Pulmonary and Cerebral Flow

Question 1

how does inspiration/expiration affect right/left flow?

Answer 1

inspiration- right up/left down. expiration- right down/left up

Question 2

describe the vasculature muscle in the pulmonary circuit

Answer 2

very little. walls are extremely compliant. almost no resistance

Question 3

how do o2 and co2 levels affect dilation/constriction in the pulmonary circuit?

Answer 3

low o2 and high co2 lead to constriction. this is opposite of the systemic circuit. hypothetically, could be to avoid nonfunctional lung areas

Question 4

how is nutrient exchange different in the cerebral circuit

Answer 4

the BBB means no pore in the epithetlium and the starling hypothesis is not applicable

Question 5

cushing reflex

Answer 5

intracranial pressure puts pressure on brainstem causing decreased HR and BP

Question 6

how does the cerebral circuit respond to hypoxia and hypercapnia

Answer 6

dilators

Question 7

how does the nervous system affect the cerebral circuit

Answer 7

sympathetic- adrenergic- constriction; parasympathetic- cholinergic- dilation

Question 8

in the skin, what sets the resting vasotone

Answer 8

nervous system

Question 9

the skin is important for regulating what?

Answer 9

temperature

Question 10

in muscle, what regulates vaso-tone

Answer 10

at rest- sympathetic nervous system. during use- local vasodilators

Question 11

what are the 5 extrinsic regulators of MAP?

Answer 11

1. parasympathetic and sympathetic innervation of SA node- HR (via affecting depolarization)
2. sympathetic innervation of ventricles- SV (via contractility)
3. sympathetic innervation of vasomotor musculature- TPR
4. sympathetic innervation of venomotor tone- venous return
5. sympathetic innervation of kidneys- renin- volume

Question 12

why is BRR a short term solution?

Answer 12

it adapts to stimulation

Question 13

what does sympathetic innervation do in kidneys

Answer 13

1. increases resistance, decreasing transmural pressure and increasing retention
2. renin

Question 14

what does the atrial LBP do?

Answer 14

1. decrease sympathetic innervation in kidney 2. inhibit ADH

Question 15

what are the affects of ANP?

Answer 15

inhibits ADH, aldosterone, Na retention in kidneys

Question 16

describe how gravity dependent distribution of flow in the lung leads to edema

Answer 16

flow is greater at the base of the lung than at the top, and there is a column of blood creating an increased driving pressure at the base. thus, the “P out” is greatest at the base of the lung, and so that is where fluid will leave into the paranchyma.

Question 17

what are the intrinsic mediators of the heart

Answer 17

contractility, preload (EDV), afterload, HR, SV

Question 18

inotropic effects vs chronotropic

Answer 18

ino- contractility/ chrono- HR