Integrative Functions (neural and Humoral Control)

Question 1

What factors demonstrates the integrative functions of the cardiovascular system?

Answer 1

Gravity, exercise, and hemorrhage.

Question 2

Due to gravitational forces what changes occur within the cardiovascular system when a person moves from a supine position to a standing position?

Answer 2

1. When a person stands = blood pools at LE.
2. Due to blood pooling in LE–> increased local venous pressure,( Pc) –> fluid filtered into interstitium
3. Venous return decreases –> SV and CO decreases (Frank-Starling relationship)
4. arterial pressure decreases.
5. Carotid sinus baroreceptors responds to decreased arterial pressure to –> increase HR, contractility, TPR, and venous return –> BP increase toward normal
6. orthostatic hypotension may occur if a person’s baroreceptors reflex is impaired.