Nervous Flashcards
What elements make up the Central Nervous system
brain
spinal cord
what elements make up the peripheral nervous system
nerves
ganglia
enteric plexuses
sensory receptors
SNS, ANS, ENS
What is the somatic nervous system (SNS)
skeletal muscles
sensory neurons that conduct impulses from somatic and special receptors to the CNS and motor neurons
What is the autonomic nervous system (ANS)
smooth muscle, cardiac muscle and glands
sensory neurons from visceral organs and motor neurons that convey impulses from the CNS to muscle tissue and glands
separated into sympathetic and parasympathetic
What is the enteric nervous system (ENS)
gastrointestinal tract
neurons in enteric plexuses in the gastrointestinal tract
operates separately from the ANS AND CNS
what are neurons
specialized cells for nerve impulse conduction
what are neuroglia
structures that support nourish and protect neurons
what are afferent neurons
sensory neurons
what are efferent neurons
motor neurons
what are interneurons
connecting neurons between sensory and motor neurons
what are the major parts of a neuron
dendrite
cell body + neuron
axon
myelin sheath
axon terminal + synaptic end
What is the difference between multipolar, bipolar and unipolar neurons
the cell body is in different places
multipolar - in dendrite
bipolar - above axon
unipolar- alongside axon
What is the function of astrocytes (CNS)
supports neurons, protect from harmful substance, maintain proper chemical environment, form blood brain barrier
what is the function of Microglial cells (CNS)
protect CNS cells from disease by engulfing invading microbes
what is the function of Oligodendrocytes (CNS)
produce and maintain myelin sheath
what is the function of ependymal cells (CNS)
line ventricles of the brain and central canal of the spinal cord
what is the function of Schwann cells (PNS)
produce and maintain myelin sheath
what is the function of satellite cells (PNS)
support neurons in PNS ganglia regulate exchange of materials between neurons and interstitial fluid
what is white matter
primarily myelinated axons
what is grey matter
neuronal cell bodies, dendrites, axon terminals, unmyelinated axons, neuroglia
forms H shaped inner core in spinal cord
provides thin superficial shell to cerebellum and cerebrum in brain
what is a ganglion
cluster of neuronal cell bodies in PNS
what is a nerve
bundle of axons located in PNS
define polarized
a cell that exhibits a membrane potential
what is a resting membrane potential
-70mV
What is the process for achieving an action potential in continuous conduction
1 - Na+ channels open resulting in depolarization
2 - K+ channels open resulting in repolarization and recovery to resting
impulse generated is always constant size
what is saltatory conduction
a nerve impulse leaps from one node of ranvier to the next along a myelinated axon
How does synaptic transmission occur
at the synapse and neurotransmitter is released from a presynpatic neuron to a post synaptic neuron
what is an excitatory neurotransmitter
depolarizes the postsynaptic neurons membrane
increases the chance of once or more action potentials
what is an inhibitory neurotransmitter
hyperpolarizes the membrane of the postsynaptic neuron
inhibiting action potential generation
name some important neurotransmitters
acetylcholine, glutamate, aspartate, gamma aminobutyric acid (GABA), glycine, norepinephrine, dopamine, serotonin, neuropeptides, nitric oxide
what are the three layers of the meninges
protects brain and spinal cord
dura mater - outer
arachnoid mater - middle
pia mater - inner
What is the name of the roots of the spinal nerves
cauda equina
Where does the spinal cord branch
cervical enlargement - supplies upper limbs
lumbar enlargement - supplies lower limbs
how many pairs of spinal nerves are there
31 pairs