large opening at the base of the occipital bone through which the medulla is continuous with the spinal cord.
consists of a bundle of nerve roots of all of the spinal nerves caudal to the second lumbar vertebra
a bundle containing one or more tracts, or fasciculi, in the spinal cord
a band of gray matter extending onto both sides of the spinal cord
interneurons that make inhibitory (glycinergic) synapses of the alpha motor neurons and receive excitatory (cholinergic) collaterals from the same neurons
the area of skin supplied by the right and left dorsal roots of a single spinal segment
first-order sensory neurons that project to the nucleus gracilis and conveys tactile sensation to the ipsilateral limb
first-order sensory neurons contained in the dorsal funiculus that project to the nucleus cuneatus and conveys tactile sensation to the ipsilateral limb
formed by axons arising from the accessory cuneate nucleus.
Rostral Spinocerebellar tract
arises from the cervical cord and supplies the anterior lobe of the cerebellum, conveying whole limb movement to the anterior lobe from the upper limb.
pathway from the spinal cord to the thalamus that mediates pain, temperature, and tactile sensation.
developmental abnormality, characterized by expansion of the central canal of the spinal cord. Loss of pain and thermal sensation.
Periaqueductal gray area
gray matter surrounding the cerebral aqueduct of the midbrain
major descending pathway from the cerebral cortex to the spinal cord that mediates voluntary control of motor activity.
pathway from the superior colliculus to cervical cord which mediates postural movements in response to visual stimuli reaching the superior colliculus.
Inferior cerebellar peduncle
major afferent pathway to cerebellum from the medulla.
most caudal aspect of the brainstem extending from the pons to the spinal cord.
descending corticofugal fibers arising from lateral aspects of sensorimotor cortex. Also called corticonuclear fibers.
mediates voluntary control of movement of limbs and motor functions
region of gray matter of the dorsal horn of spinal cord that reeives mainly pain and termperature inputs from the periphery.
central core of the brainstem extending from the medulla through the midbrain. Functions include control of sensory, motor, and visceral processes and states
rostral aspect of the tectum of midbrain associated with visual refplexes and tracking movements of the eyes.
Inferior olivary nucleus
large nuclear structure situated in the ventrolateral medulla and relays transmission of impulses from the spinal cord and red nucleus to the cerebellum.
fibers originating in spinal cord that project to the inferior olivary nucleus
Lateral medullary syndrome
(Wallenberg’s Syndrom) results from a vascular lesion of the veterbral and inferior posterior cerebellar artieries. Loss of pain and temperature, hoarseness, loss of gag relex, and difficulty swallowing.
the most rostral aspect of the brainstem, situated between the forebrain and pons.
part of the brainstem extending from the midbrain to the medulla.
a bulge found along the floor of the fourth ventricle formed from fibers of the facial nerve that pass over the dorsal aspect of the abducens nucleus.
general somatic efferent nucleus of the lower pons
lies in the ventrolateral aspect of the tegmentum; innervates muscles controlling ipsilateral facial expression.
Superior salivatory nucleus
located in lower pons and provides parasympathetic innervation to the salivary glands.
Superior cerebellar peduncle
one of the three cerebellar peduncles constituting the major output pathway of the cerebellum.
Mesencephalic nucleus of CN V
located in the upper pons that receives trigeminal inputs from the muscle spindles of the face region.
largest of deep cerebellar nuclei, axons project through the superior cerebellar peduncle to the ventrolateral nucleus of thalamus.
deep cerebellar nucleus whose axons project to the reticular formation and vestibular nuclei.
superior and inferior colliculi.
most dorsal part of the midbrain.
dorsal aspect of the pons and midbrain containing the reticular formation and a variety of nuclear groups.
structure found in the ventral aspect of the midbrain associated with functions of the basal ganglia. Parts produce dopamine and gamma aminobutyric acid
ventral aspect of the midbrain containing principally corticospinal, coroticospinal, and corticopontine tracts
Central tegmental area
region of the midbrain containing the reticular formation
most rostral region of the midbrain bordering n the diencephalon, part of the pathway mediating visual reflexes.
Pupillary light reflex
(pupillary constriction) the result of shining light into the eye which is the contraction
of pupillary constrictor muscles and reduction of the size of the pupil
(Parinaud’s syndrome) disorder characterized by an upward gaze paralysis, nystagmus with downward gaze, large pupil, abnormal elevation of the upper lid, from vascular lesion or pineal tumor.
disorder affecting nerve fibers of cranial nerve III causing an oculomotor paralysis tremor of the contralateral limb, and somatosensory loss of the contralateral side of the body.
disorder affecting the ventromedial midbrain, damaging oculomotor nerve fibers and axons causing ipsilateral oculomotor paralysis and upper motor neuron paralysis of the limbs.
Medial geniculate nucleus
thalamic relay nucleus that transmits auditory information from inferior colliculus to the superior temporal gyrus
region of the forebrain which lies below the fornix and consists of the thalamus and hypothalamus.
dorsal and largest part of the diencephalon consistes of varieties of nuclie that project mainly to the cerebral cortex
ventral aspect of the diencephalon; concerns a variety of cell groups associated with
diverse visceral functions – endocrine release of the pituitary, temperature
regulation, feeding, drinking, sexual behavior, aggression, and rage.
group of structures forming the roof of the diencephalon, includes habenular complex, stria medullaris, and pineal gland.
group of structures in the posterior third of the diencephalon, including the subthalamic nucleus and the zona incerta
nucleus situated in the dorsomedial aspect of the middle third of the thalamus; receives inputs from the limbic structures and is reciprocally connected with the prefrontal cortex
Lateral geniculate nucleus
thalamic relay nucleus transmitting visual signals from the retina to the visual cortex
region of the basal forebrain situated immediately lateral to the proptic region; linked to amygdala and projects to widespread regions of the cerebral cortex.
commissure connecting the habenular complex on both sides of the epithalamus
conical shaped structure attached to the roof of the posterior aspect of the third ventricle and displays a circadian rhythm
connecting link between the hypothalamus and pituitary gland
antidiuretic hormone released from the posterior pituitary and causes water retention by decreasing kidney’s urine production
major efferent pathway of basal ganglia
H field of Forel
region immediately rostral to the red nucleus where fibers of the lenticular fasciculus and ansa lenticularis merge and begin to course rostrally.
Special visceral afferent neurons
components of afferent fibers of cranial nerves that are associated with the transmission of chemical sensation
Special sensory afferent
afferent components of cranial nerves associated with the transmission of visual, auditory, and vestibular impulses
Special visceral efferent neurons
cell groups that are derived from mesenchyme of the brachial arches
landmark in the developing nervous system that separates sensory from motor regions
mainly a motor nerve which innervate the tongue and control the shape and position of it.
Spinal accessory nerve (CN XI)
motor cranial nerve arising from ventral horn cells in the first 6 cervical segments that mediate turning and lifting the head
Vagus nerve(CN X)
consists of various afferent and efferent fibers innervating thoracic and abdominal viscera and special visceral efferent fibers innervating the larynx and pharynx.
Glossopharyngeal nerve (CN IX)
contains fibers which innervate the otic ganglion and special visceral efferent fibers which innervate the stylopharyngeus muscle.
Vestibulochlear nerve (CN VIII)
special sensory afferent nerves mediating auditory and vestibular inputs through separate receptors inputs through separate receptors and neural pathways
Facial Nerve (CN VII)
mixed cranial nerve of the lower pons that affects salivary, lacrimal, and pterygopalitine glands; also taste signals from the tongue, and innervates muscles of facial expression
Trigerminal nerve (CN V)
supplies muscles of mastication to produce biting and chewing; sensation from palate, teeth, gum, face, and cornea.
supporting cells located in the central nervous system; nonexcitable and more numerous than neurons
monosynaptic stretch reflex, occurring after stimulation of muscle spindles in the masseter muscle of the lower jaw causing a jaw closing response
trigeminal neuralgia (severe pain in the face)
secondary afferents arising from intrafusal fibers located on nuclear chain and nuclear bag fibers on each of the annulosprial endings
low-threshold, rapidly adapting receptors sensitive to rapid indentation of the skin caused by high frequency vibrations; located in dermis layer of hairy and glabrous skin
eight to ten specialized muscle fibers in the connective tissue capsule of a muscle spindle
large skeletal muscle fibers surrounding the connective tissue capsule of a muscle spindle; involved in the movement of the limb.
neurons interspersed between alpha-motor neurons in the ventral horn of the spinal cord; regulate the sensitiviey of muscle spindles.
primary afferents arising from intrafusal fibers; located on the central part of the nuclear bag and nuclear chain fibers
major ascending pathway involved in conveying pain signals to higher centers
enhancement of the pain sensation.
characterized by burning sensation caused by increased sympathetic efferent activity after a peripheral nerve injury
an undecapeptide (composed of 11 amino acids); a neurotransmitter or neuromodulator.
major excitatory amino acid neurotransmitter in the central nervous system synthesized from glutamine in presence of the enzyme glutaminase
descending pathway that inhibits dorsal horn neurons that relay pain sensation by activating enkephalingeric interneurons