C&b 070 Special Circulations And The Control Of Blood Flow

Front 1

Skin has a low requirement for oxygen, so why does it have such a rich blood supply?

Back 1

So that body temperature can be well regulated

Front 2

If perfusion of the brain is compromised, what reflex occurs? How does it help?

Back 2

'Cushing reflex' (increased sympathetic drive)

It maintains/increases arterial blood pressure

Front 3

Which type of vasodilator fibres innervate the sweat glands? Why is this important?

Back 3

Cholinergic sympathetic vasodilator fibres.

Important as bradykinin (a vasodilator) is produced by sweatglands

Front 4

What is bradykinin?

Back 4

A vasoDILATOR (also contracts skeletal muscle)


1838300111 Weekend with Jess after 3 weeks :)

Front 5

Is bradykinin a vasoconstrictor or vasodilator? Where is it produced?

Back 5

Vasodilator produced by sweat glands

Front 6

The right coronary artery *principally* supplies which chambers?

Back 6

RA and RV (apart from a strip of RV, it also supplies a strip of the LV)

Front 7

The left coronary artery *principally* supplies which which chambers?

Back 7

LA and LV (and strip of LV, it also supplies a strip of the RV)

Front 8

Where does the cardiac vein drain into? (Chamber and special name)

Back 8

Drains into the coronary sinus in the right atrium (NB do not confuse with coronary sulcus, which is a groove where some coronary vessels travel)

Front 9

When is blood flow to the myocardium at its peak? Why then? It's something to do with aortic pressure

Back 9

Early diastole. Mechanical compression of coronary vessels is minimal and aortic pressure is still high

Front 10

When is coronary blood flow at its minimum? Why?

Back 10

During the isovolumetric contraction phase of the cardiac cycle. This is because the coronary blood vessels become compressed as the ventricular pressure rises

Front 11

How is the increase in coronary blood flow during increased exercise thought to be brought about? Which chemical?

Back 11

Release of the vasodilator 'adenosine'. Production of adenosine increases during increased workload.

Front 12

Sympathetic nerve supply to coronary arteries is highly important in the control of coronary blood flow T/F

Back 12

F (however, it does cause some vasodilation)

Front 13

What is the most important determinant of coronary blood flow? I.e. what stimulates it to increase?

Back 13

Metabolic hyperaemia (the increase of blood flow to different tissues in the body)

Front 14

The cutaneous (related to the skin) vessels are innervated with vasodilatory parasympathetic nerve fibres T/F

Back 14

F - AV anastomoses and arterioles are innervated by sympathetic fibres only - causing constriction when stimulated, and reduction of stimulation leads to vasodilation

Front 15

Which two arteries supply the brain?

Back 15

The internal carotid and vertebral arteries

Front 16

Why would it be infeasible to increase blood flow to the brain, even if desired?

Back 16

The brain is enclosed by the skull, swelling (caused by increased blood flow) could cause damage. Any change in the volume of blood flowing to the brain must be matched by a change in the venous outflow

Front 17

Is regional functional hyperaemia well developed in the brain? How so?

Back 17

Yes, an increase in neuronal activity evokes a local increase in blood flow (Sorry for poor question)


0745310111

Front 18

What is an important clinical indicator of a space-occupying lesion within the skull?

Back 18

Rise in blood pressure (Cushing's reflex) and fall in heart rate

Front 19

Are lipid soluble, or ionic solutes freely able to pass from the blood to the interstitium of the brain?

Back 19

Lipid soluble compounds

Front 20

Which area in the brain forms CSF?

Back 20

The choroid plexus (~500ml per day (NB there is only ~350ml of CSF at any one time))

Front 21

At which vertebra is a lumbar puncture taken? Why doesn't it damage the spinal cord?

Back 21

Between the third and fourth lumbar vertebrae. Tip of needle lies in subarachnoid space, spinal cord extends only as far as the first lumbar vertebra

Front 22

What are the two main functions of CSF?

Back 22

Hydraulic buffer to cushion the brain against damage resulting from movements of the head

Helps provide a stable ionic environment for neuronal function (it is in direct contact with the extracellular fluid of the brain)

Front 23

What is hydrocephalus?

Back 23

In babies and young children, where the skull structures are not fused, an increase in intracranial pressure leads to a disproportionate increase in the size of the head. This is known as 'hydrocephalus'

Front 24

What is the effect of hypercapnia on blood flow to the brain?

Back 24

It results in increased blood flow (NB this will be matched with an increase in venous return)