The Integumentary System

By: William Davis

Functions

1.Protect the body’s internal living tissues and organs.2. Help excrete waste through perspiration.3. Protect the body from dehydration.4. Protect the body against abrupt changes in temperature,

maintain homeostasis.5. Is a receptor for touch, pressure, pain, heat, cold.6. Generates vitamin D.7. Stores water, fat, glucose, and vitamin D.8. Formation of new cells from stratum germination to repair

minor injuries.

Diseases and Injuries

1. Rash. 8. Cold Sores.2. Blister. 9. Mosquito bites.3. Athletes’ foot. 10. Impetigo.4. Infection. 11. Rubella.5. Sunburn. 12. Cancer.6. Albinism. 7. Acne.

Layers of Skin

The Integumentary system has three layers of skin, the Epidermis, the

Dermis, and the Hypodermis.

The Epidermis This layer of skin is on top, which is made of epithelial cells. No

blood vessels are in this layer. The epidermis’ main functions are protection, absorportion of nutrients, and homeostasis. The structure consists of a kerantinized stratified squamous epithelium comprising four types of cells: keratinocytes, melanocytes, merkel cells, and langerhans’ cells. The major cell is the keratinocyte, which produces keratin. Keratin is a fibrous protein that aids in protection, it is also a water-proofing protein. Millions of them fall daily. Most of your skin is kerantinzed, meaning waterproof. Keratin stiffens epidermal tissue to make fingernails. Nails grow from the nail matrix. The lunula is the crescent shaped area at the base of the nail.

The Dermis Middle layer of skin, composed of dense irregular

connective tissues such as collagen with elastin arranged in a diffusely bundled and woven pattern. These layers serve to give elasticity to the integument, allowing stretching and conferring flexibility, while also resisting distortions, wrinkling, and sagging. The dermal layer provides a site for the endings of blood vessels and nerves. Many chromatophores are also stored in this layer, as are the bases of integument structures such as hair, feathers, and glands.

The Hypodermis The lower layer of skin. Types of cells

found in this layer are fibroblasts, adipose cells, and macrophages. It is derived from the mesoderm, but unlike the dermis, it is not derived from the dermatome region of the mesoderm. This layer is an epidermal layer of cells that secretes the chitinous cuticle.

References

WikipediaClass