Central factors of the cardiovascular regulation

Question 1

what are the 2 principles regarding Regulation of circulation, and the satisfaction of the demand

Answer 1

The demands of material transport to and from tissues should be met.
● The collapse of normal circulation should be avoided by compensating for the inproportional blood supply to different organs during different physiological activities.

Question 2

Short-run
Sympathetic effects: what is it

Answer 2

Arteries and veins are under the influence of the
sympathetic tone, which exerts vasoconstrictive effects and at the same time under the influence of the continuous local NO production that continuously dilates the vessels. The balance of these two effects results in an actual diameter of the vessel.

Question 3

Short-run
Sympathetic effects: what is the action of CNS

Answer 3

The CNS controls the diameter of the vessels via the vasomotor center in the medulla.

Question 4

Parasympathetic effects: what is it

Answer 4

The parasympathetic nervous system decreases respiration and heart rate and increases digestion.

Question 5

Parasympathetic effects: Direct parasympathetic stimulation is found in the:

Answer 5

Corpus cavernosus in penis
o Uterus
o Pancreas

Question 6

Parasympathetic effects: where does indirect vasodilation occur

Answer 6

Indirect cholinergic vasodilation occurs in the salivary glands

Question 7

Humoral factors: Epinephrine: Small dose:

Answer 7

Small dose: beta-adrenergic vasodilation in the skeletal muscle, alpha-adrenergic vasoconstriction in skin and in sphlanchnic areas

Question 8

Humoral factors: Epinephrine: high dose

Answer 8

High dose: general alpha-adrenergic vasoconstriction

Question 9

Reflex mechanisms
- Baroreceptor mechanism: where is it and what does it do?

Answer 9

Found in many places in the circulatory bed, and allow the very fast adjustment of blood pressure to the needs of the body.

Question 10

Reflex mechanisms
- Baroreceptor mechanism: how does it act on the pressure

Answer 10

Baroreceptor functions in the range of 40-170 mmHg of mean arterial blood pressure. Increased
vlood pressure decreases the sympathetic influence on the heart (drop of heart rate and contractility) and it increases the parasympathetic discharge (heart rate drops).

Question 11

Reflex mechanisms
Volume sensors: where are they found

Answer 11

Found in the lung and in the capacitance system of
vessels.

Question 12

Reflex mechanisms
Volume sensors: what do they lead to

Answer 12

Centripetal fibers from these sensors lead to the
cardiovascular center in the medulla.

Question 13

what is ANF

Answer 13

Atrial natriuretic factor (ANF) is produced in the atria as a response to increased EC volume.

Question 14

what is ADH

Answer 14

Antigiuretic hormone (ADH): Atrial stretch reflexly elicits the inhibition of the neurohypophysael let down
of this hormone.

Question 15

what is the effect of pO2 and pCO2

Answer 15

Signals from the central
and peripheral gas
sensors supply
information to the cardiovascular center of
the medulla too