SCIENCE, TECHNOLOGY & SOCIETY: Integumentary System, Lecture notes of Anatomy

Download SCIENCE, TECHNOLOGY & SOCIETY: Integumentary System and more Lecture notes Anatomy in PDF only on Docsity! INTEGUMENTARY SYSTEM Introduction for the Integumentary System 1) Also known as your Covering system which is the largest organ in our body. 2) The cellular renewal never stops it is continuous. The Integumentary system is composed of skin, hair, nails, and exocrine glands (sweat and sebaceous glands). 3) Parts: (composed largely of keratin, a hardened protein) a) Nails b) Skin c) Hair Main Functions of the Integument 1) Protection 2) Temperature maintenance 3) Synthesis and storage of nutrients 4) Sensory reception 5) Excretion and secretion Components: SKIN NAIL HAIR Type of Epidermal Cells: Composed of fingernail & toenails. located in your hands and feet. Help to make the backs of the fingertips stiff and helps you grip precisely. - Located all over your body except in the palm of your hands and soles of your feet. - Protects your head from UV radiation from the sun, cushion, and insulate your head. - The nose of the hair traps foreign particles into the body and others, like those all over the rest of your body, act as sensory receptors. - It is a structure produced in an organ called a Hair Follicle. 1) Keratinocytes - They are created in the stratum basale and pushed upward toward the skin's surface. - These cells make keratin and act to protect deeper layers of soft tissue. - The building blocks of the tough fibrous protein keratin that fives structure and durability. 1) Nail plate - The visible part of the nail. - The lunula (the whitish half- moon at the base of the nail) the rest of the nail is pinkish color due to the underlying blood vessels 2) Nail bed or Nail Matrix - Entire nail body protects the soft tip of your finger 1) Hair Follicle - Is living that produces Hair 2) Hair root plexus - The plexus of nerves that you can feel the movement of even a single hair - Arrector pili are what is responsible for goosebumps. 3) Hair shaft - The external part of the hair 2) Melanocytes - Pigmented cells of the stratum basale region that produce melanin which protects from us UV radiation. - Synthesizes Melanin that gives human skin, hair, and eyes their color. 3) Merkel Cells - Function as touch receptors in association with sensory nerve endings located at the epidermal- dermal junction. - Combine with nerve endings to create sensory receptors for touch. 4) Langerhans Cells - Are dendritic cells (antigen- presenting immune cells) of the skin, and contain organelles called Birbeck granules. - Ingest the unwanted invaders in your skin. 3) Nail root - Nail root is not visible from the surface. This is where nail production occurs. 4) Cuticle - The tissue that overlaps the plate and rims the base of the nail 5) Fingerbone or toe bone. 4) Sebaccues gland - Secretes a lubricating oily matter (sebum) into the hair follicles to lubricate the skin and hair. 5) Sweat Gland - Help you cool off I. Cutaneous Membrane or Skin: II. Subcutaneous Layer: (Fat or Hypodermis Epidermis - The epidermis is the thinnest layer that is a multi-layered, flexible, self-repairing barrier that prevents fluid loss, provides protection from UV radiation, produces vitamin D3, and resists damage from abrasion, chemicals, and pathogens - Stratified squamous epithelium - Several distinct cell layers - Thick skin—five layers On palms and soles - Thin skin—four layers On rest of body Cell Layers of The Epidermis: 1) Stratum Corneum Dermis / Corium - The middle layer that is thicker than the epidermis. - The dermis provides mechanical strength, flexibility, and protection for underlying tissues. - It is highly vascular and contains a variety of sensory receptors that provide information about the external environment. Composed of: 1) Nerve endings - transmit various stimuli such as pain, itch, pressure, and temperature - It is an energy reservoir that acts as a thermal insulator or cushion. - Beneath the dermis is the deepest layer of our skin. - Contains many collagen cells as well as fat. a. Fat [- insulate our body from the cold and act as a cushion for our internal structures (such as muscles and organs) when something hits us. - Fat can also be called upon by the body in times of great need as an energy source.]