🥇 Anatomía de la CAVIDAD ORBITARIA. (ÓRBITA OCULAR). Fácil, Rápida y Sencilla

Introduction to the Anatomy of the Orbital Cavity

In this video, Dr. Juan José Sánchez from the University of Oriente in Venezuela introduces the anatomy of the orbital cavity. He discusses the bony structure and its relationships with surrounding structures.

Anatomy of the Orbital Cavity

• The orbital cavity is a space in the skull that houses the eyes, muscles that move them, and nerves responsible for transmitting information to and from the eyeball.

• The bony structure of the orbital cavity includes the frontal bone, temporal bone, ethmoid bone, and maxillary bone.

• The relationships of the orbital cavity can be understood by examining different views of the skull:

• Superior view: Shows the anterior cranial fossa above the frontal bone.

• Lateral view: Reveals the temporal fossa adjacent to the orbital cavity.

• Medial view: Highlights structures such as ethmoid sinuses and sphenoid sinuses that are related to the medial aspect of the orbit.

Borders of the Orbital Cavity

• The borders of the orbital cavity are formed by three bones:

• Superior border: Formed by the frontal bone.

• Lateral border: Formed by a combination of frontal process of zygomatic bone (zygomaticofrontal process) and zygomatic process of frontal bone (frontozygomatic process).

• Inferior border: Formed by a combination of maxillary bone (orbital surface) and lacrimal bone.

• Medial border: Formed by a combination of ethmoid bone (ethmoidal air cells) and lacrimal bone.

Structures within Each Border

Superior Border (Supraorbital Margin)

• Consists solely of frontal bone.

• Contains a supraorbital notch or foramen, which allows the passage of the supraorbital nerve and vessels.

Lateral Border (External Orbital Margin)

• Formed by the articulation between the frontal process of zygomatic bone and the zygomatic process of frontal bone.

• Also known as the zygomaticofrontal suture or frontozygomatic suture.

Inferior Border (Infraorbital Margin)

• Formed by a combination of maxillary bone (orbital surface) and lacrimal bone.

• Contains infraorbital foramen, through which passes the infraorbital nerve and vessels.

Medial Border (Internal Orbital Margin)

• Formed by a combination of ethmoid bone (ethmoidal air cells) and lacrimal bone.

• Contains structures such as ethmoid sinuses and sphenoid sinuses.

Borders of the Orbit

Dr. Juan José Sánchez discusses in detail the borders of the orbit, including their formation and associated structures.

Borders of the Orbit

• The orbit has four borders:

• Superior border: Also known as supraorbital margin, formed solely by frontal bone.

• Lateral border: Formed by frontal process of zygomatic bone articulating with zygomatic process of frontal bone.

• Inferior border: Also known as infraorbital margin, formed by maxillary bone (orbital surface) and lacrimal bone.

• Medial border: Also known as internal orbital margin, formed by ethmoid bone (ethmoidal air cells) and lacrimal bone.

Structures within Each Border

Superior Border (Supraorbital Margin)

• Consists solely of frontal bone.

• Contains supraorbital notch or foramen for passage of supraorbital nerve and vessels.

Lateral Border (External Orbital Margin)

• Formed by articulation between frontal process of zygomatic bone and zygomatic process of frontal bone.

• Also known as zygomaticofrontal suture or frontozygomatic suture.

Inferior Border (Infraorbital Margin)

• Formed by maxillary bone (orbital surface) and lacrimal bone.

• Contains infraorbital foramen for passage of infraorbital nerve and vessels.

Medial Border (Internal Orbital Margin)

• Formed by ethmoid bone (ethmoidal air cells) and lacrimal bone.

• Contains structures such as ethmoid sinuses and sphenoid sinuses.

Conclusion

Dr. Juan José Sánchez concludes the video by summarizing the borders of the orbit and their associated structures.

Summary

• The orbit has four borders: superior, lateral, inferior, and medial.

• Each border is formed by specific bones and contains important structures such as nerves and blood vessels.

• Understanding the anatomy of the orbital cavity is crucial for studying eye-related conditions and performing surgical procedures in this area.

Timestamps are approximate.

Anatomy of the Eye Orbit

This section provides an overview of the anatomy of the eye orbit, focusing on its external borders and structures.

External Borders of the Eye Orbit

• The external border of the eye orbit is concave forward.

• The lower border, also known as infraorbital border, is formed by the malar bone and maxillary bone.

• Two centimeters below the lower border is the infraorbital foramen, through which vessels and nerves pass.

Internal Borders of the Eye Orbit

• The internal border is divided into superior and inferior parts.

• The superior border continues posteriorly with the frontal bone's supraorbital margin.

• The inferior border continues anteriorly with the lacrimal bone and posteriorly with the maxillary bone.

• The space between these borders contains the lacrimal sac.

Lacrimal Structures

• The lacrimal crest on the maxillary bone forms a posterior boundary, while a similar crest on the lacrimal bone forms an anterior boundary.

• Between these crests lies the lacrimal sac, which drains tears through the nasolacrimal duct into the inferior meatus of nasal cavity.

Walls of Eye Orbit

• The eye orbit has four walls: superior (roof), medial (inner), lateral (outer), and floor.

• The superior wall consists of frontal bone's orbital plate and lesser wing of sphenoid bone. It contains a fossa called trochlear fossa for insertion of superior oblique muscle.

• The lateral wall is formed by zygomatic bone and greater wing of sphenoid bone. It houses the lacrimal gland in its lateral part.

Parietal Walls and Orbital Fossae

This section focuses on describing parietal walls and orbital fossae within the eye orbit.

Parietal Walls

• The parietal walls of the eye orbit form a nearly 90-degree angle.

• They are composed of three bones: frontal bone, lesser wing of sphenoid bone, and greater wing of sphenoid bone.

Superior Wall

• The superior wall consists of the orbital plate of the frontal bone and lesser wing of sphenoid bone.

• It contains the optic canal, through which the optic nerve passes.

Medial Wall

• The medial wall is located towards the inner side.

• It is formed by the ethmoid bone's lamina papyracea and lacrimal bone.

• The fossa located medially is called lacrimal fossa, where the lacrimal sac is inserted.

Lateral Wall

• The lateral wall is located towards the outer side.

• It is formed by zygomatic bone and greater wing of sphenoid bone.

• The lateral part contains the lacrimal gland.

Floor

• The floor forms a base for the eye orbit.

• It consists mainly of maxillary bone and palatine bone.

Orbital Fossae and Structures

This section discusses orbital fossae within the eye orbit and their associated structures.

Trochlear Fossa

• Located medially in the superior wall, it serves as an attachment site for the trochlea (pulley) of superior oblique muscle.

Lacrimal Fossa

• Found laterally in the superior wall, it houses the lacrimal gland responsible for tear production.

Optic Canal

• Situated in the posterior part of superior wall, it allows passage for optic nerve (cranial nerve II).

Inferior Orbital Fissure

• Located between lateral and medial walls, it provides communication between the eye orbit and infratemporal fossa.

Infraorbital Groove

• Runs along the floor of the eye orbit, housing the infraorbital vessels and nerve.

Inferior Orbital Sulcus

• Located on the floor of the eye orbit, it accommodates the infraorbital vessels and nerve.

Conclusion

This section concludes the discussion on the anatomy of the eye orbit, highlighting key structures and their locations within the orbital fossae.

• The eye orbit is a complex structure with external borders, internal borders, walls, and orbital fossae.

• Understanding its anatomy is crucial for comprehending various functions related to vision and tear production.

• Each wall of the eye orbit consists of specific bones that contribute to its overall structure.

• The superior wall contains important structures like optic canal, trochlear fossa, and lacrimal fossa.

• The lateral wall houses the lacrimal gland responsible for tear production.

• The medial wall contains lacrimal sac insertion site in lacrimal fossa.

• The floor of the eye orbit plays a significant role in supporting various structures.

Anatomy of the Orbital Wall

This section provides an overview of the anatomy of the orbital wall, specifically focusing on the lateral wall.

Lateral Wall

• The lateral wall is formed by the zygomatic bone (also known as malar bone) and the superior part of the frontal bone.

• It contains two major openings:

• Superior orbital fissure (green)

• Inferior orbital fissure (red)

• The superior orbital fissure is bounded by both wings of the sphenoid bone, while the inferior orbital fissure is limited by the greater wing of sphenoid and maxillary bones.

• The superior orbital fissure allows passage for cranial nerves that innervate eye muscles, such as oculomotor nerve (III), trochlear nerve (IV), and abducens nerve (VI).

• The inferior orbital fissure allows structures to pass into the pterygopalatine fossa and infratemporal fossa.

Floor of the Orbit

This section discusses the floor of the orbit and its components.

Components

• The floor of the orbit consists of three bones:

• Maxilla (superior part)

• Zygomatic bone or malar bone (posterior part)

• Palatine bone (medial part)

Infraorbital Groove

• The maxilla has an infraorbital groove, which is different from the inferior orbital fissure. It connects to the infraorbital canal.

• The infraorbital canal serves as a pathway for structures such as infraorbital nerves and vessels.

Medial Wall of Orbit

This section focuses on the medial wall of the orbit and its composition.

Composition

• The medial wall is formed by four bones:

• Ethmoid bone (with its orbital part)

• Lacrimal bone (above)

• Frontal bone (partially, both medially and laterally)

• Sphenoid bone (body, posteriorly)

Structures

• The medial wall contains two openings for nerves:

• Anterior ethmoidal foramen

• Posterior ethmoidal foramen

Conclusion

This section concludes the video.

• The anatomy of the orbital wall includes the lateral, floor, and medial walls.

• Each wall is composed of different bones and contains specific openings for nerves and structures.

• Understanding the anatomy of the orbital wall is essential in comprehending various clinical conditions related to the eye and surrounding structures.