Untitled Quiz

Axial Skeleton

• Forms the vertical axis of the body
• Consists of the skull, vertebral column (including sacrum and coccyx), and thoracic cage (formed by ribs and sternum)
• The appendicular skeleton includes all bones of the upper and lower limbs and those connecting to the axial skeleton

Human Skull Anatomy

• The skull is a complex bony structure protecting the brain.
• Composed of various bones, sutures, foramina, and intricate features.
• These features work together to support, protect, and enable the functions of the head and face.

Skull Composition

• Composed of 22 bones (8 cranial, 14 facial)
• All bones are fused to form a rigid structure

Skull Functions

• Protects the brain
• Supports the face
• Provides attachment points for muscles and ligaments involved in vital functions (chewing, speech, facial expression)

Skull Development

• Develops from embryonic mesenchyme and cartilage.
• Bones form through intramembranous and endochondral ossification

Skull Bones (Examples)

• Frontal bone (forehead, part of eye socket)
• Parietal bones (upper sides of cranium)
• Occipital bone (posterior base and lower part of cranium)
• Temporal bones (lateral part of cranium)
• Sphenoid bones (floor of the skull)
• Ethmoid bone (barrier between nasal cavity, cranial cavity, and olfactory region)
• Maxilla (upper jaw, contains upper teeth)
• Mandible (lower jaw)
• Zygomatic bones (cheekbones)
• Nasal bones (bridge of nose)
• Lacrimal bones (associated with tear ducts and glands)
• Palatine bones (roof of the mouth)
• Vomer (part of the nasal septum)

Skull Foramina and Canals

• Vascular foramina allow blood vessels and nerves to pass.
• Neural foramina provide openings for cranial nerves.
• Bony canals are hollow passages for structure transmission.

Paranasal Sinuses

• Frontal sinuses are located above the eyes.
• Maxillary sinuses are the largest, in the maxilla.
• Ethmoid sinuses are between the eyes, in the ethmoid bone.
• Sphenoid sinuses are behind the eyes, in the sphenoid bone.

Temporomandibular Joint (TMJ)

• Connects the mandible to the temporal bone.
• Enables complex jaw movements (chewing, speaking, yawning).
• Critical for proper oral function and jaw movement.

Craniosynostosis and Macrocephaly and Cleft Palate

• Craniosynostosis: Premature fusion of skull sutures
• Macrocephaly: Abnormally large head size (often due to increased fluid or brain volume)
• Cleft Palate: Incomplete fusion of the palate

Clinical Significance of Skull Anatomy

• Skull imaging techniques (X-rays, CT scans, MRI) are vital for diagnosing injuries, deformities, and diseases affecting the cranium and facial structures.
• Detailed skull knowledge is essential for surgical planning (craniotomies, facial reconstructions, corrective surgeries).
• Skull features are used in forensic investigations and anthropological studies for identification purposes.

Vertebral Column Anatomy

• The spine (vertebral column) is a remarkable structure providing support, flexibility, and protection.
• Composed of interconnected bones (vertebrae).

Vertebral Column Regions

• Cervical (7 vertebrae: C1-C7)
• Thoracic (12 vertebrae: T1-T12)
• Lumbar (5 vertebrae: L1-L5)
• Sacral (5 fused vertebrae)
• Coccygeal (4-5 fused vertebrae)

Vertebral Column Curvatures

• Natural curvatures provide shock absorption and support for the body's weight.

Vertebral Body

• The primary weight-bearing structure.
• Provides stability and support

Vertebral Arch

• Surrounds and protects the spinal cord.
• Forms the vertebral foramen.

Vertebral Processes

• Spinal and transverse processes act as attachment points for muscles and ligaments.

Cervical Vertebrae

• Highly mobile, allowing wide range of head and neck movements (C1-C7).
• C1 (atlas) and C2 (axis) are specialized for head rotation.
• Larger vertebral foramen to accommodate the spinal cord.

Thoracic Vertebrae

• Limited mobility compared to cervical/lumbar regions (T1-T12).
• Facets articulate with ribs, forming thoracic cage.
• Protect the spinal cord.

Lumbar Vertebrae

• Largest and strongest, bearing most upper body weight (L1-L5).
• Less mobile than cervical vertebrae but still allows significant range of motion.
• Lumbar lordosis (inward curve) helps distribute weight/provide stability

Sacral Vertebrae

• Five fused vertebrae forming the sacrum, a solid, triangular structure.
• Connects to the pelvic girdle, forming the posterior part of the pelvis.
• Provides a stable base for the upper body and transfers weight to the lower body

Coccygeal Vertebrae

• Vestigial, small, triangular structure formed by 4-5 fused vertebrae.
• Serves as an attachment point for some ligaments and pelvic floor muscles.
• Limited mobility, provides stable base for the body.

Sternum Anatomy

• Sternum is a flat, elongated bone in the center of the chest wall.
• Connects to the ribs via costal cartilages, forming the anterior part of the thoracic cavity.
• Protects the heart, blood vessels, and other mediastinal structures.

Rib Cage Anatomy

• Ribs are curved, flattened bones forming the lateral walls of the thoracic cavity.
• Connect posteriorly to the vertebral column (spinal articulation).
• Anterior ends are linked to the sternum via flexible costal cartilages.

Thoracic Cavity

• The enclosed space within the rib cage, housing essential organs (heart, lungs).
• Rib cage provides protective function.
• Cavity's shape and volume change during breathing.

Intercostal Muscles

• Muscles between ribs facilitate the expansion and contraction of the thoracic cavity.
• Crucial for inhalation and exhalation.
• Diaphragm functions in tandem with intercostal muscles.

Rib Cage Variations

• Variations in rib number, shape, and articulation exist.

Rib Cage Injuries and Imaging

• Common injuries include rib fractures, sternal fractures, and flail chest (multiple rib fractures).
• Imaging techniques (X-rays, CT scans, MRI) are used to diagnose rib cage injuries accurately.

Rib Cage Clinical Relevance and Implications

• Accurate injury assessment crucial for appropriate treatment.
• Disruptions to the rib cage can impair respiratory function.
• Knowledge of rib cage anatomy essential for surgical procedures involving the thoracic region.