ch. 11 terms Flashcards
Nervous and ? systems coordinate and regulate all body activities to maintain ?
endocrine, homeostasis
? System is slower and uses chemical messengers (Hormones) that travel
in BV to target cells
*Hormone effects last longer
*Hormones bind to receptors on target cells and change cell’s ?
endocrine, metabolism
? System is faster and uses an ? and chemical mechanisms
*Nervous system is rapid, specific, and causes almost immediate
?
*Nerve impulses will “switch on or switch off”
*Nervous impulse effects short-lived
*Neurotransmitters bind to receptors
nervous, electrical, responses
information gathered by sensory receptors is called
sensory input
processing and interpreting sensory input is called
integration
activation of effector organs to produce responses
motor output
? consists of the Brain and Spinal Cord
CNS
? consists of cranial and spinal nerves
PNS
? nerves = to and from spinal cord
? nerves = to and from brain
spinal, cranial
*? are bundles of axons (nerve fibers) in the PNS
*? are collections of neuron cell bodies
nerves, ganglia
2 functional divisions of PNS are :
sensory and motor
? (afferent) division consist of nerve fibers (axons) that carry impulses
to CNS from sensory receptors
sensory
2 branches of sensory division are: (S.V.)
somatic and visceral
? sensory fibers
Convey impulses from skin, skeletal muscles, and joints
to CNS; Consciously perceived
keeps CNS informed of events going on both
? and ? the body
somatic, inside, outside
? sensory fibers
Convey impulses from visceral organs
to CNS; Not
consciously perceived
visceral
? Division (efferent)
*Transmits impulses from CNS to effector organs
*It causes
1. Muscles to ?
2. Glands to ?
motor, contract, secrete
*? = muscles and glands
effectors
? Nervous System is the Voluntary Nervous System that controls ? muscle movemets
somatic, skeletal
? nervous system is the involuntary nervous system that regulates smooth and ? muscles
autonomic, cardiac
branches of the autonomic NS: (S.P)
sympathetic, parasympathetic
division that prepares body for ‘fight/flight’ responses
sympathetic
division that promotes ‘rest/digest’
parasympathetic
Nervous tissue consists two main cell types:
1. ? = glial cells
2. ? = nerve cells
*neuroglial (glial cells) are small cells that support the delicate ?
*neurons (nerve cells) are excitable cells that respond to a ? and transmit electrical signals
neuroglial, neurons, neurons, stimulus
change in environment triggering a response is called a
stimulus
Neuroglia of the CNS include:
1. Astrocytes- ?-shaped glial cells that support neurons and capillaries
2. ? cells- ? cells that monitor neuron health and respond to injury
3. Ependymal cells- line brain cavities & circulate CSF
4. ?- form ? sheaths around CNS nerve fibers
star, microglial, small, Oligodendrocytes, myelin
? cells surround neuron cell bodies in PNS
satellite
Schwann cells (?) surround all peripheral nerve fibers
and form insulating ? sheaths
neurolemmocytes, myelin
Special characteristics of Neurons
1. Extreme ? (lasts a person’s lifetime)
2. ? (lose ability to divide), with few exceptions
3. High metabolic rate so require continuous supply of ? and glucose
4. All have a cell body and one or more slender processes
longevity, amitotic, oxygen
? are bundles of neuron processes (axons) in CNS
? are bundles of neuron processes (axons) in PNS
tracts, nerves
? are clusters of neuron cell bodies in ? that are protected by bones of skull or vertebrae
? are clusters of neuron cell bodies in ? that are protected by transverse processes of vertebral column
nuclei, CNS, ganglia, PNS
Signals on dendrites are not called AP
*Signals on dendrites are short-distance signals called ? ? ; they have ? signals, are either ? or hyperpolarizing depending on stimulus ?, and decay with distance
graded potential, input, depolarizing, intensity
Each neuron has one axon that starts at cone-shaped area called the ? ?
axon hillock
long axons are called ? Fibers
Axons have occasional branches called axon ?
Distal endings of the terminal branches on an axon are called ? ?
nerve, collaterals, axon terminals
axolemma is the axons ? ?
cell membrane
An ? ? is a long-distance rapid sequence of changes in the voltage across a membrane that maintains the same ? and is ?polarizing
action potential, volume, depolarizing
axons that are surrounded by myelin sheaths conduct faster when they have ? fibers and form ? matter
myelinated, white
fibers w/o myelin sheaths conduct slower when they have ? fibers and form ? matter
nonmyelinated, gray
neurons w 3+ processes and are common in the CNS (polar)
multipolar
neurons w 1 axon and 1 dendrite, rare
bipolar
neurons w only 1 process, primarily sensory
unipolar
? Neurons (Afferent Neurons) transmit impulses from sensory receptors toward the CNS
sensory
? (Association Neurons) lie between motor and sensory neurons and
shuttle signals through the CNS pathways where integration occurs
*Most interneurons are found entirely within the CNS
*?% of body’s neurons are interneurons
interneurons, 99
? Neurons (Efferent Neurons) carry impulses from the CNS to effectors
*All motor neurons are ?polar
motor, multipolar
? ? potential occurs when the cell is inactive
resting membrane
? is a measure of potential energy generated by separated charges and measure as Volts (V) or millivolts (mV)
voltage
? channels (aka non-gated) are always open
leakage
? channels only open/close when part of a protein changes
gated
there are 3 types of gated channels:
1. ? gated channels- (ligand-gated)- only open with the binding of a specific chemical (ach)
2. ?-gated channels- open and close in response to changes in membrane potential/electrical charge
3. ? gated channels- open and close in response to the physical
deformation of receptors
chemical, voltage, mechanically
Resting membrane potential of a resting neuron is approximately ? mV
–70
Two factors generate the RMP
1. Differences in ionic composition of ? and ?
2. Differences in plasma membrane ?
the ? distribution of ions across the cell membrane, combined with the membrane’s selective ? to certain ions, creates the electrical potential difference known as the RMP.
ICF, ECF, permeability, unequal, permeability
Four main steps in an Action Potential (r.s/polar)
1. ?
2. ?
3. ?
4. ?
resting state, depolarization, repolarization, hyperpolarization
At ? state, all gated sodium potassium channels are ? and only sodium potassium leakage channels ?
resting, closed, open
When a stimulus comes along (such as chemicals, heat, light, or mechanical pressure) and the stimulus reaches ?, depolarization begins
threshold
depolarization occurs when the membrane potential becomes less ? than the resting potential causing ? channels to open and become more ?
negative, sodium, positive
repolarization is the process of returning back to the ? ? after ?, allowing potassium ions to flow out to restore the ? internal charge.
membrane potential, depolarization, negative
? is the process whereby the membrane potential becomes more ? than the ? potential making it difficult for the neuron to fire an AP.
hyperpolarization, negative, resting
phenomenon that states that an ‘AP occurs fully or not at all, no partial AP’
all-or-non-phenomenon
Absolute refractory period:
This is the time during which a cell cannot ? another ? potential, no matter how strong the stimulus is.
generate, action
Relative refractory period:
Following the absolute refractory period, this is the time when a cell can ? fire another AP, but only if a significantly ? stimulus is applied.
potentially, stronger
? ? (MS) is an ? disease that occurs when myelin sheaths in CNS are destroyed when the ? system attacks the myelin
multiple sclerosis, autoimmune, immune
a neuron that conducts impulses toward the synapse
presynaptic neuron
a neuron that transmits signals away from the synapse
postsynaptic neuron
6 steps involved in transfer across chemical synapses: (A.C.R.B.R.E)
Action potential arrival, Calcium influx, Release of neurotransmitter, Binding to receptors, Response in postsynaptic cell, Enzymatic breakdown/reuptake
the process of neurotransmitter reabsorption by a presynaptic neuron is called
reuptake
8 neurotransmitters by chemical structure: (E.N.D.S.G.A.G.E)
epinephrine, norepinephrine, dopamine, serotonin, GABA, acetylcholine, glutamate, endorphins
Excitatory (?polarizing)
Inhibitory (?polarizing)
depolarizing, hyperpolarizing
With ? processing, input travels along one pathway to a specific destination
serial
? are rapid, automatic responses to stimuli
reflexes
? processing is when the input travels along several pathways to different parts of circuitry and deal simultaneously with the information
parallel
Five Components of Spinal Reflex Series (R.S.C.M.E)
1. ?
2. ? neuron
3. ? integration center
4. ? neuron
5. ?
- Receptor
- Sensory neuron
- CNS integration center
- Motor neuron
- Effector
one input that leads to multiple outputs is called an ? circuit
diverging
many inputs that lead to one output is called a ? circuit
converging
