ch6 vocab Flashcards
astrocyte
Most common glial cell; has projections that cover portions of neurons and blood ves-
sels; control movement of materials out of blood vessels into nervous tissue
axon
a nerve fiber, long extension that conducts action potentials
axon hillock
cone shaped area where the axon connects to the soma
axon terminal
Also called synaptic knob or bouton: releases neurotransmitter into a synapse
bipolar neuron
has one dendrite and one axon
cell body
Soma or perikaryon; site of the nucleus and most other organelles
dendrite
Short extension that responds to a stimulus
ependymal cells
secretes serebrospinal fluid at choroid plexus in brin ventricles
ganglion
Collection of neuron cell bodies in the PNS
gray matter
Collection of neuron cell bodies in the CNS
interneuron
(Association neuron, internuncial neuron, connector neuron); a multipolar neuron that
conducts impulses within the CNS; its axon is a tract in the brain or spinal cord
microglia
Phagocytic glial cells in the CNS
motor neuron
Multipolar neuron that conducts impulses out of the CNS
multipolar neuron
has many dendrites and one axon
Myelin sheath
Tightly wrapped lipid layer around certain axons (myelinated axons)
Nerve
Collection of axons (neuron fibers) in the PNS
Node of Ranvier
Space between Schwann cells along a myelinated axon
Oligodendrocyte
Glial cell that forms myelin sheaths in the CNS
Satellite cell
Surrounds a neuron within a ganglion
Schwann cell
Glial cell that forms myelin sheaths in the PNS
Sensory neuron
Conduct impulses toward the CNS; most are unipolar, but some are bipolar
tract
Bundle of axons in the CNS
Unipolar neuron
Has a single projection extending from cell body; its dendrite and axon form one extension
White matter
Light-colored collection of axons in the CNS
3rd ventricle
Slit-like cavity between the two halves of the hypothalamus
4th ventricle
Cavity between the pons and cerebellum
Arbor vitae
Branches of white matter in the cerebellum; seen in a medial view
Central sulcus
Sulcus that separates the frontal lobe from the parietal lobe
Cerebellum
Second largest part of the brain; located beneath the occipital lobes; consists of
two cerebellar hemispheres and is important for maintaining balance and
equilibrium
Cerebral aqueduct
Tube connecting 3rd and 4th ventricles; transports CSF
Cerebrum
Largest part of the brain; consists of a right and left cerebral hemisphere
Choroid plexus
Network of capillaries and ependymal cells within a ventricle; produces cer-
ebrospinal fluid
Corpus callosum
Site of commissural fibers connecting cerebral hemispheres
Diencephalon
Between corpus callosum and midbrain; includes hypothalamus, thalamus, and
epithalamus
Epithalamus
Superior portion of diencephalon; pineal body is attached to its posterior end
Frontal lobe
Anterior to the central sulcus; closest to the frontal bone; includes the pre-
central gyrus
Gyrus
Raised ridge on the surface of the cerebrum
Hypothalamus
inferior portion of the diencephalon; center of autonomic nervous system
function
Lateral sulcus
Sulcus that separates the temporal lobe from the parietal lobe
Lateral ventricles
Two large cavities, one in each cerebral hemisphere; separated by the septum
pellucidum
Longitudinal fissure
Deep groove separating the right and left cerebral hemispheres
Medulla oblongata
Inferior bulge of the brainstem between the pons and spinal cord; contains many
“centers” for involuntary control of muscles
Occipital lobe
Posterior to the parieto-occipital sulcus and located closest to the occipital
bone
Parietal lobe
Posterior to the central sulcus; closest to the parietal bone; includes the
postcentral gyrus
Parieto-occipital sulcus
Separates the parietal lobe from the occipital lobe
Pineal gland (body)
Posterior end of epithalamus; secretes melatonin important in sleep-wake cycles
Postcentral gyrus
Gyrus immediately posterior to the central sulcus
Precentral gyrus
Gyrus immediately anterior to the central sulcus
Sulcus
Groove between adjacent gyri on the surface of the cerebrum
Temporal lobe
Inferior to the lateral sulcus; closest to the temporal bone
Thalamus
Middle portion of diencephalon surrounding the
intermediate mass
Ventricle
Cavity within the brain and it is filled with circulating cerebrospinal
fluid
Amygdala
Part of the limbic system; in the temporal lobe; processes emotions for fear, anger,
and pleasure; controls storage of emotional memories
Association fibers
Tracts that conduct impulses within a cerebral hemisphere
Auditory association area
In the temporal lobe; interpretation of sound
Auditory cortex
Gray matter for sound perception; in temporal lobes
Broca’s area
Speech center; controls motor movements for speech; usually in left frontal lobe
Commissural fibers
Tracts in the corpus callosum and connects right and left cerebral hemispheres
Frontal association area
(Prefrontal area) Gray matter for thought processing; in frontal lobes
Frontal eye field
Gray matter that controls voluntary eye movement; in frontal lobes
Gustatory cortex
Gray matter for taste perception; in the insula
Hippocampus
Part of the limbic system; controls conversion of short-term to long-term
memory, emotional responses to memories, and spatial memory (remembering
locations in space)
Interventricular foramen
(Foramen of Monro); passage for cerebrospinal fluid moving from the lateral
ventricles into the third ventricle
Limbic system
Internal brain structures associated with emotions
Longitudinal fissure
Groove in the sagittal plane that separates the cerebral hemispheres
Motor cortex
Gray matter for voluntary muscle movement; in precentral gyrus of frontal lobe
Motor speech area
(Broca’s area); gray matter for speech control; usually in lateral side of left frontal
lobe
Nuclei
Gray matter in brain regions deep to the cortex
Olfactory cortex
Gray matter for smell perception; in temporal lobes
Optic chiasma
Beneath frontal lobes and anterior to pituitary gland; where the two optic nerves
unite
Pons
Part of brain stem; relay center between medulla oblongata and higher brain
centers
Postcentral gyrus
in parietal lobe immediately posterior to central
sulcus; contains somatosensory cortex
Precentral gyrus
In frontal lobe immediately anterior to central sulcus; contains primary
motor cortex
Prefrontal area
Gray matter for problem-solving, imagination, artistic skills; in frontal
lobes
Premotor area
Gray matter for memory of reflexive motor skills; in frontal lobes
Projection fibers
Tracts that connect the cerebrum to lower brain centers
Putamen
A basal nucleus; not well understood
Septum pellucidum
Membrane in sagittal plane and separates the lateral ventricles
Somatosensory association
area
Gray matter for interpretation of somatosensory input; in parietal lobes
Somatosensory cortex
Gray matter for perception of touch, temperature, pressure; in
postcentral gyrus
Tracts
Bundles of white matter (neuron axons) in the CNS
Visual association area
Gray matter for interpretation of visual input; in occipital lobes
Visual cortex
Gray matter for light perception; in occipital lobes
Wernicke’s area
(Auditory association area); gray matter for interpreting speech; in left
temporal lobe
Anterior column
White matter between anterior horns
Anterior horns
Gray matter projections on anterior side of cord
Cauda equina
Nerve roots at inferior end of cord; resembles horse’s tail
Central canal
Small canal along entire length of cord
Lateral columns
White matter around lateral horns
Lateral horns
Lateral projections of gray matter in cord
Posterior columns
White matter between posterior horns
Posterior horns
Gray matter projections on posterior side of cord
Arachnoid mater
mmediately superficial to pia mater; resembles spider web
Dura mater
Most superficial meninx; tough and fibrous
Pia mater
Deepest meninx; thin membrane attached to surface of brain and spinal cord
Subarachnoid space
Between arachnoid and pia mater
Subdural space
Between dura mater and arachnoid
