Chapter 11: Integumentary System

• functions of integumentary system

  protection

  thermoregulation

  sensation

  immunity

  vitamin D synthesis
• examples of protection


  mechanical

  immunological

  UV blocking
• specific example of protection

  MRSA
• specific example of thermoregulation

  blood closer to skin releases heat
• specific example of sensation

  corpuscles

  structure combination of cellular and noncellular
• vitamin d synthesis is in

  ependymal cells

  epidermis cells
• three integumentary layers


  epidermis

  dermis

  hypodermis
• epidermis


  KSSE
• dermis


  dense irregular CT
• hypodermis

  areolar CT

  adipose CT
• subcutaneous layer of the hypodermis


  weaves together layers of skin and muscle
• superficial fascia


  looks like threads of oranges
• epidermal appendages


  epidermal pegs

  skin glands

  hair follicles/hair

  nails
• epidermal cell types


  keratinocytes

  melanocytes

  langerhans cells

  merkel cells
• keratinocytes


  most abundant

  make keratin

  structural proteins
• keratins


  series of disulfide bridges
• keratohyalin


  type of keratin filament
• melanocytes


  scattered in epidermis

  make melanin

  found in stratum spinosum

  pale cytoplasm

  dark nucleus
• melanophores


  in animals

  doesn't give melanin to other cells
• melanosomes


  bundles of melanin

  moves into keratinocytes
• langerhans cells


  microglia with big dendrites

  in layers of epidermis and stratum spinosum

  pale cytoplasm

  dark nucleus
• Merkel cells


  form merkel's body

  mechanoreceptors

  located stratum basale

  pale cytoplasm

  dark indented nucleus
• merkel's disk


  merkel body

  merkel corpuscle
• epidermal layers


  stratum basale

  stratum spinosum

  stratum granulosum

  stratum lucidum

  stratum corneum
• st basale


  pushes layers up to skin

  goes through mitosis
• st spinosum


  youngest layer

  desmosomes
• st granulosum


  produce keratohyalin

  ceramides

  pyknotic nuclei
• pyknotic nucleus


  dying pinpoint nucleus
• st. lucidium


  flattening of cells

  dying of cells (too far from blood supply)
• st. corneum


  flat keratin
• thick skin


  more layers
• thin skin


  less layers

  no stratum lucidium
• types of dermal cells

  fibroblasts

  mast cells

  macrophages

  leukocytes

  adipocytes
• dermal layers

  papillary layer: loose CT

  reticular layer: dense irregular CT
• papillary layer

  dermal papillae

  dermatoglyphs
• dermatoglyph


  fingerprints
• three types of multicellular exocrine glands

  eccrine sweat glands

  apocrine sweat glands

  sebaceous glands
• non-epidermal inclusions

  meissner's corpuscles

  pacinian corpuscles

  arteriovenous anastomoses
• hypodermis


  may be areolar or adipose tissues

  same inclusions as dermis
• two types of hairs

  vellus

  terminal