Do Now: Design the Perfect Coat

Major roles of the Integumentary System Protection Maintenance of normal body temperature Storage of fat Synthesis of vitamin D Excretion wastes Sensory perception

How the skin performs the function Why this function is important Function of skin How the skin performs the function Why this function is important   By covering our entire body Helps maintain homeostasis Protection Maintain body temperature Sweating, shivering, has insulation Helps maintain homeostasis Gives us energy stores and insulates Turns food into fat under the skin Stores fat Uses the sunlight to make it We don’t get enough vitamin D from food Synthesis of vitamin D Wastes could become toxic Excretion of wastes Sweating Sensory perception Allows you to react to danger Nerves in the skin Function of skin How the skin performs the function Why this function is important  

The Skin: 3 Major layers

The Epidermis The epidermis is the outer layer of skin. It is the thinnest layer. Cells of the epidermis are constantly shedding and replacing themselves… That’s what makes you ashy

The Epidermis Cells are shaped like columns at the base and flatten as they move upward. The top layer is constantly removed. It does not have any blood vessels.

Epidermis has special functions: Produces pigment (melanin) Frontline defense of the immune system Have highly sensitive touch receptors (neurons)

The Dermis This is the second layer of skin It is the thickest layer and has the most components

Specialized Dermal Parts Hair follicles begin in the dermis and have the cells needed to grow hair Sebaceous glands and sweat glands are also in the dermis. Blood vessels and nerves course through this layer.

Glands Galore! Sebaceous glands Sebaceous glands are located near the hair follicle and produce sebum - the natural oil of your skin. Sebum is a mixture of different waxes and fats.

Sweat Glands Sweat glands Unlike sebaceous, they do not use the hair follicle to exit sweat to the skin Each has its own pore. Sweat glands regulate body temperature. Sweat is also helpful in eliminating waste from the body.

Nerves and Blood Vessels The nerves transmit sensations of pain, pressure, itch, and temperature. The blood vessels facilitate temperature homeostasis. They get bigger to release heat, causing your skin to get red.

The Hypodermis This is the third layer of skin It is the simplest layer It contains big blood vessels and fat

Review: Epidermis and Dermis

Question 1 Which of the following are NOT functions of the integumentary system? Protection Makes vitamin D Controls movement Maintains body temperature

Question 2 What do sebaceous glands produce? Sweat Oil Hair Fat

Question 3 Blood vessels are in both the dermis and epidermis. This is a TRUE statement. This is a FALSE statement.

Question 4 Which of the following specialized cells are NOT in the epidermis? Melanocytes Merkel Cells Sebaceous glands Langerhan’s Cells

Question 5 Sweat glands use the hair follicles to release sweat. This is a TRUE statement. This is a FALSE statement.

Question 6 Structure 1 is: Sweat gland Sebaceous gland Hair follicle Dermis Epidermis 3 2 1 4

Question 7 Structure 2 is: Sweat gland Sebaceous gland Hair follicle Dermis Epidermis 3 2 1 4

Question 8 Structure 3 is: Sweat gland Sebaceous gland Hair follicle Dermis Epidermis 3 2 1 4

Question 9 Structure 4 is: Sweat gland Sebaceous gland Hair follicle Dermis Epidermis 3 2 1 4