Neuroanatomy Vocabulary

Flashcards related to Neuroanatomy vocabulary.

Neuron

Nerve cell, basic unit of the nervous system, each composed of receptive extensions (dendrites), cell body, conducting axon & transmitting axon terminal

Glial cell

Glia, nonneuronal brain cells that provide structural, nutritional & other types of support to the brain

Synapse

Cellular location at which information is transmitted from a neuron to another all

Input zone

Part of the neuron that receives information from other neurons / specialized sensory structures

Dendrite

An extension of the cell body that receives information from other neurons.

Integration zone

Part of a neuron that initiates neural electrical activity

Cell body (soma)

Region of a neuron that is defined by the presence of the cell nucleus

Axon (nerve fiber)

A single extension from the nerve cell that carries action potentials from the cell body toward axon terminals

Axon collateral

Branch of axon.

Output zones

Part of a neuron at which the cell sends information to another all

Axon terminal (bouton)

End of an axon or axon collateral which forms a synapse onto a neuron/other target all; serves as output zone

Dendritic spines

Small projections from the surface of the dendrite that add additional space for synapses; receives additional synaptic inputs; neuron's soma integrates/combines the information that has been received to determine whether or not to send a signal of its own

Conduction zones

Axon carries the neuron's own electrical signals away from the cell body

Motor neuron

Transmits neural messages to muscles/glands

Sensory neuron

Nerve cell that is directly affected by changes in environment (light, touch, odor…)

Interneuron

Nerve cell that is neither a sensory or motor neuron; receive input from & send output to other neurons

Multipolar neuron

Nerve cell with many dendrites & a single axon

Bipolar neuron

Nerve cell that has a single dendrite at one end & a single axon at the other end

Unipolar neuron (monopolar)

Nerve cell with a single branch that leaves the cell body & extends in 2 directions; one end input & other is output

Presynaptic

"Transmitting" side of a synapse

Postsynaptic

Region of a synapse that receives & responds to the neurotransmitter

Presynaptic membrane

Specialized membrane on the axon terminal of a nerve cell that transmits information by releasing neurotransmitters

Synaptic cleft

The space between the presynaptic & postsynaptic neurons at a synapse

Postsynaptic membrane

Specialized membrane on the surface of a neuron that receives information by responding to neurotransmitter from a presynaptic neuron.

Synaptic vesicle

Small, spherical structure that contains molecules of neurotransmitters

Neurotransmitter (synaptic/chemical)

Chemical released from the presynaptic axon terminal that serves as basis of communication between neurons.

Neuroplasticity

Ability of the nervous system to change in response to experience / environment

Axon hillock

Cone-shaped area on the cell body from which the axon originates

Innervate

To provide neural input to

Anterograde transport

Moves materials toward the axon terminals

Retrograde transport

Moves axonal used materials back to the cell body for recycling

Axonal transport

Transportation of materials from the neuronal cell body toward the axon terminals & from the axon terminals toward the cell body.

Oligodendrocytes

Type of glial cell that forms myelin in the central nervous system

Schwann cell

Type of glial cell that forms myelin in the peripheral nervous system.

Myelin

Fatty insulation around an axon, formed by glial cells; boosts 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

Astrocyte

Star-shaped glial cell with numerous processes (extensions) that run in all directions

Microglial cell

Extremely small motile glial cells that remove cellular debris from injured / dead cells

Gross neuroanatomy

Anatomical features of the nervous system that are apparent to the naked eye

Central nervous system (CNS)

Portion of the nervous system that includes brain & spinal cord

Peripheral nervous system (PNS)

Portion of the nervous system that includes all the nerves & neurons outside the brain & spinal cord

Nerve

Collection of axons bundled together outside the central nervous system

Motor nerve

A nerve that transmits information from the CNS to the muscles & glands

Sensory nerve

A nerve that conveys information from the body to the CNS

Somatic nervous system

A part of the PNS that supplies neural connections mostly to skeletal muscles & sensory systems of the body (cranial nerves & spinal nerves)

Autonomic nervous system

A part of the PNS that provides the main neural connections to the internal organs.

Cranial nerve

A nerve that is directly connected to the brain.

Spinal nerves

A nerve that emerges from the spinal cord.

Cervical

Topmost 8 segments of the spinal cord; in neck region

Thoracic

12 spinal segments below the cervical (neck) portion of the spinal cord; in the torso

Lumbar

5 spinal segments in the upper part of the lower back

Sacral

5 spinal segments in the lower part of the lower back

Coccygeal

Lowest spinal vertebra (coccyx, tailbone)

Sympathetic nervous system

Part of the autonomic nervous system that generally prepares the body for action

Parasympathetic nervous system

Part of the autonomic nervous system that generally prepares the body to relax/recuperate

Sympathetic ganglia

Small clusters of neurons found outside the CNS.

Sagittal plane

Plane that divides the body or brain into right & left portions

Coronal plane (frontal/transverse)

Plane that divides the body or brain into front & back portions

Horizontal plane

Plane that divides the body or brain into upper & lower portions.

Medial

Toward the middle

Lateral

Toward one side

Ipsilateral

A location on the same side of the body.

Contralateral

A location on the opposite side of the body.

Superior

Above

Inferior

Below

Basal

Toward the base / bottom of a structure

Anterior (rostral)

Toward the head end of an organism

Posterior (caudal)

Toward the tail end of an organism

Proximal

Near the trunk / center of an organism

Distal

Toward the periphery of an organism or end of a limb

Afferent

Carrying an action potential toward the brain, or toward one region of interest from another region of interest

Efferent

Carrying an action potential away from the brain, or away from one region toward another

Dorsal

Back of body, top of brain.

Ventral

Toward the belly or front of the body, bottom of brain

Gray matter

Areas of the brain that are dominated by cell bodies & devoid of myelin, mostly receives & processes information

White matter

Light-coloured layer of tissue, consists mostly of myelin sheathed axons that lies underneath the gray matter of the cortex, mostly transmits information

Cerebral hemisphere

One of the 2 halves - right or left - of the forebrain

(Cerebral) cortex

Outer covering

Gyrus

Ridged or raised portion of the cortical surface

Sulcus

Crevice or valley of the cortical surface

Frontal lobe

The most anterior portion of the cerebral cortex.

Parietal lobe

Large region of cortex lying between the frontal & occipital lobes in each cerebral hemisphere

Temporal lobe

Large lateral region of cortex in each cerebral hemisphere; continuous with the parietal lobe posteriorly & separated from frontal by Sylvian fissure

Occipital lobe

Large region of cortex that covers much of the posterior part of each cerebral hemisphere

Sylvian fissure (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

Main band of axons that connect the 2 cerebral hemispheres

Postcentral gyrus

Strip of parietal cortex, just posterior to the central sulcus that receives somatosensory information from the entire body

Precentral gyrus

Strip of frontal cortex, just anterior to the central sulcus that is crucial to motor control

Neural tube

An embryonic structure with subdivisions that corresponds to the future forebrain, midbrain, & hindbrain

Forebrain

The frontal division the neural tube, containing the cerebral hemisphere, thalamus, & hypothalamus

Midbrain

Middle division of the brain.

Hindbrain

Rear division of the brain, which in mature vertebrate contains the cerebellum, pons, & medulla

Telencephalon

Anterior part of the fetal forebrain, which will become the cerebral hemispheres in the adult brain

Diencephalon

Posterior part of the fetal forebrain, which will become the thalamus & hypothalamus in the adult brain.

Brainstem

Region of the brain that consists of the midbrain, pons, medulla

Nucleus

A collection of neuronal cell bodies within the central nervous system

Tract

Bundle of axons found within the central nervous system.

Pyramidal cell

Type of large nerve cell that has a roughly pyramid-shaped cell body & is found in the cerebral cortex

Cortical column

One of the vertical columns that constitute the basic organization of the cerebral cortex