foramen
(fŏ-rā'mĕn 
, fŏ-ram'ĭ-nă)
Plural: foramina
[L. foramen, stem foramin-, hole, opening]
A passage, opening or communication between two cavities, or a hole in a bone, often for the passage of vessels or nerves.
alveolar f.In the skull, any of the tiny foramina on the outer surface of the tuberosity of the maxilla through which nerves and vessels pass.
anterior condyloid f.Hypoglossal canal
anterior sacral f.Any of the four paired foramina on the anterior surface of the sacrum through which pass the first four pairs of ventral rami of the sacral nerve roots. The fifth pair of sacral anterior rami passes between the sacrum and the coccyx. The anterior sacral foramina connect to the sacral canal via the sacral interventricular foramina.
apical f.The foramen in the end of the root of a tooth through which the blood and nerve supplies pass to reach the dental pulp.
SEE: under Bochdalek, Vincent.
caval f.The foramen in the central tendon of the diaphragm at the T8 vertebral level, through which the vena cava passes from the abdominal cavity into the thoracic cavity.
f. cecum 1In the skull, a small round foramen in the midline of the floor of the anterior fossa between the base of the frontal crest and the crista galli of the ethmoid bone.2On the tongue, the small midline foramen at the border between the anterior (oral) and the posterior (pharyngeal) portions of the tongue. It is the point from which the thyroid diverticulum (the tubular duct destined to form the thyroid gland ) descended in the embryo.
dorsal sacral f.Posterior sacral foramen
emissary f.Any of the small foramina in the bones of the skull through which blood vessels pass.
epiploic f.Foramen of Winslow.
ethmoidal f.Either of two foramina, the anterior ethmoid foramen or posterior ethmoid foramen, that transmit neurovascular elements into the nasal cavity from the orbit.
external auditory f.External auditory meatus
greater sciatic f.The larger of two posterior foramina into the bony pelvis. On the posterior margin of the ilium and ischium, there are two semicircular indentations, the greater and lesser sciatic notches. Two crossed ligaments (the sacrotuberous and sacrospinous ligaments) make these notches into enclosed ovals, the greater and lesser sciatic foramina. The greater sciatic foramen is the upper and larger of these. The gluteal and some hip-joint structures, such as the piriformis and the gluteal nerves and blood vessels, leave the pelvic cavity through this opening, as do the sciatic nerve and the posterior cutaneous nerve of the thigh.
SEE: lesser sciatic foramen.
incisive f.In the skull, the foramen in the hard (bony) palate immediately behind the central incisors. This foramen lies at the frontmost tip of the intermaxillary suture and is the bottom end of the incisive canal. SYN: palatine foramen; incisive fossa.
infraorbital f.In the skull, the foramen in the maxilla, just below the orbit, through which the infraorbital branch of the maxillary division of the trigeminal nerve passes.
internal auditory f.The foramen in the petrous portion of the temporal bone through which the seventh and eighth cranial nerves pass.
interventricular f.Foramen of Monro.
intervertebral f.The foramen between adjacent vertebrae through which spinal nerves pass.
intraventricular f.Foramen of Monro.
jugular f.A large irregular foramen between the occipital bone and the petrous portion of the temporal bone on either side of the base of the skull. The internal jugular vein emerges from the cranial cavity through this foramen, along with the glossopharyngeal (CN IX), vagus (CN X), and accessory (CN XI) nerves.
f. lacerum A foramen in the base of the middle fossa of the skull medial to the foramen ovale and just below the anterior end of the carotid canal at the point where it turns upward to form the carotid sulcus along the lateral side of the sella turcica. The foramen lacerum has a fibrous covering that is pierced by a few small vessels and the greater petrosal nerve.
lesser sciatic f.The foramen bounded by the hip bone, sacrum, and sacrospinous ligament.
SEE: greater sciatic foramen.
lingual f.A small midline foramen on the lingual (internal) surface of the mand ible above the genial tubercles.
SEE: under Luschka, Hubert von.
SEE: under Magendie, François.
f. magnum The large foramen in the base of the occipital bones between the posterior cranial fossa of the skull and the vertebral canal through which the spinal cord passes as it becomes the hindbrain.
mand ibular f.The foramen on the medial (interior) surface of the ramus of the mand ible through which the inferior alveolar vessels and nerve enter the mand ibular canal. The lingula of mand ible shelters the medial edge of this foramen.
mastoid f.A small foramen, usually found on the outer surface of the mastoid part of the temporal bone of the skull, through which a small vein and artery pass.
mental f.A foramen on the outer surface of each side of the body of the mand ible below the premolars, through which the mental nerve and blood vessels exit.
SEE: under Monro, Alexand er (secundus).
nutrient f.A foramen in the surface of a bone through which vessels and nerves enter and exit.
SEE: nutrient canal.
obturator f.The large oval foramen (in males) or the triangular foramen (in females), in each hip bone, formed by the inner edges of the pubis and the ischium. This foramen is almost entirely covered by the attached obturator membrane.
olfactory f.Any of the foramina in the cribriform plate of the ethmoid bone for passage of the olfactory nerves.
f. ovale 1The foramen that is located in the septum between the two atria of the fetal heart and permits blood to bypass the lungs by flowing directly from the right to the left atrium. This foramen usually closes shortly after birth as a result of hemodynamic changes related to respiration, leaving an oval depression (fossa ovalis) on the right side of the interatrial septum. Incomplete closure of the foramen ovale can lead to cardiac symptoms later in life, for which surgical or transcatheter repair is usually recommended.
SEE: fetal circulation.
2 Along the base of the middle fossa of the skull, an oval foramen in the lower margin of the greater wing of the sphenoid bone and just anterior and medial to the foramen spinosum. The mand ibular division of the trigeminal nerve (CN V), the accessory meningeal artery, and the lesser petrosal nerve pass through this foramen.palatine (greater and lesser) f.In the posterior corners of the hard palate, the larger (anterior) and smaller (posterior) foramina at the lateral edge of the horizontal plate of each palatine bone. The greater and lesser palatine nerves and vessels pass through their respective foramina.
parietal f.A foramen near the superior (sagittal) edge of the parietal bone of the skull through which a vein and sometimes an artery pass. This foramen is not always present.
posterior condyloid f.The foramen posterior to the condyle of the occipital bone. A small vein passes through it.
posterior sacral f.Any of the four pairs of foramina on the posterior (dorsal) surface of the sacrum through which the posterior (dorsal) rami of the sacral roots pass. The posterior sacral foramina, which connect to the sacral canal via the sacral interventricular foramina, are smaller than the anterior sacral foramina. SYN: dorsal sacral foramen.
f. rotundum A round foramen in the anterior medial edge of the greater wing of the sphenoid bone, just below the superior orbital fissure, through which the maxillary division of the trigeminal nerve (CN V) passes. The foramen rotundum is anterior to the foramen ovale in the middle fossa of the skull.
sphenopalatine f.A rounded foramen in the suture between the sphenoid bone and the superior edge of the palatine bone. It is located behind the orbit and connects the nasal cavity with the pterygopalatine fossa. The sphenopalatine branch of the maxillary artery and the nasopalatine nerve pass through this foramen.
f. spinosum The foramen in the outer edge of the greater wing of the sphenoid bone through which the middle meningeal artery passes as it enters the middle cranial fossa.
stylomastoid f.A foramen in the base of the skull between the mastoid process and the styloid process. The motor root of the facial nerve (CN VII) and the stylomastoid artery pass through this foramen.
supraorbital f.Supraorbital notch.
transverse f.An oval foramen in the transverse processes of each cervical vertebra and found only in the cervical vertebrae. The vertebral arteries pass consecutively through all these foramina except the foramina in cervical vertebra C7.
vertebral f.The large foramen between the neural arch and the body of the vertebra that contains the spinal cord.
SEE: under Vesalius, and reas.
SEE: foramen of Winslow.