ANS (Autonomic Nervous System) Lecture

Question 1

ANS Subdivisions

Answer 1

1. Parasympathetic
2. Sympathetic

– ANS is INVOLUNTARY

Question 2

Parasympathetic (Subdivision)
- characteristic

Answer 2

“rest and digest system”
- involved with normal homeostasis

Question 3

Sympathetic (subdivision)
- characteristic

Answer 3

“flight or fight”
- involved with stress either emotional or physical stress (4-5 mile run)

Question 4

Dual Innervation

Answer 4

Heart is influenced by both parasympathetic and sympathic

Question 5

Parasympathetic (Anatomical)

Answer 5

“craniosacral division”
- vagus nerve (cranial nerve)
– length of neurons
(long PREgang. neurons + short POSTgang.)
– location of ganglia
(terminal ganglia; right on the organ, end of synapse)
- minimal branching caused by NO mass activation

Question 6

Sympathetic (Anatomical)

Answer 6

“thoracolumbar division”
- thoracic and lumbar area
– length of neurons
(short PREgang. neurons + long POSTgang.)
– location of ganglia
(sympathetic trunk ganglia; alongside the vertebral column)
- extensive branching or “diveregence” caused by mass activation (many organs effected)

Question 7

Parasympathetic (Functions)

Answer 7

• Postgang. secrete Ach

Question 8

Sympathetic (Functions)

Answer 8

• Postgang. N secrete NE (norepinephrine)
  ^ those secreting to the Sweat Glands secrete ACH
• Postgang. N stimulate adrenal glands = secretion of adrenaline

Question 9

Adrenaline is what?

Answer 9

A hormone that is secreted into the blood, it will then travel throughout the body. Which enhances and prolongs the sympathetic nervous effects

Question 10

Constriction vs Dilation

Answer 10

• Constriction means decrease of material flow by closing a passageway
• Dilation means an opening/widening a passageway to increase material flow

Question 11

Effects of the parasympathetic

Answer 11

• pupils constrict
• decreased heart rate (normal 60-80 bpm)
• no effect on adrenaline secretion
• bronchoconstriction
• little effect on blood vessels
• increases peristalsis in the GI tract
• increase glucose uptake
• NO effect on metabolic rate, blood coagulation, lipolysis

Question 12

Effects of the sympathetic

Answer 12

• under stress = dilation of the pupil
• increased H.R (~240 bpm)
• secretion of adrenaline = prolong/enhance the effect
• bronchodilation
• constriction of B.V (abdomen and skin)
• dilate B.V to the skeletal muscles = preservation
• slow peristalsis
• increased blood glucose
• increased coagulation of blood
• increased metabolic rate
• increased lipolysis (fat breakdown)
• decreased urine output
• stimulate sweat glands

Question 13

Why do we have opposing effects (dilation, inhibit)

Answer 13

Because of different receptor types
- Beta 1 on heart and adipose (NE + Beta 1 = stimulatory)
- Beta 2 Receptor on the Bronchiole = inhibitory of bronchiole dilation

Question 14

Receptor Types

Answer 14

1. Cholinergic: responds to ACH
2. Adrenergic: respond to NE

Question 15

Cholinergic Receptors
- subtype

Answer 15

1. Nicotinic Receptor: respond to nicotine and ACH
   - found on ALL postgang. N and the adrenal medulla
   - effect: excitatory (ex. cigs = increased nicotine in blood which stimulates the adrenal medulla = increased epinephrine overall increases H.R [ constriction of B.V + increased B.P / Metabolism
2. Muscarinic Receptor: targets all parasympathetic organs, for most it causes excitation
   - found in the intestines = stimulates peristalsis
   - inhibits cardiac muscle (decreased H.R)

Question 16

Adrenergic Receptors
- subtype

Answer 16

1. Beta 1 Receptors: On the Heart = increases heart rate when stimulates
   - tend to be excitatory
2. Beta 2 Receptors: Found in the Lungs, most are on sympathetic organs
   - tend to be inhibitory = bronchodilation, slows peristalsis,
3. Alpha 1 Receptor: most sympathetic organs
   - constrict B.V = increase B.P
   - found in the pupil

Question 17

Effects of Drugs on the ANS

Answer 17

1. Sympathomimetics: target adrenergic receptors which increase the release of NE
   - Albuterol drug to treat asthma; dilates bronchioles + targets B2
   - Phenylephrine; acts as a nasal decongestant
   - binds to A1 receptors which thins out the secretion
2. Sympatholytic; target adrenergic receptor that will block them (disabling)
   - Propranolol; beta blockers causing dilation of blood vessels. To treat hypertension
3. Nicotinic Agents
   - Nicotine; stimulates the sympathetic NS causes increase in BP

Question 18

What is it that controls the ANS

Answer 18

1. Hypothalamus: peristalsis, body temp, water balance
2. Medulla Oblongata: HR, vasomotor center, resp. center
3. Limbic System: emotional response

Question 19

ANS Disorders

Answer 19

1. Hypertension “high BP”: BP is 140 over 90 OR greater, result from an overactive symp. NS could be stress
   - damage to the heart and vessels
   - beta blockers used as a treatment
2. Raynauds Disease: causes excessive vasoconstriction of the fingers or toes
   - due to exposure to cold temps or emotional stress
3. Autonomic Dysreflexia: uncontrolled activation of the ANS
   - due to quadriplegia occurring within the first year of injury
   - causes increased BP 300 over 220

Question 20

Epi-Pen

Answer 20

a syringe containing epinephrine
- used for severe allergies or bad asthma
- allergy has been activated they can either get bronchoconstriction (decreases O2) OR vasodilation ( decreases BP + BV)

• when injection has occurred to will cause brochodilation and vasoconstriction; reversing the above to save their life