Integumentary System The Skin you re in!
Did you know? Your skin is fascinating!! Video: Crash Course SKIN!
Function of the Integumentary System The integumentary system is an organ system consisting of the skin, hair, nails, and exocrine glands. The skin is only a few millimeters thick yet is by far the largest organ in the body. The average person s skin weighs 10 pounds and has a surface area of almost 20 square feet. Skin forms the body s outer covering and forms a barrier to protect the body from chemicals, disease, UV light, and physical damage.
Functions of the Integumentary System 1. Forms a protective covering over the body that prevents infections and water loss.
Functions of the Integumentary System 2. Maintains homeostasis by helping to regulate body temperature
Regulation of body temperature a. Blood vessels in skin help release/hold heat b. Perspiration (sweating) to keep cool and shivering to keep warm
Functions of the Integumentary System 3. Excretes wastes such as sodium chloride (salt) and, water in your sweat, and urea, which is also in your urine
Functions of the Integumentary System 4. Sensory receptors Our sense of touch is controlled by a network of nerve endings and touch receptors in the skin known as the somatosensory system. This system is responsible for all the sensations we feel - cold, hot, smooth, rough, pressure, tickle, itch, pain, vibrations, and more
Functions of the Integumentary System 5. Produces vitamin D in the epidermis using sunlight
Which is NOT a function of the integumentary system? 1. To prevent substances from entering the body 2. To help keep body temperature stable 3. To remove wastes from the body 4. To absorb oxygen into the body
Layers of Skin 1. Epidermis = surface layer a) Cells on top part are dead b) New cells are constantly produced at the bottom c) Melanocytes: cells produce melanin - pigment that protects your skin and gives it color
Layers of Skin 2. Dermis = layer under epidermis a) Thicker than epidermis b) Contains blood vessels, nerves, oil and sweat glands 3. Hypodermis - Fat cells stored under the dermis, this insulates the body
Which part of the skin makes new skin cells? 1. Epidermis 2. Dermis 3. Fat cells/hypodermis 4. Sweat glands
Label the Skin For the next few slides, find the appropriate place on your notes page to label and/or identify the skin and parts of the integumentary system
Skin Cross-section 1. Epidermis 2. Dermis 3. Hypodermis 4. Hair from hair follicle 5. Sweat Gland 6. Oil gland 7. Nerve 8. Blood Vessels 4 5 6 7 8 1 2 3
HAIR: - Made of the protein keratin, grows from follicle - Found all over body except lips, palms and soles of feet - Functions in warmth, protection, and immune defense - Characteristic of mammals Epidermis Hair Shaft Oil Gland Muscle Dermis Follicle
Hair color Hair color happens because of a kind of pigment called melanin. Hair has only two types of this pigment - dark (eumelanin) and light (phaeomelanin). They blend together to make up the wide range of hair colors. If your hair has a lot of eumelanin, it will be black; a little eumelanin and your hair will be blonde. What determines the amount of eumelanin is your genetic make up (there are a lot of genetic factors that go into hair color we won t discuss them)
Hair raising facts: An average scalp has 100,000-150,000 hairs. Hair is so strong that each hair can withstand the strain of 100 grams (3.5 ounces). An average head of hair could hold 10-15 tons if only the scalp was strong enough! Human hair grows autonomously, that is each hair is on its own individual cycle. If all our hair were on the same cycle, we would molt! Hair has the highest rate of mitosis (cell division). An average hair grows 0.3 mm a day and 1 cm per month.
NAILS: - Made of the protein keratin, grows from root - Found on fingers and toes (phalanges) - Functions in protection and as a tool for precise activities Root Lunula Nail Plate Free Margin Matrix Nail Bed
More on our skin: Walk a bout! You will go to each station and complete the questions on your page When done, you will put this page with the notes your have just taken