Revision 1: Introduction to CVS/Anatomy of CVS Flashcards Preview

Cardiovascular System (ESA 2) > Revision 1: Introduction to CVS/Anatomy of CVS > Flashcards

Flashcards in Revision 1: Introduction to CVS/Anatomy of CVS Deck (12)
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1
Q

Factors affecting exchange of substances between blood in capillaries and surrounding tissue

A

98% of exchange is done by diffusion, which is affected by:

1) area available -> cap. density
2) diffusion resistance -> nature of barrier and molecules, also the distance that diffusion occurs over, the path length
3) conc. gradient, depends on flow of blood through capillaries to maintain this

2
Q

Blood flow in the body

A

ml/min

Brain 750

kidneys 1200

heart 300->1200

gut 1400->2400

skel. muscle 1000->16000

skin 200->2500

rest of body 200

OVERALL ~5000->24,500

3
Q

describe the major functional components of a circulation system -> CVS

A

pump -> heart

distribution vessels -> vessels

flow control -> via resistacne vessels, the arterioles and pre-capillary sphincters

capacitance -> veins store blood that can be used when a higher CO is necessary

4
Q

distribution of blood volume over major parts of circulation

A

67% in veins

17% in heart and lungs

11% in arteries and arterioles

5% in capillaries

5
Q

Artery types, defining features and structures

A

Elastic/Large arteries: intima: endothelial cells arranged w/ long axis parallel to artery length

Media: main feature is 40-70 fenestrated elastic membranes w/ SMCs and collagen in between the lamella

Adventitia: layor of fibroelastic CT w/ vaso vasorum, lymphatic vessels and nerve fibres

Muscular: intima: endoth w/ subendo. layer, thick intenral elastic lamella

media: main feature is 40 layers of SMCs w/ prominent external elastic lamella
adventitia: non-prominent vaso vasorum w/ lymph vessels and nerve fibres

Arterioles: defining feat. is a diameter <0.1mm, 1-3 SMCs in media (in smaller ones a single SMC encircles the vessel), scant adventitia

-Metarterioles: supply blood to cap. bed, different from arterioles as they have a non continuous layer of SMCs - pre cap. sphincters that allow for flow control

6
Q

layers of a blood vessel

A

tunic intima (endothelium and sub-endothelial layer)

internal elastic lamella

tunica media (SMCs, collagen)

external elastic lamella

tunica adventitia (CT, w/ vaso vasorum sometimes)

7
Q

capillary types and structure

A

Continuous: most common, found in nervous, muscle and CT, lungs, exocrine glands

  • continuous endoth layer joined by tight/occluding junctions

Fenestrated: found in gut, endo. glands, renal glomerulus

-windows/interruptions exist across thin parts of endoth.

Discontinuous/sinusoidal (aka sinusoids): found in liver, spleen, bone marrow

-gaps allow whole cells to move across, the lumen is much wider than usual and the flow rate is slower

Pericytes form a branching network on the outer surface of the endoth., can divide to muscle cells/fibroblasts in angiogenesis, tumour growth, wound healing

8
Q

veins types, defining features and structures

A

Venules: diam. 0.05-1mm, SM fibres begin to assoc. w/ endoth (media starts to form)

-post capillary: more permeable than cap.s, w/ a similar structure (has pericytes), low press. so fluid drains into it, site where WBCs enter blood

Medium/small veins: well developed adventitia, superf. veins of legs have well defined muscle wall to resist distension from gravity, valves act w/ contraction to return blood to heart

Large veins: eg vena cava, iliac, internal jugular, well developed longitud. orientated SMCs in adventitia in addition to circularly arranged SMCs in media

9
Q

name major arteries

A
10
Q

name major veins

A
11
Q

name major coronary arteries and cardiac veins

A

anterior interventricular=left anterior descending

12
Q

name major coronary arteries and cardiac veins of posterior heart

A