Chapter 13: Anatomy of the Nervous System Flashcards
Abducens nerve
sixth cranial nerve; responsible for contraction of one of the extraocular muscles
Alar plate
developmental region of the spinal cord that gives rise to the posterior horn of the gray matter
Amygdala
Nucleus deep in the temporal lobe of the cerebrum that is related to memory and emotional behavior
Anterior column
White matter between the anterior horns of the spinal cord composed of many different groups of
axons of both ascending and descending tracts
Anterior horn
gray matter of the spinal cord containing multipolar motor neurons, sometimes referred to as the ventral
horn
Anterior median fissure
deep midline feature of the anterior spinal cord, marking the separation between the right
and left sides of the cord
Anterior spinal artery
blood vessel from the merged branches of the vertebral arteries that runs along the anterior
surface of the spinal cord
Arachnoid granulation
outpocket of the arachnoid membrane into the dural sinuses that allows for reabsorption of
CSF into the blood
Arachnoid mater
middle layer of the meninges named for the spider-web–like trabeculae that extend between it and
the pia mater
Arachnoid trabeculae
filaments between the arachnoid and pia mater within the subarachnoid space
Ascending tract
central nervous system fibers carrying sensory information from the spinal cord or periphery to the
brain
Axillary nerve
systemic nerve of the arm that arises from the brachial plexus
Basal forebrain
nuclei of the cerebrum related to modulation of sensory stimuli and attention through broad
projections to the cerebral cortex, loss of which is related to Alzheimer’s disease
Basal nuclei
nuclei of the cerebrum (with a few components in the upper brain stem and diencephalon) that are
responsible for assessing cortical movement commands and comparing them with the general state of the individual
through broad modulatory activity of dopamine neurons; largely related to motor functions, as evidenced through
the symptoms of Parkinson’s and Huntington’s diseases
Basal plate
developmental region of the spinal cord that gives rise to the lateral and anterior horns of gray matter
Basilar artery
blood vessel from the merged vertebral arteries that runs along the dorsal surface of the brain stem
Brachial plexus
nerve plexus associated with the lower cervical spinal nerves and first thoracic spinal nerve
Brain stem
region of the adult brain that includes the midbrain, pons, and medulla oblongata and develops from the
mesencephalon, metencephalon, and myelencephalon of the embryonic brain
Broca’s area
region of the frontal lobe associated with the motor commands necessary for speech production and
located only in the cerebral hemisphere responsible for language production, which is the left side in approximately
95 percent of the population
Brodmann’s areas
mapping of regions of the cerebral cortex based on microscopic anatomy that relates specific areas
to functional differences, as described by Brodmann in the early 1900s
Carotid canal
opening in the temporal bone through which the internal carotid artery enters the cranium
Cauda equina
bundle of spinal nerve roots that descend from the lower spinal cord below the first lumbar vertebra and
lie within the vertebral cavity; has the appearance of a horse’s tail
Caudate
nucleus deep in the cerebrum that is part of the basal nuclei; along with the putamen, it is part of the striatum
Central canal
hollow space within the spinal cord that is the remnant of the center of the neural tube
Central sulcus
surface landmark of the cerebral cortex that marks the boundary between the frontal and parietal lobes
Cephalic flexure
curve in midbrain of the embryo that positions the forebrain ventrally
Cerebellum
region of the adult brain connected primarily to the pons that developed from the metencephalon (along
with the pons) and is largely responsible for comparing information from the cerebrum with sensory feedback from
the periphery through the spinal cord
Cerebral aqueduct
connection of the ventricular system between the third and fourth ventricles located in the
midbrain
Cerebral cortex
outer gray matter covering the forebrain, marked by wrinkles and folds known as gyri and sulci
Cerebral hemisphere
one half of the bilaterally symmetrical cerebrum
Cerebrum
region of the adult brain that develops from the telencephalon and is responsible for higher neurological
functions such as memory, emotion, and consciousness
Cervical plexus
nerve plexus associated with the upper cervical spinal nerves
Choroid plexus
specialized structures containing ependymal cells lining blood capillaries that filter blood to produce
CSF in the four ventricles of the brain
Circle of Willis
unique anatomical arrangement of blood vessels around the base of the brain that maintains perfusion
of blood into the brain even if one component of the structure is blocked or narrowed
Common carotid artery
blood vessel that branches off the aorta (or the brachiocephalic artery on the right) and
supplies blood to the head and neck
Corpus callosum
large white matter structure that connects the right and left cerebral hemispheres
Cranial nerve
one of twelve nerves connected to the brain that are responsible for sensory or motor functions of the
head and neck
Cranial nerve ganglion
sensory ganglion of cranial nerves
Descending tract
Central nervous system fibers carrying motor commands from the brain to the spinal cord or
periphery
Diencephalon
region of the adult brain that retains its name from embryonic development and includes the thalamus
and hypothalamus
Direct pathway
connections within the basal nuclei from the striatum to the globus pallidus internal segment and
substantia nigra pars reticulata that disinhibit the thalamus to increase cortical control of movement
Disinhibition
disynaptic connection in which the first synapse inhibits the second cell, which then stops inhibiting the
final target
Dorsal (posterior) nerve root
axons entering the posterior horn of the spinal cord
Dorsal (posterior) root ganglion
sensory ganglion attached to the posterior nerve root of a spinal nerve
Dura mater
tough, fibrous, outer layer of the meninges that is attached to the inner surface of the cranium and vertebral
column and surrounds the entire CNS
Dural sinus
tough, fibrous, outer layer of the meninges that is attached to the inner surface of the cranium and vertebral
column and surrounds the entire CNS
Endoneurium
innermost layer of connective tissue that surrounds individual axons within a nerve
Enteric nervous system
peripheral structures, namely ganglia and nerves, that are incorporated into the digestive
system organs
Enteric plexus
neuronal plexus in the wall of the intestines, which is part of the enteric nervous system
Epineurium
outermost layer of connective tissue that surrounds an entire nerve
Epithalamus
region of the diecephalon containing the pineal gland
Esophageal plexus
neuronal plexus in the wall of the esophagus that is part of the enteric nervous system
Extraocular muscles
six skeletal muscles that control eye movement within the orbit
Facial nerve
seventh cranial nerve; responsible for contraction of the facial muscles and for part of the sense of taste, as
well as causing saliva production
Fascicle
small bundles of nerve or muscle fibers enclosed by connective tissue
Femoral nerve
systemic nerve of the anterior leg that arises from the lumbar plexus
Fibular nerve
systemic nerve of the posterior leg that begins as part of the sciatic nerve
Foramen magnum
large opening in the occipital bone of the skull through which the spinal cord emerges and the
vertebral arteries enter the cranium
Forebrain
anterior region of the adult brain that develops from the prosencephalon and includes the cerebrum and
diencephalon
Fourth ventricle
the portion of the ventricular system that is in the region of the brain stem and opens into the
subarachnoid space through the median and lateral apertures
Frontal eye field
region of the frontal lobe associated with motor commands to orient the eyes toward an object of
visual attention
Frontal lobe
region of the cerebral cortex directly beneath the frontal bone of the cranium
Gastric plexus
neuronal networks in the wall of the stomach that are part of the enteric nervous system
Globus pallidus
nuclei deep in the cerebrum that are part of the basal nuclei and can be divided into the internal and
external segments
Glossopharyngeal nerve
ninth cranial nerve; responsible for contraction of muscles in the tongue and throat and for
part of the sense of taste, as well as causing saliva production
Gyrus
ridge formed by convolutions on the surface of the cerebrum or cerebellum
Hindbrain
posterior region of the adult brain that develops from the rhombencephalon and includes the pons, medulla
oblongata, and cerebellum
Hippocampus
gray matter deep in the temporal lobe that is very important for long-term memory formation
Hypoglossal nerve
twelfth cranial nerve; responsible for contraction of muscles of the tongue
Hypothalamus
major region of the diencephalon that is responsible for coordinating autonomic and endocrine control
of homeostasis
Indirect pathway
connections within the basal nuclei from the striatum through the globus pallidus external segment
and subthalamic nucleus to the globus pallidus internal segment/substantia nigra pars compacta that result in
inhibition of the thalamus to decrease cortical control of movement
Inferior colliculus
half of the midbrain tectum that is part of the brain stem auditory pathway
Inferior olive
nucleus in the medulla that is involved in processing information related to motor control
Intercostal nerve
systemic nerve in the thoracic cavity that is found between two ribs
Internal carotid artery
branch from the common carotid artery that enters the cranium and supplies blood to the brain
Interventricular foramina
openings between the lateral ventricles and third ventricle allowing for the passage of CSF
Jugular veins
blood vessels that return “used” blood from the head and neck
Kinesthesia
general sensory perception of movement of the body
Lateral apertures
pair of openings from the fourth ventricle to the subarachnoid space on either side and between the
medulla and cerebellum
Lateral column
white matter of the spinal cord between the posterior horn on one side and the axons from the anterior
horn on the same side; composed of many different groups of axons, of both ascending and descending tracts,
carrying motor commands to and from the brain
Lateral horn
region of the spinal cord gray matter in the thoracic, upper lumbar, and sacral regions that is the central
component of the sympathetic division of the autonomic nervous system
Lateral sulcus
surface landmark of the cerebral cortex that marks the boundary between the temporal lobe and the
frontal and parietal lobes
Lateral ventricles
portions of the ventricular system that are in the region of the cerebrum
Limbic cortex
collection of structures of the cerebral cortex that are involved in emotion, memory, and behavior and are
part of the larger limbic system
Limbic system
structures at the edge (limit) of the boundary between the forebrain and hindbrain that are most
associated with emotional behavior and memory formation
Longitudinal fissure
large separation along the midline between the two cerebral hemispheres
Lumbar plexus
nerve plexus associated with the lumbar spinal nerves
Lumbar puncture
procedure used to withdraw CSF from the lower lumbar region of the vertebral column that avoids
the risk of damaging CNS tissue because the spinal cord ends at the upper lumbar vertebrae
Median aperature
singular opening from the fourth ventricle into the subarachnoid space at the midline between the
medulla and cerebellum
Median nerve
systemic nerve of the arm, located between the ulnar and radial nerves
Meninges
protective outer coverings of the CNS composed of connective tissue
Mesencephalon
primary vesicle of the embryonic brain that does not significantly change through the rest of
embryonic development and becomes the midbrain
Metencephalon
Secondary vesicle of the embryonic brain that develops into the pons and the cerebellum
Midbrain
middle region of the adult brain that develops from the mesencephalon
Myelencephalon
secondary vesicle of the embryonic brain that develops into the medulla
Nerve plexus
network of nerves without neuronal cell bodies included
Neural crest
tissue that detaches from the edges of the neural groove and migrates through the embryo to develop into
peripheral structures of both nervous and non-nervous tissues
Neural fold
elevated edge of the neural groove
Neural groove
region of the neural plate that folds into the dorsal surface of the embryo and closes off to become the
neural tube
Neural plate
thickened layer of neuroepithelium that runs longitudinally along the dorsal surface of an embryo and
gives rise to nervous system tissue
Neural tube
precursor to structures of the central nervous system, formed by the invagination and separation of
neuroepithelium
Neuraxis
central axis to the nervous system, from the posterior to anterior ends of the neural tube; the inferior tip of the
spinal cord to the anterior surface of the cerebrum
Occipital lobe
region of the cerebral cortex directly beneath the occipital bone of the cranium
Occipital sinuses
dural sinuses along the edge of the occipital lobes of the cerebrum
Oculomotor nerve
third cranial nerve; responsible for contraction of four of the extraocular muscles, the muscle in the
upper eyelid, and pupillary constriction
Olfaction
special sense responsible for smell, which has a unique, direct connection to the cerebrum
Olfactory nerve
first cranial nerve; responsible for the sense of smell
Optic nerve
second cranial nerve; responsible for visual sensation
Orthostatic reflex
sympathetic function that maintains blood pressure when standing to offset the increased effect of
gravity
Paravertebral ganglia
autonomic ganglia superior to the sympathetic chain ganglia
Parietal lobe
region of the cerebral cortex directly beneath the parietal bone of the cranium
Parieto-occipital sulcus
groove in the cerebral cortex representing the border between the parietal and occipital
cortices
Perineurium
layer of connective tissue surrounding fascicles within a nerve
Phrenic nerve
systemic nerve from the cervical plexus that enervates the diaphragm
Pia mater
thin, innermost membrane of the meninges that directly covers the surface of the CNS
Plexus
network of nerves or nervous tissue
Postcentral gyrus
ridge just posterior to the central sulcus, in the parietal lobe, where somatosensory processing
initially takes place in the cerebrum
Posterior columns
white matter of the spinal cord that lies between the posterior horns of the gray matter, sometimes
referred to as the dorsal column; composed of axons of ascending tracts that carry sensory information up to the
brain
Posterior horn
gray matter region of the spinal cord in which sensory input arrives, sometimes referred to as the dorsal
horn
Posterior median sulcus
midline feature of the posterior spinal cord, marking the separation between right and left
sides of the cord
Posterolateral sulcus
feature of the posterior spinal cord marking the entry of posterior nerve roots and the separation
between the posterior and lateral columns of the white matter
Precentral gyrus
primary motor cortex located in the frontal lobe of the cerebral cortex
Prefrontal lobe
specific region of the frontal lobe anterior to the more specific motor function areas, which can be
related to the early planning of movements and intentions to the point of being personality-type functions
Premotor area
region of the frontal lobe responsible for planning movements that will be executed through the primary
motor cortex
