Neuroanatomy Flashcards
Neuron
Aka nerve cell
The basic unit of the nervous system, each composed of a cell body, receptive extension(s) - dendrites, and a transmitting extension - axon.
Glial Cells
Aka: glia or neuro-glia
Nonneuronal brain cells that provide structural, nutritional, and other types of support to the brain.
Neuron Doctrine
The hypothesis that the brain is composed of separate cells that are distinct structurally, metabolically, and functionally.
Synapse
The tiny gap between neurons where information is passed from one to the other.
Mitochondria
Cellular organelles that provide metabolic energy for the cell’s processes
Cell Nucleus
The spherical central structure of a cell that contains the chromosomes
Ribosomes
Structures in the cell body where genetic information is translated to produce proteins
Dendrite
One of the extensions of the cell body that are the receptive surfaces of the neuron
Input zone
The part of a neuron that receives information from other neurons or from specialized sensory structures. Usually corresponds to the cells dendrites.
Cell Body
Aka: soma
The region of a neuron that is defined by the presence of the cell nucleus.
Integration zone
The part of the neuron that initiates nerve electrical activity. Usually corresponds to the neuron’s axon hillock.
Axon
A single extension from the nerve cell that carries actions potentials from the cell body to other neurons
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.
Axon collateral
A branch of an axon from a single neuron
Axon terminal
Aka: synaptic bouton
The end of the axon or axon collateral, which forms a synapse on a neuron or other target cell
Output zone
The part of the neuron, usually corresponding to the axon terminals, at which the cell sends information to another cell
Multipolar neuron
A nerve cell that has many dendrites and a single axon
Bipolar neuron
A nerve cell that has a single dendrite at one end and a single axon at the other end
Unipolar neuron
Aka: monopolar neuron
A nerve cell with a single branch that leaves the cell body and then extends in two directions; one end is the receptive pole, the other end the output zone.
Motor neuron
Aka: motoneuron
A never sleek that transmits motor messages, stimulating a muscle or gland
Sensory neuron
A neuron that is directly affected by changes in the environment, such as light, odor, or touch.
Interneuron
A neuron that is neither a sensory neuron nor a motor neuron; it revives input from and sends output to other neurons
Arborization
The elaborate branching of the dendrites of some neurons
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 of the axon terminal of the neuron that transmits information by releasing neurotransmitter.
Synaptic cleft
The space between the presynaptic and postsynaptic elements
Postsynaptic membrane
The specialized membrane on the surface of the cell that receives information by responding to neurotransmitter from a presynaptic neuron
Synaptic vesicle
A small, spherical structure that contains molecules of neurotransmitter
Neurotransmitter
Aka: synaptic transmitter, chemical transmitter, or transmitter
The chemical released from the presynaptic axon terminal that serves as the basis of communication between neurons.
Receptor
Aka: receptor molecule
A protein that binds and reacts to molecules of a neurotransmitter or hormone
Axon hillock
A cone-shaped area from which the axon originates out of the cell body. Functionally, the integration zone of the neuron.
Innervate
To provide neural input
Motor protein
A specialized kinetic protein molecule that conveys a load, such as a vesicle, from one location to another within a cell
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.
Astrocyte
A star-shaped glial cell with numerous processes (extensions) that run in all directions
Microglial cells
Aka: microglia
Extremely small glial cells that remove cellular debris from injured and dead cells
Oligodendrocyte
Glial cell that forms myelin in the central beehive system
Schwann cell
Glia cell that forms myelin in the peripheral nervous system
Myelination
The process of myelin formation
Myelin
The fatty insulation around the axon, formed by glial cells, that improves the speed of conduction of action potentials
Node of Ranvier
A gap between successive segments of the myelin sheath where the axon membrane is exposed
Edema
The swelling of tissue, such as in the brain, in response to injury
Multiple sclerosis
Literally, “many scars”. A disorder characterized by wide-spread degeneration of myelin
Gross neuroanatomy
Anatomical features of the nervous system that are apparent to the naked eye
Peripheral nervous system
The portion of the nervous system that includes all nerves and neurons outside the brain and spinal cord
Central nervous system (CNS)
The portion of the nervous system that includes the brain and spinal cord
Nerve
A collection of axons bundled together outside the central nervous system
Motor nerve
And nerve that conveys natural activity to muscle tissue and causes it to contract
Sensory nerve
A nerve that convey sensory information from the periphery into the central nervous system
Somatic nervous system
The part of the peripheral nervous system that provides neural connections to the skeletal musculature
Autonomic nervous system
The part of the peripheral nervous system that supplies neural connections to glands and smooth muscles of internal organs
Cranial nerve
A nerve that is connected directly to the brain
Spinal nerve
Aka: somatic never
The nerve that emerges from the spinal cord
Dorsal root
The branch of a spinal nerve, entering the dorsal horn of the spinal cord, that carries sensory information from the peripheral nervous system to the spinal cord
Ventral root
The branch of a spinal nerve, arising from the ventral horn of the spinal cord, that carries motor messages from the spinal cord to the peripheral nervous system
Cervical
Referring to the top most eight 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 five spinal segments that make up the upper part of the lower back
Sacral
Referring to the five spinal segments that make up the lower part of the lower back
Coccygeal
Referring to the lower spinal vertebra (also called the 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
Literally, “before the ganglion”. Referring to neurons in the autonomic nervous system that run from the central nervous system to the autonomic ganglia
Postganglionic
Literally, “after the ganglion”. 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 arrives 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 arrives from both the cranial nerves and the sacral spine cord
Acetylcholine
A neurotransmitter produced and released by parasympathetic postganglionic neurons, by motor neurons, and by neurons throughout the brain
Enteric nervous system
An extensive mesh-like system of neurons that governs the functioning of the gut
Cerebral hemispheres
The right and left halves of the forebrain
Gyrus
A rigid or raised portion of the convoluted brain surface
Sulcus
A furrow of a convoluted brain surface
Frontal lobe
The most anterior portion of the cerebral cortex
Parietal lobe
Large region of the cortex lying between the frontal and occipital lobes of each cerebral hemisphere
Temporal lobe
Large lateral cortical region of each cerebral hemisphere, continuous with the parietal lobe posteriorly and separated from the frontal lobe by the sylvian fissure
Occipital lobe
Large region of cortex covering much of the posterior part of each cerebral hemisphere
Sylvian fissure
Aka: lateral sulcus
A deep fissure that demarcates the temporal lobe
Central sulcus
A Fissure that divides the frontal lobe from the parietal lobe
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
Gray matter
Areas of the brain that are dominated by cell bodies and are devoid of myelin
White matter
A pale-coloured layer underneath the cortex that consists largely of axons with white myelin sheaths
Neural tube
An embryonic structure with subdivisions that correspond to the future forebrain, midbrain, and hindbrain.
Forebrain
The anterior division of the brain, 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 , ponds, 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 the hypothalamus
Metencephalon
A subdivision of the hindbrain that includes 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
Brainstem
The region of the brain that consists of the midbrain, pons, and the medulla
Nucleus
Here, a collection of neurons within the central nervous system
Ex. The caudate nucleus
Tract
A bundle of axons found within the central nervous system
Allocortex
Cortical tissue with three layers of unlayered organization, in contrast with six-layered neocortex
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 sell 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
Basal ganglia
A group of forebrain nuclei, including caudate nucleus, globes pallidus, and putamen, found deep within the cerebral hemispheres
Caudate nucleus
One of the basal ganglia; it has a long extension or tail
Putamen
Globus pallidus
One of the basal ganglia
Substantia nigra
A brain stem structure in humans that innervates 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
Mammillary body
One of a pair of nuclei at the base of the brain
Hippocampus
A medial temporal lobe structure that is important for learning and memory
Fornix
A fiver tract that extends from the hippocampus to the mammillary body
Septal nuclei
A collection of gray matter structures lying medially below the corpus callosum, implicated in the perception of reward
Cingulate Gyrus
A cortical portion of the limbic system, found in the frontal and parietal midline
Olfactory bulb
And anterior projection of the brain that terminates in the upper nasal passages and, through small openings in the skull, provides receptors for smell
Stria terminalis
A lymbic pathway connecting the amygdala and hypothalamus
Thalamus
The brain regions that surround the third ventricle
Hypothalamus
Part of the diencephalon, lying ventral to the thalamus
Tectum
The dorsal portion of the midbrain, including the inferior and superior colliculi
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 intend stimuli
Inferior colliculi
Paired gray matter structures of the dorsal midbrain that receive auditory information
Red nucleus
A brain stem structure related to motor control
Reticular formation
And extensive region of the brainstem (extending from the medulla through the thalamus) that is involved in arousal (waking)
Purkinje cell
A type of large nerve cell in the cerebellar cortex
Granule cell
A type of small nerve cell
Parallel fibre
One of the axons of the granule cell that forms the outermost layer of the cerebellar cortex
Meninges
The three protective sheets of tissue- dura mater, pia mater, and arachnoid - that surround the brain and spinal cord
Dura mater
The outer most of the brain three meninges that surround the brain and spinal cord
Pia mater
The innermost of the three meninges that surround the brain and spinal cord
Arachnoid
The thin covering of the brain that lies between the Dura mater and the pia mater
Cerebrospinal fluid
CSF
The fluid that fills the cerebral ventricles
Meningitis
And acute inflammation of the meninges , usually caused by a viral or bacterial infection
Meningiomas
Several classes of the non-cancerous tumours arising from the meninges
Ventricular system
A system of fluid-filled cavities is 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 cerebrospinal fluid
Third ventricle
The midline ventricle that conducts cerebrospinal fluid from the lateral ventricle to the fourth ventricle
Fourth ventricle
The passageway within the pons that receives cerebrospinal fluid 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 internal carotid arteries, that provide blood to the anterior poles and
medial surfaces of the cerebral hemispheres
Middle cerebral arteries
Two large arteries, arising from the internal carotid arteries , that provide blood to most of the lateral surfaces of the cerebral hemispheres
Posterior cerebral arteries
Two large arteries, arising from the bacillar 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 the posterior cerebral arteries
Circle of Willis
A vascular structure at the base of the brain that is formed by the joining of the carotid and basilar arteries
Stroke
Damage to a region of brain tissue that results from 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
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 radiopaque dye by means of a catheter
Computerized axial tomography
CAT or CT
A noninvasive technique for examining brain structure in humans through computer analysis of x-ray absorption at several positions around the head
Magnetic resonance imaging
MRI
A noninvasive technique that uses magnetic energy to generate images that reveal some structural details in the living brain
Diffusion tensor imaging
DTI
A modified form of MRI in which the diffusion of water in a confined space is exploited to produce images of axonal fibre tracts.
Fractional anisotrophy
FA
The tendency of water to diffuse more readily along the long axis of an enclosed space, such as an axon. FA is the basis of diffusion tensor imaging.
DTI Tractography
Aka: fibre tracking
Visualization of the orientation and terminations of white matter tracts in the living brain via diffusion tensor imaging
Positron emission tomography
PET
A technique for examining brain function by combining tomography with injections of radioactive substances used by the brain
Functional MRI
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
Transcranial magnetic stimulation
TMS
Localized, noninvasive stimulation of cortical neurons through the application of strong magnetic fields
Magnetoencephalography
MEG
A passive and noninvasive functional brain imaging technique that measures the tiny magnetic field produced by active neurons, in order to identify regions of the brain that are particularly active during a given task
Lesions
Regions of damage within the brain
Social neuroscience
The use of neuroscience techniques to understand the neural basis of social processes
Dyadic functional MRI
dfMRI
An fMRI technique in which the brains of two interacting individuals are simultaneously imaged
