Science terms after reading quiz Flashcards
tapers into strong tendons that fasten the biceps to the scapula above and to the radius below
fascia
extend the length of the muscle cell
myofibrils
give skeletal muscle its banded, or striated, appearance
sarcomeres
The point at which a motor neuron connects to a muscle cell
neuromuscular junction
. A motor neuron and the group of muscle cells it controls
motor unit
When a muscle fiber is stimulated to contract, it does so completely and then relaxes completely until another nerve impulse reaches it.
all-or-none principle
Enlargement of muscles through use
hypertrophy
Muscle degeneration
atrophy
Muscle fibers that contain many mitochondria and large amounts of myoglobin
red fibers
muscle fibers containing fewer mitochondria and less myoglobin
white fibers
total awareness of body movements
muscle sense
includes the brain and the spinal cord, which are both encased in bone for protection
central nervous system
principle organ of the nervous system
brain
a thick bundle of nerve fibers located within the spinal cavity
spinal cord
he spinal cord and brain are covered by a triple layer
of protective tissues known as the what
meninges
one of the strongest tissues of the body, serves primarily as a flexible protective layer
dura meter
composed of thin fibers, like the fibers of a spider’s web, that form an intricate threedimensional network around the brain
arachnoid mater
circulates through the fibers of the arachnoid mater, cushioning the brain when you bump your head
cerebrospinal fluid
forms a delicate covering that rests directly against the brain and spinal cord.
pia mater
support and insulate nerve tissue
glial cells
the actual nerve cells
neurons
, branched extension of the cell that receives nerve impulses from other neurons and conducts them toward the cell body
dendrite
a long extension that relays nerve impulses from the cell body to other neurons.
axon
found within the brain and spinal
cord consists largely of the cell bodies of neurons and is gray because the cell bodies lack the white, specialized covering known as myelin [
gray matter
is composed of axons and glial cells that are white because of their myelin content.
white matter
is composed of axons and glial cells that are white because of their myelin content.
ganglia
, a network of interconnected nerve fibers going to or from a region
plexus
A group of cell bodies in the brain or spinal cord
nerve center
Neurons that transmit information to the central nervous system from the senses of sight, hearing, taste, touch, and smell, as well as those that transmit pain signals
sensory neurons
. Neurons that relay signals from the central nervous system to the other parts of the body
motor neurons
are found only in the central nervous system, relay signals between neurons or groups of neurons and are responsible for the processing of information by
the brain, like the logic circuits of a computer.
Interneurons
protect the central nervous system from being permanently damaged every time you get sick.
blood-brain barrier
, the bloodbrain barrier must open slightly to allow additional white blood cells to squeeze through and fight the invaders, causing inflammation and swelling inside the skull.
meningitis
a state of prolonged unconsciousness
coma
bundles of nerve fibers (axons) branching from the brain and spinal cord and connecting the central nervous system to the extremities of the body
nerves
nerves that contain both sensory and motor fibers
mixed nerves
carry impulses from light, taste, sound, touch, and pain from other parts of the body to the spinal cord and brain for analysis
sensory nerve fiber
carry impulses from the brain and spinal cord to produce action in muscles and organs
motor nerve fibers
the part of the peripheral nervous system that controls the heart and other internal organs
autonomic nervous system
generally responds
to your body’s needs during increased activity and in emergency situations by causing heartbeat and breathing rates to increase, thus supplying more blood to your body so
that you can respond quickly
sympathetic divison
acts as a
balance to counteract the actions of the sympathetic division
parasympathetic division
controls
the muscles of the forearm and the muscles and skin of the hand, is representative of how all peripheral nerves are designed
median nerve
h produce layers of myelin sheathing that acts much like the insulation on an electrical wire
Schwann cells
occurs when the body’s immune system attacks the glial cells that provide myelin sheaths for nerve cell axons
Multiple sclerosis
the inability of the muscles to move
paralysis
propagated by fast acting, voltage sensing ion gates that quickly open and close, allowing sodium and potassium ions to briefly flow into and out of the cell
action potential,
an enclosed junction between two neurons or a neuron and another cell
synapse
a powerful poison that is responsible for the most deadly type of food poisoning
botulinum toxin
The simplest act of the nervous system
reflex
the upper part of the brain, coordinates thought, memory, and learned behaviors.
cerebrum
, the lower part of the brain, helps control balance and coordinate voluntary muscle activity
cerebellum
the part that connects to the spinal cord, controls the involuntary muscles and activities of the autonomic nervous system.
brain stem
two halves of the brain
hemispheres
The two hemispheres communicate with each other through a mass of nerve fibers called the what
corpus callosum
the outer layer
of the cerebrum
cerebral cortex
The convlutions of each of the cerebral hemispheres are divided by grooves into various regions called what
lobes
associated
with personality, judgment, and self control.
frontal lobes
They analyze the senses on their respective sides of the body to allow us to feel sensations such as temperature, pressure, and pain and to make judgments about such things as shape and texture.
parietal lobes
he sense of vision is interpreted by what lobes
occipital
lobes
re associated with the senses of hearing, taste, and smell.
temporal lobes
Damage to the cerebral motor area before or shortly after birth
cerebral palsy
is located between the cerebrum
and the spinal cord Because of its location, all nerve fibers connecting the brain and spinal cord must pass through it, consists of the medulla oblongata, pons, and midbrain.
brain system
contains nerve centers that monitor and regulate breathing, heartbeat, blood pressure, and other vital body functions such as swallowing; it also is responsible for triggering you to sneeze.
medulla oblongata
assists the medulla oblongata in regulating breathing; it also helps coordinate some eye movements and facial expressions.
pons
help coordinate the movements of both eyes, adjust the size of the pupils in response to light, and operate the lens muscles to focus the eyes on the object of your attention.
midbrain
most important function is serving as the “master switch” of the cerebrum
reticular formation
involved in coordinating the activity of the different parts of the brain; they also seem to be important in generating and regulating emotions and desires in coordination with incoming sensory information and the powers of reason in the cerebrum
limbic system
acts like a switch-board, routing activation signals from the reticular formation and sensory impulses from various parts of the body to the appropriate areas of the cerebral cortex.
thalamus
the control unit for your body’s automatic systems
hypothalamus
processes factual memories for storage
hippocampus
helps generate emotions and processes emotional memories
amygdala
complete hearing loss
sensorineural deafness
degeneration and inflammation of nerves
neuritis
