ANS

Question 1

Sympathetic nervous system outflow?

Answer 1

Thoraco-lumbar (T1-L3)

Question 2

Parasympathetic nervous system outflow?

Answer 2

Cranio-sacral (Midbrain, medulla, S2,3,4)

Question 3

Central control and itnegration between sympathetic and parasympathetic system occurs where?

Answer 3

Hypothalamus

Question 4

Fibres of the sympathetic nervous system?

Answer 4

Short pre-ganglionic fibres arise from lateral horn of spinal cord
Ascend/descend 1/2 segments
Emerge along with posterior segmental roots
Synapse in ganglia of sympathetic chain alongside spine
Give rise to long post-ganglionic neurons

Question 5

What is “special” about the sympathetic nervous system?

Answer 5

The adrenal medulla
Specialised sympathetic ganglion
Instead of of post-ganglionic fibres, there are secretory cells
Noradrenaline, adrenaline and dopamine (central catechloamines)

Question 6

Parasympathetic nerve fibres?

Answer 6

Cranial nerves III, VII, IX, X (3, 7, 9, 10)
Long pre-ganglionic fibres
Parasympathetic ganglia close to effector organs

Question 7

Alpha and beta receptor function?

Answer 7

Alpha-1: vasoconstriction
(Alpha-2: brain vasodilation)
Beta-1: heart (increases HR)
Beta-2: bronchodilation
(Beta-3: brown fat thermorefulation)

Question 8

Sympathetic vs parasympathic function?

Answer 8

Sympathetic: “fight or flight” response, and important for stress responses and bodily defensive mechanisms

Parasympathetic: “rest and digest”

Question 9

Neurotransmitters in the autonomic nervous system?

Answer 9

ACh

Noradrenaline