Ch. 11 Nervous System Flashcards
(20 cards)
homeostasis
a state of relative stability within the body. Homeostasis is critical for survival
The nervous system
The brain and spinal cord, and the nerves that emerge from them and connect them to the rest
of the body.
central nervous system
consists of the brain and spinal cord,
integrates and processes info
peripheral nervous system
-includes nerves that carry sensory
messages to the central nervous system
and nerves that send information from
the CNS to the muscles and glands.
-further divided into the somatic & autonomic system
the somatic system
consists of sensory receptors in the head and
extremities, nerves that carry sensory
information to the central nervous
system, and nerves that carry instructions
from the central nervous system.
autonomic system
-controls glandular secretions and the functioning of the smooth and cardiac muscles
-further divided into the sympathetic and parasympathetic systems.
sympathetic and parasympathetic system
regulate the involuntary processes of
the body. Involuntary processes, such as
heartbeat and peristalsis
Neurons
The basic structural and functional units of the nervous system. They are specialized to
respond to physical and chemical stimuli,
to conduct electrochemical signals, and
to release chemicals that regulate various
body processes
Gilal cells
nourish the neurons, remove their wastes, and defend against infection. Glial cells also provide
a supporting framework for all the
nervous-system tissue.
The 3 main types of neurons
- sensory input
- integration
- motor output.
Sensory input
Sensory neurons
gather information from the sensory
receptors (senses) and transmit
these impulses to the central nervous
system (brain and spinal cord)
Integration
-{They process and integrate incoming
sensory information and relay
outgoing motor information.}
Interneurons are found
entirely within the central nervous
system. They act as a link between
the sensory and motor neurons.
Motor output
transmit information from the central nervous system to the muscles,
glands, and other organs (effectors)
Reflex Arcs
simple connections of neurons that
explain reflexive behaviours. They can be
used to model the basic organization of
the nervous system.
Dendrites
short, branching
terminals that receive nerve impulses
from other neurons or sensory receptors,
and relay the impulse to the cell body.
The dendrites are numerous and highly
branched, which increases the surface
area available to receive information.
cell body
contains the nucleus and is the
site of the cell’s metabolic reactions. The
cell body also processes input from the
dendrites
myelin sheath
the fatty, insulating layer that the axons of some neurons are enclosed in.
Schwann cells
a type of glial cell that form myelin by
wrapping themselves around the axon.
myelinated and unmyelinated neurons
white matter
grey matter
