08-09 - Role of CO & TPR and Reg. of Tissue BF

Question 1

Arteriole radius is regulated in 3 ways…

Answer 1

1. Local
2. Hormonal
3. Neural

Question 2

Auto regulation of tissue blood flow is a type of local control. It keeps flow constant through…

Answer 2

Myogenic response, which is intrinsic to the smooth muscle. Increased stretching of the vessel causes constriction, reducing flow.

Question 3

Metabolic control is a form of local control of arterioles which relies on substances called….

Answer 3

Metabolism-derived vasodilator

Question 4

Metabolism-derived vasodilators may be released in response to (6)…

Answer 4

Increases in [CO2], [H+], [adenosine], [K+], osmolality and temperature

Question 5

Hormonal control of arterioles relies on hormonal vasodilators and hormonal vasoconstrictors.

Angiotensin II is a hormonal (vasodilator/vasoconstrictor)…

Answer 5

Vasoconstrictor

Question 6

Hormonal control of arterioles relies on hormonal vasodilators and hormonal vasoconstrictors.

Vasopressin is a hormonal (vasodilator/vasoconstrictor)…

Answer 6

Vasocontrictor

Question 7

Hormonal control of arterioles relies on hormonal vasodilators and hormonal vasoconstrictors.

Histamine is a hormonal (vasodilator/vasoconstrictor)…

Answer 7

Vasodilator

Question 8

Hormonal control of arterioles relies on hormonal vasodilators and hormonal vasoconstrictors.

When binding to B2-adrenergic receptors, adrenaline acts as a (vasodilator/vasoconstrictor)…

Answer 8

Vasodilator

When binding to A1-adrenergic receptors it acts as a vasoconstrictor

Question 9

How does the sublingual administration of an NO precursor treat angina?

Answer 9

Angina is pain caused by insufficient blood flow to heart muscles.

The NO precursor increases levels of NO in the blood.

NO acts as a vasodilator

Vasodilation improves blood flow to the heart and reduces its workload, alleviating angina.

Question 10

Neural control of arterioles can be divided into (3)…

Answer 10

1. Sympathetic vasoconstrictor fibres
2. Sympathetic vasodilator fibres (cholinergic)
3. Parasympathetic vasodilator fibres

Question 11

During exercise there is both an increase in Cardiac Output AND a…

Answer 11

Redistribution of flow (with more blood reaching the skeletal muscles)

Question 12

During exercise the average mean arterial pressure ( increases / does not increase ) significantly…

Answer 12

Does not increase significantly

Because although the cardiac output increases, peripheral resistance decreases