1. Muscular System
Chapter 13.3

2. Introduction to the Muscular System
The muscles in the body make all movement possible.
Muscles move body parts, allowing for proper functioning such as heartbeat, breathing, digestion of food, and the movement of the body from place to place

3. Muscle Functions
Skeletal muscles comprise about 40% of the mass of the average human body
Muscles are the engine that your body uses to propel itself turning energy into motion
Muscles are made up of elastic fibers
These fibers are like rubber bands that lengthen and shorten
Thick and thin filaments do the actual work of a muscle

4. Thick filaments are made of a protein called myosin and thin filaments are made up of a protein called actin
A muscle contraction occurs when these fibers generate tension through the action of actin and myosin cross-bridging
Muscles cannot push; they can only pull.
Main functions are produce heat, produce movement, and maintain posture

5. Types of muscles
Voluntary: you contract when you want to move (skeletal muscles.
You control these muscles; the movement is not automatic
Involuntary: contract automatically (stomach, intestine, heart)
The heart pumps automatically
The stomach digests food automatically
You cannot tell the heart or stomach to start or stop

6. Tendons Tendons connect muscle to bone
When the muscle moves, it moves the tendon and the bone
The longest tendon is the Achilles tendon
This tendon attaches the calf muscle to the heel bone

7. Types of muscle tissue
Muscle tissue is classified into three categories:
Skeletal- voluntary muscles
Visceral (smooth muscles) form the walls of the internal organs
Cardiac muscles form the wall of the heart

9. Basic movements of the skeletal muscle
Adduct- moving a body part toward the midline
Abduct- moving a body part away from the midline
Extend- increases the angle of the muscle
Flex- decreases the angle of the muscle
Rotate- turning a body part on its axis

11. Diseases of the Muscular System

12. Medical Terminology

13. Jobs and Professions Myologist Physical Therapist
Sports Medicine Assistant
Tenotomist

14. Questions
1. What position is your leg in when you are sitting normally in a chair?
2. Describe the three types of muscle tissue and what they do.
3. What are the three functions of muscles?
4. What does contract mean?
5. What is a tendon?

15. Sources
Badasch, S. A., & Chesebro, D. S. (2011). Asepsis and Standard Precautions. In Health Science Fundamentals: Exploring Career Pathways (1st ed., Revised , pp ). Upper Saddle River, NJ: Pearson.