L9: PNS Flashcards
What are the two motor neurons of the peripheral nervous system?
Somatic and autonomic (visceral)
How many motor neurons are involved in somatic and how many are involved in autonomic?
Somatic = 1 motor neuron
Autonomic = 2 motor neurons
What is the effector in somatic motor and the effector in autonomic motor?
Somatic = skeletal muscle
Autonomic (visceral) = cardiac muscle, smooth muscle and glands
What are the neurotransmitters in somatic and autonomic motor?
Somatic = Ach (acetylcholine)
Autonomic = Ach & norepinephrine
Where are somatic and autonomic motor branches found? (The origin)
Somatic= anterior grey horn, nuclei of brain stem
Autonomic = lateral grey horn, nuclei of brain stem
What are the two subdivisions of the autonomic nervous system?
Sympathetic and parasympathetic
What do the sympathetic and parasympathetic nervous system have in common (similarities)
- intervate viscera
- organs have dual innervation ➡️ use both
- not on or off rather baseline firing of neurons increases or decreases
What is the main function of the sympathetic and parasympathetic nervous system?
Sympathetic- fight or flight
Parasympathetic- rest and digest
Origin of sympathetic and parasympathetic nervous system
Sympathetic- thoracolumbar
Parasympathetic- craniosacral
What is the neuron length within the sympathetic and parasympathetic NS?
Sympathetic- short ➡️ long
Parasympathetic - long ➡️ short
Where are the ganglia (collection of cell bodies) located in the sympathetic and parasympathetic NS?
Sympathetic- near spinal cord
Parasympathetic- near/ in effector
Does the parasympathetic or the sympathetic NS cause mass activation?
Sympathetic
What at is mass activation?
turns on entire response/ activation all at once
What is divergence? Convergence?
Divergence = 1 spinal cord level ➡️ many ganglia
Convergence = many levels of spinal cord ➡️ 1 ganglion
What’s the adrenal gland’s role in the ANS?
Sympathoadrenal system
- releases epinephrine from adrenal medulla ( adrenaline)
What are the neurotransmitters in the ANS and where can they be found?
Ach, Epinephrine, Norepinephrine
Ach = pre ganglion in both sympathetic and parasympathetic
Norepinephrine = binds to effector in sympathetic
What are the two types of cholinergic receptors? (Bind Ach)
Nicotinic and muscarinic
Properties of a Nicotinic receptor
Excitatory ( na+ rushes in)
Ach receptor
Found on: post synaptic membrane of
- all autonomic ganglia
- all neuromuscular junctions
Properties of muscarinic receptors
- binds epinephrine
- produces parasympathetic nerve effect in heart, smooth muscle & glands
- contain G proteins ( allowing 2 responses) ➡️ sympathetic do one thing and parasympathetic other
Why is signal transduction necessary?
Many ligands are polar therefore they can’t enter the cell without help
Signal transduction
Ligands bind to membrane bound receptors and initiates intracellular responses
What are the adrenergic receptors?
Alpha adrenergic receptor
& beta adrenergic receptor
Cholinergic muscarinic receptors are both inhibitory and excitatory- true or false
True
Medulla oblongata
Control center for blood pressure: baroreceptor reflex
