skel and reoroductive

• Organs of the skeletal system

  • Bones
  • Cartilages
  • Ligaments
  • Joints
• Bones


  • Rigid organ that constitutes part of the vertebrate skeleton
  • Protect various organs
  • Produce red and white blood cells
  • Store minerals
  • Provide structure and support for the body
  • Enable mobility
• Osteoblasts


  Responsible for making new bone and repairing older bone<|>Produce a protein mixture called osteoid, which is mineralized and becomes bone<|>Manufacture hormones including prostaglandins
• Osteocytes


  Inactive osteoblasts that have become trapped in the bone they created<|>Maintain connections to other osteocytes and osteoblasts, important for communication within bone tissue
• Osteoclasts


  Large cells with more than one nucleus<|>Function to break down bone<|>Release enzymes and acids to dissolve minerals in bone and digest them<|>Help remodel injured bones and create pathways for nerves and blood vessels
• Bone marrow


  • Found in almost all bones where cancellous bone is present
  • Responsible for making around 2 million red blood cells every second
  • Produces lymphocytes or the white blood cells involved in the immune response
• Extracellular matrix of bones

  Organic components, mostly type 1 collagen<|>Inorganic components, including hydroxyapatite and other salts such as calcium and phosphate<|>Collagen gives bone tensile strength<|>Hydroxyapatite gives bones compressive strength
• Functions of bones


  • Mechanical - provide a frame to support the body, protect internal organs
  • Synthesizing - produce blood cells, destroy old red blood cells
  • Metabolic - store minerals, fat, regulate pH, detoxify, release hormones, regulate calcium
• Types of bones


  • Long bones
  • Short bones
  • Flat bones
  • Sesamoid bones
  • Irregular bones
• Parts of the skeletal system

  • Appendicular skeleton
  • Axial skeleton
• Bone remodeling


  1. Reabsorption - osteoclasts break down and remove bone

  2. Formation - new bone tissue is laid down
• An estimated 10 percent of an adult's skeleton is replaced each year
• Cartilage


  Resilient and smooth elastic tissue<|>Rubber-like padding that covers and protects the ends of long bones at the joints<|>Structural component of the rib cage, ear, nose, bronchial tubes, intervertebral discs
• Types of cartilage


  • Elastic
  • Hyaline
  • Fibro
• Ligaments


  Short bands of tough, flexible fibrous connective tissue that connect two bones or cartilages or hold together a joint
• Types of joints


  • Fibrous (immovable)
  • Cartilaginous (partially moveable)
  • Synovial (freely moveable)
• Types of joint movements

  • Flexion
  • Extension
  • Abduction
  • Adduction
  • Circumduction
  • Rotation
  • Supination
  • Pronation
  • Inversion
  • Eversion
• The reproductive system is the biological system made up of all the anatomical organs involved in sexual reproduction
• Parts of the male reproductive system

  • Testes
  • Sperm duct
  • Glands
  • Urethra
• Route taken by sperm as it leaves the body

  1. Sperm leaves testes and travels down sperm duct

  2. Sperm duct passes through glands that provide sperm with food for swimming

  3. Sperm duct joins urethra

  4. Urethra carries sperm out of the body
• Parts of the female reproductive system

  • Uterus
  • Cervix
  • Vagina
  • Ovum
  • Ovary
  • Oviduct
• Sperm


  The male sex cell, adapted to swim from the vagina to the egg
• Testes


  After puberty, these make sperm continuously
• Scrotum


  A sac of skin which holds the testes