ICPP S9 The Autonomic Nervous System Flashcards
Where do parasympathetic nerves originate?
What can be said about their post/pre-ganglionics?
What can be said about their ganglia?
Originate in the lateral horn of the medullary/ brainstem and spinal cord segments S2-S4.
Long myelinated pre-ganglionics and short unmyelinated post ganglionics.
Ganglia located near/ within the innervated tissues.
Where so sympathetic nerves originate?
What can be said about their pre/post-ganglionics?
What can be said about their ganglia?
Originate in the intermediolateral cell column, of the lateral horn through spinal cord segments T1-L2.
Pre ganglionics are short and myelinated and post ganglionics are long and non-myelinated.
Ganglia are either in the paravertebral ganglia or prevertebral ganglia.
All pre-ganglionic neurones are ________.
Release ___ that acts on post-ganglionic ________.
nAChRs are ________-________.
cholinergic
ACh
nAChRs
Ligand gated
What can be said about the NT at post-ganglionics of the PSNS?
What type of receptor is activated?
Cholinergic
mAChRs.
What can be said about the NT’s pf the post-ganglionics of the SNS?
What type of receptor do they interact with?
Mainly nor-adrenergic
Alpha and beta adrenoceptors.
What are some exceptions to the sympathetic post-ganglionics NTs, where are these exceptions made?
What do they activate?
Post-ganglionics innervate gets sweat glands and hair follicles (piloerection) are cholinergic - activate mAChRs?
Post-ganglionics that innervate that terminate in the kidney release dopamine on D1 receptors.
In the adrenal medulla the post-ganglionics are chromaffin cells.
What some NANCs?
ATP - purinoceptors - purinergics.
5-HT - serotonin
NO - blood pressure regulation
Neuropeptides - vasoactive intestinal peptide, substance P.
What does activation of M1 mAChRs lead to?
Secretion from salivary glands
Secretion from stomach
What does activation of M2 muscarinic s lead to?
SA node - bradycardia
Reduced atrial contractile force
AV node - reduced conduction velocity of AV node.
What does activation of M3 mAChRs lead to?
Smooth muscle contraction
Bronchoconstriction
Increased endocrine and exocrine secretions from salivary glands and stomach
Eye accommodation
- ciliary contraction and iris sphincter contraction.
What does NO generation lead to?
Vasodilation
Penile erection via vasodilation
What does B1 activation cause?
Ventricles - +ve inotropy
SA node - +ve chronotropy
AV node - +ve dromotropy - increased cardiac conduction velocity
Increased amylase secretion
What does B2 activation cause?
Smooth muscle relaxation - bronchodilation.
What does B3 activation cause?
Lipolysis
Relaxation of detrusor muscle in the bladder.
What does alpha 1 activation cause?
Smooth muscle contraction
Vasoconstriction in skin, mucosa and abdominal viscera.
Sphincter contraction of the GI tract and urinary bladder.
What does alpha 2 activation cause?
Relaxation and contraction of smooth muscle
Norepinephrine inhibition
Platelet activation.
What doe sensory neurones monitor?
CO2 levels O2 levels Nutrients levels Arterial levels GI tract content and chemical composition
What do the chemoreceptors in the carotid body sense?
Via what nerve is this information relayed to the CNS?
CO2, O2 and pH.
Glossopharyngeal nerve
What is the nucleus tractus solitarius?
What is its role?
Where is it found?
Where else does it receive input from, what does this region sense and cause?
Where primary sensory neurones project to secondary sensory neurones.
Integrates all visceral afferent information.
Medulla oblongata
Area postema - detects toxins in the CSF and blood.
Essential for chemically induced vomiting and conditional taste aversion.
What is dysautonomia?
What 2 broad ways may dysautonomia occur?
Umbrella term for malfunctions of the ANS
Primary disorder or as a result of secondary condition for example Parkinson’s and diabetes.
Name 3 example of dysautonomia - briefly describe them.
Neruocardiogenic syncope
- Syncope is a loss of consciousness due to fall in blood pressure
- Loss of consciousness asa result of certain triggers ie sight of blood and emotional distress.
Multiple system atrophy
- degenerative neurological disorder caused by degeneration of neurones in the brain - fatal
- affects involuntary functions - blood pressure, breathing, bladder function and muscle control
POTS
- Lying to standing causes large heart rate increase
