4.5 Chapter Summary

• The skeletal system provides essential structure and function: It supports the body, protects vital organs (like the brain and heart), enables movement through joints and muscle attachments, produces blood cells in bone marrow, and stores minerals such as calcium.
• There are four major bone types, each with specific roles: Long bones (e.g., femur, humerus) aid in movement, short bones (e.g., carpals, tarsals) offer stability, flat bones (e.g., ribs, skull) protect organs, and irregular bones (e.g., vertebrae, pelvis) have complex shapes for specialized functions.
• The skeleton is divided into two parts – the axial and appendicular skeleton. The axial skeleton includes the skull, spine, and ribcage and provides central support and protection. The appendicular skeleton includes limbs, shoulders, and pelvis and is responsible for movement and interaction with the environment.
• Each bone in the body has a specific location and purpose: For example, the femur supports body weight, the radius and ulna control forearm rotation, and the vertebrae protect the spinal cord while allowing flexibility.
• Bones grow and change over time: Babies are born with approximately 270 bones, which fuse into 206 bones by adulthood, particularly in the skull and spine, reflecting the body’s development and specialization.

OpenAI. (July 22nd, 2025). ChatGPT. [Large language model]. https://chat.openai.com/chat. Prompt: Summarize the following content into five key takeaways.

• Appendicular Skeleton: Bones of the limbs and girdles (shoulders, hips) that attach to the axial skeleton.
• Axial Skeleton: Central part of the skeleton: skull, spine, ribs, and sternum.
• Bone Marrow: Soft tissue inside bones that produces red and white blood cells.
• Carpals: 8 small wrist bones.
• Calcaneus: Heel bone; supports weight and absorbs shock.
• Cervical Vertebrae: 7 bones in the neck region (C1–C7).
• Clavicle: Collarbone; connects the sternum and scapula.
• False Ribs: Next 3 pairs that attach to the sternum indirectly.
• Femur: Thigh bone; longest and strongest bone in the body.
• Fibula: Slender bone beside the tibia; helps stabilize ankle and lower leg.
• Flat Bones: Thin and often curved; protect organs and allow muscle attachment (e.g., ribs, sternum, skull).
• Floating Ribs: Last 2 pairs that do not attach to the sternum.
• Frontal Bone: Forehead and front part of the skull.
• Humerus: Upper arm bone; connects shoulder to elbow.
• Ilium: Upper part of the pelvis; has the iliac crest.
• Irregular Bones: Complex shapes; serve specialized purposes (e.g., vertebrae, pelvis, facial bones).
• Ischium: Lower back part of the pelvis; what you sit on.
• Long Bones: Longer than they are wide; used for movement and support (e.g., femur, humerus).
• Lumbar Vertebrae: 5 strong lower back bones.
• Mandible: Lower jawbone; only moveable skull bone, used for chewing.
• Maxilla: Upper jawbone; holds upper teeth.
• Metacarpals: 5 hand bones connecting wrist to fingers.
• Metatarsals: 5 long bones in the middle of the foot.
• Nasal Bone: Bridge of the nose.
• Occipital Bone: Back and base of the skull; has an opening for the spinal cord.
• Parietal Bone: Top and upper sides of the skull.
• Pelvis: Large basin-shaped structure that connects spine to legs and supports weight.
• Phalanges: Finger and toe bones.
• Pubis: Front part of the pelvis where the two sides join.
• Radius: Forearm bone on the thumb side; rotates to allow wrist movement.
• Scapula: Shoulder blade; large flat bone that connects with the humerus.
• Short Bones: Cube-shaped; provide stability and support with limited motion (e.g., carpals, tarsals).
• Skeletal System: The internal framework of the body; supports, protects, enables movement, produces blood cells, and stores minerals.
• Sternum: Flat chest bone (breastbone) in the centre of the ribcage.
• Talus: Bone at the top of the foot; part of the ankle joint.
• Tarsals: 7 small ankle bones.
• Tibia: Shin bone; larger and weight-bearing lower leg bone.
• Temporal Bone: Lower sides of the skull, near ears.
• Thoracic Vertebrae: 12 mid-back bones that attach to the ribs.
• True Ribs: First 7 pairs of ribs that attach directly to the sternum.
• Ulna: Forearm bone on the pinky side; forms the elbow’s point.
• Zygomatic Bone: Cheekbone.

OpenAI. (July 22nd, 2025). ChatGPT. [Large language model]. https://chat.openai.com/chat. Prompt: Create a simple list of key terms and their definitions in the content provided.