learning outcomes

Question 1

describe the anatomy of the sympathetic and parasympathetic systems?

Answer 1

sympathetic- nerves at thoracic and lumbar (L1-2,T1,2)
nerves either lie near spinal cord ( paravertebral) or in collateral (pre-vetebral). pre-ganglion usually enters synaptic trunk-makes synapse- long post-ganglion.
pre-ganglion is myelinated-white ramus
post ganglion is non-myelinated- grey-ramus.

Parasympathetic- nerves at spinal cord(4)and sacral (2)
pre-ganglion longer than post-ganglion. post-ganglion usually near target.

Question 2

describe the neurotransmitters, receptors and functional aspects of the autonomic nervous system?

Answer 2

sympathetic
pre-ganglion synapses Ach onto cholinergic nicotinic
post-ganglion synapses NA onto adrenergic alpha/beta receptor.
adrenal medulla does not have a post-synaptic ganglion so releases NA straight into the blood.

parasympathetic;
pre-ganglion releases Ach onto nicotinic cholinergic.
post-ganglion releases Ach onto muscarinic cholinergic.

Question 3

describe the effect of innervation on major organs?

Answer 3

1- single innervation with dual effect: blood vessels
2- dual innervation with antagonist action: heart rate, lungs, gut
3- dual innervation with complementary effects: blood vessels
4- singles innervation: strength of heart contraction.