block 2- 3. Autonomic Nervous system

this may be a little dodgy just copied from chat gpt

Q: What does the Peripheral Nervous System (PNS) encompass?

A: All neural structures and nerves outside the CNS; it connects the CNS to limbs and organs.

Q: What are the two main functional divisions of the PNS?

A: Somatic Nervous System (SNS) and Autonomic Nervous System (ANS). (Diagram on slide 3)

Q: What does the Somatic Nervous System control?

A: Voluntary skeletal muscle movements and sensory input from external senses. (Diagram on slide 3)

Q: What does the Autonomic Nervous System regulate?

A: Involuntary, automatic functions such as heart rate, digestion and breathing. (Diagram on slide 3)

Q: What are the three parts of the ANS?

A: Sympathetic, parasympathetic and enteric nervous systems. (Diagram on slide 3)

Q: What are the main functions of the three ANS divisions?

A: Sympathetic: fight or flight. Parasympathetic: rest and digest. Enteric: gastrointestinal function and movement. (Diagram on slide 3)

Q: How does the ANS help maintain homeostasis?

A: It mediates internal homeostasis without conscious intervention or voluntary control.

Q: How do sympathetic and parasympathetic nerves commonly affect organs?

A: They often have opposing effects, allowing fine balance and optimum organ function.

Q: Name some processes involving the ANS.

A: Breathing rate, digestion, urination, sexual arousal and sweating. Sympathetic: fight or flight. Parasympathetic: rest and digest.

Q: How many vertebral bones are listed, and how are they divided?

A: 33: 7 cervical, 12 thoracic, 5 lumbar, 5 sacral and 4 coccygeal. (Diagram on slide 5)

Q: How many pairs of spinal nerves are there?

A: 31 pairs: 8 cervical, 12 thoracic, 5 lumbar, 5 sacral and 1 coccygeal. (Diagram on slide 5)

Q: What are the two neurotransmitters used in the ANS?

A: Acetylcholine (ACh) and noradrenaline (NA). (Diagram on slide 7)

Q: Which receptors does ACh act on in the ANS?

A: Nicotinic receptors at ganglia and muscarinic receptors at target organs. (Diagram on slide 7)

Q: Which receptors does NA act on?

A: α and β adrenoceptors in target organs. (Diagram on slide 7)

Q: What neurons make up each ANS division?

A: A preganglionic neuron and a postganglionic neuron. (Diagram on slide 7)

Q: Compare the lengths of parasympathetic and sympathetic neurons.

A: Parasympathetic: long preganglionic, short postganglionic. Sympathetic: short preganglionic, long postganglionic. (Diagram on slide 7)

Q: What is another name for parasympathetic outflow?

A: Craniosacral outflow. (Diagram on slide 8)

Q: What is the general effect of the parasympathetic system?

A: It tends to slow down processes, except digestion, food absorption and genitourinary functions.

Q: Where are parasympathetic preganglionic cell bodies located?

A: In nuclei in the brain stem and in the sacral spinal cord. (Diagram on slide 8)

Q: Which cranial nerve carries major parasympathetic outflow?

A: The vagus nerve. (Diagram on slide 8)

Q: What does parasympathetic stimulation do to the pupil and salivary glands?

A: Constricts the pupil for near vision and increases salivary production.

Q: What are the parasympathetic effects on the heart and lungs?

A: Slows heart rate and causes bronchoconstriction.

Q: What are the parasympathetic effects on the stomach?

A: Increases gastric juice secretion and peristalsis.

Q: What are the parasympathetic effects on the bladder?

A: Contracts the bladder muscle and relaxes the sphincters.

Q: What is the parasympathetic effect on male sexual function?

A: Erection.

Q: Which cranial nerves carry parasympathetic outflow?

A: Cranial nerves III, VII, IX and X. (Diagram on slide 9)

Q: Where are the cell bodies for sacral parasympathetic outflow?

A: In the lateral grey matter of the sacral spinal cord. (Diagram on slide 9)

Q: Where do parasympathetic preganglionic neurons synapse?

A: In terminal ganglia near the effector. (Diagram on slide 9)

Q: How many postsynaptic neurons does a parasympathetic presynaptic neuron usually contact?

A: Only 4 or 5, allowing responses to be localised to a single effector. (Diagram on slide 9)

Q: What is another name for the sympathetic system?

A: Thoracolumbar outflow.

Q: What is the general function of the sympathetic system?

A: Prepares the body to deal with stress or excitement.

Q: What are the sympathetic effects on the pupil and salivary glands?

A: Dilates the pupil for far vision and decreases salivary production.

Q: What are the sympathetic effects on the heart and lungs?

A: Accelerates heart rate and force; causes bronchodilation.

Q: What is the sympathetic effect on liver glycogen?

A: Converts glycogen to glucose.

Q: What are the sympathetic effects on the stomach and intestines?

A: Reduces peristalsis and intestinal activity, closes sphincters and causes vasoconstriction.

Q: What are the sympathetic effects on the bladder?

A: Relaxes the bladder muscle and closes the sphincters.

Q: Where are sympathetic preganglionic cell bodies located?

A: In the lateral horns of the grey matter in the 12 thoracic and first 2–3 lumbar spinal segments. (Diagram on slide 11)

Q: What happens at sympathetic ganglia?

A: Preganglionic and postganglionic neurons synapse. (Diagram on slide 11)

Q: What are the two types of sympathetic ganglia?

A: Trunk (vertebral chain/paravertebral) ganglia and prevertebral ganglia. (Diagram on slide 11)

Q: Which five prevertebral ganglia are listed?

A: Celiac, superior mesenteric, inferior mesenteric, aorticorenal and renal ganglia. (Diagram on slide 11)

Q: How many postganglionic neurons can one sympathetic preganglionic fibre synapse with?

A: 20 or more, due to its many axon collaterals. (Diagram on slide 11)

Q: How many neurons can the enteric nervous system contain?

A: Up to 500 million neurons associated with the gastrointestinal tract.

Q: Where is the enteric nervous system located?

A: In the GI wall and the walls of accessory organs, including the pancreas and gallbladder. (Diagram on slide 12)

Q: How does the enteric nervous system operate?

A: More or less independently, using its own reflex rules.

Q: Why is the enteric nervous system classified as a separate ANS component?

A: Many GI functions, such as peristalsis, continue without sympathetic or parasympathetic supervision.

Q: What are the two main enteric plexuses and their functions?

A: Submucosal (Meissner's): secretion. Myenteric (Auerbach's): motor activity, e.g. peristalsis. (Diagram on slide 13)

Q: What are the three functional neuron groups in the enteric system?

A: Sensory neurons, local circuit neurons and motor neurons. (Diagram on slide 13)

Q: What do enteric sensory neurons monitor?

A: Mechanical and chemical conditions in the gut. (Diagram on slide 13)

Q: What do enteric motor neurons influence?

A: Gut smooth muscle activity and glandular secretions, including digestive enzymes, mucus, stomach acid and bile.

Q: How far do the enteric plexuses extend?

A: Along the entire gastrointestinal tract, from oesophagus to anus. (Diagram on slide 14)

Q: What receptor type is shown in mouse ileum?

A: α1-adrenoceptors, visualised using fluorescent prazosin. (Image on slide 15)

Q: What are interstitial cells of Cajal (ICCs) shown adjacent to?

A: Myenteric plexuses. (Image on slide 16)

Q: Which agonist is shown activating ICCs?

A: Carbachol, a muscarinic and nicotinic agonist. (Image on slide 16)

Q: What type of agonist is Oxo-M?

A: A non-selective muscarinic agonist. (Diagram on slide 16, if included)

Q: What type of antagonist is AF-DX 116?

A: A reversible, selective M2 antagonist. (Diagram on slide 16, if included)

Q: Which receptor is shown using a green antibody stain?

A: The 5-HT3 receptor. (Image on slide 17)

Q: Do all sympathetic postganglionic fibres release noradrenaline?

A: No. Some release acetylcholine (ACh).

Q: Which transmitter do sympathetic fibres to eccrine sweat glands release?

A: ACh, acting on muscarinic receptors to stimulate sweating.

Q: What do certain sympathetic vasodilator fibres release in some animals?

A: ACh, which dilates skeletal muscle blood vessels during active exercise.

Q: What do all sympathetic preganglionic fibres release?

A: ACh; they are cholinergic and communicate with postganglionic neurons or adrenal medulla chromaffin cells. (Diagram on slide 18, if included)

Q: What is hexamethonium?

A: A ganglion blocker.

Q: What does hexamethonium block?

A: All ANS nicotinic ganglion receptors. (Diagram on slide 19, if included)

Q: What causes autoimmune autonomic gangliopathy (AAG)?

A: Autoantibodies targeting ganglionic acetylcholine receptors (gAChR), disrupting ANS transmission.

Q: What are the symptoms of AAG?

A: GI and urinary problems, anhidrosis, dry eyes and mouth, abnormal pupil responses and orthostatic hypotension.

Q: How may AAG be treated?

A: Plasma exchange, IVIG or immunosuppressants; symptom management with fluids, salt, compression stockings and BP medicines.

Q: What are possible sites of drug action in the ANS?

A: Neurotransmitter synthesis, breakdown, storage, reuptake, pre- or postsynaptic receptors, and ANS ganglia. (Diagram on slide 21, if included)

Q: Which examples of drugs or drug classes are given for ANS targets?

A: MAO inhibitors: breakdown; reserpine: storage; cocaine: reuptake; muscarinic or adrenergic blockers: receptors; hexamethonium: ganglia.

Q: What is the main question posed by the final eye image?

A: What has happened to her left eye? (Image on slide 22)

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