HPP LEC CHAP 8 Flashcards
Nervous System Functions
- Receiving sensory input
- Integrating information
- Controlling muscles and glands
- Maintaining homeostasis
- Establishing and maintaining mental activity
brain and spinal cord
Central nervous system
All the nervous tissue outside the CNS
Peripheral nervous system
Conducts action potentials from sensory receptors
to the CNS
Sensory division
Conducts action potentials to effector organs, such
as muscles and glands
Motor division
Transmits action potentials from the CNS to skeletal
muscles.
Somatic nervous system
Transmits action potentials from the CNS to cardiac
muscle, smooth muscle, and glands
Autonomic nervous system
A special nervous system found only in the digestive
tract.
Enteric nervous system
receive stimuli, conduct action potentials, and
transmit signals to other neurons or effector organs.
Neurons
supportive cells of the CNS and PNS, meaning these
cells do not conduct action potentials.
Glial cells
contains a single nucleus
Cell body
which is a cytoplasmic extension from
the cell body, that usually receives information from
other neurons and transmits the information to the
cell body
Dendrite
which is a single long cell process that leaves
the cell body at the axon hillock and conducts
sensory signals to the CNS and motor signals away
from the CNS
Axon
have many dendrites and a
single axon.
Multipolar neurons
have two processes: one
dendrite and one axon.
Bipolar neurons
have a single process
extending from the cell body, which divides into
two processes as short distance from the cell
body.
Pseudo-unipolar neurons`
serve as the major supporting cells in
the CNS.
Astrocytes
Astrocytes can stimulate or inhibit the signaling
activity of nearby neurons and form?
blood-
brain barrier.
line the cavities in the brain
that contains cerebrospinal fluid.
Ependymal cells
act in an immune function in the
CNS by removing bacteria and cell debris.
Microglial cells
provide myelin to neurons in
the CNS.
Oligodendrocytes
provide myelin to neurons in the
PNS.
Schwann cells
are specialized layers that wrap
around the axons of some neurons, those
neurons are termed, myelinated.
Myelin sheaths
Gaps in the myelin sheath
nodes of
Ranvier
lack the myelin sheaths.
Unmyelinated axons
consists of groups of neuron cell
bodies and their dendrites, where there is very
little myelin.
Gray matter
consists of bundles of parallel
axons with their myelin sheaths, which are
whitish in color.
White matter
Nervous tissue exists as?
gray matter and white
matter.
what potentials occur in neurons
Resting membrane potentials and action potentials
always open
Leak channels
generally closed, but can be opened due
to voltage or chemicals.
gated
channels
compensates for the
constant leakage of ions through leak channels.
sodium-potassium pump
conducted slowly in
unmyelinated axons and more rapidly in
myelinated axons.
Action potentials
What do you call the type of action potential conduction
saltatory conduction
lightly myelinated axons,
characteristic of autonomic neurons, conduct
action potentials at the rate of about 3 to 15
meters per second
Medium-diameter
heavily myelinated axons conduct
action potentials at the rate of 15 to 120 m/s.
Large-diameter
breaks down the
acetylcholine
acetylcholinesterase
is either actively transported back into
the presynaptic terminal or broken down by enzymes.
Norepinephrine
is a simple pathway in
which two or more neurons synapse with the
same postsynaptic neuron.
converging pathway
is a simple pathway in which
an axon from one neuron divides and synapses
with more than one other postsynaptic neuron.
diverging pathway
