Nervous Issue and Bone Functions

Functions of Bones:

Muscle attachments: Provide leverage to muscles enabling movement.

Protection: Protect vital organs (e.g., brain, heart, lungs) and support the body's structure.

Blood cell formation: Bones are sites of hematopoiesis (blood cell formation).

Storage: Store inorganic salts, chiefly calcium.

Types of Bones:

Long Bones: Longer than they are wide (e.g., femur, humerus, radius, ulna).

Short Bones: Nearly equal in length and width (e.g., wrist bones, ankle bones).

Sesamoid Bones: Small, round bones that develop within tendons (e.g., patella).

Flat Bones: Thin, flattened bones (e.g., skull bones, ribs, scapula).

Irregular Bones: Bones with complex shapes (e.g., vertebrae, zygomatic bone).

Bone Structure:

Epiphysis: Ends of the bone, where articular cartilage covers.

Diaphysis: The long shaft of the bone.

Articular Cartilage: Covers epiphysis; wears down with age.

Periosteum: Dense connective tissue covering the bone.

Medullary Cavity: Hollow center filled with bone marrow.

Endosteum: Lining of the medullary cavity containing cells.

Types of marrow:

• Red Marrow: Produces blood cells.
• Yellow Marrow: Stores fat.

Types of Cells in Bone:

Osteocytes: Mature bone cells located in lacunae.

Osteoblasts: Bone-forming cells depositing bony matrix; important for bone growth.

Osteoclasts: Cells that break down bone; crucial for bone remodeling and calcium release.

Bone Growth and Repair:

Ossification: Process of bone formation from cartilage, important during fetal development and childhood.

Growth plates (epiphyseal plates): Areas of cartilage that allow for the lengthening of bones during growth.

Hormonal regulation: Growth hormone and sex hormones influence bone growth and ossification.

Physical stress from exercise stimulates bone density and strength.

Bone Health:

Importance of calcium and vitamin D in bone health; calcium needed for muscle function and neural activity.

Osteoclasts and osteoblasts work in remodeling bones throughout life, achieving balance in bone density.

Protection and Support Functions:

Bones provide shape and support to the body.

Protective Structures: Ribs protect thoracic organs; skull protects the brain; pelvic girdle protects lower organs.

Nervous System Connection:

Nerves run through bones, making them sensitive to injury.

Pain signals alert to injuries, helping prevent further damage.

Exercise Importance:

Regular physical activity increases bone strength and helps prevent osteoporosis.

Bones adapt to the intensity of physical demands placed on them.

Quiz Preparation:

Key terms: Remember your definitions (e.g., epiphysis, diaphysis, osteoblast, osteoclast).

Focus on bones of the skull and ribcage for the upcoming quiz: Frontal, parietal, occipital, temporal, zygomatic, maxilla, mandible, sternum, and their parts (body, manubrium, xiphoid process).

Understand bone growth dynamics, types of bones, and their physiological roles.