The foramen lacerum is a triangular hole in the base of the skull

Human skull

The human skull is a bony structure, skeleton, that is in the human head and which supports the structures of the face and forms a cavity for the brain.In humans, the adult skull is normally made up of 22 bones...

 located at the base of the medial pterygoid plate

Medial pterygoid plate

The medial pterygoid plate of the sphenoid is narrower and longer than the lateral pterygoid plate; it curves lateralward at its lower extremity into a hook-like process, the pterygoid hamulus, around which the tendon of the Tensor veli palatini glides.The lateral surface of this plate forms part...

.

Transit through the foramen lacerum

The internal carotid artery

Internal carotid artery

In human anatomy, the internal carotid arteries are two major arteries, one on each side of the head and neck. They arise from the common carotid arteries where these bifurcate into the internal and external carotid artery, and they supply the brain....

 passes superiorly from the carotid canal

Carotid canal

On the interior surface of the temporal bone, behind the rough surface of the apex, is the large circular aperture of the carotid canal, which ascends at first vertically, and then, making a bend, runs horizontally forward and medialward.-Contents:...

 in the base of the skull, emerging via that part of the foramen lacerum which is not occluded by cartilage

Cartilage

Cartilage is a flexible connective tissue found in many areas in the bodies of humans and other animals, including the joints between bones, the rib cage, the ear, the nose, the elbow, the knee, the ankle, the bronchial tubes and the intervertebral discs...

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The artery of pterygoid canal, the nerve of pterygoid canal

Nerve of pterygoid canal

The nerve of the pterygoid canal is formed by the junction of the great petrosal nerve and the deep petrosal nerve within the pterygoid canal containing the cartilaginous substance which fills the foramen lacerum.-Course:...

 and some venous drainage also pass through the foramen lacerum.

• The nerve of pterygoid canal comprises the deep petrosal nerve
  Deep petrosal nerve
  The deep petrosal nerve is given off from the carotid plexus, and runs through the carotid canal lateral to the internal carotid artery....
  
   and the greater petrosal nerve the former carrying sympathetic fibres and the latter parasympathetic fibres of the autonomic nervous system
  Autonomic nervous system
  The autonomic nervous system is the part of the peripheral nervous system that acts as a control system functioning largely below the level of consciousness, and controls visceral functions. The ANS affects heart rate, digestion, respiration rate, salivation, perspiration, diameter of the pupils,...
  
   to blood vessels, mucous membranes, salivary glands, and lacrimal glands.

• Furthermore, one of the terminal branches of the ascending pharyngeal artery
  Ascending pharyngeal artery
  The ascending pharyngeal artery, the smallest branch of the external carotid, is a long, slender vessel, deeply seated in the neck, beneath the other branches of the external carotid and under the Stylopharyngeus...
  
   (itself a branch of the external carotid artery
  External carotid artery
  In human anatomy, the external carotid artery is a major artery of the head and neck. It arises from the common carotid artery when it bifurcates into the external and internal carotid artery.-Course:...
  
  ) passes through the foramen lacerum. The ascending pharyngeal artery is one of three possible "meningeal branches" of this vessel.

• Lastly, some emissary veins
  Emissary veins
  The emissary veins are valveless veins which normally drain external veins of the skull into the dural venous sinuses. However, because they are valveless, pus can flow into the skull through them as well, making them a possible route for transmission of extracranial infection to get into the...
  
   pass through the foramen lacerum. These connect the extracranial pterygoid plexus
  Pterygoid plexus
  The pterygoid plexus is a venous plexus of considerable size, and is situated between the temporalis muscle and lateral pterygoid muscle, and partly between the two pterygoid muscles.-Tributaries received:...
  
   with the intracranial cavernous sinus
  Cavernous sinus
  The cavernous sinus , within the human head, is a large collection of thin-walled veins creating a cavity bordered by the temporal bone of the skull and the sphenoid bone, lateral to the sella turcica.-Contents:...
  
   and present an unopposed route for infection
  Infection
  An infection is the colonization of a host organism by parasite species. Infecting parasites seek to use the host's resources to reproduce, often resulting in disease...
  
  .

External links

- "Internal view of skull."

• Image at ucsd.edu