The pterygoid plexus (;Entry "pterygoid"
in
Merriam-Webster Online Dictionary
'. from

Greek Greek may refer to: Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group *Greek language, a branch of the Indo-European language family **Proto-Greek language, the assumed last common ancestor of all kno ...

''pteryx'', "wing" and ''eidos'', "shape") is a fine venous plexus upon and within the

lateral pterygoid muscle The lateral pterygoid muscle (or external pterygoid muscle) is a muscle of mastication. It has two heads. It lies superior to the medial pterygoid muscle. It is supplied by pterygoid branches of the maxillary artery, and the lateral pterygoid n ...

. It drains by a short maxillary vein.

Anatomy

It is a venous plexus of considerable size, situated between the

temporalis muscle In anatomy, the temporalis muscle, also known as the temporal muscle, is one of the muscles of mastication (chewing). It is a broad, fan-shaped convergent muscle on each side of the head that fills the temporal fossa, superior to the zygomatic a ...

and

, and partly between the two pterygoid muscles. The plexus features

venous valves Veins () are blood vessels in the circulatory system of humans and most other animals that carry blood towards the heart. Most veins carry deoxygenated blood from the tissues back to the heart; exceptions are those of the pulmonary and fetal c ...

. The contractions of the lateral pterygoid muscle promote venous drainage.

Tributaries

The plexus drains all veins that correspond to the branches of the

maxillary artery The maxillary artery (eg, internal maxillary artery) supplies deep structures of the face. It branches from the external carotid artery just deep to the neck of the mandible. Structure The maxillary artery, the larger of the two terminal branches ...

(however, much of the blood delivered by the maxillary artery is returned by other routes), as well as two additional veins. It receives the following veins: * sphenopalatine * middle meningeal * deep temporal (anterior & posterior) * pterygoid * masseteric * buccinator * alveolar * some palatine veins (palatine vein which divides into the greater and lesser palatine v.) * inferior ophthalmic vein * deep facial vein * infraorbital vein

Anastomoses

The plexus is connected with the intercranial

cavernous sinus The cavernous sinus within the human head is one of the dural venous sinuses creating a cavity called the lateral sellar compartment bordered by the temporal bone of the skull and the sphenoid bone, lateral to the sella turcica. Structure The ...

by emissary veins passing through the foramen ovale and foramen lacerum.

Relations

This plexus communicates freely with the anterior facial vein; it also communicates with the

, by branches through the foramen Vesalii, foramen ovale, and foramen lacerum. Due to its communication with the cavernous sinus, infection of the superficial face may spread to the cavernous sinus, causing

cavernous sinus thrombosis Cavernous sinus thrombosis (CST) is the formation of a blood clot within the cavernous sinus, a cavity at the base of the brain which drains deoxygenated blood from the brain back to the heart. This is a rare disorder and can be of two types–sept ...

. Complications may include edema of the eyelids, conjunctivae of the eyes, and subsequent paralysis of cranial nerves which course through the cavernous sinus. The pterygoid plexus of veins becomes the maxillary vein. The maxillary vein and the

superficial temporal vein The superficial temporal vein is a vein of the side of the head which collects venous blood from the region of the temple. It arises from an anastomosing venous plexus on the side and top of the head. The superficial temporal vein terminates with ...

later join to become the

retromandibular vein The retromandibular vein (temporomaxillary vein, posterior facial vein) is a major vein of the face. It is formed within the parotid gland by the confluence of the maxillary vein, and superficial temporal vein. It descends in the gland and split ...

. The posterior branch of the retromandibular vein and

posterior auricular vein The posterior auricular vein is a vein of the head. It begins from a plexus with the occipital vein and the superficial temporal vein, descends behind the auricle, and drains into the external jugular vein. Structure The posterior auricula ...

then form the

external jugular vein The external jugular vein is a paired jugular vein which receives the greater part of the blood from the exterior of the cranium and the deep parts of the face, being formed by the junction of the posterior division of the retromandibular vein wi ...

, which empties into the

subclavian vein The subclavian vein is a paired large vein, one on either side of the body, that is responsible for draining blood from the upper extremities, allowing this blood to return to the heart. The left subclavian vein plays a key role in the absorption ...

References

External links

* - "Infratemporal Fossa: The Pterygoid Plexus of Veins"
Pterygoid Plexus
Veins of the head and neck {{circulatory-stub