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fossa[fos´ah] (pl. fos´sae) (L.)
a trench or channel; in anatomy, a hollow or depressed area.
amygdaloid fossa the depression in which the tonsil is lodged.
cerebral fossa any of the depressions on the floor of the cranial cavity.
condylar fossa (condyloid fossa) either of two pits on the lateral portion of the occipital bone.
coronoid fossa a depression in the humerus for the coronoid process of the ulna.
cranial fossa any one of the three hollows (anterior, middle, and posterior) in the base of the cranium for the lobes of the brain.
digastric fossa a depression on the inner surface of the mandible, giving attachment to the anterior belly of the digastric muscle.
1. one in the epigastric region.
2. urachal fossa.
ethmoid fossa the groove in the cribriform plate of the ethmoid bones, for the olfactory bulb.
glenoid fossa mandibular fossa.
hyaloid fossa a depression in the front of the vitreous body, lodging the lens.
hypophyseal fossa a depression in the sphenoid lodging the pituitary gland; called also pituitary fossa.
iliac fossa a concave area occupying much of the inner surface of the ala of the ilium, especially anteriorly; from it arises the iliac muscle.
incisive fossa a slight depression on the anterior surface of the maxilla above the incisor teeth.
infraclavicular fossa the triangular region of the chest just below the clavicle, between the deltoid and pectoralis major muscles.
infratemporal fossa an irregularly shaped cavity medial or deep to the zygomatic arch.
interpeduncular fossa a depression on the inferior surface of the midbrain, between the two cerebral peduncles, the floor of which is the posterior perforated substance.
ischiorectal fossa a potential space between the pelvic diaphragm and the skin below it; an anterior recess extends a variable distance.
mandibular fossa a depression in the inferior surface of the pars squamosa of the temporal bone at the base of the zygomatic process, in which the condyle of the mandible rests; called also glenoid fossa.
mastoid fossa a small triangular area between the posterior wall of the external acoustic meatus and the posterior root of the zygomatic process of the temporal bone.
nasal fossa the portion of the nasal cavity anterior to the middle meatus.
1. the lateral expansion of the urethra of the glans penis.
2. a depression on the internal pterygoid process of the sphenoid, giving attachment to the tensor veli palatini muscle.
3. vestibular fossa.
fossa ova´lis cor´dis a fossa in the right atrium of the heart; the remains of the fetal foramen ovale.
fossa ova´lis fe´moris the depression in the fascia lata that is bridged by the cribriform fascia and perforated by the great saphenous vein.
ovarian fossa a shallow pouch on the posterior surface of the broad ligament of the uterus in which the ovary is located.
paravesical fossa the fossa formed by the peritoneum on each side of the urinary bladder.
pituitary fossa hypophyseal fossa.
popliteal fossa the hollow at the posterior part of the knee.
subarcuate fossa a depression in the posterior inner surface of the pars petrosa of the temporal bone.
subpyramidal fossa a depression on the internal wall of the middle ear.
subsigmoid fossa a fossa between the mesentery of the sigmoid flexure and that of the descending colon.
supraspinous fossa a depression above the spine of the scapula.
temporal fossa an area on the side of the cranium bounded posteriorly and superiorly by the temporal lines, anteriorly by the frontal and zygomatic bones, and laterally by the zygomatic arch, lodging the temporal muscle.
tibiofemoral fossa a space between the articular surfaces of the tibia and femur mesial or lateral to the inferior pole of the patella.
urachal fossa one on the inner abdominal wall, between the urachus and the hypogastric artery.
vestibular fossa (fossa of vestibule of vagina) the vaginal vestibule between the vaginal orifice and the fourchette (frenulum of pudendal labia). Called also navicular fossa.
A depression in the inferior wall of the middle ear. It is inferior to the round window and posterior to the pyramid.
See also: fossa