Chapter 11: Fundamentals of the Nervous System and Nervous Tissue Study Guide

Nerve cell
A cordlike bundle of neuronal axons and/or dendrites and associated connective tissue coursing together outside the central nervous system
Central nervous system
peripheral nervous system
afferent division of the PNS
sensations that encompass typical sensations (sensory) in addition to things like hunger, breathing, pH level in blood, etc.
Sensory TO the CNS
efferent division of the PNS
handles outgoing information and can be divided into the somatic and autonomic nervous systems
carries motor commands from the CNS to muscles, glands, adipose tissue (effector tissues)
parasympathetic nervous system
the division of the autonomic nervous system that calms the body, conserving its energy
deactivates or shows down activities of muscles and glands (rest-and-digest response); slowing down of heart rates, pupillary constriction
sympathetic nervous system
The division of the autonomic nervous system that arouses the body, mobilizing its energy in stressful situations.
property of cell that it may create and conduct an electrical current when stimulated;
Cells that support, insulate, and protect neurons. These cells are able to divide and are usually involved in brain tumors.
glial cells
Cells in the nervous system that support, nourish, and protect neurons.
Provide structural and metabolic support for neurons.
What cells contribute to the blood-brain barrier and proliferate in response to CNS injury?

CNS cells responsible for physical support and maintaining blood brain barrier, GFAP marker (glial fibrillary astrocyte protein)

Act as phagocytes, eating damaged cells and bacteria, act as the brains immune system
ependymal cells
What are ciliated CNS neuroglia that play an active role in moving the cerebrospinal fluid called?
CNS (line ventricles of brain and central canal of spinal cord) / Active rolein formation and circulation of CSF
Type of glial cell in the CNS that wrap axons in a myelin sheath.
satellite cells
Glial cells that surround the neurons in ganglia ar
Which of the following supportive cells of the nervous system are part of the blood nerve barrier in the peripheral nervous system? (Mark all that apply)
Schwann cells
Type of glia in the PNS, Supporting cells of the peripheral nervous system responsible for the formation of myelin.
action potential
A neural impulse; a brief electrical charge that travels down an axon. The action potential is generated by the movement of positively charged atoms in and out of channels in the axon’s membrane.
Neurons lose their ability to divide early in our life. This makes them ___.
can’t reproduce (if you loose it, you can’t regrow it), but some specific regions display adult nuerogenesis (hippocampus [memory] and olfactory bulb [keep smelling]
Nissil bodies
what is the rough endoplasmic reticulum made of in the neuron?
groups of free ribosomes and rough ER. Dark regions in a sagittal section of the brain
Which of the following are bundles of neurofilaments that are important in maintaining the shape and integrity of neurons?
bundles of actin filaments
a complex organic substance present in living cells, especially DNA or RNA, whose molecules consist of many nucleotides linked in a long chain
Collections of nerve cell bodies
An anatomically distinct collection of sensory or motor neuron cell bodies within the PNS
Easily controlled or managed, docile; easily shaped or molded
A cordlike bundle of neuronal axons and/or dendrites and associated connective tissue coursing together outside the central nervous system
myelin node of ranvier
white matter
The portions of the central nervous system that are abundant in axons rather than cell bodies of neurons. The colour derives from the presence of the axon’s myelin sheaths
gray matter
a portion of the CNS consisting of cytons (cell bodies), their dendrites and synaptic connections
Brain and spinal cord tissue that appears gray with the naked eye; consists mainly of neuronal cell bodies (nuclei) and lacks myelinated axons.
multipolar neuron
A neuron with a single axon and multiple dendrites; the most common type of neuron in the nervous system.
bipolar neuron
A neuron with a single axon and a single dendrite, often projecting from opposite sides of the cell body. Bipolar neurons are typically associated with sensory organs; an example is the bipolar neuron in the retina of the eye. – note that one axon may innervate many different muscles, or other things.
unipolar neuron
A neuron with one axon attached to its soma; the axon divides, with one branch receiving sensory information and the other sending the information into the central nervous system.
sensory neuron
Neurons that carry incoming information from the sensory receptors to the brain and spinal cord.
motor neuron
a neuron that sends an impulse to a muscle or gland, causing the muscle or gland to react
Neurons within the brain and spinal cord that communicate internally and intervene between the sensory inputs and motor outputs.
The potential difference measured in volts. The amount of work to be done to move a charge from one point to another along an electric circuit.
In psychoanalysis, the blocking from consciousness of anxiety-laden material.
A material’s opposition to the flow of electric current.
A flow of electric charge.
Ohm’s law
A conductor obeys ohms law if its resistance is independent of applied voltage; if R remain constant even if V is changed
chemically gated ion channel
The receptor is a closed ion channel that opens when a ligand binds to it. Permits ions in when open and prevents them from leaving when closed.
voltage gated ion channel
Protein that selectively allows particular ions to cross a membrane in response to a change in membrane potential. Found mainly in electrically excitable cells such as nerve and muscle cells.
electrochemical gradient
The combination of forces that acts on membrane potential.
The process through which electrons are attracted to or repelled by an external electric field, causing the electrons to move within their own atoms
The movement of the membrane potential of a cell away from rest potential in a more negative direction.
The process during the action potential when sodium is rushing into the cell causing the interior to become more positive.
graded potential
shift in electrical charge in a tiny area of the neuron (temporary); transmits a long cell membranes leaving neuron and polarized state; needs higher than normal threshold of excitation to fire
The level of stimulation required to trigger a neural impulse
absolute refractory period
The minimum length of time after an action potential during which another action potential cannot begin.
relative refractory period
a period after firing when a neuron is returning to its normal polarize state and will only fire again if the incoming message open parentheses impulse) is stronger than usual; returning to arresting state
A junction where information is transmitted from one neuron to the next.
dendrodendritic synapse
one connecting two dendrites of different neurons
dendrosomatic synapse
a synapse bt/w a dendrite of one neuron and the soma of another
presynaptic neuron
conducts impulses toward the synapse
post synaptic neuron
Transmits impulses away from the synapse
axodendritic synapse
the junction between the processes of two neurons or between a neuron and an effector organ, where neural impulses are transmitted by chemical means. The impulse causes the release of a neurotransmitter (e.g., acetylcholine) from the presynaptic membrane of the axon terminal. The neurotransmitter molecules diffuse across the synaptic cleft, bind with specific receptors on the postsynaptic membrane, causing depolarization or hyperpolarization of the postsynaptic cell.
electrical synapse
A type of syanpse in which the cells are connected by gap junctions, allowing ions (and therefore an action potential) to spread easily from cell to cell, usually in smooth and cardiac muscle. – compared to chemical synapse.
chemical synapse
A type of synapse at which a chemical (a neurotransmitter) is released from teh axon of a neuron into the ysnaptic cleft where it binds to receptors on the next structure in sequence, either another neuron or an organ.
Excitatory postsynaptic potential; a slight depolarization of a postsynaptic cell, bringing the membrane potential of that cell closer to the threshold for an action potential.
Inhibitory postsynaptic potential; a slight hyperpolarization of the postysynaptic cell, moving the membrane potential of that cell further from threshold.
temporal summation
Summation by a postsynaptic cell of input (EPSPs or IPSPs) from a single source over time.
Numerous nerve impulses arriving at a synapse at closely timed intervals exert a cumulative effect
spatial summation
Integration by a postsynaptic neuron of inputs (EPSPs and IPSPs) from multiple sources.
Chemical messengers that cross the synaptic gaps between neurons. When released by the sending neuron, neurotransmitters travel across the synapse and bind to receptor sites on the receiving neuron, thereby influencing whether that neuron will generate a neural impulse.
neural integration
the process by which inhibitory and excitatory postsynaptic potentials summate and control the rate of firing of a neuron
neuronal pools
groups of neurons that make hundreds of synaptic connections with each other and work together to perform a common function
series circuit
A circuit in which all parts are connected end to end to provide a single path of current.
parallel circuit
A closed electrical circuit in which the current is divided into two or more paths and then returns via a common path to complete the circuit.
reflex arc
A relatively direct connection between a sensory neuron and a motor neuron that allows an extremely rapid response to a stimulus, often without conscious brain involvement.