1. 9 November 2011 Properties of Blood Vessels Capillary Exchange Baroreceptors
Test 2 Recap and Grading Strategy Four versions, all new this year Degree of Difficulty Not Graded: N9d, V3,M9d, C2c, C8
Reviewing your test

2. Properties of Blood Vessels
Arteries
Arterioles
Capillaries
Venules
Veins
Elastic, low compliance, large diameter, low resistance vessels
Variable Resistance vessels
MAP = TPR x CO
Exchange
Wall = simple squamous endothelium
No smooth muscle; cannot change diameter
Capacitance vessels, high compliance, low pressure, valves for unidirectional flow

3. S 2
Receptors for other ligands
Alpha receptors more common except in skeletal muscle arterioles which have more B2 receptors

4. Fig. 12.36 Adjust TPR to maintain MAP
Match blood flow to metabolism of cells
S 3
Fig
Metabolic vasodilators
No parasympathetic innervation of arterioles!
Importance of basal “tone.”
12.36.jpg
Three forms of local control: 1) Metabolic autoregulation, 2) flow autoregulation, 3) myogenic autoregulation

5. Figure 12.02 Arteries = 10% of Blood Volume
Veins = 60% of Blood Volume
Arterioles = Resistance vessels
Capillaries = 5% of Blood Volume

6. S 5
Capillaries: Continuous, discontinuous, and fenestrated capillaries:
Ex: brain liver endocrine glands
Figure 12.38
Generate vasodilators and vasoconstrictors
Arterioles:
1) Extrinsic control by hormones and nerves 2) Intrinsic (local) control by …..a) metabolic autoregulation, …..b) flow autoregulation, and …..c) myogenic autoregulation.

7. S 6
Capillary exchange by: Diffusion, vesicle transport, bulk flow, mediated transport

8. Diffusion is the most important mode of exchange of nutrients
Fig
Diffusion is the most important mode of exchange of nutrients
12.40.jpg

9. Figure 12.41 Colloids Crystalloids Bulk Flow S 8
= colloids (impermeable proteins)
Bulk Flow

10. Cell Membrane: selectively permeable
Capillaries: highly permeable except to proteins

11. S 10
Figure 12.42
Bulk Flow through aqueous channels and intracellular clefts
Starling Forces
Regulated by arterioles
Net filtration = 4L/day
Main difference in the Pulmonary circuit?

12. S 11
Fig Pc Pc
12.43.jpg Pc

13. Who Cares? Aunt Esther S 12 Cancer of the liver;
Failure of hepatocytes to produce plasma colloids

14. S 13
Figure 12.41
Colloids
Crystalloids
Bulk Flow