Class Notes (806,973)
Canada (492,546)
Physiology (885)
PHGY 210 (301)
Ann Wechsler (112)
Lecture 15

Lecture 15.docx

1 Page
Unlock Document

McGill University
PHGY 210
Ann Wechsler

Lecture 15 Orthostasis: Ortho: straight. Stasis: standing. The mean blood pressure does not change, thus allowing for the person not to faint when standing up. When standing up, the blood flows out of the chest, which then allows for the right atrial pressure to drop. The baroreceptor effect makes it so that the contractility increases and the constriction of the arteries. During extended period of standing, pumping the calf muscles allows for the blood to be forced back into the heart, to restore the blood pressure. Venous valves and muscle pumps shifting blood and preventing them from back flowing. Venous pressure while standing is about 80mmHg at the bottom of the foot. Plasma volume is pumped out from the cell junctions, the longer one stands, the more the fluid leaks out. As such, 15 minutes of standing would lead to nearly 700mL of volume lost. The muscle pumps also lower the venous pressure in the veins and capillaries. Valvular incompetence leads to venous hypertension. Aerobic Exercise: Heart rates maxed out at 220 minus age. Stroke volume increases until it becomes too fast to completely fill. Cardiac output is increased nearly linearly. MAP = CO x TPR, the total peri
More Less

Related notes for PHGY 210

Log In


Don't have an account?

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.