structure and function of blood vessels and heart

Question 1

ventricular fibrillation

Answer 1

irregular heartbeat
spasm
heart not pumping blood around the body

Question 2

infarction

Answer 2

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

Question 3

Diffusion speed relation to distance

Answer 3

fast over short distances, slow over 1mm

Question 4

Function of CVS in relation to efficiency

Answer 4

speeds up gas and solute transport over long distances

reduces DD for O2 and nutrients

Question 5

Other functions of CVS

Answer 5

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

Question 6

what drives movement of blood (excluding the heart)

Answer 6

Pressure differences

Question 7

What is blood pressure determined by

Answer 7

CO
blood volume
peripheral resistance

Question 8

2 circuits in cardiovascular circulation

Answer 8

systemic and pulmonary

Question 9

Composition of blood

Answer 9

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

Question 10

Order of pumping blood around the body

Answer 10

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

Question 11

Where is most blood distributed

Answer 11

veins and venules- acts as reservoir

61%, slow moving

Question 12

Blood flow (at rest)

Answer 12

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

Question 13

Components of BVS

Answer 13

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

Question 14

arteries

Answer 14

large lumen

thick layer smooth muscle and connective tissue

Question 15

function of thick elastic smooth muscle in arteries

Answer 15

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)

Question 16

arterioles

Answer 16

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

Question 17

capillaries

Answer 17

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

Question 18

Exchange occurs by

Answer 18

diffusion down gradients

Question 19

venules/veins

Answer 19

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

Question 20

muscle layers in the heart

Answer 20

pericardium (outermost)
Epicardium
Myocardium (innermost)

Question 21

Septum

Answer 21

divides left and RHS of heart

Question 22

What are valves held in place by

Answer 22

chordae tendineae and papillary muscle

Question 23

2 SL valves

Answer 23

pulmonary and aortic

Question 24

2 AV valves

Answer 24

left- bicuspid

right-tricuspid

Question 25

blood supply to the heart

Answer 25

supplied with oxygenated blood via coronary arteries

which branch off the aorta

Question 26

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

Answer 26

via coronary sinus vein

Question 27

coronary arterial disease

Answer 27

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

Question 28

Causes of coronary arterial disease

Answer 28

atherosclerosis
blood clot
drugs, surgery

Question 29

Function of CSF

Answer 29

protects brain against brain damage

Question 30

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

Answer 30

via arachnoid villi (valves)

Question 31

Where is CSF produced

Answer 31

specialised epithelial cell called choroid plexus

Question 32

BBB

Answer 32

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

Question 33

exceptions that can cross BBB

Answer 33

lipophilic molecules eg anaesthetics, alcohol

Question 34

why can brain damage occur so quickly

Answer 34

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

Question 35

stroke

Answer 35

loss of supply and death of neurons

Question 36

exchange in brain

Answer 36

by diffusion down gradients

facilitated by slow blood and large SA