Integumentary System

• It is the skin and its derivatives

  Integument
• Skin consists of?


  Epidermis, dermis, and hypodermis
• It is the outer epithelium made up entirely of cells which are arranged in more or less distinct layers.

  Epidermis
• What are the five layers of the epidermis?

  Stranum basale, stratum spinosum, stratum granulosum, stratum lucidum, and stratum corneum
• It is the bottom layer of the epidermis

  Stratum basale
• It is a column-shaped keratinocytes which are constantly divings and pushing already-formed cells towards the skin's surface

  Basal cells
• It is the cell that produces melanin

  Melanocytes
• It is the pigment which provides your skin its color.

  Melanin
• In this layer, also known as the prickle cell or squamous cell layer, cells move in and change from column-shape to multi-sided.

  Stratum spinosum
• Cells in this layer are responsible for making keratin.

  Stratum spinosum
• This is the fibrous protein that gives skin, hair, and nails their hardness and water-resistant properties

  Keratin
• This layer have lost their center (nuclei). This allows them to contain a high proportion of keratin to form the rigid cell layer of skin.

  Stratum granulosum
• They appear as flattened cells containing dark clumps of cytoplasmic material, which are the parts of the cell minus the nucleus.

  Stratum granulosum
• Activities in the stratum granulosum layer.

  Keratin proteins and lipids work together to create many of the cells responsible for the skin's protective barrier
• This layer is only present in the thicker skin of the palms and soles. Its main function is to reduce friction between the stratum corneum and stratum granulosum.

  Stratum lucidum
• The name itself comes from the Latin for "clear layer," which describes the transparency of the cells themselves.

  Stratum lucidum
• These cells have flattened out and are considered dead.


  Corneocytes of Horny Cells
• Composed mainly of keratin proteins, corneocytes provide structural strength to the stratum corneum but also allow for the absorption of water. They serve as an effective barrier to any chemicals that might harm the living cells just beneath them

  Stratum corneum
• This sits directly beneath the epidermis, providing support for it.

  Dermis
• It contains skin cells, blood vessels, nerves, glands, and hair follicles and is much thicker in size than the epidermis

  Dermis
• The _____ layer of the dermis connects with the bottom layer of the epidermis. It is a thin layer that resembles “egg-crate” foam, because it contains wavelike projections that curve up and down at the border of the dermis and epidermis.

  Papillary layer
• The _____ layer of the dermis connects with the papillary layer. It is much thicker than the papillary layer and consists primarily of collagen protein fibers that travel in every direction throughout the layer.


  Reticular layer
• Important structures in reticular layer

  Hair follicles, sweat glands, sebaceous glands, nerves, and blood vessels.
• Three main cells types that travel through the dermis

  Fibroblasts, mast cells, and fat cells
• These are special cells that produce proteins important for wound healing and scarring.

  Fibroblasts
• They are immune system cells that mediate immune reactions like allergies.

  Mast cells
• They are full of fat, which protects the dermis by cushioning it.

  Fat cells
• The color of the human skin depends upon the presence of this certain cell.

  Melanocytes
• Side of the dermis in contact with the epidermis is thrown into rows of _____, which are most prominent on the palms and soles, which provide the greatest possible friction with a surface

  Papillae
• Pigment cells


  chromatophores
• Black or brown pigment

  melanophores
• red pigment


  erythrophores
• yellow pigment


  xanthophores
• Red, yellow, and orange pigment

  lipophores
• white and silver pigment

  leucophores or purines
• blue pigment


  cyanophores
• It is the ability of certain animals to change the color of their skin

  Metachrosis
• The secretory function of the skin is subserved by _____.

  glands
• This gland is distributed over the surface of the human body except on the lips, glans penis, ear drum and nail bed. Their ducts open directly or indirectly on the surface of the skin

  Sweat glands
• This glands are distributed over the greater part of the surface of the skin, being notably absent from the palms and soles. With few exceptions the duct of the gland opens into a hair follicle. The oily secretion serves to keep the hair and skin smooth and soft and also imparts to the animal an individual scent or odor

  Sebaceous glands