integuementary system

• Body membranes


  Surround and protect various surfaces of the body
• Epithelial membranes


  • Function as a lining for both external and internal body surfaces
  • Consist of a sheet of epithelial cells and a layer of connective tissue
  • Include mucous, serous, cutaneous and synovial membranes
• Mucous Membrane


  • Line body cavities open to the outside world
  • Consist of epithelium and a layer of connective tissues called lamina propria
  • Moist and secrete for protection and substrate transport
• Serous Membrane


  • Line closed body cavities
  • Outer layer of squamous epithelium and thin layer of connective tissues
  • Form double lining with a parietal layer (outer lining of cavity) and visceral layer (inner living covering organs)
  • They secrete fluids which lubricate the cavities, reducing friction and protecting organs
• Cutaneous Membrane


  • Refers to the skin
  • Has a structure of keratinising (changing into), stratified squamous epithelium over dense, fibrous connective tissue
  • Considered a dry membrane when sweat not present (although it contains sweat glands)
• Synovial Membrane


  • Is a connective tissue membrane
  • Does not contain epithelial cells
  • They line capsules around synovial joints, tendon sheaths and bursae
  • They secrete fluids which cushions and reduces friction in moving structures
• Integumentary System


  • Skin
  • Sweat and oil glands
  • Hair
  • Nails
• Functions of Integumentary Systems

  • Skin acts as a protective layer for underlying tissues
  • Keratin (strong natural protein) provides structural strength and protects against chemicals
  • Regulation of body temp achieved through capillaries (delicate blood vessels) and sweat glands in the skin
  • Skin produces melanin to protect against UV radiation and synthesises vitamin D
  • Cutaneous sensory receptors in the skin transfer info about touch, pressure, pain and temp
• Anatomy of the skin

  • Skin consists of two layers: epidermis and dermis
  • Epidermis and dermis vary in thickness (thick in soles of foot, thin on eyelids)
  • Hypodermis is below the dermis
• Epidermis


  • Outer most layer of skin
  • Consist of 5 layers (stratum corneum, stratum lucidum, stratum granulosum, stratum spinosum and stratum Basale)
  • Do not have direct blood supply
  • Receive nutrients from dermis through stratum basale
  • Majority of cells in epidermal are keratinocytes (produce keratin)
• Dermis


  • Dense fibrous tissue composed of collagen and elastic fibres
  • Rich blood supply, aiding in heat regulation
  • Sensory receptors for touch, vibration, pain and temp are present
  • Phagocytes in dermis ingest foreign materials and dead cells
• Papillary layer


  Outer layer of dermis containing dermal papillae (form patterns on palm skin) with capillaries and nerve endings
• Reticular layer


  • Beneath papillary layer
  • Has an irregular arrangement of collagen and elastic fibres
• Hypodermis (subcutaneous fascia)


  • Consist of fibrous connective tissue and adipose tissue
  • Fats cells are present providing padding, insulation and energy storage
• Appendages of the skin

  • Sudoriferous glands
  • Sebaceous glands
  • Hair
  • Nails
• Sudoriferous glands


  • Found throughout dermis
  • High concentrations under the arms, on palms soles and forehead
  • 2-3 million sweat glands in each persons body
  • Two types of sweat glands: eccrine and apocrine glands
• Eccrine glands


  • Major sweat glands, opening directly onto the skin
  • Clear containing water, waste products and vitamin C
  • Nerve endings in sweat glands stimulate sweat production in response to increased body and external temp
• Apocrine glands


  • Larger than eccrine
  • Found in genital and armpit areas
  • Secrete milky fluids containing sweat, fatty acids and proteins
  • Apocrine gland ducts empty into hair follicles
• Sebaceous glands


  • Found throughout body except for palms and soles
  • Produce oily substance called sebum
  • Sebaceous glands mostly empty in hair follicles while some secrete directly onto skin
• Hair


  Hair follicles are structures within the dermis that produce hair
• Nails


  • Nail bed is specialised region of the stratum basale underlying each nail
  • Nail matric is located at the proximal end of the nail bed, responsible for nail growth
  • Nail growth occurs in matrix as new cells become keratinised
  • Nails appear pink due to capillary supply beneath the stratum basale
  • Lunule is the white, moon shaped region at the base of nail
• Locations of body membranes

  • External and internal cavities
  • Synovial joint capsules (in the knee)
  • Skin
  • Respiratory, digestive, urinary and reproductive tracts
  • Pleura (thin layer of tissue covering the lungs)
  • Pericardium (fibrous sac enclosing the heart)
  • Peritoneum (lines the abdominal cavity)
• Serous membranes


  Produce serous fluids which make the cavities greasy, reducing the friction and protecting the organs
• Epidermis


  Outermost layer of skin
• Dermis


  Beneath epidermis, contains connective tissues, blood vessels, lymphatic vessels and sweat glands
• Hypodermis


  Bottom layer of skin
• Melanocytes


  Produce melanin
• Cell in stratum basale


  Continuously produces new skin cells which gradually move to surface and die
• Collagen


  Provide toughness, bind with water
• Elastic


  Help keep skin youthful
• Sebum


  • Helps keep skin and hair soft
  • Contains chemicals that have antibacterial properties
• Keratinocytes


  Cells in the epidermis that produce keratin
• Cells in the stratum spinosum and stratum granulosum

  • Become flatter and more filled with keratin, making them tough and water resistant
• Stratum lucidum


  A clear layer found in thick skin areas like palms, soles, and fingers
• Stratum corneum


  The outer layer of the epidermis, consisting of dead cells filled with keratin that continuously shed
• The epidermis completely regenerates every 25 to 45 days