hms 2 Flashcards
types of information transmitted
somatic afferent (sensory) e.g see somatic efferent (motor) e.g run autonomic afferent (sensory) e.g blood pressure autonomic efferent (motor) e.g heartbeat
features of somatic motor efferent
voluntary control
single neuron between CNS and effector cell body in spinal cord (CNS) axon in spinal nerves (PNS) axon is myelinated neurotransmitter = acetylcholine (ACh)
motor unit number
single neuron contacts one or more muscle fibres
single muscle fibre never innervated by >1 neuron
features of autonomic motor efferent
involuntary control
2 neurons between CNS and effector
Neuron 1 in autonomic motor efferent involuntary
Cell body in CNS Axon in PNS Synapse of autonomic ganglion Pre-ganglionic neuron neurotransmitter= (ACh) Myelinated
Neuron 2 in autonomic motor efferent involuntary
Cell body in PNS Axon in PNS Synapse on effector organ Post-ganglionic neuron Neurotransmitter= (ACh) OR noradrenaline (NE) Unmyelinated
Autonomic nervous system: sympathetic
“fight/flight system”, “acute stress responses- effects”
increase heart rate decrease blood to skin, increase blood to muscles increase pupil size increase sweating decrease gastric motility decrease salivation
Autonomic nervous system: parasympathetic
“rest and digest system” “restful situations”
decrease heart rate
decrease pupil size
increase gastric motility
increase salivation
structure of sympathetic system
Neurotransmitter = ACh and NE
ganglion close to CNS (short, long)
structure of parasympathetic system
Neurotransmitter = ACh and ACh
ganglion far from CNS (long, short)
sympathetic neurons exit from CNS
thoracolumbar levels
how many pairs of sympathetic chain ganglia
21-23 pairs
how many main collateral ganglia
3
Exit of parasympathetic nervous system
cranial and sacral levels (craniosacral nerves)
