Integument System

• Skin

  A) epidermal ridge

  B) hair shaft

  C) free nerve ending

  D) epidermis

  E) papillary region

  F) dermis

  G) reticular region

  H) subcutaneous layer

  I) dermal papilla

  J) capillary loop

  K) sweat pore

  L) sebaceous gland

  M) arrector pilli muscle

  N) hair follicle

  O) eccrine sweat gland

  P) apocrine sweat gland

  Q) adipose tissue

  
• three main layers to the skin:

  • epidermid
  • dermis
  • subcutaneous layer
• Functions of the skin:

  • protection
  • excretion
  • regulation of body temperature
  • sensation
  • synthesis of vitamin D
• What is the epithelial tissue of the skin called?


  epidermis
• what is the connective layer of the skin called?

  dermis
• Portion of the epidermis

  A) stratum corneum

  B) stratum lucidum

  C) stratum granulosum

  D) stratum spinosum

  E) stratum basale

  F) dermis

  G) superficial

  
• Cells within the epidermis

  A) dead keratinocytes

  B) lamellar granules

  C) keratinocytes

  D) langerhans cells

  E) merkel cells

  F) tactile disc

  G) sensory neurone

  H) melanocytes

  I) dermis

  
• Cell types of the epidermis:

  • keratinocyte (90%)
  • melanocytes (8%)
  • langerhans cells
  • merkel cell
• what does a langerhans cell do?


  Recognise and process microbial invaders#
• types of skin:

  • thick
  • thin
• Thin skin:

  • covers whole body except for palms, palm side of digits and soles of the feet
  • lacks a stratum lucidum
  • stratum spinosum and corneum are relatively thin
  • fewer sensory receptors
• Thick skin:

  • covers palms, palm surface of digits and soles of feet
  • lacks hair follicles, arrector pili muscle and oil glands
• Epidermis:

  • stratified squamous epithelium - distinct strata
  • cells produced in stratum basale
  • they migrate upwards
  • kertain is synthesised and accumulated
  • uppermost layer are dead, dry, scale like cells. Lipid rich secretion between cells. waterproof
• Dermis:

  • mainly collagen and elastic fibres
  • anchors epidermis in place
  • papillary region - fingerlike projections give more surface area to stratum basale
  • reticular region
• Accessory skin structures:

  • hair
  • sebaceous (oil) glands
  • sudoriferous (sweat) glands
  • nails
• Sebaceous (oil) glands:

  • secrete oily sebum
  • lubricates skin, coats hair
  • some antibacterial action
  • large on face, breasts, chest and neck
  • smaller on trunk and limbs
  • Acne results from inflammation of sebaceous glands colonised by bacteria
• Sudoriferous (sweat) gland:

  2 types:

  • eccrine and apocrine

  Eccrine

  • sweat contains water, sodium, chloride ions, urea, uric acid ammonia, amino acids, glucose lactic acid
  • 600ml per day
  • secreted on to body surface regulates body temperature

  Apocrine

  • secrere 'thick' sweat into hair follicle ducts
• Hair embedded in skin

  A) hair shaft

  B) hair root

  C) arrector pili muscle

  D) eccrine sweat gland

  E) sebaceous gland

  F) hair root plexus

  G) bulb

  H) papilla of the hair

  I) apocrine sweat gland

  J) blood vessels

  
• Internal structure of hair

  A) hair matrix

  B) papilla of hair

  C) blood vessel

  D) bulb

  E) epithelial root sheath

  F) internal root sheath

  G) external root sheath

  H) cuticle

  I) cortex

  J) medulla

  K) dermal root sheath

  
• Nail structure

  A) nail root

  B) nail matrix

  C) lunula

  D) nail body

  E) sagittal plane

  F) free edge of nail

  G) hyponychium (nail bed)

  H) epidermis

  I) dermis

  J) phalanx (finger bone

  K) eponychium (cuticle)

  
• nail:

  tightly packed keratinised cells

  protect ends of fingers and toes