soma
cell body
input zone
the part of a neuron that receives information, from other neurons or from specialized sensory structures. Usually corresponds to the cell's dendrites
integration zone
the part of the neuron that initiates nerve electrical activity. Usually corresponds to the neuron's axon hillock
conduction zone
the part of the neuron over which the nerve's electrical signal may be actively propagated. Usually corresponds to the cell's axon
output zone
the part of a neuron, usually corresponding to the axon terminals, at which the cell sends information to another cell
golgi stain
a histological stain that fills a small proportion of neurons with a dark, silver-based precipitate
nissl stain
a histological stain that outlines all cell bodies because the dyes are attracted to RNA, which encircles the nucleus
autoradiography
a histological technique that shows the distribution of radioactive chemicals in tissues
immunocytochemistry
labeling a structure's antibodies with a dye or radioactive element then exposing slices of brain to antibodies
in situ hybridization
a method for detecting particular RNA transcripts in tissue sections by providing a nucleotide probe that is complementary to, and will therefore hybridize with, the transcript of interest
immediate early genes
a class of genes that show rapid but transient increases in experession in cells that have become activated
c-fos
an immediate early gene commonly used to identify activated neurons
multipolar neurons
have many dendrites and a single axon, and they are the most common type of neuron
bipolar neurons
have a single dendrite at one end of the cell and a single axon at the other end. This type of neuron is especially common in sensory systems, such as vision
unipolar neurons
have a single extension usually thought of as an axon, that branches in two directions after leaving the cell body. On end is the input zone with branches like dendrites; the other, the output zone
astrocyte
a star-shape glial cell with numerous processes (extensions) that run in all directions
microglial cells
extremely small glial cells that remove cellular debris from injured or dead cells
node of Ranvier
a gap between successive segments of the myelin sheath where the axon membrane is exposed
multiple sclerosis
literally "man scars" a disorder characterized by widespread degeneration of myelin
oligodendrocyte
a type of glial cell that forms myelin in the central nervous system
schwann cell
the glial cell that forms myelin in the peripheral nervous system
edema
the swelling of tissue, especially in the brain, in response to injury
arborization
the elaborate branching of the dendrites of some neurons
cauda equina
the caudal-most spinal nerves, which extend beyond the spinal cord proper to exit the spinal column
peripheral nervous system
the portion of the nervous system that includes all the nerves and neurons outside the brain and spinal cord
central nervous system
the portion of the nervous system that includes the brain and the spinal cord
cranial nerve
a nerve that is connected directly to the brain
spinal nerve
aka somatic nerve, a nerve that emerges from the spinal cord
autonomic nervous system
the part of the peripheral nervous system that supplies neural connections to glands and to smooth muscles of internal glands
CN 1
olfactory
CN 2
optic
CN 3, 4, 6
oculomotor, trochlear, abducens, (moves eyes)
CN 5
trigeminal, face, sinuses, teeth
CN 7
facial, tongue, soft palate
CN 8
vestibulocochlear, inner ear
CN 9
glossopharyngeal, taste and other mouth sensations
CN 10
vagus, information from internal organs
CN 11
spinal accessory, neck muscles
CN 12
hypoglossal, tongue muscles
cervical
referring to the topmost 8 segments of the spinal cord, in the neck region
thoracic
referring to the 12 spinal segments below the cervical (neck) portion of the spinal cord, corresponding to the chest
lumbar
referring to the 5 spinal segments that make up the upper part of the lower back
sacral
referring to the 5 spinal segments that make up the lower part of the lower back
coccygeal
referring to the lowest spinal vertebra (AKA tailbone)
autonomic ganglia
collections of nerve cell bodies, belonging to the autonomic division of the peripheral nervous system, that are found in various locations and innervate the major organs
preganglionic
Referring to neurons in the autonomic nervous system that run from the central nervous system to the autonomic ganglia
postganglionic
Referring to neurons in the autonomic nervous system that run from the autonomic ganglia to various targets in the body
sympathetic nervous system
a component of the autonomic nervous system that arises from the thoracic and lumbar spinal cord
sympathetic chain
a chain of ganglia that runs along each side of the spinal column; part of the sympathetic nervous system
parasympathetic nervous system
a component of the autonomic nervous system that arises from both the cranial nerves and the sacral spinal cord
norepinephrine
AKA noradrenaline. A neurotransmitter produced and released by sympathetic postganglionic neurons to accelerate organ activity. Also produced in the brainstem and found in projections throughout the brain
acetylcholine
a neurotransmitter produced and released by parasympathetic postganglionic neurons, by motoneurons, and by neurons throughout the brain
enteric nervous system
an extensive meshlike system of neurons that governs the functioning of the gut
cerebral hemispheres
the right and left halves of the forebrain
gyrus
a ridged or raised portion of a convoluted brain surface
sulcus
a furrow of a convoluted brain surface
frontal lobe
the most anterior portion of the cerebral cortex
parietal lobes
Large regions of cortex lying between the frontal and occipital lobes of each cerebral hemisphere
temporal lobes
Large lateral cortical regions of each cerebral hemisphere, continuous with the parietal lobes posteriorly, and separated from the frontal lobe by the Sylvian fissure
occipital lobes
Large regions of cortex covering much of the posterior part of each cerebral hemisphere
sylvian fissure
A deep fissure that demarcates the temporal lobe
central sulcus
A fissure that divides the frontal lobe from the parietal lobe
cerebral cortex
The outer covering of the cerebral hemispheres, which consists largely of nerve cell bodies and their branches
postcentral gyrus
The strip of parietal cortex, just behind the central sulcus, that receives somatosensory information from the entire body
precentral gyrus
the strip of frontal cortex, just in front of the central sulcus, that is crucial for motor control
corpus callosum
the main band of axons that connects the two cerebral hemispheres
white matter
a shiny layer underneath the cortex that consists largely of axons with white myelin sheaths
gray matter
Areas of the brain that are dominated by cell bodies and are devoid of myelin
neural tube
an embryonic structure with subdivisions that correspond to the future forebrain, midbrain, and hindbrain
forebrain
also called prosencephalon. The frontal division of the neural tube, containing the cerebral hemispheres, the thalamus, and the hypothalamus
midbrain
also called mesencephalon. The middle division of the brain
hindbrain
also called rhombencephalon. The rear division of the brain, which, in the mature vertebrate, contains the cerebellum, pons, and medulla
telencephalon
the frontal subdivision of the forebrain that includes the cerebral hemispheres when fully developed
diencephalon
the posterior part of the forebrain, including the thalamus and hypothalamus
metencephalon
a subdivision of the hindbrain that includes the cerebellum and the pons
cerebellum
a structure located at the back of the brain, dorsal to the pons, that is involved in the central regulation of movement
pons
a portion of the metencephalon; part of the brainstem connecting midbrain to medulla
medulla
the posterior part of the hindbrain, continuous with the spinal cord
brainstem
the regions of the brain that consists of the midbrain, pons, and the medulla
nucleus
Here, a collection of neuronal cell bodies within the central nervous system
tract
a bundle of axons found within the central nervous system
basal ganglia
a group of forebrain nuclei, including caudate nucleus, globus pallidus, and putamen, found deep within the cerebral hemipsheres
caudate nucleus
one of the basal ganglia; it has a long extension or tail
putamen
one of the basal ganglia, p one
globus pallidus
one of the basal ganglia, gp
substania negra
a brainstem structure in humans that is related to the basal ganglia and is named for its dark pigmentation
limbic system
a loosely defined, widespread 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 cortical portion of the limbic system, found in the frontal and parietal midline
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
mammilary body
one of a pair of nuclei at the base of the brain
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 receive visual information and are involved in direction of visual gaze and visual attention to intended stimuli
inferior colliculi
paired gray matter structures of the dorsal midbrain that receive auditory information
tectum
the dorsal portion of the midbrain, including the inferior and superior colliculi
red nucleus
a brainstem structure related to motor control
reticular formation
an extensive region of the brainstem that is involved in arousal
purkinje cell
a type of large nerve cell in the cerebellar cortex
granule cell
a type of small nerve cell
parallel fiber
one of the axons of the granule cells that form the outermost layer of the cerebellar cortex
neocortex
cerebral cortex that is made up of 6 distinct layers
allocortex
brain tissue with 3 layers or unlayered organization
pyramidal cell
a type of large nerve cell that has a roughly pyramid-shaped cell body; found in the cerebral cortex
apical dendrite
the dendrite that extends from a pyramidal cell to the outermost surface of the cortex
basal dendrite
one of several dendrites on a pyramidal cell that extend horizontally from the cell body
cortical column
one of the vertical columns that constitute the basic organization of the neocortex
meninges
the 3 protective sheets of tissue-dura matter, pia matter, and arachnoid-that surround the brain and spinal cord
dura matter
the outermost of the 3 meninges that surround the brain and spinal cord
pia matter
the innermost of the 3 meninges that surround the brain and spinal cord
arachnoid
the thin covering of the brain that lies between the dura matter and the pia matter
CSF
the fluid that fills the cerebral ventricles
meningitis
an acute inflammation of the meninges, usually caused by a viral or bacterial infection
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 highly vascular portion of the lining of the ventricles that secretes CSF
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 surround the brain and spinal cord
carotid arteries
the major arteries that ascend the left and right sides of the neck to the brain, supplying blood to the anterior and middle cerebral arteries
anterior cerebral arteries
two large arteries, arising from the carotids, that provide blood to the anterior poles and medial surfaces of the cerebral hemispheres
middle cerebral arteries
two large arteries, arising from the carotids, that provide blood to most of the lateral surfaces of the cerebral hemispheres
posterior cerebral arteries
two large arteries, arising from the basilar artery, that provide blood to posterior aspects of the cerebral hemispheres, cerebellum, and brainstem
vertebral arteries
arteries that ascend the vertebrae, enter the base of the skull, and join together to form the basilar artery
basilar artery
an artery, formed by the fusion of the vertebral arteries, that supplies blood to the brainstem and to the posterior cerebral arteries
circle of willis
a structure at the base of the brain that is formed by the joining of the carotid and basilar arteries
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
angiography
a brain-imaging technique in which a specialized x-ray image of the head is taken shortly after the cerebral blood vessels have been filled with a radiopaque dye by means of a catheter
CAT
a noninvasive technique for examining brain structure in humans through computer analysis of x-ray absorption at several positions around the head
MRI
a noninvasive technique that uses magnetic energy to generate images that reveal some structural details in the living brain
PET
a technique for examining brain function by combining tomography with injections of radioactive substances used by the brain
fMRI
magnetic resonance imaging that detects changes in blood flow and therefore identifies regions of the brain that are particularly active during a given task
optical imaging
a method for visualizing brain activity in which near-infrared light is passed through the scalp and skull
TMS
localized, noninvasive stimulation of cortical neurons through the application of strong magnetic fields
MEG
a passive and noninvasive functional brain-imaging technique 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