The foramen rotundum is a circular hole in the
sphenoid bone
The sphenoid bone is an unpaired bone of the neurocranium. It is situated in the middle of the skull towards the front, in front of the basilar part of occipital bone, basilar part of the occipital bone. The sphenoid bone is one of the seven bones ...
of the skull. It connects the
middle cranial fossa
The middle cranial fossa, deeper than the anterior cranial fossa, is narrow medially and widens laterally to the sides of the skull. It is separated from the posterior fossa by the clivus and the petrous crest.
It is bounded in front by the pos ...
and the
pterygopalatine fossa
In human anatomy, the pterygopalatine fossa (sphenopalatine fossa) is a fossa in the skull. A human skull contains two pterygopalatine fossae—one on the left side, and another on the right side. Each fossa is a cone-shaped paired depression deep ...
. It allows for the passage of the
maxillary nerve
In neuroanatomy, the maxillary nerve (V) is one of the three branches or divisions of the trigeminal nerve, the fifth (CN V) cranial nerve. It comprises the principal functions of sensation from the maxilla, nasal cavity, sinuses, the palate a ...
(V
2), a branch of the
trigeminal nerve
In neuroanatomy, the trigeminal nerve ( lit. ''triplet'' nerve), also known as the fifth cranial nerve, cranial nerve V, or simply CN V, is a cranial nerve responsible for sensation in the face and motor functions such as biting and chewin ...
.
Structure
The foramen rotundum is one of the several circular apertures (the
) located in the
base of the skull
The base of skull, also known as the cranial base or the cranial floor, is the most inferior area of the skull. It is composed of the endocranium and the lower parts of the calvaria.
Structure
Structures found at the base of the skull are for ...
, in the anterior and medial part of the
sphenoid bone
The sphenoid bone is an unpaired bone of the neurocranium. It is situated in the middle of the skull towards the front, in front of the basilar part of occipital bone, basilar part of the occipital bone. The sphenoid bone is one of the seven bones ...
.
The mean area of the foramina rotunda is not considerable, which may suggest that they play a minor role in the dynamics of blood circulation in the venous system of the head.
Development
The foramen rotundum evolves in shape throughout the fetal period, and from
birth
Birth is the act or process of bearing or bringing forth offspring, also referred to in technical contexts as parturition. In mammals, the process is initiated by hormones which cause the muscular walls of the uterus to contract, expelling the f ...
to adolescence. It achieves a perfect ring-shaped formation in the fetus after the 4th fetal month. It is mostly oval-shaped in the fetal period, and round-shaped after birth (generally speaking). After birth, the rotundum is about 2.5 mm and in 15- to 17-year-olds about 3 mm in length. The average diameter of the foramen rotundum in adults is 3.55 mm.
Function
The foramen rotundum allows the passage of the
maxillary nerve
In neuroanatomy, the maxillary nerve (V) is one of the three branches or divisions of the trigeminal nerve, the fifth (CN V) cranial nerve. It comprises the principal functions of sensation from the maxilla, nasal cavity, sinuses, the palate a ...
(V
2), a branch of the
trigeminal nerve
In neuroanatomy, the trigeminal nerve ( lit. ''triplet'' nerve), also known as the fifth cranial nerve, cranial nerve V, or simply CN V, is a cranial nerve responsible for sensation in the face and motor functions such as biting and chewin ...
.
It also allows the passage of the artery of the foramen rotundum and an emissary vein.
History
Etymology
Foramen is the Latin term designating a hole-like opening. It derives from the Latin forare meaning to bore or perforate. Here, the opening is round as indicated by the Latin rotundum meaning round.
See also
*
Foramen ovale
*
Foramen spinosum
The foramen spinosum is a hole located in the greater wing of the sphenoid. It is located posterolateral to the foramen ovale and anterior to the sphenoidal spine. It allows the passage of the middle meningeal artery, middle meningeal vein and ...
*
Foramina of skull
This article lists foramina that occur in the human body.
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Skull
The human skull has numerous openings (foramina), through which cranial nerves, arteries, veins, and other structures pass. These foramina vary in size and number, with ...
References
External links
*
* ()
Superior view of the base of the skull at winona.edu
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Foramina of the skull