1. Control of Muscle Contraction
Skeletal muscles are useful only if the contract in a controlled fashion
Neuromuscular junction: point of contact between a motor neuron and a skeletal muscle cell

2. Control of Muscle Contraction
Acetylcholine: neurotransmitter that diffuses across a synapse and produces an impulse in the cell membrane of a muscle cell

3. How Muscles and Bones Interact
Tendon: tough connective tissue that joins skeletal muscles to bones
They pull on bones and make them work like levers

4. The Integumentary System
Skin and its related structures (hair, nails and some glands)
A barrier against injection and injury

5. The Integumentary System
Helps regulate body temperature
Removes waste products from the body
Provides protection against UV radiation from the sun

6. The Skin The largest component of the integumentary system
Contains several types of sensory receptors for pressure, heat, cold, pain
Two main layers

7. The Skin: The Epidermis
Outer layer of the skin
Two layers: outer dead cells, inner living cells
Keratin: tough, fibrous protein found in skin, what the dead cells help make
Melanin: dark-brown pigment found in skin

8. The Skin: The Dermis Innermost layer of skin
Lies beneath the epidermis
Contains collagen fibers, blood vessels, nerve endings, glands, sense organs, smooth muscles and hair follicles!!!

9. The Skin: The Dermis Contains 2 major types of glands: Sweat
Sebaceous/Oil

10. Hair Made mainly of keratin
Covers almost every exposed surface of the body
Hair follicles: tube-like pocket of epidermal cells that extends into the dermis; cells at the base of hair follicles produce hairs

11. Nails
Made mainly of keratin
Protect the tips of the fingers and toes