Cardio Lecture 11--Extrinsic And Local Control Of Cv System

Front 1

MAP = ?

Back 1

MAP = CO X TPR

Front 2

MAP is influenced by what?

Back 2

Neurohormonal factors only

Front 3

What are the afferent pathways of the baroreceptor reflex? What are the efferent pathways? What is the integrating center? Where is this reflex located? What organs are effected?

Back 3

Afferent--Glossopharyngeal(carotid sinus) and Vagus(aortic arch)
Efferent--SNS and PNS
Integrating Center--Medulla(NTS)
Location--Carotid sinus, aortic arch
Organs--Heart, vessels, kidneys, adrenal glands

Front 4

As the MAP increases, what happens to the tone in neurons that convey the baroreceptor signals?

Back 4

Firing of these neurons increases

Front 5

Where do baroreceptor signals go in the brain? What do they do there?

Back 5

The NTS in the medulla oblongata--they stimulate preganglionic fibers of the parasympathetic system to lower the heart rate which lowers the CO which lowers BP--sympathetic stimulation is also decreased by the NTS

Front 6

Other than baro and chemo input, what else controls the NTS?

Back 6

Proprioreception from skeletal muscle during physical activity and Higher brain centers(emotion, stress, body temp increase)

Front 7

True/False: TPR is changed by adjusting parasympathetic outflow.

Back 7

FALSE--the only vessels innervated by the Parasymp system are those of the external genitalia

Front 8

What receptors are found on the blood vessels?

Back 8

Alpha 1 and Beta 2--more alpha than beta(except for in the coronary arteries of the heart, where there are more b2's than a1's)--also M2 receptors are found in blood vessels but they are not innervated so they can only be affected by drugs

Front 9

What receptors are found on the heart? Which is the most sensitive to Norepi?

Back 9

B1, B2, and A1--B1 is most sensitive

Front 10

Which receptors found in blood vessels are most sensitive to Norepi? Which are most sensitive to Epi?

Back 10

A1 most sensitive to Norepi and B2 most sensitive to Epi

Front 11

What happens in the blood vessels as you begin Epi release and it increases?

Back 11

In small amounts, it stimulates the most sensitive B2, which causes vasodilation. In larger amounts, it stimulates the A1 receptors to cause overall vasodilation

Front 12

What are the afferent pathways of the Cardiopulmonary baroreceptor reflex? What are the efferent pathways? What is the integrating center? Where is this reflex located? What organs are effected?

Back 12

Afferent--vagus
Efferent--SNS, PNS
Integrating Center--NTS
Location--atria, ventricles, pulmonary blood vessels, and lungs
Effector organs--heart, blood vessels, pituitary glands, kidneys

Front 13

Where are the chemoreceptors found? What do they do?

Back 13

In the carotid body near the bifurcation of the common carotid and also central chemoreceptors in the brain--last ditch response triggered by brain ischemia will show a marked increase in SNS stimulation and intense vasoconstriction and cardiac stimulation

Front 14

What is the Cushing reflex?

Back 14

Triggered by an intense increase in intracranial pressure that causes an increase in sympathetic outflow and a marked rise in MAP

Front 15

What is the dive reflex?

Back 15

Combination of marked bradycardia and vasoconstriction(dual Symp and Parasymp) to all organs except the brain and heart

Front 16

What is the volume reflex?

Back 16

Stretching of atrial walls--causes signal from CNS to decrease sympathetic outflow to the kidney so that glomerular capillary pressure increases and more filtration occurs and reduction of ADH release from the hypothalamus

Front 17

Superficial pain causes what? Deep pain causes what?

Back 17

Superficial--increases SNS and MAP
Deep pain--decreases SNS and MAP

Front 18

What do the adrenal medulla hormones do to the BP?

Back 18

Norepi and Epi released from the medulla increase BP by enhancing SNS stimulation

Front 19

What does ADH do?

Back 19

Causes intense vasoconstriction in the case of extremely low BP and also causes water retention by the kidney

Front 20

Angiotensin II does what?

Back 20

Causes intense vasoconstriction and the release of aldosterone to cause Na+ retention by the kidney

Front 21

What does ANP do in the body?

Back 21

Causes blood volume and pressure to decrease

Front 22

What does alcohol do in the body?

Back 22

Causes BP to drop by inhibiting ADH secretion

Front 23

What are some characteristics of vascular smooth muscle that differentiate it from cardiac muscle?

Back 23

1. VSM is capable of graded contraction (contraction is not all or nothing)
2. VSM contract and relax more slowly.
3. VSM develop active tension over a greater range of muscle lengths.
4. VSM can change their contractile activity as a result of action potentials or changes in resting membrane potential (electromechanical coupling).
5. VSM may change their contractile activity in absence of changes in membrane potential (pharmaco-mechanical coupling).
6. VSM maintain tension for prolonged periods at low energy costs.
7. VSM can be activated by stretch.
8. VSM commonly manifest tone- a state of partial contraction which is maintained for prolonged periods of time.