W14 Physiological systems Flashcards
what are 4 main receptors
enzymes
transporters
ion channels
receptors
What does pns stand for
peripheral nervous system
what does the PNS represent
output of the CNS and acting independently to regulate the body’s internal environment
what are the 2 parts of the PNS
autonomic nervous system
Somatic (motor) nervous system
what do efferent nerves control
movement by innervating skeletal muscle
what do afferent nerves respon to
external stimuli e.g. pain sensing fibres
what are the 3 parts of the autonomic nervous system
Parasympathetic nervous system
Sympathetic nervous system
Enteric nervous system
what is the parasympathetic nervous system
cranial sacral output
synapse at ganglia close to innervated tissue.
what is sympathetic nervous system
thoracic lumbar output synapse at ganglia either side of vertebral column
ganglia distal to innervated tissue
what is enteric nervous system
neurones with cell bodies in the wall of the intestine that innervates GI tract, pancreas and gall bladder.
what are the main processes that the ANS regulate
heart beat
smooth muscle contraction and relaxation
all exocrine function
some endocrine secretions
some steps in intermediate metabolism
in general what does the sympathetic system do
evokes a flight and fight response whilst the parasympathetic system mediates a rest and digest state.
what is cholinergic transmission
all motor nerves releases acetyl choline which act on nicotinic acetylcholine receptors
all postganglionic parasympathetic nerves release acetyl choline which act on muscarinic acetylcholine receptors
What is acetyl choline regulated by
inhibitory presynaptic m2 muscarinic acetylcholine receptors
where are the m1 receptors located
Ganglia
CNS
where are the m2 receptors located
Cardiac
CNS
where are the m3 receptors located
Glands
Smooth Muscle
Blood Vessels
where are the m4 receptors located
CNS
where are the m5 receptors located
CNS
why is it important to know about different receptor types
selectivity
what are the parasympathetic effects
Bradycardia Vasodilation Increases secretion Bronchoconstriction Increased gut motility Reduction of itraocular pressure
what actions of atropine
block secretion Tachycardia Pupillary dilation and cillary muscle paralysis inhibits gut motility paralysis of bladder smooth muscle relaxation CNS effects: excitatory
what are the three types of ACh receptors
muscle
ganglion
cns
What are depolarizing blockers
Agonists which cause a depolarizing block of the muscle fibre endplate = depolarizing blockers.
