The NS - ANS & Somatic (W5) Flashcards
What is the difference between CNS & PNS
the CNS is the brain and spinal cord, while the PNS is everything put the CNS i.e. all the nerves in the body
What is the
- afferent
- efferent divison
- Incoming stimuli
- sensory & visceral - Out going information towards muscles
Name a function of the ANS
- regulates activities of internal organs ( smooth muscle, cardiac muscle and glands)
- homeostasis
Where do the
- sympathetic
- parasympathetic nerves originate from
- thoracic nerves
- cranial and sacral nerves
What does each nerve conatin
preganglionic, ganglion and post ganaglionic neurons
What is the difference between pre and post ganglionic neurons
Pre - myelinated and travel its origin in the brain or spinal cord to a ganglion
Post - unmeylinated neuron begins in and travels from the ganglion to the smooth muscle or gland being innervated
Where are
- sympathetic
- parasympathetic
ganglia located and their length
- located close to CNS - short
- located close to target organ , if not embedded - lomng
What are the paravertbral ganglia
also called sympathetic trunk or chain aligned in a row on each side of the spinal cord
What re the prevertrebral ganglia
carry efferent information and are located anterior to the aorta and vertebral column
Explain the process of the release of ACh
- ACh is made form choline and acetyl CoA and placed into a synaptic vesicle
- AP arrives causing calcium channels to open releasing calcium into the vesicle
- The calcium moves the ACh vesicle to the plasma membrane where they bind and ACh is released via exocytosis
What is the role of acetylcholinesterase
- Synaptic cleft ACh is broken down rapidly by acetycholinerase
- Choline is transported back into the axon terminal and is used to make more ACh
What are the different kinds of cholinergic receptors
- Nicotinic
- Muscarinic
Describe Nicotinic receptors
- work in skeletal muscles
- ACh or nicotine binds they allow +ve ions to flow
What effect does an nicotinic receptor have
- overall +ve net flow
- ionotropic meaning ligand binding directly affects the permeability of the channel
Describe muscarinic receptors
- ACh or muscarine binds they relase G-proteins which begin a cascade of information
What effect does an muscarinic receptor have
- effect is metabotropic. meaning ligand binding alters the permeability of ion channels
- several types may be stimulatory or inhibitory
What are adrenoreceptors
when epinephrine or norepinephrine binds they release G proteins which begin a cascade of information
What are the subtypes of adreno receptors
alpha and beta
- both are metabotropic
What is the role of;
- motor cortex
- basal ganglia
- cerebellum
in motor control
- plans the movement
- initiates and maintains the movement
- coordinates movement by electing correct sequences
What are upper and lower motor nuerons
Upper - produce voluntary movements
Lower - produce contraction via motor units
What is the corticospinal tract
major neuronal pathway providing voluntary motor function
- using the upper motor neurons
What can influence the somatic neurone
sympathetic nerves running along side it and can have receptors that aren’t affecting or creating APs but can release G proteins which can affect what the nucleus is making
What are the 2 types of reflex arcs
- Autonomic reflex arc
- affects inner organs (often completely unaware of these occurring) - Somatic reflex arc
- affects muscles
Describe the pathway of a somatic reflex arc
- sesnor (or receptor)
- afferent pathway to the spinal cord or brainstem
- integrating centre, grey matter of the spinal cord or brainstem synapse
- efferent pathway to the muscles
- effector muscles give response
