1. Essential Question: What is the Muscular system?
Do Now: In what ways do you use your muscles daily?

2. Support Muscles and bones Muscular system Three types of muscle

3. Muscular System
Skeletal muscle tissue is made up of elongated cells called Muscle Fibers
Each fiber has dark and light lines called Striation
Fascicles are the dense bundles of muscle fibers
Voluntary Muscles are consciously controlled
Skeletal Muscles
Because most of its movements cannot be consciously controlled, Smooth and Cardiac muscle is referred to as Involuntary Muscles

4. Skeletal muscle Allow movement Voluntary muscle You can control them
Can only pull bones, not push
Work in pairs – flexor(bends), extensor(straightens)
Actin and myosin cause muscles to work

6. Smooth muscle Involuntary You cannot control them
blood vessels, stomach, other organs
Diaphragm
lowers to increase size of chest cavity
Air moves in due to low pressure

7. Cardiac muscle Involuntary Transmits electrical impulses
Pump blood through heart and rest of body

8. Each muscle fiber consists of Myofibrils
Each myofibrils is composed of two proteins:
Myosin- Thick filaments
Actin-Thin Filaments
Where all of the actin are anchored together is the Z-Line
From z-line to the next is considered a Sarcomere

9. Neuromuscular junction is to point in which the motor neuron and a skeletal muscle meet
The neurotransmitter released at this junction is Acetylcholine

10. Muscle are attached to periosteum by a Tendon
The point where a muscle attaches to a stationary bone is called the Origin
The point where a muscle attaches to a moving bone is called the Insertion
Flexor- Muscle that bends the joint- Bicep
Extensor- Muscle that straightens the joint- Triceps