Fossa for lacrimal sac

Anatomical feature of the human skull

Diagram of the fossa for the lacrimal sac

The fossa for the lacrimal sac is a depression in the human skull that houses the lacrimal sac, a component of the lacrimal apparatus. This fossa is located in the medial wall of the orbit, specifically between the frontal process of the maxilla and the lacrimal bone.

Anatomy

The fossa for the lacrimal sac is formed by the convergence of two bones: the frontal process of the maxilla and the lacrimal bone. The fossa is a shallow depression that provides a protective space for the lacrimal sac, which is part of the tear drainage system.

Location

The fossa is situated in the anterior part of the medial wall of the orbit. It is bounded anteriorly by the frontal process of the maxilla and posteriorly by the lacrimal bone. The fossa is continuous inferiorly with the nasolacrimal canal, which allows tears to drain from the lacrimal sac into the nasal cavity.

Structure

The fossa is approximately 12 mm in height and 4 mm in width. It is lined with periosteum, and the lacrimal sac is enveloped by a thin layer of connective tissue. The lacrimal sac itself is a membranous structure that collects tears from the lacrimal canaliculi and channels them into the nasolacrimal duct.

Function

The primary function of the fossa for the lacrimal sac is to house and protect the lacrimal sac. The lacrimal sac plays a crucial role in the drainage of tears from the surface of the eye into the nasal cavity. This drainage is essential for maintaining the health and function of the eye by keeping it moist and free from debris.

Clinical significance

The fossa for the lacrimal sac is of clinical importance in ophthalmology and otolaryngology. Conditions such as dacryocystitis, an infection of the lacrimal sac, can arise due to obstruction of the nasolacrimal duct. Surgical procedures, such as dacryocystorhinostomy, may be performed to restore proper drainage by creating a new passageway between the lacrimal sac and the nasal cavity.

Related pages

• Lacrimal apparatus
• Orbit (anatomy)
• Nasolacrimal duct
• Dacryocystitis