lecture 12

Upper Limb Bones

• Clavicle (Collarbone): Connects the arm to the body; serves as a strut.

• Scapula (Shoulder Blade):

  • Shape: Flat bone.

  • Orientation: Lateral view when looking from the outside.

  • Glenoid Cavity: Socket where humerus fits, forming a ball-and-socket joint.

  • Coracoid Process:

    • Located at the front; attachment point for biceps tendon.

  • Important to note: Focus on key structures rather than memorizing all parts from slides provided.

• Humerus (Upper Arm Bone):

  • Type: Long bone.

  • Key features:

    • Surgical Neck: Common fracture site; requires surgery for repair.

    • Anatomical Neck: Where the head of the humerus connects to the shaft.

    • Tubercles: Greater and lesser tubercles that provide attachment points for muscles.

    • Intertubercular Sulcus: Groove where biceps tendon runs.

  • Fossa on posterior side: Specifics of the structures here to be recognized.

• Wrist Bones:

  • Key to know: Scaphoid (most commonly fractured wrist bone).

  • Carpal Bones: Eight total, divided into rows:

    • Top Row: Four bones.

    • Bottom Row: Four bones; pisciform sits atop the triquetrum (not always visible).

• Phalanges (Finger Bones):

  • Structure: Three bones per finger (proximal, middle, distal).

  • Numbering: Thumb is 1 to pinky 5; similarly for toes.

Pelvic Girdle and Lower Limbs

• Sacrum: Central bone of the pelvis; connects to spine.

• Iliac Bones:

  • Anterior Superior Iliac Spine: Bony landmark located at the top of the pelvis.

  • Pubic Arch: Angle indicative of wider pelvic structure in females.

• Foot Bones (Tarsals):

  • Key Bones to Know:

    • Talus: Connects to tibia and fibula, smooth surface.

    • Calcaneus: Largest bone in the foot, forms the heel.

• For lower limbs, it's essential to remember all tarsals, correlating them to the carpals in the wrist.

Differences Between Male and Female Pelvis:

• General Structure:

  • Male Pelvis: Tends to be narrower and sturdier.

  • Female Pelvis: Has a wider and more spacious structure, adapted for childbirth.

• Pelvic Inlet:

  • Male Pelvis: Heart-shaped, with limited space.

  • Female Pelvis: Oval-shaped and more expansive, aiding in the delivery process.

• Pelvic Arch:

  • Male Pelvis: Typically features a narrower pubic arch with an angle of less than 90 degrees.

  • Female Pelvis: Displays a wider pubic arch, with an angle exceeding 90 degrees, which supports a larger birth canal.

• Iliac Bones:

  • Male Pelvis: Iliac bones are oriented more vertically.

  • Female Pelvis: Iliac bones protrude outward, enhancing overall width.

• Type of Cartilage:

  • Female Pelvis: Contains more elastic cartilage, which provides flexibility and resilience necessary for childbirth.