2.2 Vessel Structure Flashcards Preview

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Flashcards in 2.2 Vessel Structure Deck (34):
0

Major types of vessel?

Art, vein, capp, lymph

1

Histology of typical blood vessel. Three layers?

Tunica externa, media, interna.
More obvious in arteries than veins

2

The layers. Outside to in?

Nerves, bv, adventitia, external elastic layer, tunica media, internal elastic layer, sub-endothelial ct, tunica interna: endothelial layer, basal lamina

3

Arteries to arterioles. Classification based on morphology.

SM proportion increases. Elastic decreases.
Layers of sm decreases

4

Aorta major branches

Subclavian, common carotid, brachiocephalic, common iliac, pulmonary

5

Size of artery wall near heart? And why?

Thick.

Preserve pressure - recoil during diastole - maintain arteriole pressure

6

Elastic arteries....

Not conc in external and internal lamina
Lp - elastic fibres and mod. Sm cells -> myointimal -> age accumulate
Lipids

7

Muscular arteries

Less elastic (int ext lamina), higher sm, vasoconstriction

8

Difference between muscular and small muscular artery?

20-30 layers - concentric - sm
3-10 concentric layers of SM

9

Resistance vessels

Control blood - organs
Partial contractive
2-5 layers of sm cells
Major determinants of systemic blood pressure

10

Ateriole (5)

Thicker wall rel lumen. Int ext elastic lamina
T interna - no subendothelial tossue
T media - thickest 1-2 sm layer
T externa - fibroelastic

11

5 types of arterial anastomoses

Inosculation (direct end to end or multiple arcades)
Capillary network
Convergence
Branches


12

Capillary network.
Microvascular bed (3) outline components.
What are preferential channels? And example?
How blood bypass capillary network?
Function of pre-capillary sphincters?
How is blood flow regulated?

Terminal arteriole, capillary bed, post capp venule
-continuous blood flow (larger capillaries - met-arteriole)
-av shunt or anastomoses
-contract relax - control blood flow into bed
-vasomotor nerves, chemical changes

13

Av shunts - where found? (4) Structure, difference compared to precapp sphincter, important in?

Fingertips, nose, lips, corpora cavernosa (penis)
Rich bv, nerves. Capsule, thick sm layer.
Opposite to sphincter. Contraction - blood into bed.
Thermoregulation

14

Capillaries ?

Single layer endothelial, one rbc pass, pericytes.
Function: gas exchange, hormone, ions, nutrients, wastes etc

15

Examples of Tissues where not rich capillary supply? (5)
Types of capillaries (3) where each found (3 each)

Tendons, ligaments, cornea, lens, epithelial tissue
Continuous: brain, lung, muscle
fenestrated intestine kidney endocrine glands, si, ciliary process of eye
discontinuous: liver spleen bone marrow, some endo glands, lymphoid tissue

16

Continous capp?

PP L O PP
Lack pores, impermeable, uninterrupted lining, occluding junctions, pinocytotic vesicles, pericytes.

Blood (brain, testis, thymus barrier)

17

Fenestrated capp?

80-100nm. Dynamic. basement membrane continuous across fenestrations.
Where? Kidney, si, cillary process of eye, endocrine glands

Where filtration or absorption occur

18

Discontinuous/sinusoidal capp

Large lumen, permeable.
No diaphragm, discontinuous basal lamina
Liver, spleen, some endocrine glands, lymphoid tissue, bone amrrow

19

Properties of endothelium?

Selectively permeable barrier - diffusion, active transport, pinocytosis, receptor mediated endocytosis
Nonthrombogenic barrier - secretion : anticoagulants, anti/pro thrombogenic agents
Mod blood flow, vascular resistance - secretion : vaso-constrictors/dilators
Reg. cell growth - secret. Growth stim / inhibiting factors
Immune response - reg. : leukocyte migration, immune functions
Extracellular matrix - syn basal lamina, glycocalyx
Lipoprotein met - free rad production

20

Veins (7). Where origin. Function. Pressure. Structure. Extra (2)

Origin - capp network
Valves (semilunar/sparrows nest) - tunica intima, fibroelastic tissue (veins >2mm)
Lower pressure than arteries
Thinner, less elastic tissue
Several anastomosis
Capacitance and reservoir vessel

21

Blood volume %. Veins. Lungs. Heart. Arteries. Capillaries.

65
10
10
10
5

22

Veins types

Small - post capp. Mucular. Collecting venules
Medium
Large

23

Veins structure

Less well defined tunicas
adventitia greater than media
Less elastic tissue
Elastic membranes poorly developed.

24

Veins categorised based on movement (2) and different areas in respect

Receptive - head, neck, curtaneous, upper limb

Propulsive - thicker, more sm
Lower limbs, inferior vena cava, portal, splenic, superior mesenteric, external iliac, renal, arzygos

25

Post capillary venules. (6)
Main site of?
Diammeter etc?

Smallest. Porous endothelium. No sm.
Allow fluids, wbc.
Main site of vasoactive agents - inflammation, allergic reactions
10-50um

26

Example of vasoactive agent?

Histamine

27

Muscular venules amd its diammeter

Few sm layers.
80-100um

28

Where are high endothelial venules found?
Differences in endo?

Lymph nodes.
T cells enter lymph nodes via HEV(lymphatic vessels)
All secondary lymphoid organs except spleen
Endo - plump than squamous

29

Medium sized vein. And thickest layer - what is it composed of?

Tunica adventitia - collagen fibres - longitudinal.

30

Large vein. Tunica media and Tunica adventitia arranged?

Narrow tunica media - small amounts of sm - circular
Adventitia - Longitudinal SM + collagen fibres

Elastic fibres scattered throughout

31

Lymphatic vessels? (5)

Adjunct to bv.
Unidirectional
Drain into venous circulation
Drain protein rich plasma/ecm fluids
Immune system

32

How backflow prevents in lymphatic vessels?
Lv larger in size?
What is a lymphangion?
In SI what are they called?
Compared to cap (2)?
Fucntion of anchoring filaments with Lymphatic Capp?

Valves.
Larger - more sm - contraction - propulsion of fluids
Functional unit between 2 valves
Lacteal
1)2) more permeable, lack basal lamina
Prevent vessel collapse under increased pressure

33

What forms the intrinsic enteric nervous system? (2)

Meissner and myenteric plexuses