Integument

• The skin and its accessory structures make up

  integumentary system
• protection, sensation, temperature regulation, vitamin d production, excretion are the fuctions of ______ system

  Integumentary
• What are the three major layers of the integumentary system?

  Epidermis: The outermost layer of the skin. , Dermis: Lies deep to the epidermis. , Hypodermis: not strictly considered integument. Lies deep to the dermis. The hypodermis covers mostly muscle and is the layer between the dermis and muscle in most places.
• The outermost layer of the skin.

  Epidermis
• Lies deep to the epidermis

  Dermis
• Not strictly considered integument. Lies deep to the dermis. The hypodermis covers mostly muscle and is the layer between the dermis and muscle in most places


  Hypodermis
• The epidermis is composed of what kind of cells?

  Stratified squamous epithelial
• What layer of skin produces melanin?

  Epidermis
• What is the top layer of the skin called?

  Epidermis
• 1. Melanocytes - these cells produce the protein melanin. It functions to protect the nucleus of cells dividing in the Stratum Basale from UV radiation.2. Dendritic cells (Langerhans cells) - Are immune cells that surveil the epidermis, act as phagocytes, and can "alert" the immune system by presenting "antigens".3. Touch receptors--receptor cells sensitive to touch and pressure.

  functions of the different epidermal cells.
• these cells produce the protein melanin. It functions to protect the nucleus of cells dividing in the Stratum Basale from UV radiation.

  Melanocytes
• Are immune cells that surveil the epidermis, act as phagocytes, and can "alert" the immune system by presenting "antigens".

  Dendritic cells (Langerhans cells)
• receptor cells sensitive to touch and pressure.

  Touch receptors
• What are the layers of the epidermis from innermost (deepest) to outermost? (Usually only 4 layers but there is 5 on palms of hands and soles of feet)

  Stratum Basale, Stratum Spinosum, Stratum Granulosum, Stratum Lucidum, Stratum Corneum
• Most Superficial Layer. Keratinocytes are dead. It is 20-30 cell layers thick and is approx. 75% of the epidermal thickness.

  Stratum Corneum
• Deepest layer. Actively mitotic.

  Stratum Basale
• Clear Layer (only in palms of hands and soles of feet)

  Stratum Lucidum
• Fibrous keratin is forming and pushing out on cells.

  Stratum Spinosum
• Cells are flattening and organelles are disappearing and cells are dying.

  Stratum Granulosum 
• What layer of the skin contains sweat glands?

  Dermis
• Support layer below the epidermis


  dermis
• The dermis is mostly made of

  dense irregular connective tissue that is divided to two layers
• What are the two layers of the dermis?

  papillary layer and reticular layer
• Closest to surface(superficial)Conncetive tissue loosely woven with collagen and elastic fibers(stretch a little)Many blood vesselsDermal papilae, many with capillary loops, nerve endings(pain)

  papillary layer
• In a growing fetus, fingerprints form where the cells of the stratum basale of the epidermis meets the papillae of the underlying dermal layer (papillary layer), resulting in the formation of the ridges on your fingers that you recognize as fingerprints.

  papillary layer
• Under the papillary layer, much thicker reticular layer, makes up around 80% of the dermis and is well vascularized and has a rich sensory and sympathetic nerve supply.--appears net like

  reticular layer
• Elastin fibers provide some elasticity to the skin, enabling movement.Collagen fibers provide structure and strength

  reticular layer
• the layer of skin beneath the dermis, which serves as a storage for fatmade up of the adipose tissue and areolar connective tissue

  Hypodermis
• What influences the color of skin?

  a number of pigments, melanin (brown and black colors), carotene (yellow/orange), hemoglobin (pinkish).
• Simple squamous epithelial cells are best described as:

  A single layer of flattened cells
• What are the different exocrine glands in the skin?

  Sweat glands (eccrine and appocrine), Sebaceous glands, Mammary glands, ceruminous glands,
• --Used for thermoregulation.--Secretions are 99% Water and 1% NaCl, Wastes, and Metabolites. ---Found all over the body especially palms, soles, forehead.

  function of eccrine sweat glands
• --Scent glands found in axilla and anogenital regions.--Secrete lipids and proteins that can be metabolized by bacteria producing odor.

  function of appocrine sweat glands
• --Produce sebum secreted into hair follicles. Sebum makes skin and hair shiny, it lubricates and protects the skin and hair. These glands become most active at puberty.--Inflammed and infected sebaceous glands result in acne.

  function of sebaceous glands
• Modified apocrine glands that produce milk.

  function of mammary glands
• Modified apocrine glands that produce ear wax

  function of ceruminous glands.
• --Modified stratum corneum (outermost layer)--Scale like and found on dorsum of fingers and toes--Major parts of a nail include the free edge, nail body, nail root, lanula and eponychium (cuticle).

  origin and structure of nails.
• -comprised of keratinocytes.--The hair bulb is found in the dermis and the root extends from the dermis through the epidermis. The hair shaft extends out from the epidermis externally.--Natural hair color is related to variations in melanin and is genetically determined. Hormones may also affect hair color.--Hair functions in sensation, thermoregulation, and protection.

  components and function of hair
• specialized type of skin found on the palms of the hands and soles of the feet otherwise known as papillary skin or volar skin


  Friction ridge skin
• absence of hair, absence of sebaceous glands which secrete oils, high concentration of sweat glands, high concentration of pores on the surface of the ridges

  features of friction ridge skin