Autonomic Nervous system

Question 1

Autonomic Nervous system

Answer 1

Automatic reflex, two antagonist branches
-control of cardiac and smooth muscle and glands in homeostasis

Sympathetic: fight or flight, adrenalin rush. Increased BP and HR, adrenalin released

Parasympathetic: rest and digest, slower hr and lower bp

Balance between two at all time

Question 2

The Hypothalamus, Pons, and Medulla

Answer 2

Hypothalamus: Hormones
Pons: breathing
Medulla: HR and breathing

Coordination of homeostatic responses
-Autonomic
-Endocrine
-Behavioural

Question 3

Autonomic Branches

Answer 3

Sympathetic neurons:
Short pre-ganglionic neurons
Long post-gangionic neurons
Ach at ganglion, Epinephrin at Effector organ

Parasympathetic neurons
Long pre-ganglionic neurons
Short post-ganglionic neurons
Ach at ganglion and effector organ

Question 4

Cholinergic Receptors

Answer 4

Bind Acetylcholine
Nicotinic receptors found at the
-Sympathetic Ganglia
-Parasympathetic Ganglia
-Neuromuscular junction (skeletal muscle)
Muscarinic Receptors found at the
-Parasympathetic effector organs

Question 5

Adrenergenic Receptors (Alpha)

Answer 5

Alpha 1 (epi and norepi)
-Vasoconstricts blood vessels – heart, muscle, gut, kidneys, skin
-Increased sweat gland secretion/goose bumps
-Dilates pupils
-Propels urine

Alpha 2 (epi and norepi)
-Inhibits insulin release / constricts gut sphincters
-Decreases norepinephrine release

Question 6

Adrenergenic Receptors (Beta), exercise

Answer 6

Beta 1 (epi and norepi)
Increases heart rate and contractility
Increased renin from kidney

Beta 2 (only epi)
Vasodilates blood vessels – muscle, heart
Bronchodilation
Relaxes gut wall and uterus

Beta 3
Lipolysis – fat tissue
Relaxes bladder

Question 7

Somatic vs Autonomic

Answer 7

Somatic:
1. Consists of a single neuron between CNS and skeletal muscle cells
2. Innervates only skeletal muscle
3. Only excitation

Autonomic:
1. Two-neuron chain (connected by a synapse) between CNS and effector organ
2. Innervates smooth and cardiac muscle, glands and GI neurons
2. Inhibitory vs Excitatory

Question 8

Sympathetic vs Parasympathetic locations

Answer 8

Sympathetic: Thoracic and
lumbar regions

Parasympathetic: Cranio-sacral

Question 9

Sympathetic effects

Answer 9

↑ heart rate and contractility
↑ breathing rate and depth
Blood vessel effects
Vasoconstriction to non-essentials (eg. Gut)
vasodilation to muscle
↓ Gut activity and secretions
↓ kidney function and urine output
Pupil dilation

Question 10

Parasympathetic effects

Answer 10

↓ heart rate and contractility
↓ breathing rate and depth
NO EFFECT ON BLOOD VESSELS
↑ Gut activity and secretions
↑ kidney function and urine output
Pupil constriction