Autonomic Nervous System (ch14

Question 1

Autonomic Nervous System

Answer 1

• it branches out into 2:
• Sympathetic nervous system
  – fight or flight
• Parasympathetic nervous system
  – rest and digest

Question 2

Somatic vs Autonomic

Answer 2

• Somatic motor division
• 2 neurons
• Skeletal muscle
• voluntary
• Autonomic motor division
• 2 neurons
• smooth muscle cells
• cardiac muscle cells
• glands
• involuntary actions

Question 3

The types of Neurotransmitters & Receptors?

Answer 3

• Preganglionic –> Targets Postganglionic neuron. acetylcholine= “ACh for Action” - important for muscle action.
• Postsynaptic → target cells = norepinephrine (80%), epinephrine or ACh
  –Receptors for norepinephrine & epinephrine =
  adrenergic (Adrenergic activate the sympathetic)
• Receptors for ACh =cholinergic (cholinergic activate the parasympathetic)
• Medications often work at receptors – either
  blocking (antagonist) or mimicking/ increasing
  (agonist)

Question 4

Androgenic Receptors?

Answer 4

• Alpha-1 Receptors
• Alpha-2 Receptors
• Beta-1 Receptors
• Beta-2 Receptors
• Beta-3 Receptors

Question 5

Alpha-1 Receptors:

Answer 5

• Location: Plasma membranes of smooth muscle cells in various organs.
• Effects: Pupil dilation, vasoconstriction in skin and digestion.
• Neurotransmitter: NE (Norepinephrine)
  Cue:
  “Alpha-1 starts with A, just like Arrector Pili muscles and arteries.”

Question 6

Alpha-2 Receptors

Answer 6

• Location: Plasma membranes of preganglionic sympathetic neurons.
• Effects: Inhibits preganglionic sympathetic neurons.
• Neurotransmitter: NE (Norepinephrine)
  Cue:
  “Alpha-2 inhibits, just like its location in preganglionic neurons.”

Question 7

Beta-1 Receptors

Answer 7

Location: Plasma membranes of cardiac muscle cells, certain kidney cells, and adipose cells.
- Effects: Increases force and rate of cardiac contractions.
- Neurotransmitter: NE (Norepinephrine)
Cue:
“Beta-1 boosts the heart rate, like the number 1 in Beta-1.

Question 8

Beta-2 Receptors

Answer 8

• Location: Plasma membranes of smooth muscle cells in bronchioles, urinary bladder, skeletal muscles, liver, pancreas, and salivary glands.
• Effects: Dilates bronchioles, vasodilation to skeletal muscles, decreases digestive secretion, increases glucose release.
• Neurotransmitter: NE (Norepinephrine)
  Cue:
  “Beta-2 breathes easily with bronchioles and boosts blood flow to muscles.”

Question 9

Beta-3 Receptors

Answer 9

• Location: Primarily in adipose cells and smooth muscle cells in the digestive tract.
• Effects: Relaxation of digestive tract, contraction of sphincters.
• Neurotransmitter: NE (Norepinephrine)
  Cue:
  “Beta-3 bends the belly and boosts sphincter strength.”

Question 10

Cholinergic Receptors?

Answer 10

• Muscarinic Receptors: binds muscarine, Sweat glands in the skin.
• Increased secretion of sweat glands.
• Nicotinic Receptors: Membranes of postganglionic neurons in sympathetic ganglia and adrenal medullae. Binds nicotine.
• Effect: Stimulates the release of neurotransmitters, including NE and
  E.
  –> Both respond to the neurotransmitter Acetylcholine ACh.

Question 11

Sympathetic Nervous System (SNS) Effects on Target Cells?

Answer 11

CSSCA
1) Cardiac Muscle Cells:
- Effect: Raises rate and force of contraction.
- Outcome: Increased blood delivery, higher blood pressure during physical activity.
2) Smooth Muscle Cells: it does a lot dilation, constriction, relaxation, contraction of blood vessels, muscles etc
3) Cellular Metabolic Rate:
NE Effects:
> Beta-3 receptors on adipocytes: Triggers lipid breakdown.
> Beta-2 receptors on liver cells: Releases glucose from glycogen.
> Beta-2 receptors on pancreas cells: Triggers glucagon release, raising blood glucose.
- Increased ATP requirements
4) Sweat glands
- Maintenance of body temperature.
- Mechanism: ACh release onto sweat gland cells via postganglionic sympathetic neurons.
5) Adrenal Medulla.
- ACh release onto adrenal medulla cells.
- Outcome: Stimulation of norepinephrine and epinephrine release as hormones into the bloodstream.

Question 12

Where does the Parasympathetic Nervous System arise from?

Answer 12

Arises from cranial nerves (especially the vagus nerve, CN X) and sacral spinal nerves (S2-S4).

Question 13

Parasympathetic Neurotransmitters and Receptors?

Answer 13

Preganglionic & postganglionic = Ach
* ALL postganglionic parasympathetic neurons = Nicotinic
* Parasympathetic target cells = Muscarinic