L16 Systemic Circulation II

Question 0

MAP

Answer 0

average pressure over the cardiac cycle

MAP = DP + 1/3 Pulse Pressure
MAP = DP + 1/3 (SP-DP) = *****2/3 DP + 1/3 SP*****

Question 1

Physiological factors that affect Mean Arterial Pressure (MAP)

Answer 1

CO (affects systolic) and Peripheral resistance (affects diastolic bc affects return process)

Rp influenced by Baroreceptor; ANS; local metabolic regulation
CO influence by Baroreceptor; ANS
Exercise increases SP. Pulse pressure widens, MAP increases

Question 2

Primary affecters of Systolic BP

Answer 2

Things that affect output

1. CO
2. exercise
3. Hypertension (afterload)
4. volume of blood

Question 3

Primary affecters of Diastolic P

Answer 3

1. Peripheral resistance
2. hypertension
3. infarct, CHF, bradycardia, sepsis
4. lack of compliance (aortic valve 2˚ pump)

Question 4

Compliance and pressures

Answer 4

Low compliance - stiff - HIGH SP LOW DP - pulse pressure widens

High compliance - LOW SP HIGH DP - narrow pulse pressure

Question 5

Exercise and Cardiac adjustments

Answer 5

HR increases
O2 consumption increases
SP increases
DP increases and then decreases as resistance decreases
SV increases but drops off at extremely high HR
CO increases
MAP increases bc SP increases slightly more than DP
Rp decreases so blood can flow (vasodilation)
Arteriovenous oxygen difference increases bc more O2 unloaded

Blood shunted from viscera –> muscles.
Blood to heart and brain stays constant
Blood to cutaneous increases to release heat (until the point that it shunts it all to muscles –> this = you’ll probably pass out)