
23
Q
Lower limb veins?
A
- deep veins accompany the arteries - same names
- superficial veins lie directly under skin - great (long) saphenous vein, small (short) saphenous vein
24
Q
What connects deep and superficial veins?
A
perforating veins
- superficial to deep due to valves
25
What causes varicose veins?
incompetence of valves
26
What helps with venous return to the heart against gravity?
- valves
- contraction of muscles
- arterial pulsation
- negative inter thoracic pressure
27
Upper limb veins?
- deep - with arteries - same names
- superficial - lie under skin - cephalic , basilica, median cubital ( used in phlebotomy) - care to avoid brachial artery and median nerve
(connection between deep and superficial not as important as in lower limb)
28
Inferior vena cava?
```
venous blood of
- lower lombs
-pelvic organs
- kidneys
- abdominal walls
drain to IVC which enters tight atrium after passing through diaphragm
```
29
Superior vena cava?
drains venous blood of:
- head, neck, upper limbs
- azygos vein drains venous blood of thoracic wall to SVC
30
Azygous system?
- thoracic veins
- enters SVC
- doesn't follow arterial supply
31
(hepatic) Portal vein?
venous blood from the GI tract, spleen do not return directly to heart
- venous blood goes through liver before joining the IVC
32
Vaso vasorum?
- found in larger vessels
- network of small vessels that supply the walls of large blood vessels
- vessels branch into adventina and outer of media
- nourish the media
- because of muscles in vessels they need blood
33
What does the lymphatic system consist of?
> lymph - fluid between cells
> lymphatic vessels - carry lymph
> lymph nodes - filter lymph
> lymph organs
34
List lymph organs?
- tonsils - around oral and nasal cavities
- thymus
- spleen
- certain regions on the walls of small intestines
35
Lymphocytes?
- WBCs
| - formed and stored at lymph nodes and lymph organs
36
Function of lymphatic system?
- part of immune system
| - helps veins to remove interstitial fluid which becomes lymph
37
What are lymph capillaries?
- absorb interstitial fluid
- thin walled endothelial tubes
- join lymph vessels
38
Lymph nodes?
- clustered at specific sites
| - contain lots of leukocytes - part of immune system
39
Superficial lymph nodes?
- related to veins
| - just below skin
40
Deep lymph nodes?
- related to arteries
| - deeper
41
Features of lymph vessels?
- valves that prevent retrograde flow (back flow)
| - contraction of muscle and pulsation of arteries allow flow of lymph to lymph nodes
42
How does the lymphatic system relate to cancer?
- lymphatic system mops the interstitial space - can cause spread of disease - cancer cells become detached from tumour
- cancer cells may enter lymph capillaries then lymph vessels and be carried to lymph nodes where leucocytes try to fight them
- some cancer can grow in lymph nodes and give rise to secondary tumours (metastasis)
- if cancer is expected always examine lymph nodes - of disease has spread - not good for prognosis
43
What lymph nodes are palpable?
superficial if enlarged
44
superficial/deep Inguinal lymph node features?
- superficial
- groin area - inferior to inguinal ligament
- clustered around great saphenous vein (superficial lower limb vein)
( - deep inguinal vein located deeper alongside femoral artery and vein)
- these nodes drain - lower limbs, buttock, external genitalia, lower back, abdominal wall below umbilicus - infection of these areas causes enlarged nodes
45
Axillary lymph nodes?
- located in axillary fossa (armpit)
- axillary artery, axillary vein
- lateral to, medial , deep to pectorals minor
- lymph comes from upper limbs, anterior and posterior thoracic walls, upper abdominal wall above umbilicus and breast
46
Cervical superficial lymph nodes?
- under jaw,
- over parotid,(salivary gland)
- behind ear,
- occipital (back lobe of brain)
drain head and neck
47
Cervical superficial lymph nodes?
alongside internal jugular vein
| - drain head and neck
48
After drained what happens to lymph?
always returns to venous system
49
Largest lymph vessel?
thoracic duct
50
thoracic duct?
drains - lower limbs, abdominal and pelvic organs and cavities
- opens at junction of left subclavian and internal jugular veins (left pirgoffs angle) - into systemic circulation
- receives lymph from upper left limb, left side of head and neck, left side of thoracic cavity/organs
- lymph from rest of body is drained by right lymphatic duct - opens into systemic circulation at junction of right subclavian vein and right internal jugular veins
