Autonomic Control

Question 1

Medulla Oblongata

Answer 1

CVD and respiratory control centers

Question 2

Effector Organs

Answer 2

Cardiac Muscle
Smooth Muscle
Glands
Adipose Tissue

Question 3

Sympathetic Division

Answer 3

Releases norepinephrine (NE)- from post ganglionic cells
Excites an effector organ
After stimulation NE is removed from synpase or inactivated

Question 4

Parasympathetic Division

Answer 4

Releases Acetylcholine (ACH)
Inhibits effector organ
After release, ACh is degraded by acetylcholinesterase

Question 5

Cholinergic Receptors: Nicotinic Cholinergic Receptors

Answer 5

• Activated by nicotine
• Found on postganglionic cells in all autonomic ganglia
• Respond to release of ACH from both sympathetic and parasympathetic preganglionic fibers
• Channel opening results in depolarization
• Effect depends on target cell
• Two subtypes (N1 & N2)

Question 6

Cholinergic Receptors: Muscarinic Cholinergic Receptors

Answer 6

Activated by mushroom poison, muscarine
◦ Found on effector cell membranes (smooth muscle, cardiac muscle and glands)
◦ Bind ACH released by parasympathetic postganglionic fibres
◦ 5 subtypes (M1-M5)

Question 7

Atrophine

Answer 7

• Blocks effect of ACH at muscarinic receptors
• Does not affect nicotinic receptors
• So affects parasympathetic system but not sympathetic —Suppress salivary and bronchial secretions before/during surgery

Question 8

a1 receptors

Answer 8

Excitatory response (Arteriolar constriction)

Question 9

a2 receptors

Answer 9

Inhibitory response in effector organ

Eg. Decreased smooth muscle contraction in digestive tract

Question 10

Properties of b1 adrenergic receptors

Answer 10

◦ Located in cardiac muscle and kidneys
◦ Usually excitatory
◦ Equal affinity for norepinephrine and epinephrine

Question 11

Properties of b2 adrenergic receptors

Answer 11

◦ Located in some blood vessels and smooth muscle
◦ Usually inhibitory
◦ Greater affinity for epinephrine than norepinephrine

Question 12

Salbutamol

Answer 12

Bronchodilator
Acts through b2 receptor activation
Acts to relax smooth muscle of the airways
Allows dilation of the airways without undesirably stimulating the heart (it contains mostly b1 receptors)

Question 13

Only blood vessels that receive that receive both para and symp innverations

Answer 13

Privates (Pen + C) :P

Question 14

Parasympathetic Activity

Answer 14

◦ Quiet, relaxed states
◦ Active in “rest and digest” or “breed and feed” ◦ Increases gastrointestinal activities
◦ Decreases heart rate and blood pressure

Question 15

Sympathetic activity

Answer 15

◦ Fight-or-flight response
◦ Prepares for emergency, stress, and exercise
◦ Increases heart rate and blood pressure
◦ Mobilizes energy stores
◦ Dilates pupils
◦ Decreases gastrointestinal and urinary functions

Question 16

Changes in nerve activity: Symp

Answer 16

Epi and Norepi
Increase funny channel (Na+) permeability
Increase Ca inward current

Question 17

Changes in nerve activity: Parasymp

Answer 17

ACH
Increase in K outflow
Decrease in Na and Ca inward currents
Hyperpolarizes cell

Question 18

Heart Rate Variability

Answer 18

May be most indicative measure of high stress situations

Refers to variations in time between an individuals heartbeats

Time between beats is very consistent = low variability

High variation or inconsistency in time between heart beats= high variability

Question 19

Low HRV has been associated with

Answer 19

Asthma 
Diabetic neuropathy 
Anxiety disorders
PTSD
Congestive heart failure 
Concussion 
Cirrohsis of liver 
Sudden Cardiac Death 
Predictive of death after a heart attack

Question 20

High HRV

Answer 20

Cardiac conduction abnormalities (especially in elderly)

Question 21

Changes in HRV found with (5)

Answer 21

• Neural Injury
• Drugs that affect CNS
• Diseases/conditions that cause systemic inflammation
• Exercise
• Psychological stress/trauma

Question 22

Long term exposure to NE

Answer 22

Can cause myocardial B-adrenoreceptor down regulation, cardiac hypertrophy, ischemia, cardiac arrhythmia, tissue necrosis