Neurological System 1 Flashcards
The nervous system contains two main divisions: ______
The central nervous system (CNS), The peripheral nervous system (PNS)
The central nervous system consists of: _______
Brain and spinal cord
Three essential roles of nervous system: ______
Sensing, Integrating and Responding
PNS consists of ___ paired nerves: ___ pairs of cranial nerves and ___ pairs of spinal nerves
43, 12, 31
_________ : All body systems working together to maintain a stable internal environment; internal conditions fluctuate within a limited range; essential to survival
Equilibrium/ (Homeostasis)
_________ coordinates rapid and precise responses to stimuli using action potentials
The nervous system
________ regulate body functions, maintains homeostasis and long-term control using chemical signals- hormones
The endocrine system
Compare nervous system and endocrine system. Give 3 difference.
Nervous System’s means of communication are electrical Impulses and neurotransmitters, while endocrine system’s are hormones.
Neurotransmitters are released at synapses at target cells in nervous system while hormone released into blood stream for distribution throughout body in endocrine system.
Have relatively local and specific effects for nervous system while wide spread and general effects for endocrine system.
Describe the process from sensory input to motor output.
Receptors at the PNS collect information. PNS then send the
information to CNS for processing and evaluation. CNS determines if action / response is needed. CNS send nerve
impulses to the effector cells through the PNS.
What types of muscle do somatic nervous system control?
skeletal muscles
What types of muscle do autonomic nervous system control?
smooth and cardiac muscle, (glands)
Somatic nervous system’s neuron consists of ________
a single neuron between CNS and skeletal muscle cells
Autonomic nervous system’s neuron consists of ________
2 neuron chain (connected by synapse) between CNS and effector organ
________: Can lead only to muscle excitation
Somatic Nervous System
________: Can either be excitatory or inhibitory
Autonomic Nervous System
Sensory (_____) division
Motor (_____) division
afferent, efferent
Function of Nervous Tissue: ____________
Transmit the information from one part of the body to another, by means of nerve impulse
Nervous cells called ______ consists of 3 parts
________: Contain nucleus and other organelles
________: Short projections to receive inputs
________: Single, thin and long projection to conduct output
impulse
neurons, Cell body, Dendrites, Axon
Cells support neurons called _______
neuroglia
Three classes of neurons:
Multipolar neurons: Interneurons/ Motor neurons
(e.g. within CNS)/(e.g. from CNS to muscle/gland)
Bipolar neurons: Sensory neurons (e.g. from retina to brain)
Unipolar neurons: Sensory neurons (e.g. from skin to CNS)
Axons contact another neuron at a very specialized region of the cell membrane called ______.
synapse
Nerve impulse reaches a synapse, release signalling
chemicals called “________” to travel a
short distance to next cell membrane and attach to the
receptors.
neurotransmitters
Axons wrapped in a white, fatty, segmented covering called a ________.
myelin sheath
Cell body can also called _____,
it cotains _____for __________
and _____for __________.
soma,
many mitochondria, cell respiration and energy production,
Nissl bodies, protein synthesis
Function of dendrites:
Receive impulses from other
cells toward the cell body
Function of axons:
conduct nerve impulses away from cell bodies
How many axon to all neurons?
Only one
4 types of channels:
_______: found in membranes all over the nerve cell; allow ions to move in or out of the cell
_______: found on the ________ ; only open if detect a certain voltage; responsible for generating an action potential
_______: found on ________; only open the fated when activated by a chemical messenger; also named receptor
_______: found on ________; only open when activated by mechanical stimulus
Passive/Leak ion channels,
Voltage-activated ion channels, axon membrane and soma
Chemically activated ion channels, dendrites and soma
Mechanically gated ion channels, dendrites and soma
Multipolar neurons usually have ____ dendrites and ___axon
several, one
Give examples of the location of multipolar neurons(_____).
In the brain and spinal cord, (motor neurons)
Bipolar neurons have ____ main dendrite and ____ axon.
one, one
Give examples of the location of bipolar neurons(_____).
Found in the retina of the eye, the inner ear, and the olfactory(smell) area of the brain, (Interneuron)
Unipolar Neurons have one _____ that are fused together to form a continuous process that emerges from the cell body
axon
Function of unipolar neurons
Function as sensory receptors that detect a sensory stimulus such as touch, pressure, pain, or thermal stimuli
The cell bodies of unipolar neurons are located in _____.
the ganglia of spinal and cranial nerves
Unipolar neurons mostly reside in ________.
the sensory nerves of the peripheral nervous system
________: Integrate sensory information from sensory neurons and then elicit a motor response by activating the motor neurons
Interneurons or association neurons
________: Convey nerve impulses away from the CNS to
effectors (muscles and glands) through cranial or
spinal nerves (PNS)
Motor neurons or efferent neurons
________: a stimulus activates a sensory receptor to form a
nerve impulse in its axon; the nerve impulse is conveyed into the CNS through cranial or spinal nerves
Sensory neurons or afferent neurons
Most of the sensory neurons are _______ in structure.
unipolar
Most of the motor neurons are _______ in structure.
multipolar
Most of the interneurons neurons are _______ in structure.
multipolar
Each neuron contains ~_____ neuroglia (_____) which has similar shape to neuron but have fiber-like extensions; have membrane receptors and channels but not conduct _______.
50, supportive cells of the nervous system, nerve impulses
The most abundant glial cells: ______
Astrocytes, “star cells”
Give two functions of astrocytes
*Produce chemical factors that affect repair and
regeneration processes; repair by stabilizing
the injured site and prevent further injury
* Cause nearby blood vessels to dilate which
increases blood flow to the area, enable the
neurons to obtain oxygen and glucose more
quickly
* Provide structural framework for neurons
* Direct neuron development
* Supply nutrients to neurons
* Help neurons maintain their electrical potential
by regulating Na+ and K+
ions
* Regulate the concentration of transmitters
* Form part of the blood-brain barrier (BBB) -
prevents harmful molecules from entering the
brain.
________(one of the five types of glia): phagocytic cells that ingest and digest microorganisms and waste products from injured neurons; release low levels of growth factors that help neurons to survive
Microglia
________(one of the five types of glia): line the four cavities in the brain, called ventricles, and the choroid plexuses; possess microvilli and cilia; help produce cerebrospinal fluid (CSF)
Ependymal cells
________(one of the five types of glia): support and electrically insulate CNS axons by forming protective myelin sheaths; have fewer branch than astrocytes
Oligodendrocytes
Ependymal cells line the four cavities in the brain,
called ____________.
ventricles, and the choroid plexuses
The two kinds of PNS neuroglia: ______ and ______
Satellite cells, Schwann cells
______: surround neuron cell bodies located in the PNS; the same functions as astrocytes do in the CNS
Satellite cells
_________:
surround all nerve fibres in the PNS;
form myelin sheaths around the thicker nerve fibres; functionally similar to oligodendrocytes – faster nerve impulse conduction through axon;
regeneration of damaged peripheral nerve fibres
Schwann cells
Function of myelin sheath
Increases the speed of nerve impulse conduction
Two types of neuroglia produce myelin sheaths:
______(in the CNS) - forms myelin sheaths for several axons
______(in the PNS) - wrap themselves completely around one axon
Oligodendrocytes, Schwann cells
________: display little regrowth after injury due to the absence of ______.
Oligodendrocyte, neurolemma
________: has ____that aids regeneration by forming a regeneration tube that guides and stimulates regrowth of the injured axon
Schwann cells, neurolemma
A collection of neuron cell bodies in the CNS is called ____.
nucleus
A collection of neuron cell bodies in the PNS is called ____.
ganglion
A bundle of axons in the CNS is called ____.
tract
A bundle of axons in the PNS is called ____.
nerve
White matter: composed of _______
myelinated axons
Grey matter: contains _____
neuronal cell bodies, dendrites, unmyelinated axons, axon terminals, and neuroglia
White matter in the spinal cord in _____
outer
White matter in the brain in _____
inner
Describe the electricity among the cell membrane when resting membrane potential
The inside of the cell is negatively charged with respect to the outside.
_____(one of the 4 types of ion channels):
the membrane’s permeability to ___ is much higher than its permeability to ___
Leak Channels,
K+, Na+
_____(one of the 4 types of ion channels):
Opens or closes in response to ______ stimulation in
the form of vibration (such as ________)
Found in ________
Mechanically gated channel, mechanical
sound waves, touch, pressure, or tissue stretching,
auditory receptors in the ears, in receptors that
monitor stretching of internal organs, and in touch
receptors and pressure receptors in the skin
_____(one of the 4 types of ion channels):
Opens and closes in response to the binding of a
______(chemical) stimulus—including __________
Located in the dendrites of some sensory neurons,
such as _______, and in dendrites and cell
bodies of interneurons and motor neurons
Ligandgated channel, ligand,
neurotransmitters, hormones, and particular ions,
pain receptors
_____(one of the 4 types of ion channels):
Opens in response to a change in membrane potential
Voltage-gate channel
The direction an ion moves (into or out of the cell) is determined by the __________
electrochemical gradient
The electrochemical gradient has two components:
Concentration gradient, electrical gradient
The _____ stabilizes the resting membrane potential
sodium-potassium pump (Na+-K+ATPase)
______: a decrease in membrane potential;
the inside of the membrane becomes less negative (moves
closer to zero) than the resting potential;
increases the probability of producing nerve impulses
Depolarization
______: an increase in membrane potential;
the inside of the membrane becomes more negative (moves
farther from zero) than the resting potential;
reduces the probability of producing nerve impulses
Hyperpolarization
_____: a brief change of membrane potential with a total amplitude (change in voltage) (from ___ mV to ___ mV)
Action potentials, -70, +30
In a neuron, an action potential is also called a ____, and is typically generated only in ____ (voltage-gated channels)
nerve impulse, axons
The change in voltage only occurs at the _____ and these stepwise transmission called “______”
Nodes of Ranvier, saltatory conduction
Factors that affect the speed of propagation
Amount of myelination, Axon diameter, Temperature
The nerve impulse travels down __________
Dendrites → Cell body → Axon → Synaptic knob → Synaptic cleft
_____: a region where communication occurs between two neurons or between a neuron and an effector cell (muscle cell or glandular cell).
A synapses
_____: a nerve cell that carries a nerve impulse toward a synapse
Presynaptic neuron
_____: the cell that receives a signal; carries a nerve impulse away from a synapse or an effector cell that responds to the impulse at the synapse
Postsynaptic neuron
_____: less common type of synapses
Electrical synapses
Two main advantages of electrical synapses
Faster communication, synchronization (coordinate the
activity of a group of neurons or muscle fibres)
_____: the most common type of synapse
Chemical synapses
A chemical/ chemical messenger called a
_______bridges a very narrow gap (the ______) to carry the message from the ____ neuron to the _____ neuron
neurotransmitter, synaptic cleft, presynaptic, postsynaptic
Two types of chemical synapses:
______ - the binding of the neurotransmitter to its receptor
cause_______; the membrane potential change is referred to _______
______ - the binding of the neurotransmitter _______; the membrane potential change is referred to _________
Excitatory chemical synapses, more Na+ into the cell, excitatory postsynaptic potential
Inhibitory chemical synapses, opens the Cl-channel, inhibitory postsynaptic potential
When nerves are injured (such as from a cut, crushing injury, or some other type of trauma), their ability
to repair themselves depends on _______
the extent of the injury as well as their location
Nerves in the peripheral nervous system can regenerate as long as the _____ are intact
soma and neurilemma
Nerves in the central nervous system lack a _______, they cannot regenerate (most injuries to the brain and spinal cord cause permanent damage)
neurolemma
Neurotransmitter receptors are classified as:
________: a type of ligand-gated channel; three most plentiful cations (Na+, K+, and Ca2+) through the postsynaptic cell membrane
________: the ___ either directly opens (or closes) the ion channel or acts indirectly by activating another molecule, a “______”, which in turn opens (or closes) the ion channel
ionotropic receptors,
metabotropic receptors, G protein, second messenger
_____: at neuromuscular junction; released by cholinergic neurone (parasympathetic neurons of the vagus X)
Acetylcholine (Ach)
_____: plays roles in arousal (awakening from deep sleep), dreaming, and regulating mood; a “feel good” neurotransmitter
Norepinephrine
_____: active during emotional responses, addictive behaviors, and pleasurable experiences; regulate skeletal muscle tone and some aspects of movement due
to contraction of skeletal muscles; a “feel good” neurotransmitter
Dopamine
_____: involved in sensory perception, temperature regulation, control of mood, appetite, and the induction of sleep
Serotonin
_____: an important excitatory neurotransmitter
secreted in the brain, spinal cord, suprarenal glands, and nerves to the penis and has widespread effects throughout the body
Nitric Oxide
_____: protect against excess neuronal activity; related to dilation of blood vessels, memory, sense of smell, vision, thermoregulation, insulin release, and antiinflammatory activity
Carbon Monoxide
