circulatory system part 4

Question 1

what moderates heart rate

Answer 1

autonomic nerves and adrenal medulla?

Question 2

equation for mean arterial pressure

Answer 2

MAP = cardiac output x total peripheral resistance

Question 3

how do arterioles control blood distribution?

Answer 3

vasoconstriction/dilation changes in resistance alter flow

• auto regulation: response of arteriole smooth muscle
• intrinsic factor: metabolic state
• extrinsic factor: nervous/endocrine system

Question 4

myogenic auto regulation of flow

Answer 4

smooth muscle cells in arterioles are sensitive to stretch
contract (decrease diameter increase resistance) when blood pressure increases
- negative feedback prevents excessive flow of blood

Question 5

metabolic activity regulates blood flow

Answer 5

levels of metabolites need to match requirements

when low O2 and high waste/CO2 levels - VASODILATION

Question 6

norepinephrine effects on blood flow

Answer 6

released from sympathetic neurons

causes vasoconstriction

Question 7

vasopressin (ADH)

Answer 7

released from posterior pituitary

causes vasoconstriction

Question 8

angiotensin 2

Answer 8

produced in response to decreased blood pressure

causes vasoconstriction

Question 9

atrial natriuretic peptide (ANP)

Answer 9

produced in response to increased blood pressure

causes vasodilation

Question 10

what are baroreceptors

Answer 10

stretch-sensitive mechanoreceptors

send nerve signals to medulla oblongata

Question 11

what is the affect of high baroreceptor firing

Answer 11

vasodilation, decreased force of contraction, decrease heart rate, lower MAP