The Nervous System Flashcards
a sitmulus
is any change in your enviroment
a receptor
is a nerve cell that detects the stimulus.
a neuron
is a specilised cell that carries electrical messages (impulses) around the body
an impulse
is an electrical message that is carried along a neuron
PNS =
Peripheral nervous system [ nerve and nerve endings].
CNS =
central nervous system [ brain and spinal cord ].
sensory neuron Aka…
Afferent neuron [ sense organs => brain ]
motor neuron Aka…
Efferent neuron [ brain => muscles ]
an ____ connects sensory neurons with motor neurons
Interneuron
the direction of impulse always goes towards the
neurotransmitter swellings and axon terminals
axon carries impulses ____ ____ the cell body..
away from
carries impulses to the cell body they also connect to neurons via synapse …..?
Dendrite
the refractory period
is the delay between any two impulses. it is a very short period of time during which the neuron fails to react to an impulse because it has just reacted to one. It’s a recovery time.
a reflex action
is an automatic, involuntary, unthinking response to a stimulus i.e grasp reflex in babies, blinking, protective actions
The Thalmus
is the sorting centre, it directs incoming impulses to the correct centre in the brain.
The Hypothalamus
responsible for HOMEOSTASIS
whats homeostasis in relation to the hypothalamus
the regulating of the internal environment of a body i.e temperature, water content, PH, appetite. it links with the pituitary gland to control and regulate the production of hormones.
axon terminals/neurotransmitter swellings
these mark the end of the particular neuron .they contain neurotransmitter substances in their swellings that are released into the space between one neuron and the next (the synapse) which allows the impulse in one neuron to continue on to the next neuron.
the synapse (the synaptic cleft )
is the space at the end of one neuron and the beginning of the next into which chemicals are released that will allow a connection between one neuron and the next.
Schwann cells
are located along the length of the neuron and secrete the myelin sheath.
myelin sheath
ist an insulating membrane made of fat and keeps the impulse running along the axon and dendrite , prevents it dispersing
