Physiology 534 Final: Local Regulation

Front 1

Regulation of individual tissues of the body is handled locally. What are the exceptions?

Back 1

1. Skin blood flow has to be regulated for regulation of body temp.

2. Muscle blood flow inc. in anticipation of exercise via ANS

3. Changes of external genitalia during sex

Front 2

Metabolic regulation of blood flow

Back 2

When metabolism increases-->arterial dilatation

Front 3

What causes the metabolic vasodilators?

Back 3

1. Adenosine: released when there is an increased metabolism

2. K+: released with every AP

3. CO2:

4. H

5. Decreased arteriolar [oxygen] dilates arterioles (except in the lungs)

Front 4

Myogenic regulation of blood flow

Back 4

Constricts w/ inc. Ptm
Dilates w/ dec. Ptm

When arteriolar pressure inc--> arterioles stretch-->wall stretches-->smooth muscle responds to stretch by contracting-->causes constriction of arterioles

When arteriole pressure falls-->stretch on the arteriole wall dec.-->smooth muscle relaxes-->dilates

Front 5

Paracrine regulation of blood flow

Back 5

Relase of a mediator from one cell type that acts on another cell within a tissue

Front 6

Examples of paracrine regulation

Back 6

1. Nitric Oxide
2. Histamine
3. Prostacyclin
4. Prostaglandin E2
5. Thromboxane A2
6. Endothelin

Front 7

Nitric Oxide

Back 7

released from endothelial cells and causes vasodilation

Front 8

Histamine

Back 8

released from mast cells and causes vasodilation

Front 9

Prostacyclin

Back 9

released from endothelial cells and causes vasodilation

Front 10

Prostaglandin E2

Back 10

released from parenchymal cells and causes vasodilation

Front 11

Thromboxane A2

Back 11

released from platelets and causes vasoconstriction

Front 12

Endothelin

Back 12

released from endothelial cells and causes vasoconstriction

Front 13

Active Hyperemia

Back 13

Inc. in blood flow associated with inc. metabolic activity

Ie: thinking, exercising

Front 14

Reactive Hyperemia

Back 14

Increase in blood flow that follows a period of low blood flow

Ie: when you occlude a vessel and when you release, there is an inc. blood flow

Front 15

autoregulation of blood flow

Back 15

An adjustment of arteriolar resistance of a tissue so as to keep blood flow constant despite changes in arterial pressure

Front 16

Reactive hyperemia and autoregulation is caused by what mechanisms

Back 16

1. Metabolic regulation
2. Myogenic regulation
2. Paracrine regulation

Front 17

Standing

Back 17

All the small vessels of the feet are filled with blood from the venous side, inc. Ptm

Front 18

Prone

Back 18

With lower venous Ptm the vessels of the feet are not filled with blood

Front 19

Angiogenesis

Back 19

The development of new blood vessels from existing capillaries and venules

Front 20

Prolonged period of low oxygen (hypoxia) causes?

Back 20

Production of a substance called hypoxia inducible factor (HIF)-->release of vascular endothelial growth factor (VEGF)-->activates TK-->proliferation of endothelial cells to form more tubes.

Front 21

Conditions that stimulate angiogenesis

Back 21

1. Inflammation
2. Wound healing
3. Uterine endometrial growth
4. Exercise training
5. Living at high altitude
6. Tissue ischemia
7. Tumor growth

Front 22

Tissue ischemia

Back 22

Results from occlusion of arteries causing inadequate blood flow--angiogenesis and collateral vessel formation to go around blockade.

Front 23

Hypercapnia (inc. pCo2)

Back 23

Causes dilation of brain blood vessels and increases H+

Front 24

What happens to the flow when there is decreased pO2

Back 24

causes dilation

Front 25

Skin blood flow

Back 25

Useful as a measure of the vascular filling and the state of oxygenation in skin.

Front 26

2 pigments of skin

Back 26

Hb & melanin

Front 27

Hb & melanin

Back 27

Color of Hb is determined by oxygenation

Normoxia is red, hypoxia is blue

Melanin doesn't change color

Front 28

Cadaveric pallor

Back 28

Poor vascular filling so little color from Hb, and the color is from melanin

Front 29

Skin temperature

Back 29

Higher the blood flow of the skin, the higher the temperature of the skin

Front 30

Neuroregulation of skin blood flow

Back 30

-Only sympathetic nerves to skin, release NE and bind to alpha adrenergic receptors-->vasoconstriction

Front 31

Skin participates in a number of reflexes

Back 31

1. Baroreflex
2. Cardiopulmonary reflex
3. Chemoreceptor reflex
4. Fight/flight response
5. Emotional response

Front 32

Local heating of skin

Back 32

Can cause skin to become pink-->causes skin vessels to dilate via NO

Front 33

Body core heating causes skin vessels to dilate by

Back 33

1. Withdrawl of sympathetic tone to blood vessels (since SNS causes constriction)
2. Sympathetic cholinergic nerves which release Ach-->stimulates sweat glands ) and VIP causing dilation

Front 34

What will take priority: maintanence of temperature or blood pressure?

Back 34

Temperature!

Front 35

During decreased temperature?

Back 35

Local cooling causes vasoconstriction by local release of NE from sympathetic nerves.

Front 36

Cutaneous response to injury

Back 36

1. Flare (vasodilation)
2. Produce histamine & bradykinin and cause capillaries to release proteins-->local swelling called a wheal

Front 37

Wheal

Back 37

Caused by the leak of proteins and increased Pc

Front 38

Bradykinin

Back 38

released from sweat glands in skin and causes vasodilation

Front 39

Histamine

Back 39

Causes increased capillary permeability to plasma protein