Unit 2: The Skin The Integumentary System

INTRODUCTION Structures: Skin, hair, nails, glands, muscles, and nerves Functions: – Protects the body – Maintains body temp – Provides sensory information – Excretion and Absorption – Synthesis of Vitamin D

General Anatomy A large organ composed of all 4 tissue types 22 square feet 1-2 mm thick Weight 10 lbs.

3 Layers of the Skin Epidermis: outer layer, very thin, protects the body Dermis: middle layer, contains blood vessels, nerves, glands and hair follicles Subcutaneous: deep to the dermis, stores fat and anchors the skin

Tattoos and Piercings Tattooing is when ink is injected into the dermis. 1 in 5 college students have a tattoo. 1 in 3 college students have a body piercing, which can result in infection, allergic reactions, anatomical and nerve damage

Skin Color Pigments Melanin is a pigment produced in the epidermis by melanocytes – results vary from pink/white to yellow to tan to brown coloring

Accessory Structures of Skin When you are an embryo, some skin cells become: – hair – glands – nails

HAIR Hairs, or pili, are present on most skin surfaces except: – the palms of the hands, palmar surfaces of the fingers, the soles of the feet, and plantar surfaces of the toes. – Hair is used to protect the body from heat and sun, to shield the eyes, ears, and nose from particles, and to help us feel touch

GLANDS Gland are located in the dermis: Sebaceous (oil) glands Sudiferous (sweat) glands Ceruminous (wax) glands Mammary (milk) glands

NAILS Tightly packed, hard, dead, keratin cells Free edge: part that sticks up past the finger Nail body – visible pink portion Nail root – buried under skin layers Lunula – Crescent shaped white layer Eponychium (cuticle) -attaches the nail body to the root

Nail Growth Fingernails grow about 1 mm per week Toenails grow slightly slower

Nails Function: – Help grasp and manipulate small objects – Provide protection against finger trauma – Allow us to scratch things

Unit 2 Diseases and Disorders Disease CauseSymptomsSusceptibilityTreatmentPrognosis Skin Cancer Burns Pressure Ulcers Psoriasis Albinism Vitiligo Cyanosis Jaundice Erythemia Pallor Hirsutism Androgenic Alopecia Acne Impacted Cerumen Aging

Unit 2 Project, Groups of 1-3 Format: Vocal or Instrumental Music Due date: 9/30 (1 st ) or 10/1 (4 th ) Compose a song/rap/spoken word that includes: – The overall functions of the skin – The structure and function of all 3 layers of the skin – The accessory structures (hair, nails, glands) – Diseases or disorder – You must submit the lyrics AND a written component that describes how your project meets the requirements above (REFER TO YOUR RUBRIC!)