Systems: Local And Systemic Control

Front 1

What will occur if resistance exceed the pressure difference?

Back 1

No flow

Front 2

How does viscosity effect flow?

Back 2

inversely

Front 3

How does segment length effect flow?

Back 3

inversely

Front 4

How does the radius of the vessel effect flow?

Back 4

directly (4th power)

Front 5

What controls the flow of blood in each region?

Back 5

Each tissue will control its own local blood flow

Front 6

What alters a tissue's blood flow needs?

Back 6

metabolic activity

Front 7

At what level is blood normally regulated?

Back 7

at a bare minimum

Front 8

Why do tissues require blood flow?

Back 8

Supply nutrients (Oxygen, glucose, amino acids, FAs)
Remove waste (CO2, H+)
Maintain ion balance
Transport hormones

Front 9

What are four regulatory mechanisms to increase or decrease blood flow?

Back 9

1. Change cardiac output
2. Change vessel diameter
3. Change capacitance of veins
4. Change extracellular fluid volume

Front 10

What are three intrinsic regulatory mechanisms?

Back 10

Pressure flow autoregulation
Active hyperemia
Reactive hyperemia

Front 11

At values below 60 mmHg, why can't resistance be further decreased?

Back 11

Vessels are all fully dilated.

Front 12

What happens to vessel resistance at pressures above 160 mmHg?

Back 12

Resistance decreases because the pressure forces dilations

Front 13

What is the normal range for blood flow and mean arterial pressure?

Back 13

80-125% of normal flow
60-160 mmHg MAP

Front 14

What tissues have hallmark autoregulation mechanisms?

Back 14

Brain
Heart
Kidney

Front 15

What is the function of autoregulation?

Back 15

To maintain blood flow at varying pressures by changing vascular resistance.

Front 16

Which variable is altered during autoregulation?

Back 16

Resistance

Front 17

What is the vasodilator theory?

Back 17

Lack of oxygen causes a release of vasodilators

Front 18

What is the metabolic theory?

Back 18

When metabolic needs are increased, more vasodilators are released

(also) When oxygen to the tissue in low.

Front 19

What is the oxygen demand theory?

Back 19

Smooth muscle contraction is inhibited by lack of oxygen, AA, FA, or vitamins.

Front 20

What is the myogenic theory?

Back 20

Sudden stretch of small blood vessels causes smooth muscle contractions in the vessel walls.

Reduced stretch means reduced contraction.

Front 21

What is active hyperemia?

Back 21

Increased blood flow caused by increased tissue activity

Front 22

What is reactive hyperemia?

Back 22

Excess flow following an arterial occlusion

Front 23

What prevents a drop in blood pressure due to generalized vasodilation?

Back 23

Autonomic nervous system

Front 24

What are the three angiogenic factors?

Back 24

Endothelial cell growth factor
Fibroblast growth factor
Angiogenin

Front 25

Which tissues release angiogenic factors?

Back 25

Ischemic tissues
Tissue under rapid growth
Tissue with high metabolic rates

Front 26

How is collateral circulation modulated locally?

Back 26

Through dilation of vessels around the blockage

Front 27

What is the mechanism and function of EDRF?

Back 27

Endothelium derived Relaxing Factor
Vasodilator: Triggers NO, which activates Guanyl Cyclase to increase cGMP and increases sequestering of calcium causing less contraction.

Front 28

How does endothelium response to increased shear stress?

Back 28

Release of EDRF (Endo Relax Factor) to cause dilation and reduce blood velocity

Front 29

What hormones are released from the adrenal medulla? What is the majority?

Back 29

Epinephrine (80%) and Norepinephrine

Front 30

What is pheochromocytoma?

Back 30

is a neuroendocrine tumor of the medulla of the adrenal glands (originating in the chromaffin cells), or extra-adrenal chromaffin tissue that failed to involute after birth and secretes excessive amounts of catecholamines, usually epinephrine and norepinephrine.

Front 31

What are the adrenoceptors?

Back 31

Alpha 1-2
Beta 1-2

Front 32

What does the alpha 1 receptor regulate?

Back 32

Vasoconstriction
Increased peripheral resistance
Increased blood pressure

Front 33

What does the alpha 2 receptor regulate?

Back 33

Inhibits the release of NE
Vasoconstriction (Veins>arteries)

Front 34

What does the beta 1 receptor regulate?

Back 34

Tachycardia
Increased cardiac contractility

Front 35

What does the beta 2 receptor regulate?

Back 35

Vasodilation
Decrease in peripheral resistance (Slight)

Front 36

What adrenoceptors will regulate vasoconstriction?

Back 36

Alpha 1-2

Front 37

What adrenoceptor will regulate vasodilation?

Back 37

Beta 2

Front 38

Norepinephrine will preferentially bind what receptors?

Back 38

Alpha and Beta 1

Front 39

Epinephrine will bind what receptors?

Back 39

Alpha 1-2
Beta 1-2

Front 40

Isopreterenol will bind what receptors?

Back 40

Beta 1-2

Front 41

What do Beta 2 receptors do in skeletal muscle?

Back 41

vasodilation

Front 42

What is the primary function of NE stimulated alpha and beta 1 receptors?

Back 42

Vasoconstriction

Front 43

What are the differences of circulating epinephrine and NE?

Back 43

Epinephrine:
Increased heart rate
Increase flow to muscles

NE:
Decreased heart rate
Decreased flow to muscles

Front 44

What is the effect of endothelins?

Back 44

Proteins that constrict blood vessels and raise blood pressure. They are normally kept in balance by other mechanisms, but when they are over-expressed, they contribute to high blood pressure and heart disease.

Front 45

How are the kinin and rennin-angiotensin systems connected?

Back 45

Through ACE.

Front 46

What are the functions of ACE?

Back 46

Converts angiotensin I to active angiotensin II

Degrades kinins

Front 47

What is the role of bradykinin?

Back 47

arteriolar dilation and increased capillary permeability
Causes local edema

Front 48

What is the role of the angiotensin system?

Back 48

To increase blood pressure (vasoconstriction)

Front 49

Which substrates are concentrated by an ACE inhibitor?

Back 49

Angiotension I
Bradykinin
Lysylbradykinin

Front 50

Atrial distension causes the release of what peptide?

Back 50

Atrial natriuretic peptide (ANP)

Front 51

What is the function of Atrial natriuretic peptide?

Back 51

Natriuresis (sodium excretion)
Lower blood pressure
Decrease responsiveness to vasoconstrictors
Increases cGMP

Front 52

What is the precursor to angiotensin I made by the liver?

Back 52

Angiotensinogen

Front 53

How does the kidney respond to the angiotensin stimulation?

Back 53

With renin production

Front 54

What are the three vasodilation mechanisms?

Back 54

Tissue metabolites
Local hormones
Endothelial factors

Front 55

What two intrinsic factors are able to constrict or dilate the vessel?

Back 55

Endothelial factors
Local hormones

Front 56

What is pharmacomechanical coupling?

Back 56

Eliciting a contraction without depolarization using NTs/hormones

Front 57

Inhibition of the cAMP pathway will cause what?

Back 57

vasoconstriction

Front 58

What pathway is activated by NO to cause dilation?

Back 58

cGMP

Front 59

What factors can be released by the endothelium to regulate vessel diameter?

Back 59

EDRF/NO (-)
endothelin (+)
Prostacyclin (-)

Front 60

When will vasodilation be stimulated by the SNS?

Back 60

At the onset of exercise the sympathetic vasodilator system causes initial vasodilatation
even before muscles require increased nutrients.