Ianowski - theme 13 and 14

Question 1

With condom vs without condom - pressure:

Answer 1

Pressure fluctuates high without condom. Condom keeps pressure fairly consistent.

Question 2

If the condom hardens:

Answer 2

Systolic pressure rises and hypertension results

Question 3

Max systolic pressure in humans:

Answer 3

120 mmHg

Question 4

Minimum diastolic pressure in humans:

Answer 4

80 mmHg

Question 5

Mean arterial pressure equation: (2)

Answer 5

MAP = diastolic pressure + (difference between systolic and diastolic)

MAP = cardiac output * total peripheral resistance

Question 6

Effect of cardiac output on MAP:

Answer 6

Positive linear relationship!

Question 7

Effect of arteriole diameter change on MAP:

Answer 7

Smaller diameter = higher peripheral resistance = higher pressure = higher MAP

Question 8

Cardiac output equation:

Answer 8

Cardiac Output (mL/min) = heart rate (beats/min) * stroke volume (mL/beat)

Question 9

Poiseuille’s law:

Answer 9

Q (blood flow, also cardiac output?**) = delta P / R
P is pressure.
R is resistance. R = 8ηL/πr^4

Question 10

Which cells are pacemaker cells?

Answer 10

SA node cells

Question 11

What is the most important factor for determining flow resistance?

Answer 11

Arteriole radius

Question 12

Parasympathetic effect on cardiac output:

Answer 12

Slows heart rate.

Question 13

Sympathetic effect on cardiac output:

Answer 13

Increases heart rate and stroke volume. Increases tone of veins to increase venous return, raising end diastolic volume, raising stroke volume.

Question 14

Mammalian veins contain what % of total blood volume?

Answer 14

Over 60%

Question 15

What determines the amount of blood flow that goes to an organ?

Answer 15

Number and diameter of arterioles

Question 16

Local (intrinsic) changes to arteriole diameter:

Answer 16

Local metabolic changes, histamine, temperature, stretch receptors

Question 17

Extrinsic control of arteriole diameter:

Answer 17

Sympathetic stimulation redirects blood away from nonessential organs to heart and skeletal muscles. NE or epinephrine activate alpha-1 receptors in most tissues to cause vasoconstriction. Lungs and brain do not have alpha-1 receptors. Epinephrine activates beta-2 receptors in heart and skeletal muscles and cause vasodilation.

Question 18

The gigantic story of renin and angiotensin:

Answer 18

Kidney stimulated by symp NS, hypotension, or decreased sodium delivery. Secretes renin. Renin breaks angiotensinogen into A1. A1 is broken down into A2 by ACE. Then A2 does everything.

Question 19

Effects of angiotensin II:

Answer 19

Cardiac and vascular hypertrophy.
Systemic vasoconstriction to raise arterial pressure.
Thirst and renal retention of sodium and fluids to increase blood volume to increase cardiac output to increase arterial pressure.
Increased aldosterone production from adrenal cortex to increase renal retention again.

Question 20

Response to hemorrhage:

Answer 20

Trying to keep the brain oxygenated. Bunch of stuff happens to lower arterial pressure, which causes symp to increase heart rate and contractility, resistance, and venous tone. You bleed to death real fast.
Also, hormonal. I think the takehome message is that there are a bunch of ways of controlling arterial pressure. ***