1. The Muscular System

2. Muscular system functions Muscle types Muscle movements
Essential Question
Muscular system functions
Muscle types
Muscle movements
What are the structures of the muscular system?

3. Abduction vs. Adduction

4. The Muscular System
Comprises nearly half our weight.
Over 650 muscles.
Each muscle is made up of hundreds or thousands of muscle fibers.
Muscles never, ever push… THEY ALWAYS PULL. Flexor versus Extensor.

5. Flexor vs Extensor Muscles
A flexor muscle bends a joint, For example, the muscle at the top and front of the arm, the biceps brachii, flexes or bends the arm at the elbow. An extensor muscle straightens a joint. Example: the muscle at the back of the arm, the triceps brachii, straightens it back out, extending it.

6. Flexor and Extensor Relastionship
flexor is (anatomy) a muscle whose contraction acts to bend a joint or limb while extensor is (anatomy) a muscle whose contraction extends or straightens a limb or body part. 

7. Agonist and Antagonist Muscles
Antagonist and agonist muscles often occur in pairs, called antagonistic pairs. As one muscle contracts, the other relaxes. An example of an antagonistic pair is the biceps and triceps, to contract - the triceps relaxes while the biceps contracts to lift the arm.

8. Agonist Muscles
Agonist muscles and antagonist muscles refer to muscles that cause or inhibit a movement.
Agonist muscles cause a movement to occur through their own contraction. For example, the triceps brachii contracts during the up phase of a push-up (elbow extension).
During the down phase of a push-up, the same triceps brachii actively controls elbow flexion while relaxing. It is still the agonist, because while resisting gravity during relaxing, the triceps brachii continues to be the prime mover, or controller, of the joint action.
Agonists are also interchangeably referred to as "prime movers," since they are the muscles considered primarily responsible for generating a specific movement. This term typically describes skeletal muscles.

9. Antagonist Muscles
Antagonist muscles oppose a specific movement. This controls a motion, slows it down, and returns a limb to its initial position. Antagonism is a role that a muscle plays depending on the motion. If a motion is reversed, agonist and antagonist muscles switch roles. Because a flexor muscle is always a flexor, in flexion it is the agonist, and in extension it is the antagonist.

10. Synergistic Muscles
Synergist muscles perform, or help perform, the same set of joint motion as the agonists.
Synergists muscles normally act on movable joints.
Synergists are sometimes referred to as "neutralizers" because they help cancel out, or neutralize, extra motion from the agonists to make sure that the force generated works within the desired plane of motion.
Synergists are muscles that facilitate the fixation action.
Fixation of the wrist during full flexion of the fingers in clenching the fist.
Try IT Now!!

11. Voluntary and Involuntary Muscles
15 minutes research and write down the meaning/function of these two terms in your notes, using an example for each and an analogy for each, to share.

12. The Muscular System: Muscle Fibers
Bundles of threadlike structures called myofibrils
Composed of:
Myosin
Actin
Form overlapping pattern called sarcomere
muscle muscle fiber
sarcolemma sarcomere
functional unit of muscle movement

13. Structures of the muscular system
Muscles
Skeletal
Smooth
Cardiac
Sphincter
Connective tissue
Tendons
Fascia

14. Structures of the muscular system
Types of muscle
Skeletal
Smooth
Cardiac
Sphincter
Dilator

15. Structures of the muscular system
Types of Muscle
Skeletal muscles
Attached to bone
Striated (striped) appearance
Voluntary
Multinucleated muscle cell bundles

16. Structures of the muscular system
Types of Muscle
Smooth muscles
Also known as visceral muscles
Involuntary
Located in walls of digestive system, uterus & blood vessels

17. Structures of the muscular system
Types of Muscle
Cardiac muscle
Found only in the heart
Striated, branched
Involuntary
Cells are fused- when one contracts, they all contract, creating the heartbeat

18. Structures of the muscular system
Types of Connective tissue
Tendons
Fascia

19. Structures of the muscular system
Connective tissue
Tendons
dense bands that connect skeletal muscle to the bone

20. Structures of the muscular system
Connective tissue
Fascia
Fibrous connective tissue sheets that wrap around muscle bundles

21. How do skeletal muscles get their names?
Location
Location of origin and insertion
Size
Action flexor
Direction
Extensor
Number of origins
Depressor
However,
not all muscles are named by the above methods!

22. Head & Neck Muscles

23. Anterior Torso/Trunk (anterior)

24. Torso/Trunk (anterior)

25. Posterior Torso/Trunk (posterior)

26. Upper extremities

27. Lower extremities

28. The Muscular System Review http://www.anatomyarcade.com/games/PAM/PAM.html

29. The muscular system review Posterior view

30. Sphincter Muscles
A sphincter is a circular muscle that normally maintains constriction of a natural body passage or orifice and which relaxes as required by normal physiological functioning. Sphincters are found in many animals.
There are over 60 types in the human body.
But there only about four or five we will discuss.
Sphincters relax at death, often releasing fluids.

31. Any of the ring like muscles surrounding and able to contract or close a bodily passage or opening.
One of the most important human sphincter muscles is the sphincter pylori, a thickening of the middle layer of stomach muscle around the pylorus (opening into the small intestine) that holds food in the stomach until it is thoroughly mixed with gastric juices.
Other sphincters are involved in excretion of waste: the sphincter ani externus keeps the anal opening closed by its normal contraction,
The sphincter urethrae is the most important voluntary control of urination.
There is a sphincter in the eye, the sphincter pupillae, a ring of fibres in the iris that contracts the pupil in the presence of bright light.
Compare dilator muscle.

32. Sphincter Hot Topic Total Misconceptions
Some say there are millions of microscopically small precapillary sphincters muscles, a band of smooth muscle that adjusts blood flow into capillaries. It is a highly debated topic and some researchers have suggested the term precapillary resistance instead.
The muscles of the mouth, is not actually a sphincter, but a complex of four muscles in the lips that encircles the mouth called the orbicularis oris muscles.

33. Sphincter Muscles: Two Classifications
Sphincters can be further classified into functional and anatomical sphincters:
Anatomical sphincters have a localized and often circular muscle thickening to facilitate their action as a sphincter.
Functional sphincters do not have this localized muscle thickening and achieve their sphincter action through muscle contraction around (extrinsic) or within (intrinsic) the structure. Sphincters can also be voluntarily or involuntarily controlled:
Voluntary sphincters are supplied by somatic nerves.
Involuntary sphincters are stimulated by autonomic nerves.

34. the iris dilator (of the eye) muscle
Dilator Muscles
any of the muscles that widen/dilate a body part,
the iris dilator (of the eye) muscle 
or the dilator naris  (of the nose) muscle.