The lambdoid suture (or lambdoidal suture) is a dense, fibrous

connective tissue Connective tissue is one of the four primary types of animal tissue, along with epithelial tissue, muscle tissue, and nervous tissue. It develops from the mesenchyme derived from the mesoderm the middle embryonic germ layer. Connective tiss ...

joint A joint or articulation (or articular surface) is the connection made between bones, ossicles, or other hard structures in the body which link an animal's skeletal system into a functional whole.Saladin, Ken. Anatomy & Physiology. 7th ed. McGraw- ...

on the posterior aspect of the

skull The skull is a bone protective cavity for the brain. The skull is composed of four types of bone i.e., cranial bones, facial bones, ear ossicles and hyoid bone. However two parts are more prominent: the cranium and the mandible. In humans, th ...

that connects the

parietal bones The parietal bones () are two bones in the skull which, when joined at a fibrous joint, form the sides and roof of the cranium. In humans, each bone is roughly quadrilateral in form, and has two surfaces, four borders, and four angles. It is named ...

with the

occipital bone The occipital bone () is a cranial dermal bone and the main bone of the occiput (back and lower part of the skull). It is trapezoidal in shape and curved on itself like a shallow dish. The occipital bone overlies the occipital lobes of the cer ...

. It is continuous with the occipitomastoid suture.

Structure

The lambdoid suture is between the paired

and the

of the

. It runs from the

asterion In Greek mythology, Asterion ( Greek: , gen.: , literally "starry") or Asterius () may refer to the following figures: * Asterion, one of the Potamoi. * Asterius, one of the Giants. * Asterion, an attendant of the starry-god Astraeus. * As ...

on each side.

Nerve supply

The lambdoid suture may be supplied by a branch of the

supraorbital nerve The supraorbital nerve is one of two branches of the frontal nerve, itself a branch of the ophthalmic nerve. The other branch of the frontal nerve is the supratrochlear nerve. Structure The supraorbital nerve branches from the frontal nerve mi ...

, a branch of the frontal 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 che ...

Clinical significance

At birth, the bones of the skull do not meet. If certain bones of the skull grow too fast, then

craniosynostosis Craniosynostosis is a condition in which one or more of the fibrous sutures in a young infant's skull prematurely fuses by turning into bone (ossification), thereby changing the growth pattern of the skull. Because the skull cannot expand perpe ...

(premature closure of the sutures) may occur. This can result in skull deformities. If the lambdoid suture closes too soon on one side, the skull will appear twisted and asymmetrical, a condition called "

plagiocephaly Plagiocephaly, also known as flat head syndrome, is a condition characterized by an asymmetrical distortion (flattening of one side) of the skull. A mild and widespread form is characterized by a flat spot on the back or one side of the head cause ...

". Plagiocephaly refers to the shape and not the condition. The condition is craniosynostosis. The lambdoid suture can be damaged by a

fall Autumn, also known as fall in American English and Canadian English, is one of the four temperate seasons on Earth. Outside the tropics, autumn marks the transition from summer to winter, in September (Northern Hemisphere) or March ( Southe ...

backwards.

Etymology

The lambdoid suture is named due to its uppercase

lambda Lambda (}, ''lám(b)da'') is the 11th letter of the Greek alphabet, representing the voiced alveolar lateral approximant . In the system of Greek numerals, lambda has a value of 30. Lambda is derived from the Phoenician Lamed . Lambda gave ri ...

-like shape.

Additional images

File:Lambdoid suture - animation03.gif, Animation. Lambdoid suture shown in red. File:Lambdoid suture - animation05.gif,

Parietal bone The parietal bones () are two bones in the skull which, when joined at a fibrous joint, form the sides and roof of the cranium. In humans, each bone is roughly quadrilateral in form, and has two surfaces, four borders, and four angles. It is n ...

s (above) and

(below). File:Lambdoid suture - skull - posterior view.png, Skull seen from behind. Showing -like shape of the lambdoid suture. File:Sobo 1909 46 - Lambdoid suture.png, Lambdoid suture seen from above. File:Sobo 1909 47 - Lambdoid suture.png, Lambdoid suture seen from inside. File:Skull - midsaggital section P.2005 - Lambdoid suture.png, Lambdoid suture, medial view. Indicated by yellow line. File:Lambdoid suture.jpg, Lambdoid suture with wormian bones, seen from behind.

References

* "Sagittal suture." ''Stedman's Medical Dictionary, 27th ed.'' (2000). * Moore, Keith L., and T.V.N. Persaud. ''The Developing Human: Clinically Oriented Embryology, 7th ed.'' (2003).

External links

* (Posterior) * (Lateral) * {{Authority control Bones of the head and neck Cranial sutures Human head and neck Joints Joints of the head and neck Skeletal system Skull