turtle anatomy

Shoulder Girdle

  • The shoulder girdle is a complex structure that consists of bones, cartilage, and muscles.

    • Main Components:

    • Clavicle (collarbone): Connects the arm to the body. It is a double curved bone that acts as a strut to support the shoulder.

    • Scapula (shoulder blade): Triangular-shaped bone that connects with the humerus (upper arm) and forms an important part of the shoulder joint.

    • Functionality:

    • Provides attachment for muscles that enable arm movement.

    • Facilitates a wide range of motion for the upper limb, crucial for activities such as throwing and lifting.

    • Connects the upper limb to the axial skeleton (the skull and trunk).

Pelvic Girdle

  • The pelvic girdle, often referred to as the pelvis, consists of several bones that form a basin-shaped structure.

    • Components:

    • Ilium: The bone commonly referred to as the hip bone. It is the largest part of the pelvis and includes the superior portion.

    • Ischium: The lower and back part of the pelvis, which bears weight when sitting.

    • Pubis: The front part of the pelvis; the two pubic bones meet at the pubic symphysis.

    • Sacrum: A triangular bone at the base of the spine, connecting the spine to the pelvic girdle.

    • Coccyx (tailbone): A small bone also part of the pelvis, providing a point of attachment for ligaments and muscles.

    • Functionality:

    • Support the weight of the upper body when sitting and standing.

    • Protects pelvic organs such as the bladder and reproductive organs.

    • Provides attachment for lower limbs and serves as a fulcrum for motion.

Ribs

  • The ribs are a set of long curved bones that form the rib cage. This structure surrounds the thoracic cavity and protects vital organs such as the heart and lungs.

    • Structure of Ribs:

    • Typically, humans have 12 pairs of ribs, categorized into:

      • True Ribs (1-7): Attach directly to the sternum through individual costal cartilages.

      • False Ribs (8-10): Attach to the sternum indirectly via the costal cartilage of the ribs above them.

      • Floating Ribs (11-12): Do not attach to the sternum at all.

    • Functionality:

    • Provides flexibility and support to the thoracic cavity while allowing for respiratory movements.

    • Protects organs within the rib cage, specifically the heart and lungs, from physical damage.

    • Assists in the mechanics of breathing.

Anatomical Relationships

  • The anatomical position of the shoulder girdle and pelvic girdle shows they are situated inside the rib cage structure in terms of their proximity to the central body core.

    • Comparison:

    • While the shoulder girdle connects upper extremities to the axial skeleton, the pelvic girdle does so for lower extremities.

    • The close relationship of these girdles to the rib cage underlines their integral roles in protecting vital systems within the body while serving as structural supports.