1. Muscular System
Unit F

2. Describe the structure of the muscles.

3. Muscular System Nearly half our weight comes from muscle tissue.
There are 650 different muscles in the human body.
Muscles give us shape, posture, movement and form.
Muscles produce most of our body heat.

4. Types of Muscles Skeletal muscle Voluntary. Attached to bone.
Striated (striped) appearance.
Voluntary.
Multinucleated muscle cell bundles (muscle cells = muscle fibers).
Sarcolemma = cell membrane.
Contract quickly, fatigue easily, can’t maintain contraction or long period of time.

5. Types of Muscles Cont. Smooth muscle. Involuntary.
Visceral (organ) muscle.
Found in walls of digestive system, uterus and blood vessels.
Cells small and spindle-shaped.
Involuntary.
Controlled by autonomic nervous system.
Act slowly, do not tire easily, can remain contracted for long time.

6. Types of Muscle Cont. Cardiac muscle. Found only in the heart.
Striated and branched.
Involuntary.
Cells are fused- when one contracts, they all contract.

7. Muscle Anatomy

8. Analyze the function of the muscular system

9. Characteristics of Muscles
When a muscle becomes shorter, thicker & causes movement, it is said to have?
CONTRACTIBILITY

10. Excitability (irritability)- the ability to respond to certain stimuli by producing impulses.

11. Extensibility- the ability to be stretched.
Elasticity- ability of muscle to return to its original length when relaxing.

12. Movement 1.Muscles move bones by pulling on them.
2. Groups of muscles usually contract to produce a single movement.
As a muscle contracts, it pulls the insertion bone closer to the origin bone. Movement occurs at the joint between the origin and the insertion.
Rule: A muscle’s insertion bone moves toward its origin bone.

13. Movement Cont. Motor unit-
a motor neuron plus all the muscle fibers it stimulates.

14. Muscle Fatigue
Muscle fatigue- caused by the accumulation of lactic acid in the muscles.

15. Neuromuscular Junction
Neuromuscular junction- the junction between the motor neuron’s fiber which transmits the impulse-and the muscle cell membrane.

16. Acetylcholine Is a chemical neurotransmitter, diffuses across the
synaptic cleft (carries
impulse across
synaptic cleft).

17. If a muscle cell is stimulated repeatedly without rest it losses its ability to contract! This is called?

18. What thoracic muscle aids in breathing?

19. Muscles that are partially contracted at all times are said to be in a constant state of what?

20. Identify characteristics & treatment of common muscle disorders.

21. Disorders and Related Terminology
Atrophy- wasting away of
muscles.
Massaging the muscle helps
atrophy.
Failing to exercise can make
muscles weak, flaccid &
cause them to atrophy.

22. Myalgia- muscle pain.

23. Tendonitis- inflammation of a tendon.

24. Strain- tear in the muscle resulting
from excessive use. Bleeding inside
the muscle can result in considerable
amount of pain & swelling. Ice packs
will help stop the bleeding and
reduce swelling.

25. Sprain-stretched ligament

26. Hypertrophy- an increase in the size of the muscle cell.
A person who lifts weights &
overuses his muscles will
enlarge their size.

27. Muscle spasm (cramp)- sustained
contraction of the muscle, usually
because of overuse. Severe calf pain at
night is caused by muscle spasms.

28. Sphincter
Special circular muscles in openings of esophagus and stomach, stomach and small intestine, anus, urethra and mouth.

29. What muscle is found in the neck?

30. Major muscle that lies over the upper ribs?

31. Muscle that abducts the upper arm at the shoulder joint?

32. Medical name for the calf muscle?

33. Circular muscles in the openings between the esophagus & stomach are?

34. The main muscle in the lower back is the?

35. The main muscle of the upper back is the?

36. What muscle is found in the arm?

37. What muscle is considered VOLUNTARY?

38. Which kind of muscle forms the walls of the heart?

39. Joanie is experiencing oxygen dept. What has he been doing?
Oxygen debt- after exercise,
the amount of oxygen needed
by the muscle to change lactic
acid back to glucose.

40. If you want to improve your extensibility you should do what every morning?