Organ | Location/Description | Notes |
---|---|---|
anterior median fissure | midline fissure on the anterior surface of the spinal cord and medulla | anterior spinal artery courses on the superficial surface of the spinal cord in this fissure |
apex of cuneus | portion of the cuneus seen in an inferior view of the cerebral hemisphere | contains part of the visual cortex |
arachnoid granulations | projections of arachnoid mater which pass through the meningeal layer of the dura into the dural venous sinuses; they are most prominent in the superior sagittal sinus | CSF returns to the venous circulation by passing from arachnoid granulations into the blood contained within the dural venous sinuses |
arachnoid mater | intermediate one of the three layers of meninges | arachnoid mater is a thin membrane which is pressed against the inner surface of the dura mater by cerebrospinal fluid pressure; arachnids are spiders, the space deep to this layer (subarachnoid space) has a spider web-like appearance |
aryepiglottic fold | a fold of mucous membrane within the laryngopharynx that extends from the arytenoid cartilage to the epiglottis | aryepiglottic fold covers the aryepiglottic muscle |
arytenoid cartilage | a pyramid-shaped cartilage located on the superior margin of the cricoid lamina of the larynx | arytenoid cartilage is connected: above to the epiglottis via aryepiglottic m. and anteriorly to the thyroid cartilage via the vocal ligament; the paired arytenoid cartilages are pulled together (adducted) by the arytenoid mm. (transverse and oblique) |
body of fornix | a group of nerve cell fibers arching beneath the corpus callosum | main efferent fiber system of the hippocampal formation |
brain stem | comprised of: midbrain, pons & medulla oblongata | contains the nuclei of cranial nerves III-XII |
choroid plexus | vascular membranes that occur within the ventricles | choroid plexus produces cerebrospinal fluid |
corniculate cartilage | a small cartilage located on the apex of the arytenoid cartilage of the larynx | corniculate cartilage is located at the posterior end of the aryepiglottic fold |
central canal of spinal cord | small opening in the center of the spinal cord | continuous with the central canal of the medulla and, through it, with the fourth ventricle of the brain |
cerebral hemispheres | comprised of: cortex featuring gyri, sulci, fissures & lobes; commissures connecting parts; basal ganglia; contains lateral ventricles; termination of the olfactory tract (cranial nerve I) | also known as: telencephalon |
cerebral aqueduct | canal connecting the third and fourth ventricles, passing through the midbrain | also known as: aqueduct of Sylvius |
cerebral peduncle | a large fiber bundle that connects the forebrain with the hindbrain | contains axons that control voluntary movement (corticospinal and corticopontine tracts); also known as: crus cerebri |
cerebellum | posterior part of the metencephalon | largest part of hindbrain; important for coordination of movement |
cerebellar peduncle, middle | largest (and intermediate) of the three cerebellar peduncles | connects the cerebellum to the pons |
CN II (optic) | the portion of the visual pathway between the retina and the optic chiasm; it passes through the optic canal to enter the cranial cavity | vision |
CN III (oculomotor) | emerges from the ventral surface of the brainstem near the midline at the caudal end of the midbrain; courses through the lateral wall of the cavernous sinus and exits the middle cranial fossa by passing through the superior orbital fissure | motor supply to skeletal mm.: levator palpebrae superioris, superior rectus, medial rectus, inferior rectus, inferior oblique; preganglionic parasympathetic to ciliary ganglion, postganglionic parasympathetic via short ciliary nn.to: ciliary m. & sphincter pupillae m. |
CN IV (trochlear) | emerges from the dorsal surface of the midbrain near the midline, just caudal to the inferior colliculus; courses through the lateral wall of the cavernous sinus and exits the middle cranial fossa by passing through the superior orbital fissure | motor supply for the superior oblique muscle of the eye; only cranial nerve to cross the midline of the brainstem - this crossover happens inside of the brainstem |
CN V (trigeminal) | large sensory nerve arising from the ventral surface of the pons, also contains a motor component; courses to the middle cranial fossa where it separates into three divisions at the trigeminal ganglion: ophthalmic division passes out of cranial cavity by passing through superior orbital fissure, maxillary division passes through foramen rotundum, mandibular division passes through foramen ovale; ophthalmic and maxillary divisions course through the lateral wall of the cavernous sinus | motor to the muscles of branchial arch origin: temporalis, masseter, lateral & medial pterygoid, anterior belly of digastric, mylohyoid, tensor veli palatini, tensor tympani; three divisions supply sensory innervation the to skin of the face, mucosa of the nasal & oral cavities, mucosa of the anterior 2/3rds of tongue (general sense only) |
CN VI (abducens) | small cranial nerve arising from the caudal end of the pons; emerges from the junction of the pons and medulla; courses anteriorly through the cavernous sinus lateral to the internal carotid artery, then exits the middle cranial fossa by passing through the superior orbital fissure | motor innervation of the lateral rectus muscle of the eye |
CN VII (facial) | cranial nerve arising from the caudal end of the pons; emerges from the junction of the pons and medulla just lateral to the abducens nerve; courses laterally to exit the posterior cranial fossa by entering the internal acoustic meatus | motor to muscles of facial expression; special sensory (taste) to anterior 2/3 of the tongue; secretomotor (parasympathetic) to: lacrimal, submandibular, sublingual, and mucous glands of nasal & oral cavities |
CN VIII (vestibulocochlear) | cranial nerve arising from the caudal end of the pons; emerges from the junction of the pons and medulla just lateral to the facial nerve; courses laterally to exit the posterior cranial fossa by entering the internal acoustic meatus; divides within the temporal bone into vestibular and cochlear parts | vestibular portion: balance/proprioception; cochlear portion: hearing |
CN IX (glossopharyngeal) | cranial nerve emerging from the rostral end of the ventral surface of the medulla lateral to the olive; it emerges rostral to the vagus nerve and caudal to the vestibulocochlear nerve; it courses inferiorly to exit the posterior cranial fossa by passing through the jugular foramen in company with the vagus and accessory nn. | motor to the stylopharyngeus m.; secretomotor to the parotid gland (preganglionic parasympathetic via lesser petrosal n. to otic ganglion, postganglionic parasympathetic via auriculotemporal n.); taste to posterior 1/3 of the tongue; sensory to middle ear and auditory tube |
CN X (vagus) | cranial nerve emerging from the ventral surface of the medulla lateral to the olive and just caudal to the glossopharyngeal nerve; it courses inferiorly to exit the posterior cranial fossa by passing through the jugular foramen in company with the glossopharyngeal and accessory nn. | the primary parasympathetic nerve to the organs of the neck, thorax and abdomen; motor supply to intrinsic muscles of the larynx, pharynx (except stylopharyngeus), and palate (except tensor veli palatini); brings back visceral sensations from the thoracic and abdominal organs |
CN XI (accessory) | cranial nerve emerging from the ventral surface of the medulla lateral and inferior to the olive and just caudal to the vagus nerve and from the ventral surface of the cervical spinal cord; its cranial root joins the vagus nerve; its spinal root arises from upper levels of the cervical spinal cord and courses superiorly to enter the posterior cranial cavity by passing through the foramen magnum; the spinal portion courses inferiorly to exit the posterior cranial fossa by passing through the jugular foramen in company with the glossopharyngeal and vagus nn. | motor innervation to the sternocleidomastoid and trapezius mm. |
CN XII (hypoglossal) | cranial nerve arising from the ventral surface of the medulla in the sulcus between the pyramid and the olive; it courses anteriorly to exit the posterior cranial fossa by passing through the hypoglossal canal | motor innervation of the intrinsic and extrinsic muscles of the tongue |
corpus callosum | midline part of the great cerebral commissure | connects the paired cerebral hemispheres |
commissure, anterior | a bundle of association fibers located anterior to the third ventricle | connects the left and right temporal lobes |
commissure, posterior | a bundle of association fibers located posterior to the third ventricle, just inferior to the pineal gland | connects various areas of the right and left sides of the midbrain |
cranial dura mater | outermost covering of the brain, described as 2 layers: periosteal outer layer and meningeal inner layer | dural venous sinuses lie between layers of the cranial dura; meningeal layer forms three infoldings that help to support the brain: falx cerebri, falx cerebelli, tentorium cerebelli |
cricoid cartilage | inferior and posterior cartilage of the larynx; arch is narrow anteriorly, lamina is broad posteriorly | cricoid cartilage is connected: above to the thyroid cartilage via the inferior horn of the thyroid cartilage; above to the conus elasticus; above to the arytenoid cartilages (on lamina); below to the 1st tracheal ring via the cricotracheal ligament |
cuneus | part of the cerebral cortex that forms the upper wall of the calcarine fissure | cortical projection of the lower half of the contralateral visual field |
cuneiform cartilage | small fibrocartilage nodule located in the posterior end of the aryepiglottic fold | cuneiform cartilage is anterior to the corniculate cartilage |
conus elasticus | elastic membrane attaching on the upper margin of the arch of the cricoid cart and ending in the vocal ligament | thickened upper margin of the conus elasticus is the vocal ligament |
diaphragma sellae | dura mater forming the roof of the hypophyseal fossa | surrounds the stalk of the hypophysis (pituitary gland) |
diencephalon | caudal portion of prosencephalon/forebrain | comprised of: thalamus, metathalamus, subthalamus, epithalmus; contains the third ventricle |
denticulate ligament | a lateral extension of pia mater from the spinal cord | denticulate ligament attaches to the dura mater to anchor the spinal cord; it forms a scalloped free border; there are 2 (one on each side) |
dura mater | outermost of the meningeal layers covering the brain and spinal cord | "tough mother"; it is the most durable of the meninges and provides support and protection for the brain and spinal cord; two types are described which differ in structure: cranial and spinal |
dura mater, cranial | outermost of the meningeal layers covering the brain; it has 2 layers: periosteal (outer layer) and meningeal (inner layer) | cranial dura mater participates in the formation of the dural venous sinuses; it forms infoldings between portions of the brain that help to support the brain: falx cerebri, falx cerebelli, tentorium cerebelli, diaphragma sellae |
dura mater, meningeal | inner layer of the cranial dura mater | dural venous sinuses lie between layers of the cranial dura mater; the meningeal layer forms folds that help to support the brain: falx cerebri, falx cerebelli, tentorium cerebelli |
dura mater, periosteal | outer layer of the cranial dura mater | the periosteal layer of cranial dura mater attaches loosely to the inner surface of the cranial cavity; equivalent to periosteum of the cranial bones; participates in the formation of the dural venous sinuses |
dura mater, spinal | outermost covering of the spinal cord, it forms the dural sac containing the spinal cord within vertebral canal | dural sac ends at S2, coccygeal ligament (filum terminale externum) continues inferiorly to attach to coccyx |
epidural space | the space external to the sac of spinal dura mater within the vertebral canal | the epidural space contains epidural fat and the internal vertebral plexus of veins which is valveless (clinically relevant) |
epiglottis | a single midline cartilage forming the superior part of the larynx | epiglottis contains the epiglottic cartilage; it moves posteriorly during swallowing to direct food and liquids around the opening into the larynx |
esophagus | the portion of the gastrointestinal tract between the pharynx and the stomach | connects: superiorly with laryngopharynx at lower border of cricoid cartilage; inferiorly it passes through diaphragm at the T10 vertebral level to reach the stomach; the upper 1/3 is skeletal muscle innervated by the recurrent laryngeal, the lower 2/3rds is smooth muscle innervated by the vagus nn. via the esophageal plexus |
falx cerebri | crescent-shaped fold of dura mater located in the sagittal plane | falx cerebri lies between the cerebral hemispheres |
falx cerebelli | small, crescent-shaped fold of dura mater located in the sagittal plane | falx cerebelli lies between the cerebellar hemispheres, but does not pass deeply between them |
filiform papillae | small taste buds covering the dorsum of the tongue | slender, conical papillae found on the anterior 2/3 of the tongue |
filum terminale internum | thread-like extension of the pia mater from the conus medullaris of the spinal cord | filum terminale internum is best seen between vertebral levels L2 and S2; it becomes enclosed within the filum terminale externum |
filum terminale externum | thread-like extension of the dura mater below the end of the dural sac at S2 | it attaches to the coccyx; also known as the coccygeal ligament |
foramen cecum (of the tongue) | depression located on the midline of tongue in the "V" of the sulcus terminalis | foramen cecum is a remnant of the thyroid diverticulum |
forebrain | telencephalon (cerebral hemispheres) plus diencephalon | site of termination of cranial nerves I and II; contains lateral and third ventricles; also known as: prosencephalon |
frenulum of the tongue | fold of mucous membrane in the midline under the tongue | sublingual caruncles (drainage of the submandibular gland) can be seen on either side of the frenulum |
fungiform papillae | medium-sized papillae located on the sides and tip of the tongue | fungiform papillae are mushroom-shaped and have a rich blood supply that gives them a red color |
glottis | the vocal folds plus the rima glottidis | rima glottidis is the opening between the vocal folds |
gyrus, precentral | most caudal gyrus of the frontal lobe; it lies rostral to the central sulcus | contains the primary motor cortex |
gyrus, postcentral | most rostral gyrus of the parietal lobe; it lies caudal to the central sulcus | contains the primary sensory cortex |
gyrus, superior temporal | gyrus between the lateral sulcus and the superior temporal sulcus | contains the primary auditory cortex |
gyrus, lingual | the portion of the occipital lobe that lies inferior to the calcarine sulcus | cortical projection of the upper half of the contralateral visual field |
gyrus, middle temporal | gyrus between the superior and inferior temporal sulci | |
gyrus, inferior temporal | gyrus between the inferior temporal sulcus and the inferior margin of the temporal lobe | |
gyrus, parahippocampal | gyrus on the inferior surface of the temporal lobe that lies lateral to the midbrain | the uncus is a medial projection of the parahippocampal gyrus |
gyrus, straight | gyrus located on the medial side of the olfactory tract | also known as: gyrus rectus |
gyrus, cingulate | the portion of the limbic lobe that lies superior to the corpus callosum | cingulate gyrus is bounded by the callosal sulcus and the cingulate sulcus |
hindbrain | comprised of: metencephalon (pons and cerebellum) and myelencephalon (medulla oblongata) | site of origin for cranial nerves V-XII (except spinal part of the accessory nerve); contains the fourth ventricle; also known as: rhombencephalon |
hypophysis | midline projection of neural and endocrine tissue attached to the floor of the diencephalon | also known as: pituitary gland |
hypothalamus | a collection on nuclei forming the anterior portion of the lateral wall of the third ventricle | controls visceral activity and elicits phenomena associated with the emotions |
inferior colliculus | elevation of the midbrain tectum; paired | part of the corpora quadrigemina; important for auditory reflexes |
infundibulum | midline stalk of the pituitary gland attached to the floor of the diencephalon | involved in regulating hormone release from the anterior pituitary |
infraglottic cavity | the portion of the laryngeal cavity that lies inferior to the vocal folds | bounded superiorly by the glottis and opens inferiorly into the trachea |
insula | portion of the cerebrum located deeply within the lateral sulcus | also known as: island of Reil |
interventricular foramen | communication between the lateral ventricle and the third ventricle; paired, one on each side | also known as: foramen of Monro |
isthmus | constricted midline connection between the lateral lobes of the thyroid gland | it lies anterior to tracheal rings 2-4 |
lacrimal gland | tear gland; located in superolateral orbit beneath the orbital plate of the frontal bone | lacrimal gland is innervated by postganglionic parasympathetic fibers from the pterygopalatine ganglion via the communicating br. from the zygomaticotemporal br. of the zygomatic n. to the to lacrimal n. |
lacrimal papilla | a projection located on the edge of the upper or lower eyelid at the medial angle of the eye | a lacrimal punctum is located at the apex of each lacrimal papilla |
lacrimal punctum | an opening located on the edge of the medial end of the upper or lower eyelid | a lacrimal punctum is located at the apex of each lacrimal papilla; there are two puncta, one on each eyelid, that drain tears into the lacrimal canaliculi |
lacrimal sac | a sac located within the medial wall of orbit, between the orbit and the nasal cavity | lacrimal sac receives the lacrimal canaliculi; it drains tears into the nasolacrimal duct |
laryngeal ventricle | lateral outpouching of the laryngeal mucosa located between the vestibular fold (false vocal fold) and the vocal fold (true vocal fold) | laryngeal ventricle may have a small diverticulum called the saccule |
laryngeal vestibule | opening into the larynx; the part of the larynx located below the epiglottis, between the aryepiglottic folds and above the vestibular (false vocal) folds | lateral wall of the laryngeal ventricle contains the quadrangular membrane (submucosa) |
laryngopharynx | the portion of the pharynx located posterior to the laryngeal inlet and the posterior wall of the larynx | connects: superiorly with oropharynx at the superior border of epiglottis, anteriorly with the larynx through laryngeal inlet, inferiorly with the esophagus at the lower border of the cricoid cartilage; laryngopharynx contains the piriform recesses which are lateral to the aryepiglottic folds |
larynx | located anterior to the laryngopharynx at level of C4-6 vertebrae | composed of: thyroid, cricoid, epiglottic, arytenoid, cuneiform & corniculate cartilages; contains the vocal ligaments; controls the airway |
lateral aperture | foramen draining the fourth ventricle laterally into the cerebellomedullary cistern | paired; also known as: foramen of Luschka |
lateral glossoepiglottic fold | fold of mucous membrane located between the base of the tongue and the epiglottis | lateral glossoepiglottic fold is located lateral to the valleculae epiglottica |
lobe, frontal | rostral to central sulcus | contains prefrontal (emotions, personality) and precentral (primary and secondary motor) areas |
lobe, parietal | separated from the frontal lobe by the central sulcus, separated from occipital lobe by an imaginary line through the parieto-occipital sulcus | contains the primary and secondary somatosensory areas |
lobe, temporal | separated from the frontal lobe by the lateral sulcus | primarily concerned with hearing and memory/learning |
lobe, occipital | posterior to an imaginary line through the parieto-occipital sulcus | contains the primary and secondary visual cortex |
lobe, limbic | a border (limbus = Latin for border) of cortical tissue surrounding the third ventricle | limbic lobe is comprised of: cingulate gyrus, parahippocampal gyrus, uncus and other small portions of the adjacent cortex; it is the part of the brain responsible for behavior and emotions |
longitudinal fissure | cleft located in the sagittal plane that separates the paired cerebral hemispheres | also known as: longitudinal sulcus; it contains the falx cerebri |
mamillary body | part of the hypothalamus; a small spherical projection on the inferior surface of the floor of the third ventricle posterior to the hypophysis | mamillary body is involved with memory and learning |
median aperture | midline, irregular foramen draining the fourth ventricle posteroinferiorly into the cerebellomedullary cistern | also known as: foramen of Magendie |
median glossoepiglottic fold | fold of mucosa located between the base of the tongue and the epiglottis | separates the paired valleculae epiglottica |
medulla oblongata | most caudal portion of the brainstem | medulla oblongata is continuous with the spinal cord at the foramen magnum; the upper portion forms the floor of the fourth ventricle; it is the site of origin for cranial nerves VIII, IX, X, XI (cranial root), & XII; also known as: myelencephalon |
meninges | three layers of connective tissue covering the brain and spinal cord; dura mater, arachnoid mater, and pia mater | meninges provide protection and nourishment of the brain, brainstem and spinal cord |
mesencephalon | the portion of the brain that connects the forebrain and the hindbrain | it contains the corpora quadrigemina and the cerebral aqueduct; also known as: midbrain |
metencephalon | the rostral part of the rhombencephalon | comprised of: pons & cerebellum |
midbrain | the portion of the brain that connects the forebrain and the hindbrain | midbrain is the site of origin of cranial nerves III & IV; it contains the cerebral aqueduct |
myelencephalon | the caudal part of the rhombencephalon | myelencephalon is comprised of: medulla oblongata; medulla becomes continuous with the spinal cord at the level of the foramen magnum |
nasolacrimal duct | mucosa-lined duct connecting the medial angle of the eye with the nasal cavity | drains tears from the lacrimal sac to the inferior meatus of the nasal cavity |
nasopharynx | the portion of the pharynx located posterior to the posterior nasal apertures and superior to the soft palate | nasopharynx communicates; anteriorly with the nasal cavity through the choanae and inferiorly with the oropharynx; it contains the torus tubarius, pharyngeal recess and pharyngeal tonsil |
notch, preoccipital | a shallow notch in the inferior surface of the cerebral cortex (superior to the cerebellum) as seen in lateral view | a surface landmark for defining the border between the parietal and occipital lobes |
olfactory bulb | flattened, oval enlargement at the anterior tip of the olfactory tract | olfactory bulb contains the olfactory cells which are the origin of the axons that course through the olfactory tract; the olfactory nerve begins at the bipolar olfactory cells in the nasal mucosa and courses through the cribriform plate to the olfactory bulb |
olfactory tract | a ribbon-like nerve tract that courses from the olfactory bulb to the cerebral cortex | olfactory tract carries the sense of smell; it courses in the olfactory sulcus |
olive | a elevation located lateral to the pyramid of medulla | paired; the olives contain the inferior olivary nuclei |
optic chiasm | crossover point for the nasal fibers of both retinas | lateral visual fields (medial retinal fibers) project to the contralateral occipital lobe |
optic tract | the portion of the visual pathway between the optic chiasm and the brain | visual system projects to the occipital lobe |
oropharynx | the portion of the pharynx located posterior to the palatoglossal arches of the oral cavity and inferior to the soft palate | oropharynx communicates: anteriorly with oral cavity through oropharyngeal isthmus (palatoglossal arch), superiorly with the nasopharynx through pharyngeal isthmus (posterior margin of soft palate), inferiorly with the laryngopharynx at the superior margin of epiglottis; it contains the palatine tonsil which is located in the tonsilar bed (between the palatoglossal arch and the palatopharyngeal arch) |
palatoglossal fold | fold of mucosa covering the palatoglossus m. | palatoglossal fold marks the anterior boundary of the bed of the palatine tonsil |
palatopharyngeal fold | fold of mucosa covering the palatopharyngeus m. | palatoglossal fold marks the posterior boundary of the bed of the palatine tonsil |
parathyroid glands | four small endocrine glands located on the posterior surface of the lateral lobes of the thyroid gland | two pair of glands that develop from the 3rd and 4th pharyngeal pouches; they produce parathormone which is important in regulating serum calcium levels |
parotid gland | salivary gland located lateral and posterior to the mandibular ramus, beside (para) the ear (oto) | largest salivary gland; innervated by postganglionic parasympathetic fibers from the otic ganglion via the auriculotemporal n. |
parotid duct | thick duct that crosses the superficial surface of the masseter m. | parotid duct drains the parotid gland through cheek to the oral vestibule near upper 2nd molar tooth |
pharyngeal recess | space located posterior to the torus tubarius in nasopharynx | the pharyngeal tonsil is located in this region |
pharynx | the space posterior to the nasal cavity, oral cavity and larynx | divided into three parts: nasopharynx, oropharynx and laryngopharynx; the airway and the pathway of ingested foods and liquids cross at this location |
pia mater | delicate membrane that lies on the surface of the brain and spinal cord | "delicate mother", it is the most delicate of the meninges; this layer faithfully follows all surface contours of the brain and spinal cord; pia mater has two specializations: denticulate ligament and filum terminale internum |
pineal gland | a knob-like projection from the roof of the diencephalon | an endocrine gland; also known as: pineal body |
piriform recess | shallow depression located lateral to the aryepiglottic fold in the laryngopharynx | the internal branch of the superior laryngeal n. is located immediately deep to the mucosa in this region; also known as: piriform fossa |
plica sublingualis | fold of mucosa under the tongue which covers the sublingual gland | also known as the sublingual fold |
pole, frontal | the most anterior part of the cerebral hemisphere | frontal pole is part of the frontal lobe |
pole, temporal | the most anterior part of the temporal lobe | |
pole, occipital | the most posterior part of the cerebral hemisphere | occipital pole is part of the occipital lobe; composed of primary visual cortex |
pons | the anterior portion of the metencephalon | pons is the site of origin of cranial nerves V, VI, VII & VIII; it forms part of the anterior wall of the fourth ventricle |
posterior median sulcus | midline furrow on the posterior surface of the spinal cord and medulla oblongata | posterior median sulcus starts at the obex and continues throughout the length of the spinal cord |
pyramid | an elevations on the anterior surface of the medulla oblongata | paired; the pyramids are separated by the anterior median fissure; they contain the pyramidal tracts |
pyramidal decussation | point of crossover of 80% the fibers of the corticospinal tracts; located at lower levels of the medulla | voluntary muscles of one side of the body are under the control of the contralateral cerebral cortex |
rima glottidis | the opening between the vocal folds | the glottis is the vocal fold plus the rima glottidis |
salpingopharyngeal fold | mucosal fold descending from the posterior margin of the torus tubarius | salpingopharyngeal fold contains the salpingopharyngeus m. |
spinal dura mater | outermost covering of the spinal cord, it forms the dural sac containing the spinal cord within vertebral canal | dural sac ends at S2, coccygeal ligament (filum terminale externum) continues inferiorly to attach to coccyx |
subarachnoid space | the space between the arachnoid mater and the pia mater | subarachnoid space contains cerebrospinal fluid and spider web-like filaments |
submandibular duct | duct connecting the submandibular gland to the floor of the oral cavity | submandibular duct drains the submandibular gland to the sublingual caruncle |
submandibular gland | salivary gland located beneath the mylohyoid m. in the submandibular triangle | submandibular gland is innervated by postganglionic parasympathetic fibers from the submandibular ganglion |
sublingual caruncle | a papilla on the lateral side of the sublingual frenulum of the tongue | sublingual caruncles the site of the opening of the duct of the submandibular gland |
sublingual gland | salivary gland located beneath the oral mucosa in the floor of mouth | sublingual gland is located deep to the plica sublingualis; it drains onto the floor of the oral cavity via multiple small ducts |
sulcus, calcarine | sulcus between the lingual gyrus and the cuneus | primary visual cortex is both superior and inferior to it |
sulcus, central | separates the frontal lobe from the parietal lobe; it separates the sensory cortex from the motor cortex | also known as: fissure of Rolando |
sulcus, longitudinal | cleft located in the sagittal plane that separates the paired cerebral hemispheres | it contains the falx cerebri; also known as: longitudinal fissure |
sulcus, precentral | the sulcus anterior to the precentral gyrus | in conjunction with the central sulcus, it defines the precentral gyrus (motor) |
sulcus, postcentral | the sulcus posterior to the postcentral gyrus | in conjunction with the central sulcus, it defines the postcentral gyrus (sensory) |
sulcus, lateral | separates the frontal lobe and the temporal lobe | the insula lies in the floor of this sulcus |
sulcus, olfactory | sulcus that defines the lateral margin of the straight gyrus | contains the olfactory bulb and tract |
sulcus, superior temporal | sulcus between the superior and middle temporal gyri | used to define the superior and middle temproal gyri |
sulcus, inferior temporal | sulcus between the middle and inferior temporal gyri | used to define the middle and inferior temporal gyri |
sulcus, parieto-occipital | sulcus between the parietal and occipital lobes | landmark used to define the borders of the parietal and occipital lobes when viewing the cerebral hemisphere from a medial perspective |
sulcus, cingulate | the sulcus that lies superior to the cingulate gyrus | defines the cingulate gyrus |
superior colliculus | paired elevations of the midbrain tectum | part of the corpora quadrigemina; important for reflex movements of the eye, head and neck |
tectum | the roof of the midbrain, formed by the superior and inferior colliculi; located dorsal to the cerebral aqueduct | also known as: quadrigeminal plate |
tegmentum | the collection of cells and nerve fibers located ventral to the ventricle system in the midbrain, pons and medulla | gives rise to the middle cerebellar peduncle |
telencephalon | rostral part of prosencephalon/forebrain | comprised of: cerebral hemispheres and basal ganglia; contains the lateral ventricles |
tentorium cerebelli | tent-like sheet of dura mater covering the superior surface of the cerebellum, oriented somewhat transversely | the midbrain passes through the tentorial notch |
thalamus | an egg-shaped collection of nuclei forming part of the lateral wall of the third ventricle | thalamus distributes information to appropriate areas of the cerebral cortex |
thyroid cartilage | anterior cartilage of the larynx; formed by two flat plates that fuse anteriorly in the midline to form the laryngeal prominence | thyroid cartilage is connected: above to the hyoid bone via the thyrohyoid membrane; below to the cricoid cartilage via the inferior horn; posteriorly to the paired arytenoid cartilages via the vocal ligaments and thyroartenoid mm.; posteriorly to the epiglottic cartilage via the thyroepiglottic ligament; under the action of the cricothyroid m. the thyroid cartilage tilts forward to increase tension on the vocal ligament and raise the pitch of the voice |
thyroid gland | a large endocrine bland that lies anterolateral to the lower part of the larynx and upper trachea | thyroid gland consists of two lateral lobes joined across the midline by the isthmus; it may have a pyramidal lobe extending superiorly near midline which is a remnant of development that marks its route of migration from a primordium that originates at the foramen cecum or the tongue; thyroid gland is supplied by superior and inferior thyroid aa.; it produces thyroxin |
thyroid isthmus | constricted midline connection between the lateral lobes of the thyroid gland | thyroid isthmus lies anterior to tracheal rings 2-4 |
torus tubarius | mucosal fold covering the anteromedial end of the auditory tube cartilage | torus tubarius projects toward the midline from the lateral wall of the nasopharynx |
trachea | main airway that lies anterior to the esophagus | trachea extends from vertebral level C6 to the level of the T4/5 intervertebral disc; superiorly it is connected to the cricoid cartilage via the cricotracheal ligament; it bifurcates into two primary bronchi |
uncus | portion of the cerebral cortex on the medial side of the parahippocampal gyrus and overlying the amygdala | uncus is located near the free edge of the tentorium cerebelli; it contains the olfactory cortex |
vallate papilla | the largest type of papilla located on the dorsum of the tongue; a total of 8-12 in number arranged along the anterior border of the sulcus terminalis | vallate papillae possess taste buds in a circular sulcus; also known as: circumvallate papillae |
valleculae epiglottica | fossa located between the base of the tongue and the epiglottis | paired; each of the valleculae epiglottica is located between the median glossoepiglottic fold and the lateral glossoepiglottic fold |
ventricle, lateral | paired spaces within the cerebral hemispheres | lateral ventricles drain cerebrospinal fluid to the third ventricle via the interventricular foramina (of Monroe) |
ventricle, third | a midline space within the diencephalon between the paired dorsal thalami and the hypothalamus | third ventricle communicates rostrolaterally with paired lateral ventricles via interventricular foramina, communicates posteroinferiorly with fourth ventricle via cerebral aqueduct |
ventricle, fourth | midline space between the cerebellum posteriorly and the pons and upper medulla anteriorly | fourth ventricle communicates anterosuperiorly with the third ventricle via the cerebral aqueduct; it drains CSF via the median aperture and the lateral apertures |
vestibular fold | fold of mucosa located between the laryngeal vestibule and the laryngeal ventricle | also known as: false vocal fold |
vocal folds | fold of mucosa covering the vocal ligament and the thyroepiglottic muscle (vocalis part) | located inferior to the laryngeal ventricle; also known as: true vocal fold |
vocal ligament | an elastic band of connective tissue located in the vocal fold | paired; each vocal ligament is connected to the inner surface of the thyroid cartilage anteriorly and to the vocal process of the arytenoid cartilage posteriorly; vocal ligament is the thickened superior margin of the conus elasticus; vibration creates sound; adducted by the actions of the arytenoid mm. and lateral cricoarytenoid m.; abducted by the action of the posterior cricoarytenoid m. |