Cardiovascular Compensation

Question 1

What are ganglia?

Answer 1

Clusters of nerve cells in the autonomic nervous system

Question 2

What is the thoracolumbar nervous system also known as?

Answer 2

The sympathetic nervous system

Question 3

What is the craniosacral nervous system also known as?

Answer 3

The parasympathetic nervous system

Question 4

Where is the sympathetic nervous system anatomically? What does this system require?

Answer 4

Out of the thoracolumbar of the spine

Requires high cardiac output and skeletal muscle activity

Question 5

During fight or flight, what happens to blood vessels?

Answer 5

Non-essential (most) constrict

Coronary and skeletal muscle vessels dilate

Question 6

The parasympathetic nervous system acts to ‘rest and digest’. Where is it anatomically? What happens to most vessels?

Answer 6

Out of the brain - cranial nerve 10 (vagus)

Most vessels dilate

Question 7

What receptors are involved in the parasympathetic nervous system? Where are they? What type of chemicals do they receive?

Answer 7

M2 - blood vessels
M3 - Heart
Cholinergic

Question 8

What receptors are involved in the sympathetic nervous system? What type of chemicals do they receive?

Answer 8

A1 - blood vessels
A2- blood vessels
B1- Heart
B2 - blood vessels

Question 9

Before and during exercise, what 3 mechanisms can increase cardiac output?

Answer 9

Psychogenic response
Baroreflex
Exercise reflex - muscle/joint receptors feedback to cause autoregulation

Question 10

What is hypovolaemia? What causes it?

Answer 10

Decreased blood volume

Haemorrhage, dehydration, or trapping of blood

Question 11

How does hypovolaemic shock occur?

Answer 11

Hypoloaemia causes drop in venous return
Drop in preload
Decrease in cardiac output
Leads to organ failure

Question 12

What is the body’s first reaction to hypovolaemia? What does the body do if this persists?

Answer 12

Baroreflex first

Then RAAS, starling’s law and spleen contracts

Question 13

After blood loss, what happens to packed cell volume and blood protein levels?

Answer 13

Decreased
Blood is diluted
Fluid is replaced, proteins and cells also need replacing

Question 14

Forward heart failure often leads to backwards heart failure. What is forward Heart failure?

Answer 14

Systolic failure

Question 15

What does forward heart failure lead to? What are symptoms?

Answer 15

Thready (weak) pulse
Reduced CO
Breathless, fainting

Question 16

What is backward heart failure? (Also known as congestive heart failure)

Answer 16

Inability to cope with preload

Question 17

What are the results of backward heart failure?

Answer 17

Decreased venous pressure

Increased capillary pressure (leads to oedema)

Question 18

What can often be the cause of backwards heart failure?

Answer 18

Faulty valves

Question 19

How can heart failure lead to a viscous circle?

Answer 19

Compensatory mechanisms fail
Further stimulation of compensatory mechanisms
More water retention and vasonstriction
Increased workload on failing heart

Question 20

What are natriuretic peptides?

Answer 20

Proteins which cause the excretion of sodium at the kidney

Question 21

What do natriuretic peptides cause water to do?

Answer 21

Move out of the kidney via osmosis as sodium lost from kidney

Question 22

What can natriuretic peptides be an indicator of?

Answer 22

Myocardial stretch