Cranial Fossa Anatomy

Anterior Cranial Fossa

• Foramen caecum: connects to nasal cavity, allows passage of emissary veins
• Olfactory foramina: transmit olfactory nerve endings (CNI) from nasal mucosa to brain

Middle Cranial Fossa

• Optic canal: contains optic nerve (CNII) and ophthalmic artery
• Superior orbital fissure: passage for multiple cranial nerves, including:
  • Oculomotor nerve (CNIII)
  • Trochlear nerve (CNIV)
  • Ophthalmic division of the trigeminal nerve (CNV1)
  • Abducent nerve (CNVI)
  • Ophthalmic veins
• Foramen rotundum: passage for maxillary division of the trigeminal nerve (CNV2)
• Foramen ovale: contains mandibular division of the trigeminal nerve (CNV3) and lesser petrosal nerve
• Foramen spinosum: passage for middle meningeal artery
• Foramen lacerum: passage for greater petrosal nerve
• Carotid canal: contains internal carotid artery

Upper Limb Bones

• Scapula (Shoulder Blade) is located on the posterior aspect of the thorax and has a triangular shape with a flat body and two prominent borders (superior and axillary)
• Scapula attaches to the humerus (upper arm bone) at the shoulder joint

Humerus (Upper Arm Bone)

• Long bone of the upper arm that extends from the shoulder joint to the elbow joint
• Divided into three main parts: upper end, shaft, and lower end
• Upper end consists of head, greater tubercle, and lesser tubercle
• Lower end consists of medial and lateral epicondyles, and trochlea

Radius and Ulna (Forearm Bones)

• Radius is the lateral bone of the forearm, shorter and thicker than the ulna
• Ulna is the medial bone of the forearm, longer and thinner than the radius
• Both bones articulate with the humerus at the elbow joint and with the carpal bones at the wrist joint

Carpals (Wrist Bones)

• 8 small bones that form the wrist (carpus) arranged in two rows: proximal and distal
• Proximal row consists of scaphoid, lunate, triquetrum, and pisiform
• Distal row consists of trapezium, trapezoid, capitate, and hamate

Metacarpals (Hand Bones)

• 5 long bones that connect the wrist to the fingers
• Each bone numbered from 1 to 5, starting from the thumb side

Phalanges (Finger Bones)

• 14 bones that form the fingers and thumb
• Each finger has 3 phalanges (proximal, intermediate, and distal), except the thumb which has only 2
• Phalanges articulate with the metacarpals at the metacarpophalangeal joints