nervous system 4 - muscle activation or something Flashcards
which nervous system idk controls skeletal muscle
somatic
which nervous system controls smooth muscle, cardiac muscle, gland cells - what are the two branches
autonomic - sympathetic and parasympathetic
what does the sympathetic nervous system do? neurotransmitter?
fight or flight. adrenaline
what do preganglionic neurons release in sympathetic nervous system?
what do postganglionic neurons release in sympathetic nervous system
acetylcholine in preganglionic
noradrenaline in postganglionic
what effect does binding to different postsynaptic adrenoreceptors have in the sympathetic nervous system
relaxes airways in lungs
inhibits digestion
accelerates heart rate
what can adrenaline be used to treat
patients in cardiac arrest
which neurotransmitter is used pre and post ganglionic in parasympathetic nervous system
acetylcholine
what does the parasympathetic nervous system control
digestion, metabolic functions, regulates kidney liver etc
what does binding to different postsynaptic acetylcholine receptors in the parasympathetic nervous system result in
constriction of airways, stimulates digestion, slows heart rate
lower motor neurons innervates what?
each motor neuron innervates a single muscle
lower motor neurons organisation
neurons innervating axial muscles are medial to neurons innervating distal muscles in the spinal cord. neurons innervating flexors dorsal to neurons innervating extensors
what is the motor unit
alpha motor neuron and all muscle fibres it innervates
what is a motor neuron pool
collection of alpha motor neurons that innervates a single muscle
what is needed to trigger a postsynaptic action potential in a muscle fibre
one presynaptic action potential
what is acetylcholine broken down into after binding with postsynaptic receptors
choline and acaetic acid
what uptakes choline into the presynaptic cell
choline transporter
what does choline bind with to form acetylcholine
Acetyl CoA
what is the excitable cell membrane covering a muscle fibre
sarcolemma
what in a muscle fibre contracts in response to an action potential sweeping down the sarcolemma
myofibrils
what is released in a muscle fibre when post synaptic depolarisation occurs
calcium
what does calcium bind to after being released (in a muscle fibre) and what effect does this have
troponin which causes myosin to bind with actin, creating an active pulling process which allows contraction/relaxation of muscle
when does relaxation in a muscle fibre occur
when Ca2+ or ATP levels reduce
muscle twitches to sustained contraction
single muscle twitches to temporal summation to unfused tetanus to fused tetanus
what is a reflex
involuntary instantaneous movement in response to stimulus (doesn’t require brain)
