Quiz 10

Question 1

Which sympathetic nerve receptor predominantly causes vasoconstriction?

Answer 1

Alpha 1

Question 2

Which sympathetic nerve receptor predominantly causes increased contractility?

Answer 2

Beta 1

Question 3

Definition: conduction velocity

Answer 3

Dromotropy

Question 4

Sympathetic does what?

Answer 4

• inhibits bladder contraction
• Inhibits salivation
• Inhibits paristalsis
• stimulates glucose
• secretion of adrenaline/noradrenaline
• stimulates orgasm
• accelerates HR
• Relaxes bronchi
• Dilate pupils

Question 5

Does the sympathetic nervous system primarily stimulate or inhibit the heart?

Answer 5

stimulates

Question 6

What is the “second messenger” that is involved with sympathetic stimulation of a cardiac muscle cell?

Answer 6

Know Adenylyl converts ATP to cAMP (second Messenger) – activates protein Kinase A

Question 7

Which catecholamine does the adrenal gland predominantly release with sympathetic stimulation?

Answer 7

Mostly epinephrine (80%)
lesser amount norepinephrine (20%)

Question 8

What is the Baroreceptor Reflex? Where are the receptors for this reflex located?

Answer 8

• Reflex responsible for rapid changes in BP

- Carotid sinus

Question 9

How does the Baroreceptor Reflex help with blood pressure regulation?

Answer 9

Increases or decreases:

• HR
• Contractility
• SVR

Question 10

During what surgery does Baroreceptor Reflex activation frequently cause hemodynamic changes?

Answer 10

Carotid Endarterectomy

Question 11

What is the Bainbridge Reflex? Where are the receptors for this reflex located?

Answer 11

Low pressure sensors that respond to STRETCH - located in pulmonary vein and vena cava

Ex: fluid bolus given to dog increases heart rate

Question 12

In addition to receptor activation what also contributes to the heart rate changes seen with the Bainbridge Reflex?

Answer 12

Stretch of heart and Stretch of SA node

Baroreceptor reflex often change heart rate in opposite direction of baseline (slow to fast, or fast to slow)

Question 13

The Baroreceptor Reflex responds to changes in arterial blood pressure or to changes in blood volume?

Answer 13

Changes in arterial blood pressure

Question 14

The Bainbridge Reflex responds to changes in arterial blood pressure or to changes in blood volume?

Answer 14

Blood Volume (stretch)

Question 15

What are some of the effects of Atrial Stretch Receptor activation?

Answer 15

• Decreased sympathetic kidney activity –> increased UOP
• Decreased ADH (vasopressin) –> increased UOP & decreased water reabsorption
• Increased Atrial Natriuretic Peptide –> increase natriuretic UOP and decreased BP

Question 16

What is the Bezold-Jarisch Reflex?

Answer 16

Strong contraction of an under-filled ventricle elicits the reflex, plays a role in blood pressure regulation, results in decreased BP and decreased HR

(could lead to vasovagal syncope or cardiac arrest during spinal)

Question 17

What is the CNS ischemic response?

Answer 17

Result of decreased blood flow to vasomotor center in medulla:
-increases local concentration of CO2 results in SNS stimulation in medulla, which increases BP

Question 18

What is the Cushing Response?

Answer 18

Special type of CNS ischemic response, a result of increased ICP, results in increased BP until blood flows

Question 19

What is Cushing’s Triad?

Answer 19

• Increase ICP
• Increase HTN
• Bradycardia

Question 20

What cardiovascular changes are mediated by stimulation of the Peripheral Chemoreceptors? Where are the Peripheral Chemoreceptors located?

Answer 20

-Increased
SVR
CO
MAP

-Aortic and Carotid bodies

Question 21

What is the Diving Reflex? Where are the receptors for this reflex located?

Answer 21

• Cold water on face activates thermoreceptors, decreases HR and peripheral vasoconstriction causes reduced O2 consumption by the body and myocardium
• Facial thermoreceptors

Question 22

Vasopressin is released from which part of the brain? What are the effects of vasopressin on blood pressure? What are the effects of vasopressin on the kidney?

Answer 22

• Pituitary
• Increases BP
• Renal Fluid Reabsorption= increases blood volume

Question 23

What is the stimulus for release of Atrial Natriuretic Peptide? What are the effects of ANP on blood pressure? Blood volume?

Answer 23

Atrial Distension
Sympathetic Stimulation
Angiotensin II
Endothelin

decreases BP by decreasing blood volume

Question 24

What converts angiotensinogen to angiotensin I?

Answer 24

Renin

Question 25

What converts angiotensin I to angiotensin II?

Answer 25

Angiotensin-converting enzyme

Question 26

What effects does angiotensin II have on blood pressure? Blood volume? Adrenal cortex?

Answer 26

- Angiotensin II causes vasoconstriction which leads to increased arterial blood pressure. Angiotensin II and Aldosterone promote sodium and fluid retention which leads to increased blood volume - Angiotensin II stimulates the adrenal cortex to release Aldosterone

Question 27

What are the INDIRECT effects of hypoxia on the circulatory system? What are the DIRECT effects?

Answer 27

``` -Moderate Hypoxia (Indirect Effects) Sympathetic Nervous System Activation Increased HR Increased CO Increased Contractility ``` -Severe Hypoxia (Severe Effects) Depressed Myocardial Contractility

Question 28

What are the INDIRECT effects of hypercarbia on the circulatory system? What are the DIRECT effects?

Answer 28

Indirect- SNS activation, Increased HR, CO, Contractility Direct= Depressed Myocardial Contractility

Question 29

What is the "Fight or Flight" response?

Answer 29

Mass discharge of the Sympathetic Nervous System occurs during the “Alarm” or “Stress” response

Question 30

What are the 2 types of acetylcholine receptors?

Answer 30

Muscarinic (only parasympathetic) Nicotinic (both Para and sympathetic)

Question 31

What are the differences between the innervation of the heart by the parasympathetic and sympathetic nervous systems?

Answer 31

Parasympathetic: - negative effects on chrono/ino/dromotroy, resistance vessels - zero effect on capacitance vessels Sympathetic: - Positive effects on chrono/ino/dromotropy, and resistance and capacitance vessels

Question 32

Which cranial nerve carries parasympathetic nervous input to the heart?

Answer 32

Vagus Nerve

Question 33

What amino acid is the precursor for catecholamine synthesis?

Answer 33

tyrosine

Question 34

Binding of norepinephrine to which adrenergic receptor causes inhibition of neurotransmitter release?

Answer 34

alpha 2 receptors on nerver terminal

Question 35

In which part of the brainstem is the vasomotor center located?

Answer 35

in the medulla and in the lower third of the pons

Question 36

What is the neurotransmitter released at the junction between the pre-ganglionic and post-ganglionic sympathetic fibers? Between the post-ganglionic sympathetic fibers and the effector site? Between the pre-ganglionic sympathetic fibers and the adrenal medullae?

Answer 36

- Acetylcholine/nicotine - Norepi/Epi - Norepi/Epi

Question 37

Blood vessels (except for capillaries) have predominantly sympathetic or parasympathetic nervous system innervation?

Answer 37

Sympathetic (norepi via Alpha 1 receptors)

Question 38

relaxation - active, not passive process

Answer 38

lusitropy.

Question 39

Parasympathetic does what?

Answer 39

- Constricts Pupils - Contracts bladder - Constricts Bronchi - Stimulates saliva - Slows HR - Stimulates paristalsis - Stimulates bile release

Question 40

catecholemine order for catecholamine synthasis

Answer 40

``` tyrosine dopa dopamine secretory granules dopamine norepi epi ```