Pharmacology and the Autonomic Nervous System

This image shows the different efferent nerve pathways. Label the red boxes with the neurotransmitter released from that particular synapse and label the green boxes with the receptors that receive them.

Preganglionic fibres always release acetylcholine at the synapse.

Nicotinic and muscarinic receptors respond to which neurotransmitter?

Which cholinergic receptor is a G-protein coupled receptor?

How many subtypes of muscarinic receptor are there?

Which muscarinic receptor subtype reduces the force of contraction in the cardiac atria?

Which muscarinic receptor subtype is involved in the activation of phospholipase C in smooth muscular and glandular tissue?

Which cholinergic receptors are non-selective cation channels?

How many subunits do nicotinic receptors have?

What is the correct composition of the nicotinic receptors in terms of subunits?

Which subunits does acetylcholine bind to on nicotinic receptors?

Why can we block muscle nicotinic receptors whilst not affecting ganglionic nicotinic receptors?

How many subtypes do alpha adrenergic receptors have?

The alpha adrenergic receptors have subtypes of subtypes i.e. a-1A, a-1B

Which alpha adrenergic receptor subtype stimulates phospholipase C to raise cellular Ca2+?

Which alpha receptor subtype activates Gi to inhibit adenylate cyclase and raise cellular cAMP levels?

Why are A2 adrenergic receptors often located presynaptically?

How many subtypes to the beta adrenergic receptors have?

All beta adrenergic receptor subtypes activate adenylate cyclase to increase cellular cAMP levels.

The B1 adrenergic receptor is the main subtype of what?

The B2 adrenergic receptor subtype is the main subtype of what?

The B3 adrenergic receptors are the main receptors of what?

What is NANC transmission?

When does NANC transmission often occur?

What is co-transmission?

Co-transmission allows different patterns of neurotransmitter release in response to different levels of stimulation.

NANC can occur in both ganglionic and post-ganglionic synapses.

The parasympathetic and sympathetic nervous system always act in opposition to one another.

What effect does the parasympathetic nervous system have on the heart?

Fill in the blanks below to describe the effects of the parasympathetic nervous system in the heart. The parasympathetic nervous system acts on the heart by postganglionic fibres in the [blank_start]vagus[blank_end] nerve. The parasympathetic nervous system inhibits the [blank_start]sinoatrial node[blank_end]. This reduces h[blank_start]eart rate[blank_end], reduces c[blank_start]ardiac output[blank_end] and reduces b[blank_start]lood pressure[blank_end]. The parasympathetic nervous system also reduces [blank_start]conduction velocity[blank_end] in the [blank_start]atrioventricular[blank_end] node.

Which nerves mediate parasympathetic activity on the blood vessels?

Why does the parasympathetic nervous system have little effect on total peripheral resistance?

The parasympathetic nervous system causes bronchioconstriction.

Which branch of the autonomic nervous system causes relaxation of intestinal sphincters?

The parasympathetic nervous system controls accommodation for near vision. 1. The parasympathetic nervous system causes [blank_start]contraction[blank_end] of the [blank_start]ciliary[blank_end] muscle. 2. This relaxes tension on the [blank_start]lens[blank_end]. 3. The lens [blank_start]thickens[blank_end]. 4. The [blank_start]focal distance[blank_end] shortens.

How does the parasympathetic nervous system affect the pupil?

What are the baroreceptors?

Where are the baroreceptors found? Check all that apply.

Where are pressure signals from the baroreceptors relayed back to?

Fill in the blanks to describe the baroreceptor reflex. 1. Blood pressure distends the arterial walls. 2. [blank_start]Baroreceptors[blank_end] in the c[blank_start]arotid sinuses[blank_end] and a[blank_start]ortic arch[blank_end] stimulated by tension. 3. Signals relayed to [blank_start]nucleus tractus solitarius[blank_end] in the [blank_start]brainstem[blank_end] which compares blood pressure to a set point. 4. The NTS increases [blank_start]parasympathetic[blank_end] drive to the heart and reduces [blank_start]sympathetic[blank_end] drive to the heart. This reduces h[blank_start]eart rate[blank_end] and reduces c[blank_start]ardiac output[blank_end]. The NTS also reduces arterial [blank_start]constriction[blank_end] to reduce total peripheral [blank_start]resistance[blank_end]. The NTS also reduces [blank_start]venous[blank_end] constriction to [blank_start]reduce[blank_end] cardiac output. 5. Blood pressure = c[blank_start]ardiac output[blank_end] x t[blank_start]otal peripheral resistance[blank_end], so blood pressure falls to a set point.

Which enzyme breaks down acetylcholine into choline and acetate to prevent too strong a stimulus?

How do we relate cholinergic transmission to pharmacology?

Fill in the blanks below to describe closed angle glaucoma. 1. Aqueous humour drains out of the eye via the canal of [blank_start]Shlemm[blank_end]. 2. In closed angle glaucoma, the angle between the i[blank_start]ris[blank_end] and the [blank_start]cornea[blank_end] becomes occluded, meaning drainage is [blank_start]inhibited[blank_end]. This causes pressure buildup in the eye. By administering an [blank_start]acetylcholinesterase[blank_end] inhibitor via eye drops, we can increase [blank_start]cholinergic[blank_end] transmission and [blank_start]contract[blank_end] the ciliary body in order to release tension and create a passage through which humour can drain.

How does botulinum toxin inhibit Ach release from the presynaptic neuron?

Why does the botulinum toxin reduce muscle contraction?

The autonomic nervous system directly affects peristalsis etc in the GI tract.