structure and function of blood vessels and heart Flashcards Preview

PA10315 2nd semester > structure and function of blood vessels and heart > Flashcards

Flashcards in structure and function of blood vessels and heart Deck (36)
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1
Q

ventricular fibrillation

A

irregular heartbeat
spasm
heart not pumping blood around the body

2
Q

infarction

A

dead tissue in the heart from lack of oxygen/nutrients (ischaema)
due to obstruction of coronary artery

3
Q

Diffusion speed relation to distance

A

fast over short distances, slow over 1mm

4
Q

Function of CVS in relation to efficiency

A

speeds up gas and solute transport over long distances

reduces DD for O2 and nutrients

5
Q

Other functions of CVS

A

delivers O2 and nutrients to cells, removal of CO2 and waste
Communication between organs via transport of hormones
Temp regulation
Hydrodynamic device in sexual reproduction

6
Q

what drives movement of blood (excluding the heart)

A

Pressure differences

7
Q

What is blood pressure determined by

A

CO
blood volume
peripheral resistance

8
Q

2 circuits in cardiovascular circulation

A

systemic and pulmonary

9
Q

Composition of blood

A

plasma 55% (water, ions, proteins, nutrients, hormones, metabolic wastes etc)
Hematocrit 45%
Leucocytes (WBCs) and platelets make up the buffy coat

10
Q

Order of pumping blood around the body

A

RHS heart, lungs (oxy), LHS heart, body (deoxy), back to RHS

11
Q

Where is most blood distributed

A

veins and venules- acts as reservoir

61%, slow moving

12
Q

Blood flow (at rest)

A

Most blood flowing through abdominal organs and kidneys
Majority of pumping in parallel, so most organs supplied separately
Means blocking supply to one organ doesn’t mean supply blocked to rest of the body

13
Q

Components of BVS

A

lumen
endothelial cells (tunica intima)
smooth muscle cells (tunica media)
connective tissue (tunica adventita)

14
Q

arteries

A

large lumen

thick layer smooth muscle and connective tissue

15
Q

function of thick elastic smooth muscle in arteries

A

stretches to absorb pressure coming out of the heart during systole
Prevents pressure buildup and huge release of pressure- instead pressure passed slowly onto rest of the body
During diastole smooth muscle undergoes passive recoil (releasing pressure)

16
Q

arterioles

A

thin muscular wall and small lumen
contraction of thin smooth muscle regulates diameter of the lumen to control flow of blood to different organs
Major determinant of mean arterial pressure

17
Q

capillaries

A

single layer endothelial cells
Exchange of O2, nutrients and waste across capillary walls but not proteins
Only 1 RBC can pass at a time
Exchange facilitated by slow movement of blood and large SA within the capilaries

18
Q

Exchange occurs by

A

diffusion down gradients

19
Q

venules/veins

A
thin walls
large lumen
valves
thin smooth muscle layer
low pressure
skeletal muscle contraction driving force for blood back to heart
low resistance
20
Q

muscle layers in the heart

A

pericardium (outermost)
Epicardium
Myocardium (innermost)

21
Q

Septum

A

divides left and RHS of heart

22
Q

What are valves held in place by

A

chordae tendineae and papillary muscle

23
Q

2 SL valves

A

pulmonary and aortic

24
Q

2 AV valves

A

left- bicuspid

right-tricuspid

25
Q

blood supply to the heart

A

supplied with oxygenated blood via coronary arteries

which branch off the aorta

26
Q

How does deoxy blood from the heart muscle back into the right atrium

A

via coronary sinus vein

27
Q

coronary arterial disease

A

insufficient blood flow (ischemia) associated with chest pains (angina), radiates down left arm
Severe blockage leads to death of heart region and myocardial infarction
Ventricular fibrillation and death

28
Q

Causes of coronary arterial disease

A

atherosclerosis
blood clot
drugs, surgery

29
Q

Function of CSF

A

protects brain against brain damage

30
Q

How does fluid pass into vein at the top of the skull

A

via arachnoid villi (valves)

31
Q

Where is CSF produced

A

specialised epithelial cell called choroid plexus

32
Q

BBB

A

capillaries contain tight junction and less permeable to many substances- drugs and proteins can’t get into the brain

33
Q

exceptions that can cross BBB

A

lipophilic molecules eg anaesthetics, alcohol

34
Q

why can brain damage occur so quickly

A

Blood needs constant supply of O2 and glucose- has no stored glycogen

35
Q

stroke

A

loss of supply and death of neurons

36
Q

exchange in brain

A

by diffusion down gradients

facilitated by slow blood and large SA