Chapter 2 (Cells & Structure) Flashcards
glial cells
Also called glia. Nonneuronal brain cells thta provide structural, nutritional, and other types of support to the brain.
synapse
The cellular location at which information is transmitted from a neuron to another cell.
input zone
The part of a neuron that receives information, form other neurons or from specialized sensory structures.
dendrite
An extension of the cell body that receives information from other neurons.
integration zone
The part of a neuron that initiates nerve electrical activity
cell body or soma
The region of a neuron that is defined by the presence of the cell nucleus.
conduction zone
The part of a neuron over which the nerve’s electrical signal may be actively propagated.
axon
Also called nerve fiber. A single extension from the nerve cell that carries action potentials from the cell body toward the axon terminals.
output zone
The part of a neuron at which the cell sends information to another cell.
axon terminal
Also called synaptic bouton. The end of an axon or axon collateral, which forms a synapse on a neuron or another target cell.
motoneuron
Also called motor neuron. A neuron that transmits neural messages, to muscles (or glands).
sensory neuron
A nerve cell that is directly affected by changes in the environment, such as light, odor, or touch.
interneuron
A nerve cell that is neither a sensory neuron nor a motoneuron; interneurons receive input from and send output to other neurons.
multipolar neuron
A nerve cell that has many dendrites and a single axon (most common).
bipolar neuron
A nerve cell that has a single dendrite at one end and a single axon at the other end.
unipolar neuron
Also called a monopolar neuron. A nerve cell with a single branch that leaves the cell body and extends in two directions; one end is the input zone, and the other end is the output zone.
presynaptic
Referring to the region of a synapse that releases neurotransmitter.
postsynaptic
Referring to the region of a synapse that receives and responds to neurotransmitter.
presynaptic membrane
The specialized membrane on the surface of a nerve cell that receives information by responding to neurotransmitter fro a presynaptic neuron.
synaptic cleft
The space between the presynaptic and postsynaptic neurons at a synapse.
synaptic vesicle
A small, spherical structure that contains molecules of neurotransmitter.
neurotransmitter
The chemical released from the presynaptic axon terminal that serves as the basis of communication between neurons.
neurotransmitter receptor
A protein tat captures and reacts to molecules of a neurotransmitter or hormone.
neural plasticity
The ability of the nervous system to change in response to experience or the environment.
axon hillock
The cone-shaped area on the cell body from which the axon originates.
innervate
To provide neural input to.
axon collateral
A branch of an axon
axonal transport
The transportation of materials from the neuronal cell body to distant regions in the dendrites and axons, and from the axon terminals back to the cell body.
ogliodendrocyte
A type of glial cell that forms myelin in the central nervous system.
Schwann cell
A type of glial cell that forms myelin in the peripheral nervous system.
myelin
The fatty insulation around an axon, formed by glial cells. This sheath improves the speed at which nerve impulses are conducted.
node of Ranvier
A gap between successive segments of the myelin sheath where the axon membrane is exposed.
multiple sclerosis
Literally, “many scars”; a disorder characterized by the widespread degeneration of myelin.
astrocyte
A star-shaped glial cell with numerous processes (extensions) that run in all directions.
microglial cells
Also called microglia. Extremely small glial cells that remove cellular debris from injured or dead cells.
edema
Swelling of tissue, especially in the brain, in response to injury.
gross neuroanatomy
Anatomical features of the nervous system that are apparent to the naked eye.
CNS
The portion of the nervous system that includes the brain and the spinal cord.
peripheral nervous system
The portion of the nervous system that includes all the nerves and neurons outside the brain and spinal cord.
nerve
a collection of axons bundled together outside of the CNS
motor nerve
A nerve that transmits information from the CNS to the muscles and glands
sensory nerve
A nerve that conveys information from the body to the CNS
cranial nerve
A nerve that is connected directly to the brain (12)
spinal nerve
Also called somatic nerve. A nerve that emerges from the spinal cord.
autonomic nervous system
The part of the peripheral NS that supplies neural connections to the glands and to smooth muscles of internal organs.
sympathetic nervous system
The division of the autonomic nervous system that arises from the thoracic and lumbar spinal cord. This devision prepares the body for immediate action.
parasympathetic nervous system
The division of the autonomic NS that arises from both the cranial nerves and the sacral spinal cord. This division helps the body to relax, recuperate, and prepare for future action.
cerebral hemisphere
One of the two halves–right or left–of the forebrain.
cerebral cortex
The outer covering of the cerebral hemispheres, which consists largely of nerve cell bodies and their branches.
gyrus
A ridged or raised portion of a convoluted brain surface
sulcus
A crevice or valley of a convoluted brain surface.
Sylvian fissure
Also called lateral sulcus. A deep fissure that demarcates the temporal lobe.
central sulcus
A fissure that divides the frontal lobe from the parietal lobe.
corpus callosum
The main band of axons that connects the two cerebral hemispheres.
Afferent
Afferents arrive
Efferent
Efferents exit
postcentral gyrus
(Sensory) The strip of parietal cortex, just behind the central sulcus, that receives somatosensory information from the entire body
precentral gyrus
The strip of frontrol cortex, just in front of the central sulcus, that is crucial for motor control
gray matter
Areas of the brain that are dominated by cell bodies and are devoid of myelin. Gray matter mostly receives and processes information.
white matter
A lighter-colored layer of tissue, consisting mostly of myelin-sheathed axons, that lies underneath the gray matter of the cortex. White matter mostly transmits information.
neural tube
An embryonic structure with subdivisions that correspond to the future forebrain, midbrain, and hindbrain.
forebrain
The frontal division of the neural tube, containing the cerebral hemispheres, the thalamus, and the hypothalamus.
midbrain
The middle division of the brain
hindbrain
The rear division of the brain, which, in the mature vertebrate, contains the cerebellum, pons, and medulla.
telencephalon
The anterior part of the fetal forebrain, which will become the cerebral hemispheres in the adult brain.
diencephalon
The posterior part of the fetal forebrain, which will become the thalamus and and hypothalamus in the adult brain
brainstem
The region of the brain that consists of the midbrain, the pons, and the medulla.
nucleus
Here, a collection of neuronal cell bodies within the central nervous system (e.g. the caudate nucleus)
tract
A bundle of axons found within the CNS.
pyramidal cell
A type of large nerve cell has a roughly pyramidal shape cell body and is found in the cerebral cortex.
cortical column
One of the vertical columns that constitute the basic organization of the cerebral cortex.
basal ganglia
A group of forebrain nuclei, including the caudate nucleus, globus pallidus, and putamen, found deep within the cerebral hemispheres
caudate nucleus
One of the basal ganglia; it has a long extension or tail
putamen
One of the basal ganglia.
limbic system
A loosely defined, wide-spread group of brain nuclei that innervate each other to form a network.
amygdala
A group of nuclei in the medial anterior part of the temporal lobe.
hippocampus
A medial temporal lobe structure that is important for learning and memory
fornix
A fiber tract that extends from the hippocampus to the mammilary body
cingulate gyrus
A strip of cortex, found int he frontal and parietal midline, that is part of the limbic system as is implicated in many cognitive functions
olfactory bulb
An anterior projection of the brain that terminates in the upper nasal passages and, through small openings in the skull, provides receptors for smell.
thalamus
The brain regions that surround the third ventricle.
hypothalamus
Part of the diencephalon, lying ventral to the thalamus
superior colliculi
Paired gray matter structures of the dorsal midbrain that process visual information.
inferior colliculi
Paired gray matter structures of the dorsal midbrain that process auditory information
tectum
The dorsal portion of the midbrain consisting of the inferior and superior colliculi.
substantia nigra
A brainstem structure that innervates the basal ganglia and is the source of all dopaminergenic projections.
reticular formation
An extensive region of the brainstem (extending from the medulla through the thalamus) that is involved in sleep and arousal.
cerebellum
A structure located at the back of the brain, dorsal to pons, that is involved in the central regulation of movement.
pons
The portion of the brainstem that connects the midbrain to the medulla.
medulla
The posterior part of the hindbrain, continuous with the spinal cord.
meninges
The three protective membranes–dura mater, pia mater, and arachnoid–that surround the brain and spinal cord.
dura mater
The outermost of the three meninges that surround the brain and spinal cord.
pia mater
The innemost of the three meninges that surround the brain and spinal cord.
arachnoid
The thin covering (on of three meninges) of the brain that lies between the dura mater and the pia mater.
cerebrospinal fluid (CSF)
The fluid that fills the cerebral ventricles.
meningitis
An acute inflammation of the meninges, usually caused by a viral or bacterial infection
meningioma
A noninvasive tumor of the meninges
ventricular system
A system of fluid-filled cavities inside the brain.
lateral ventricle
A complexly shaped lateral portion of the ventricular system within each hemisphere of the brain.
choroid plexus
A specialized membrane lining the ventricles that produces CSF by filtering blood.
third ventricle
The midline ventricle that conducts CSF from the lateral ventricles to the fourth ventricle
fourth ventricle
The passageway within the pons that receives CSF from the third ventricle and releases it to t surround the brain and spinal cord.
stroke
Damage to a region of brain tissue that results from the blockage or rupture of vessels that supply blood to that region.
blood-brain barrier
The mechanisms that make the movement of substances from blood vessels into brain cells more difficult than exchanges in other body organs, thus affording the brain greater protection from exposure to some substances found in the blood.
CT
A noninvasive technique for examining brain structure through computer analysis of x-ray absorption at several positions around the head.
MRI
A noninvasive technique for examining brian structure that uses magnetic energy to generate images that reveal some structural details in the living brain
fMRI
MRI that detects changes in blood flow and therefore identifies regions of the brain that are particularly active during a given task.
positron emission tomography (PET)
A technique for examining brain function that combines tomography with injections of radioactive substances used by the brain.
transcranial magnetic stimulation (TMS)
A noninvasive technique for examining brain function that applies strong magnetic fields to stimulate cortical neurons, in order to identify discrete areas of the brain that are particularly active during specific behaviors
magnetoencephalography (MEG)
A passive and noninvasive technique for examining brain function that measures the tiny magnetic fields produced by active neurons, in order to identify regions of the brain that are particularly active during a given task
