The Nervous system Flashcards
The neurons may perform one of 3 functions
sensory (Afferent ) neurons: recieve signals from a receptor cell that interacts with env
interneurons: transfer signals from neuron to neuron
motor neurons: carry signals to muscle or gland called the effector.
where are sensory neurons located?
dorsally (towards the back ) from the spinal cord
where are motor neurons located?
ventrally (towards the front or abdomen)
the nervous system has what two major divisions?
central nervous system and the peripheral nervous system
CNS AND PNS
What does the CNS consist of?
interneurons and support tissue within the Brain and the spinal cord. the function of the CNS is to integrate nervous signals between sensory and motor neurons
how is the CNS connected to the peripheral parts of the body?
via the PNS! the PNS handles the sensory and motor functions of the nervous system.
what can the PNS be further divided into?
somatic nervous system and the autonomic nervous system ( both have sensory and motor parts)
the motor parts of the ANS are parasympathetic and sympathetic
what is the somatic nervous system?
designed primarily to respond to the external environment. it has sensory and motor functions. The somatic nervous system innervates the skeletal muscles.
what about the ANS?
The sensory portion of the ANS gets signals from the viscera (organs in the ventral body cavity)
the motor portion of the ANS then conducts these signals to the smooth muscle , cardiac muscle and glands.
the function of the ANS is generally involuntary.
what are the motor portions of the ANS?
Sympathetic and parasympathetic
most internal organ systems are innervated by both systems working antagonistically.
what does the sympathetic ANS deal with ?
fight or flight !
what does the Parasympathetic ANS deal with ?
rest and digest
what neurotransmitter do the postganglionic neurons of the SNS use?
epinephrine or norepinephrine (called adrenaline or noradrenaline)
what neurotransmitter is used by postganglionic neurons in the PNS ?
Acetylcholine
what neurotransmitter is used by all PREganglionic neurons in the ANS (so both PNS AND SNS)?
ACETYLCHOLINE
