what are the major functions of the nervous system - Answers 1. Receiving sensory input
2. Integrating information
3. Controlling muscles and glands
4. Maintaining homeostasis
5. Establishing and maintaining mental activity
the nervous system is divided into two major divisions, what are they and what do they consist of -
Answers the CNS (brain and spinal cord) and PNS (nervous tissue outside the CNS like nerves and
ganglia)
the pheripheral nervous system can be divided into two parts what are they - Answers sensory
division-> afferent (toward) sensory to CNS
motor division->efferent (away) CNS to tissue
peripheral nervous system - Answers the sensory and motor neurons that connect the central
nervous system to the rest of the body
the motor divison is divided into two systems what are they - Answers somatic-> transmits action
potential from CNS to skeletal muscle
autonomic-> transmits action potentials from CNS to cardiac muscle, smooth muscle and glands
the autonomic nervous system is divided into two what are they - Answers sympathetic
parasympathetic
enteric nervous system - Answers part of the PNS and has both motor and sensory neruons within
the digestive tract
can function without input from the CNS or otehr parts of PNS
true or false, can the enteric nervous system functions without input from the CNS or PNS? - Answers
true
what are the two types of cells that make up the nervous system - Answers glial cells and neurons
neurons - Answers Individual cells in the nervous system that receive, integrate, and transmit
information.
-conduct action potentials
whats the name of the area where the neuron leaves the axon body - Answers axon hillock
an axon may remain unbranched or may branch to form ______ axons - Answers collateral
what is the insulated layer in the cells - Answers myelin sheath
three types of neurons - Answers multipolar neuron (many dendrites and one axon)
bipolar neuron (one dendrite and one axon)
pseudo unpolar neuron (single axon)
CNS glial cells - Answers astrocyetes
epednymal ells (CSF)
microglia (immune)
oligodendrocytes (insulation)
PNS glial cells - Answers Schwann cells (myelin sheath/insulation ) and satellite cells
what are the gaps in the myelin sheath called - Answers nodes of ranvier
what is the difference between white and gray matter - Answers gray->group of neurons, cell bodies
and dendrites
white->bundles of parallel axons+myelin sheath
white matter forms what - Answers nerve tracts
an uneven charge of a cell membrane means that it is - Answers polarized
in a resting cell, there is higher conc of __ inside the cell and a higher conc of ___and ___ outside the
cell - Answers k+
Na and ca
what does it mean to be an excitable cell? - Answers resting membrane potential changes in
response to stimuli
3 stages of neuron communication - Answers generation of action potential
, action potential propagation along the cell membrane
communication with target cell at the synapse
leak channel - Answers always open
gated channel - Answers A protein channel in a cell membrane that opens or closes in response to a
particular stimulus.
Action Potentials - Answers short periods of electrical activity at the membrane of a neuron,
responsible for the transmission of signals within the neuron
channels responsible for action potentials are - Answers sodium potassium channels
when a cell memebrane is at rest the cvoltage gated channels are ___ - Answers closed
when the inside of the cell memebrane becomes positive, the change is called - Answers
depolarization
if depolarization is large enough, sodium enters the cell so that it can reach _______ - Answers
threshold value
the outward flow of ____ repolarizes the cell membrane to its resting potential - Answers potassium
when the cell is returning to resting potential it briefly becomes more negative than the resting
membrane this is called - Answers hyperpolarization
the resting memebrane potential is set by the activity of the - Answers leak channels
action potentials occur in a _______ fashion - Answers all or none
action potential conduction can occur in one of two ways - Answers continuous conduction
saltatory conduction
in unmyelinated axons what type of conduction occurs - Answers continuous
saltatory conduction - Answers Rapid transmission of a nerve impulse along an axon, resulting from
the action potential jumping from one node of Ranvier to another, skipping the myelin-sheathed
regions of membrane.
the variation in speed of action potential conduction depends on what? - Answers axon diameter
the larger=the faster
synapse - Answers the junction between the axon tip of the sending neuron and the dendrite or cell
body of the receiving neuron
presynaptic terminal - Answers (end bulb or bouton) point where an axon releases chemicals
post synaptic membrane - Answers the cell membrane opposite the terminal button in a synapse; the
membrane of the cell that receives the message
synaptic cleft - Answers The narrow gap that separates the presynaptic neuron from the postsynaptic
cell.
neurotransmitters - Answers chemical messengers that cross the synaptic gaps between neurons
neutrotransmitters are stored in - Answers synaptic vesicles
when an action potential reaches the presynaptic terminal the voltage gated _____ channels open -
Answers calcium
an influx of calcium cause the release of neutrotransmitters by ____ from the presynaptic terminal -
Answers exocytosis
the neurotransmitters bind to specific receptor molecules on the ________ - Answers post synaptic
memebrane
what is a very common example of a neurotransmitter - Answers acetylcholine and norepinephrine
list the 7 neurotransmitters - Answers ach (exci/inhib)
Ne (exci)
seretonin (inhib)
dopamine (exci/inhib)
gaba (inhib)
glycine (inhib)
endorphins (inhib)
what breaks down ach after it is released into the synaptic cleft? - Answers achetylcholinesterase
neuronal pathways - Answers converging pathway (two or more synapses)
diverging pathway (neuron divids into two)
summation - Answers accumulation; total result
two types of summation - Answers spatial summation overlap in path
temporal summation overlap in time