💀ANATOMÍA en un ESFENOIDES REAL / ¡Todo lo que tienes que saber!

Understanding the Sphenoid Bone

Introduction to the Sphenoid Bone

• The sphenoid bone is described as one of the most interesting bones in the skull, often compared to a bat or butterfly in shape.

• The presentation aims to simplify learning about this complex bone by examining its various surfaces and structures.

Views of the Sphenoid Bone

• The sphenoid can be viewed from multiple angles: superior, inferior, posterior, anterior, and lateral (both right and left). Each view provides different insights into its anatomy.

• Understanding these views helps in identifying key parts such as the body of the sphenoid and its wings.

Key Structures of the Sphenoid

• The body of the sphenoid is central, with smaller (lesser) wings on either side and larger (greater) wings that are more prominent. These structures are crucial for understanding its function.

• Additionally, there are pterygoid processes that will also be discussed later in detail.

Detailed Anatomy of the Body

• From a superior view, the anterior portion is known as the "sphenopalatine yoke," which contacts with other cranial structures like the cribriform plate of the ethmoid bone.

• A significant feature behind this yoke is called the prechiasmatic groove where optic nerves pass through before forming at the optic chiasm. This area is critical for visual processing.

Importance of Surrounding Structures

• The tuberculum sellae leads to what’s termed as "Turkish saddle" or sella turcica; it houses important glands like pituitary gland which can affect vision if tumors grow here due to proximity to optic pathways.

• Further back lies a quadrilateral plate that connects with clinoid processes—both anterior and posterior—which help define boundaries around critical areas like sella turcica.

Lateral View Insights

• In lateral views, carotid canals can be observed which house internal carotid arteries supplying blood to brain regions; they delineate between body and greater wings of sphenoid bone.

• Notably, small projections called lingulae appear near these canals indicating anatomical landmarks essential for surgical reference points or studies related to vascular supply in cranial anatomy.

This structured overview captures essential aspects regarding learning about sphenoid bone anatomy while providing timestamps for easy navigation through video content.

Anatomical Overview of the Sphenoid Bone

Inferior View and Anterior Crest

• The inferior view reveals the lower crest of the sphenoid, leading to the face, transitioning to an anterior view where the anterior crest is visible.

• Lateral to the anterior crest lies part of the nasal cavity's roof, with deeper structures indicating the drainage area for the sphenoidal sinus.

Minor Wings of Sphenoid

• Discussion shifts to the minor wings of the sphenoid, highlighting their borders: anterior and posterior edges along with a triangular base defined by the optic canal.

• The base connects with both body and wings, forming an imaginary line that encompasses structures related to optic foramina.

Cranial Fossa Involvement

• The minor wings contribute significantly to cranial anatomy, specifically forming part of the anterior cranial fossa alongside its anterior body portion.

• Additionally, they include features like anterior clinoid processes and optic foramina as integral components.

Orbital Cavity Relations

• When viewed from below, minor wings also form part of orbital cavity structure; notably contributing to its roof while being involved in both anterior and middle cranial fossae.

Major Wings Characteristics

• Transitioning to major wings, these are characterized by three distinct surfaces: superior (top), lateral (external), and anterior faces when viewed from above.

• The major wing's anterior surface forms part of the lateral wall of orbit while articulating with minor wings creates a significant opening known as superior orbital fissure—distinct from optic canal.

Foramina Identification

• Observations on major wing surfaces reveal multiple foramina: starting with foramen rotundum (greater round hole), followed by foramen ovale and smaller foramen spinosum towards posterior regions.

• Naming conventions clarify distinctions between these openings based on size; e.g., "round" refers specifically when distinguishing larger from smaller foramina in context.

External Surface Features

• On external views of major wings, a notable feature is a dividing ridge called spheno-temporal crest which separates temporal fossa above from infratemporal fossa below—important anatomical landmarks in relation to surrounding structures.

Anatomical Relationships of the Sphenoid Bone

Articulation with Adjacent Bones

• The anterior part of the sphenoid bone articulates with the zygomatic bone, while its external border connects to the temporal squama.

• The internal border of the sphenoid articulates with the parietal bone, marking a significant anatomical junction known as the terion, which is crucial for understanding cranial anatomy.

Pterygoid Processes Overview

• The pterygoid processes consist of a superior base attached to both the body and greater wings of the sphenoid, culminating in a vertex that divides into two laminae.

• Each lamina (internal and external) has distinct medial and lateral surfaces; some authors refer to these as "wings" of the pterygoid processes.

Functional Anatomy of Pterygoid Structures

• At the base of each pterygoid process lies a canal known as the pterygoid canal, which transmits important neural structures from posterior to anterior.

• Between both laminae exists a fossa called the pterygoid fossa, serving as an insertion point for muscles; additionally, there is a small fossa named scaphoid fossa above it for further muscular attachment.