mathsci

• Skeletal system


  Framework of the body, composed of bones, bone marrow, joints, cartilage and ligaments
• Bones


  • Support and give shape to the body
  • Bone marrow produces red blood cells
• Joint


  Place where two bones meet<|>Cartilage covers bones with fluid to make movement easier<|>Ligaments are connective tissues that hold joints together
• Bones in the skeletal system

  • Cranium (skull)
  • Face
  • Clavicle (collar bone)
  • Scapula
  • Sternum
  • Ribs
  • Humerus ("funny" bone)
  • Vertebrae
  • Coxal bone (hip)
  • Ulna
  • Radius
  • Carpal bones (wrist)
  • Metacarpal bones
  • Phalanges (fingers)
  • Femur
  • Patella (knee cap)
  • Tibia
  • Fibula
  • Tarsal bones (ankle)
  • Metatarsal bones
  • Phalanges (toes)
• Skeletal system


  • Gives body shape and support
  • Supports body as it moves
  • Protects vital organs
  • Enables different body movements
• Humans are born with over 300 bones, but many fuse together by adulthood resulting in 206 bones
• Classifications of bones


  • Long bones
  • Short bones
  • Flat bones
  • Irregular bones
  • Sesamoid bones
• The human skeleton is composed of fused and individual bones supported by ligaments, tendons, muscles and cartilage
• The human skeleton has two distinct divisions: the axial skeleton (including the vertebral column) and the appendicular skeleton
• Integumentary system


  Organ system consisting of skin, hair, nails and endocrine glands
• Functions of the integumentary system

  • Acts as a barrier to protect the body
  • Protects against diseases
  • Helps retain body fluids
  • Eliminates waste products
• Parts of the integumentary system

  • Skin
  • Hair
  • Nails
  • Endocrine glands
• Skin


  Largest organ of the body, forms the body's outer covering, protects against chemicals, diseases, UV rays and physical damage
• Layers of the skin

  • Epidermis
  • Dermis
  • Hypodermis
• Epidermis


  Outermost layer of skin, provides waterproof barrier and creates skin tone, made of keratinocytes
• Dermis


  Deeper layer of skin, gives skin strength and elasticity, made of connective tissue, nervous tissue, blood and blood vessels
• Hypodermis


  Deepest layer of skin, made of fat and connective tissue, attaches skin to other parts
• Hair


  Accessory organ of integumentary system, aids social functioning, made of dead keratinocytes
• Parts of the hair

  • Hair follicle
  • Hair bulb
• Hair follicle


  Anchors hair into skin, regulates hair growth, opens sebaceous glands, lets oil and wax out
• Hair bulb


  Forms base of hair follicle, made of living cells that divide and grow hair shaft, modifies hair growth and structure
• Nails


  Accessory organ of integumentary system, covers tips of fingers and toes, protects from environmental damage, made of hardened keratinocytes
• Parts of the nail

  • Nail plate
  • Nail cuticle
• Nail plate


  The actual fingernail, made of translucent keratin
• Nail cuticle


  Layer of clear skin at bottom edge of nail
• Exocrine glands


  • Sebaceous gland
  • Sweat gland
• Sebaceous gland


  Small oil-producing gland in dermis, attached to hair follicles, produces sebum and waxy substances
• Sweat gland


  Small tubular structure in dermis that produces sweat, releases sweat through skin pores
• Digestion


  Process of breaking down food into nutrients for energy, growth and cell repair
• Organs of the digestive system

  • Mouth
  • Esophagus
  • Stomach
  • Small intestine
  • Large intestine (colon)
• Mouth


  First part of digestive system, contains teeth and tongue involved in food digestion
• Types of teeth


  • Incisors
  • Canine
  • Premolars
  • Molars
• Esophagus


  Muscular tube connecting pharynx to stomach, moves food through peristalsis
• Stomach


  Large J-shaped organ at end of esophagus, capacity of 50ml when empty, can expand to 2-4 liters when full, has sphincter muscle to control flow
• Parts of the small intestine

  • Duodenum
  • Jejunum
  • Ileum
• Small intestine


  Long coiled tube connected to stomach, about 7 meters long, has villi to increase absorptive area, where nutrient absorption occurs
• Large intestine (colon)


  Large coiled tube attached to end of small intestine, about 1.5 meters long, includes colon, rectum and appendix, twice as wide as small intestine
• Small intestine


  • Long coiled connected from the stomach
  • If stretched, about seven meters long
  • Has villi, small finger-like projections that protrude in the lining to increase absorptive area
  • Absorption of nutrients occurs here with the help of villi
• Parts of the small intestine

  • Duodenum (upper 20 cm connected to stomach)
  • Jejunum (about 2.5 meters long)
  • Ileum (longest, half coiled through abdominal cavity)
• Large intestine or colon


  • Large coiled tube attached to end of small intestine
  • About 1.5 meters long, including colon, rectum, and appendix
  • Twice as wide as small intestine
  • Last 20-30 cm called rectum