nervous system Flashcards
what are the 3 functions of the nervous system
- respond to internal and external environment
- decide on what action to take
- do the action
how does the nervous system respond to internal or external stimuli
sensory receptors
how does the nervous system decide on what action to take
integration center (brain)
how does mssage travel from sensory receptors to the integration center
afferent arm
how does the nervous system carry out an action
effectors
usually, what are effectors
muscles or glands
how do messages get from the integration center to the effectors
the efferent arm
what are the 2 signals cells communicate with
- electrical
- chemical
what is an example of an electrical signal
action potential
what is an example of a chmical signal
neurotransmitter
what is the difference between the nervous and endocrine system
the nervous system works faster than the endocrine system
how does a person have a reflex so fast
the sensory receptor does not have to go to the brain before the body reacts
what are the 2 sections of the nervous system
- central nervous system (CNS)
- peripheral nervous system (PNS)
what body parts are located in the central nerous system
the brain and spinal cord
what happens in the central nervous system
when the body decides on what action to take
what body parts are found in the peripheral nervous system
nerves
what takes place in the peripheral nervous system
a) the body responds to a stimli
b) the body carries out an action
what are the 2 kinds of nerves used in the peripheral nervous system
- spinal nerves
- cranial nerves
what takes place in the peripheral nervous system through spinal nerves
messages go to and from the spinal cord
what takes place in the peripheral nervous system through cranial nerves
messages go to and from the brain
at what point does the spinal cord end
L1-L2
what are the 2 divisions of the periphral nervous system
- sensory (afferent) division
- motor (efferent) division
where is the sensory (afferent) division of the peripheral nervous system directed
to the brain
where is the motor (efferent) division of the peripheral nervous system directed
to the organs
what are the 2 divisions of the motor division of the peripheral nervous system
- somatic nervous system
- autonomic nrvous system
where do impulses of the somatic nervou system of the motor division of the peripheral nervous system go.
from the CNS to the skeletal muscle
is the action of the somatic nervous system of the motor division of the peripheral nervous system voluntary or involuntary
voluntary
what kind of muscles are used in the somatic nervous system of the motor division of the peripheral nervous system
skeletal muscles
what kind of nerve fibers are used in the autonomic nervous system of the motor division of the peripheral nervous system
visceral motor nerve fibers
what kind of muscles are used in the autonomic nervous system of the motor division of the peripheral nervous system
a) smooth muscles
b) cardiac muscle
c) clands
is the action of the autonomic nervous system of the motor division of the peripheral nervous system voluntary or involuntary
involuntary
what are the 2 subdivisions of the autonmic nervous system of the motor division of the peripheral nervous system
- synapathetic
- parasympathetic
what is the synapathetic subdivisions of the autonmic nervous system of the motor division of the peripheral nervous system
fight or flight
what is the parasympathetic subdivisions of the autonmic nervous system of the motor division of the peripheral nervous system
rest or digest
what are glial cells
small cells surrounding neurons
what are neurons
the main cell resposible for transmitting electrical signals
what 4 glial cells can be found in the central nervous system
- astrocytes
- microglial cells
- ependymal cells
- oligodendrocytes
what is the function of astrocytes
position the neurons in place and nourinsh the cell
what is the function of microglial cells
phagocytosis- cleans sells by eating away at debris
what is the function of ependymal cells
line the ventricles (cavities of brain and spinal cord) and regulate flow and production of cerebrospinal fluid (CSF)
what is the function of oligodendrocytes
form the myelin sheath
what are the 2 kinds of glial cellsfound in th peripheral nervous system
- satellite cells
- schwaann cells
what is the function of satellite cells
position neurons in place and nourish the cells
what is the function of schwann cells
form the myelin sheath
what is the function of neurons
to conduct impulses
wht is unique about neurons
they are amitotic- their cells do not divide
what is a ganglion
a cluster of neuron cells in the peripheral nervous system
what is a nerve
a cluster of nerve fibers in the central nervous system
what is a nucleus
a cluster ofneurons within the central nervous system
what is a tract
a group of nerve fibers in the central nervous system
what is the function of a dendrite
convey incoming messages toward cell body as graded potentials
what is the function of the axon
generate nerve impulses and transmite them to the axon terminal
in what direction is anterograde movement
soma -> axon terminals
what moves with anterograde movement
mitochondria, sytoskeletal elements, membrane components, enzymes
in what direction is retrograde movements
axon terminal -> soma
what moves with retrograde movement
organelles to be degraded, signal moleculs, virusis, bacterial toxind
what is the importance of the myelin sheath
it allows impulses to occure quicker
the white matter in the bain and spinal cord is due to what
myelinated nerve fibers
the grey matter in the brain and spinal cord is due to what
nerve cell bodies, dendrites, neuroglia, and unmyelinated axons
what do sensory neurons do
transmit impulses from sensory receptors toward the central nerous system
what do motor neurons do
carry impulses from the central neurons to the effectors
what do interneurons do
the lie between motor neurons and sensory neurons
