1. Dr. Jim Stallworth from the University of South Carolina School of Medicine will answer questions and provide information about med school admissions.   The talk will commence at 6:30 in RMSC 122.

2. Ch 12 Cardiovascular Physiology 3 November 2008
Finish Section B The Heart Begin Section 3 The Vascular System Lab this Week: EKGs and Blood Pressure.
Wear shoes and clothes for running.
Abstract due Friday.

3. Frank-Starling Law of the Heart
12.25.jpg
Does not depend on hormones or nerves
Assure that the heart adjusts its output based on venous return

4. Fig. 09.21 Length-tension “curve” for Cardiac muscle High EDV Low EDV
Overinflation of ventricles leads to less effective pumping
09.21.jpg

5. Figure 12.25
Contractility

6. 3 Effects of Sympathetic Stimulation
1: Increase rate of contraction
2: Increase peak tension
3: Decrease twitch duration

7. Control of Stroke Volume
End diastolic volume (preload)
Contractility (strength of ventricular contraction due to adrenergic stimulation)
Afterload (pressure in arteries that must be overcome)
FS LoH
High blood pressure increases the workload of the heart….. Cardiac hypertrophy….increase chance of irregular conduction of AP through heart

8. CO = HR x SV 5L/min = 72 beat/min x 70 ml/beat 35L/min =. beat/min x
CO = HR x SV 5L/min = 72 beat/min x 70 ml/beat 35L/min = ? beat/min x ? ml/beat

9. Summary of Factors that Regulate Cardiac Output
Fig
Even persons with heart transplants can increase CO in the absence of innervation of heart.
12.28.jpg
Notice: No Parasymp innervation of Cardiac Muscle

10. Mean Arterial Pressure = Cardiac Output x Total Peripheral Resistance
MAP = CO x TPR

11. Figure 12.02 CO
x TPR =
MAP

12. Properties of Blood Vessels
All vessels and heart chambers lined with ENDOTHELIAL cells (simple squamous)
Arteries
Arterioles
Capillaries
Venules
Veins
Elastic, low compliance, large diameter, low resistance vessels
Resistance vessels
Exchange
Wall = simple squamous endothelium
Capacitance vessels, high compliance, low pressure, valves for unidirectional flow

13. Fig. 12.29 Aorta Brachial or Femoral artery Pusatile flow
Damage to artery vs vein
12.29.jpg

14. 6
Fig b
Analogy: river width and flow
12.39b.jpg

15. Fig
Elastic recoil of stretched arterial walls during ventricular systole maintains arterial pressure during diastole as blood drains into arterioles.
Atherosclerosis
12.30.jpg
Point of Confusion: Smooth muscles in arterial walls DO NOT rhythmically contract!

16. Arteries and Arterial Pressure Mean Arterial Pressure
Arteriole
Arterioles have two main functions: 1) regulate flow to tissues and organs and 2) responsible for Total Peripheral Resistance which influences Blood Pressure.
MAP = CO x TPR
Poiseulle’s Equation

17. Fig
12.50.jpg

18. Receptors for other ligands
Alpha receptors more common except in skeletal muscle arterioles which have more B2 receptors

19. 3
Fig
12.36.jpg
Metabolic autoregulation, flow autoregulation, myogenic autoregulation