The Autonomic Nervous System Flashcards
What does the autonomic nervous system control?
Involuntary movements
How may the autonomic nervous system be divided?
The sympathetic and parasympathetic nervous system
Which regions of the spinal column are associated with the sympathetic nervous system?
The thoracic and lumbar regions
Which branch of the autonomic nervous system is the vagus nerve generally associated with? Which organs does this influence?
The vagus nerve is generally associated with the parasympathetic branch of the autonomic nervous system - it deals with parasympathetic control of the heart, lungs, and digestive tract
From which specific part of the spinal cord does the vagus nerve stem?
The 10th cranial nerve
What specific region of the spinal cord is associated with the parasympathetic nervous system?
The medullary portion
How do the pre-ganglionic and post-ganglionic structures differ in the sympathetic and parasympathetic branches of the autonomic nervous system?
In the parasympathetic branch the pre-ganglionic nerve is fairly long and stems deep into the peripheral nervous system, while its post-ganglionic nerve is far shorter - conversely, in the sympathetic branch the pre-ganglionic nerve is short and stems only slightly into the peripheral nervous system, while its post-ganglionic nerve stems the majority of the peripheral nervous system
Where specifically are the ganglia of sympathetic and parasympathetic nerves located?
Parasympathetic ganglia are located in innervated tissues, while sympathetic ganglia are located in the paravertebral chain close to the spinal chord
Describe the myelination of pre- and post-ganglionic nerves in sympathetic and parasympathetic systems.
Both sympathetic and parasympathetic pre-ganglionic nerves are myelinated, while both sympathies and parasympathetic post-ganglionic nerves are unmyelinated
What neurotransmitter do pre-ganglionic nerves use? Is this the same in sympathetic and parasympathetic nerves?
Acetylcholine is the neurotransmitter used in pre-ganglionic nerves of both sympathetic and parasympathetic nervous systems
What receptors are situated on the post-ganglionic nerves?
Nicotinic acetylcholine receptors
What type of receptor are nicotinic acetylcholine receptors?
Ligand-gated ion channels
What type of receptor are adreno-receptors and muscarininc acetylcholine receptors?
They are all G protein-coupled receptors
What neurotransmitter do post-ganglionic nerves of parasympathetic and sympathetic nerve branches release?
Post-ganglionic nerves release acetylcholine in the parasympathetic branch, while they release noradrenaline in the sympathetic branch
What receptors are found on target tissues of sympathetic and parasympathetic nerves?
Muscarininc acetylcholine receptors are found on target tissues of parasympathetic nerves (as their post-ganglionic nerves are cholinergic) and adrenoreceptors are found on target tissues of sympathetic nerves (as their post-ganglionic nerves are noradrenergic)
How does a ligand activate a G protein-coupled receptor?
It binds and causes an allosteric change, causing the G protein to release GDP and bind GTP, activating it
In which cases do sympathetic nerve fibres release acetylcholine onto their target tissue as opposed to noradrenalin?
Those innervation sweat glands and hair follicles
Where in the body do chromaffin cells reside?
In the adrenal medulla
What branch of the nervous system controls voluntary movement (opposite to the autonomic nervous system)?
The somatic nervous system
How does the sympathetic nervous system act differently at the adrenal medulla?
The post-ganglionic fibres differentiate of form chromaffin cells - instead of secreting neurotransmitter onto a target tissue, they secrete adrenalin into the bloodstream to act on a wide variety of target organs
Does the somatic branch of the nervous us have pre- and post-ganglionic nerve fibres?
No
In the somatic nervous system, list the neurotransmitter used, the type of receptor it acts on, and on which tissue these receptors are located.
In the somatic nervous system acetylcholine is used, which binds nicotinic acetylcholine receptors on the surface of skeletal muscle
Which muscarininc receptor is located at the heart? Which muscarininc receptor is located at the lungs?
M2 muscarininc acetylcholine receptors are located at the heart, while M3 muscarininc acetlycholine receptors are located at the lungs
Which gas is involved with penile erection?
Nitric oxide
What is the collective term used to describe disorders of the autonomic nervous system?
Dysautonomia