1. Presented by Megan and Trisha
Muscular System
Presented by Megan and Trisha

2. Introduction
The Muscular system is composed of specialized cells called muscle fibers – Function is contractibility.
ALMOST all movement in the body is the result of muscle contraction.
Muscles are also responsible for posture, joint stability, and heat production.
Muscles may be voluntary or involuntary

3. Skeletal Muscles
The only voluntary muscle tissue – Controls every action that a person is aware of.
Most are attached to two bones across a joint, so the muscle serves to move parts of those bones closer to each other.
Powers the movement of the skeleton
Makes up a large portion of muscle tissue found in the body
There are over 450 named skeletal muscles

4. Smooth Muscles
Found in organs EX: Stomach, intestines, and blood vessels
Weakest of all muscles, smooth muscles move to contract substances through the organ.
Smooth muscles are involuntary
They have a uniform appearance when viewed under a microscope

5. Cardiac Muscles Found only in the heart.
Cardiac muscles are involuntary, responsible for pumping blood throughout the body.
Hormones and signals from the brain adjust the rate of contraction, but the cardiac muscle stimulates itself to contract.
Considered to be auto rhythmic

6. Cardiac muscle cells
The cells are striated meaning they appear to have light and dark striped when viewed under a microscope
It is caused by the arrangement of protein fibers within the cells
The cells are tightly connected by intercalated disks which indicate strong bonds.
Branched in X or Y shapes

7. Muscular Contractions
The thin and thick filaments of the muscle do not change in length
The filaments slide past each other increasing the overlap of the filaments
Myosin is a motor protein that moves along the filaments and is the basis for the reaction of the muscular contraction

8. Muscle Classification
Size can differentiate similar muscles in the same region.
The direction in which the muscle fibers run can be used to identify a muscle.
Whether or not the muscle is striated.
Muscles can also be identified by their function.

9. Disorders of the Muscular System
Muscle pain
Sprains and Strains
Bruising
Cramping
Myopathy
Chronic fatigue syndrome
Muscular dystrophy
Parkinson’s disease
Fibromyalgia
Multiple sclerosis

10. QUIZ 1.)What are the three types of muscles?
2.)How many skeletal muscles are there?
3.)The cardiac muscle is considered to be what?
4.)What are some examples of where smooth muscles are found?
5.)What are some examples of muscular disorders?

11. References
Zimmerman, By. “Muscular System: Facts, Functions & Diseases.” LiveScience. TechMedia Network, 25 Nov Wen. 4 Apr system-facts-functions-diseases.html.
"Muscular System." InnerBody. How to Media Inc, 1 Jan Web. 6 Apr
Reece, J. (2011). Sensory and Motor Mechanisms. In Campbell biology, AP edition (9th ed.). Boston, M.A.: Pearson Education/Benjamin Cummings