for-, fora- +

(Latin: bore, pierce, make holes; hole, holes; opening, openings,)

Having two pores, two openings, or two perforations.
foramen (s); foramina, foramens (pl) (nouns)
A natural hole, passage, or opening in a bone or other body structure: "Although a foramen is usually through a bone, it can be an opening through other types of body tissue which permits the passage of nerves or blood vessels."

"There are many foramens in the cranium, or skull, that make it possible for the nerves and blood vessels pass through."

"Cranial nerves supply most of the sensory structures and muscles of the head and neck and the blood vessels that carry blood to and from the brain go through the foramens."

foramen magnum (s) (noun)
The large hole at the bottom of the cranium or head:

"The foramen magnum is the large opening in the base of the skull through which the spinal cord passes."

"The foramen magnum is situated in the occipital bone which forms part of the base and the back of the skull and this hole allows the brain stem to enter the spinal canal, where it continues as the spinal cord."

foramen ovale (s), foramen ovales (pl) (nouns)
An oval opening between the two upper chambers of the heart (the atria) which is a normal characteristic of the fetal and neonatal (newborn) circulation: "The foramen ovale normally closes on its own when a person is three months of age."
The surgical removal of a large amount of bone and other tissue.

An example would be opening the foramen widely in order to free the passage for a nerve, to remove constriction, and to gain access to a herniated disc which is to the side (outside) of the spinal canal.

The foramen is the natural passage or tunnel between the vertebrae of the spine through which a nerve root exits from the spinal canal on its path to a specific tissue or organ. When this foramen becomes narrowed, the nerve can become irritated or dysfunctional.

This is commonly seen in conditions; such as, spinal stenosis, lateral disc herniations, and facet arthritis.

1. Not perforated or having no opening.
2. Not separated by rows of perforations; such as, imperforate sheets of stamps.
3. In medicine, a body part lacking an opening of the normal size; especially, because of atypical development; for example, an imperforate anus.
1. A condition in which something is abnormally closed.
2. The state of being without perforation.
interventricular foramen (s), interventricular foramina (pl) (nouns)
An opening between the lateral and third ventricles in a system of four communicating cavities within the brain that are connected to the central canal of the spinal cord: "The four ventricles consist of the two lateral ventricles, the third ventricle and the fourth ventricle:"
  1. Lateral ventricles: The lateral ventricles are in the cerebral hemispheres. Each lateral ventricle consists of a triangular central body and four horns.

    The lateral ventricles communicate with the third ventricle through the interventricular foramen (opening).

  2. The third ventricle is a median (midline) cavity in the brain that is bounded by the thalamus and hypothalamus on either side.

    Anteriorly (in front) the third ventricle communicates with the lateral ventricles and posteriorly (in back) the third ventricle communicates with what is called the aqueduct of the midbrain (or the aqueduct of Sylvius).

  3. The fourth ventricle is the most inferior (lowest) of the four ventricles of the brain.

    It extends from the aqueduct of the midbrain to the central canal of the upper end of the spinal cord with which it communicates by the two foramina (openings) of Luschka and the foramen (opening) of Magendie.

    The ventricles are filled with cerebrospinal fluid, which is formed by structures called choroid plexuses located in the walls and roofs of the ventricles.

intervertebral foramen (s) (noun), intervertebral foramina (pl)
An opening between vertebrae through which nerves leave the spine and extend to other parts of the body.
mental foramen, foramen mentale (s) (noun); mental foramina, foramen mentali (pl)
An opening on the lateral (side) part of the body of the mandible (lower jaw), inferior to (below) the second premolar teeth, through which the nerves to the chin and blood vessels pass: The mental foramen transmits the mental nerves and vessels to the skin of the face.

A mental foramen (natural opening, usually through the bone) functions as the passage of blood vessels and a nerve on the outside of the lower jaw on each side near the chin.

neural foramen (s), neural foramina (pl) (nouns)
1. To make a hole or holes in something.
2. To make a line of small holes in paper to make tearing it easier.
3. To penetrate or pass through something.
4. Dotted with small holes.
Having a hole or holes, especially a row of small holes.
Making a hole or holes in something.
1. The act of boring or piercing through a part.
2. A hole made through a part or substance.
3. The act of punching a hole; especially, a row of holes as for ease of separation.
4. A line of small holes for tearing at a particular place.