nervous system Flashcards
General and specific
functions of the nervous system
interprets internal and external signals , facilitates coordination, reflex reactions
what does the nervous system coordinate with?
endocrine system
what does the CNS consist of
brain and spinal cord
what does the CNS do
process sensory information
somatic nervous system
controls voluntary movements
autonomic nervous system
controls involuntary movements
what does the autonomic nervous system consist of
sympathetic and parasympathetic
sympathetic
“fight or flight”
parasympathetic
“rest or digest”
motor neurons
CNS to muscle and glands
sensory neurons
carry signals from the receptors in the body to the spinal cord
sympathetic actions eg
pupils dilate, inhibits salivation, relaxes bronchi, increases heartrate
parasympathetic actions eg
constricts pupils, stimulates saliva flow, contricts bronchi, slows heart rate
relay neurons
carry messages from one part of the CNS to another
dendrites
large surface area, collection information from other neurons and passes it to the cell body
myelin sheath
speeds up conduction
resting potential of a membrane
-70 mV
voltage- gated ion channels
respond to a change in cell membrane potential
ligand- gated ion channels
respond to specific neurotransmitters and other molecules
mechanically gates ion channels
respond to changes in the mechanical force on the membrane
saltatory conduction
in myelinated neurons, the signal ‘jumps’ along the axon via the nodes of ranvier
A fibres
myelinated with a large diameter - 300mph
B fibres
light myelination with medium diameter - 30 mph
C fibres
no myelination with small diameter- 2 mph
primary somatosensory cortex
receives sensory information- proprioreceptors (muscles, joints and tendons) and sensory information from the skin up from the thalamus