the muscular system objectives: describe the three types of muscle tissue and their function and...

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The Muscular System Objectives: Describe the three types of muscle tissue and their function and location. Explain the function, location, origin, and insertion of the major skeletal muscles. Evaluate the role of vitamins and other nutrients in muscle contraction and strength Compare and contrast tendons and ligaments. List examples of flexor and extensor pairs of muscles. Vocabulary: Smooth or involuntary muscle, skeletal, striated or voluntary muscle, cardiac muscle, flexors, extensors, actin, myosin, myo, striations, sprain, tendon, rigor mortis, myoglobin, origin, insertion, proximal, distal, abductors, adductors, Muscular Dystrophy, hamstrings, Achilles tendon

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Page 1: The Muscular System Objectives: Describe the three types of muscle tissue and their function and location. Explain the function, location, origin, and

The Muscular System

Objectives:

• Describe the three types of muscle tissue and their function and location.• Explain the function, location, origin, and insertion of the major skeletal muscles.• Evaluate the role of vitamins and other nutrients in muscle contraction and strength• Compare and contrast tendons and ligaments.• List examples of flexor and extensor pairs of muscles.

Vocabulary:Smooth or involuntary muscle, skeletal, striated or voluntary muscle, cardiac muscle, flexors, extensors, actin, myosin, myo, striations, sprain, tendon, rigor mortis, myoglobin, origin, insertion, proximal, distal, abductors, adductors, Muscular Dystrophy, hamstrings, Achilles tendon

Page 2: The Muscular System Objectives: Describe the three types of muscle tissue and their function and location. Explain the function, location, origin, and

There are three types of muscle tissue:1) Smooth muscle - this is often also referred to as involuntary

muscle because we have no conscious control over it. It consists of filaments that are NOT aligned with each other, but generally form “sheets” of cells. It lines the blood vessels and the gastrointestinal tract and controls the iris of the eye.

2) Skeletal Muscle - this is also called striated or voluntary muscle. The filaments are aligned and sometimes look like they form bands, or striations. These muscles are used to control our skeleton. For example, flexors bend our skeleton at the joints and extensors straighten it. Flexors and extensors are paired together.

We can easily consciously control these muscles.3) Cardiac muscle - this is the heart muscle. The fibers of cardiac

muscle branch and interconnect.

It is primarily the work of the proteins actin and myosin that allow muscles to contract. However, other proteins, such as dystrophin, are also necessary. If missing, muscles gradually weaken with age and death follows. This is what happens in the inherited disease, Muscular Dystrophy.

Page 3: The Muscular System Objectives: Describe the three types of muscle tissue and their function and location. Explain the function, location, origin, and

In order for muscles to contract, they require ATP. Therefore all of

the vitamins and other nutrients we said were important for glycolysis,

the Kreb’s cycle (a.k.a.the citric acid cycle), and the electron transport

chain are important for muscle strength and contraction. These

included vitamin C, tyrosine, and numerous B vitamins because of their

role in making Coenzyme Q-10 (which is especially important for the

heart of patient’s suffering from congestive heart failure). And,

riboflavin (part of FADH), niacin (part of NADH, etc.), and pantethine

(part of Coenzyme A) - to name a few. Muscles also need lots of

calcium and magnesium for contraction strength and muscle relaxation.

Of course, in order to maintain high levels of ATP for the muscles,

our bodies need plenty of oxygen or else we will be forced from aerobic

respiration into lactic acid fermentation. This provides little energy so

the muscles become fatigued and begin aching as lactic acid builds up

in the muscle tissue.

Page 4: The Muscular System Objectives: Describe the three types of muscle tissue and their function and location. Explain the function, location, origin, and

Bundles of skeletal muscle fibers are made of small fibers called myofibrils (“myo“ means muscle). These contain the proteins actin and myosin. These lie parallel to each other and are arranged in repeating bundles called sarcomeres which are bound on each end by “Z lines”. This arrangement is what creates the banding pattern, or striations, that give us the name “striated muscle” for skeletal muscles. In order for a muscle to contract (shorten), the myosin and actin protein fibers must slide past each other, overlapping. In order to maintain this position, calcium and ATP must be available. In order to release the contraction, magnesium must be available and calcium must exit the area. Magnesium is a natural muscle relaxant. In rigor mortis, a corpse becomes stiff because ATP is no longer being made to move calcium out of the actin/myosin bridge. The contraction of skeletal muscle usually produces movement of the bones because the muscles are attached to the bones by tendons. Like ligaments, which connect bones to other bones at joints, tendons are connective tissue. Both ligaments and tendons can be overstretched or torn causing movement problems. For tendons, this isusually called a “sprain.”

Page 5: The Muscular System Objectives: Describe the three types of muscle tissue and their function and location. Explain the function, location, origin, and

Many advertisements have been made claiming to improve athletic

performance through creatine phosphate supplements. This substance

can donate a phosphate to ADP to regenerate ATP. Normally, the

muscle will rely on stored glycogen within the muscle to help form ATP.

Remember, oxygen is needed to make ATP in sufficient amounts.

Providing the oxygen is a substance called myoglobin. Myoglobin is a

protein similar to the hemoglobin protein in blood. Myoglobin carries

oxygen to the muscles that get heavy use. Myoglobin has a reddish

color. It gives muscles their reddish color. The more heavily the

muscle is used, the redder it is. In birds that fly a lot, like wild geese

and ducks, the breasts are “dark” meat but on home raised birds, like

chickens, that walk rather than fly, the breast is “white” meat. The

muscles that are “red” from heavy use are generally “slow twitch” fibers

that fatigue slowly due to the rich oxygen supply from myoglobin. Fast-

twitch fibers don’t have a good oxygen supply so they are good only for

quick, short periods of contraction.

Page 6: The Muscular System Objectives: Describe the three types of muscle tissue and their function and location. Explain the function, location, origin, and

Every skeletal muscle inserts into bone via a tendon at 2 places.

These are the origin (the end of the muscle attached to the bone that

remains stationary during contraction) which is usually the proximal end

(closer to the main body) and the insertion (the end of the muscle that

attaches to the bone that moves during contraction), which is usually

more distal (further from the main body). How much strength is

applied, for example, when lifting a feather versus lifting a 100 pound

weight, is determined by the number of muscle fibers innervated

(activated).

Many muscles come in opposing pairs. Abductors are muscles that

move the arms and legs away from the body and out to the sides.

Adductors are muscles that pull the arms and legs back in toward the

body. (Think of “jumping jacks”.) Flexors bend one bone up closer to

another while extensors return them to an un-bent angle.

Page 7: The Muscular System Objectives: Describe the three types of muscle tissue and their function and location. Explain the function, location, origin, and

Major Skeletal Muscles

Although there are many, many muscles of the face and skull, the

sternocleidomastoids are probably one of the most important. Many of

the others are involved in facial expressions or chewing.

The sternocleidomastoids have their origins at the temporal and

occipital bones and their insertions at the sternum and clavicle. They

help us flex the neck (flexor) forward, rotate the head/neck, and tilt the

head left or right.

Page 8: The Muscular System Objectives: Describe the three types of muscle tissue and their function and location. Explain the function, location, origin, and

The trapezius muscles’ origins are at the occipital bone and the cervical

and thoracic vertebrae and their insertions are at the clavicle and

scapula. These help lift the shoulders (shrugging) and are needed to

assist in lifting the arms above shoulder height and in rotating the arm.

(The rotator cuffs {scapula and humerus attachments} and levator

scapulae also help.) The deltoids cover the shoulder. They raise your

arms to the front, side, and rear, but only to shoulder height. The

deltoids are abductors because they take the arm “away” from the

body) Their origin is at the clavicle and sternum and their insertions are

in the humerus bones.

Deltoid Trapezius

Page 9: The Muscular System Objectives: Describe the three types of muscle tissue and their function and location. Explain the function, location, origin, and

The pectoralis major muscles originate at the sternum, the clavicle,

and the anterior medial side of the last few ribs. They insert under the

humerus. If the arm is already raised, the pectoralis major contracts to

lower it. The pectoralis major also pulls the shoulder forward and,

along with the pectoralis minor (which is underneath the major), it can

lift the rib cage to expand the chest cavity for inhalation. The intercostal

muscles are located between the ribs and help raise and lower the rib

cage for breathing purposes.

Page 10: The Muscular System Objectives: Describe the three types of muscle tissue and their function and location. Explain the function, location, origin, and

The obliques and rectus abdominis muscles control abdominal contractions, bending and twisting the torso.

Pectoralis

major

Intercostals

External obliques

Rectus abdominis

Page 11: The Muscular System Objectives: Describe the three types of muscle tissue and their function and location. Explain the function, location, origin, and

The latissimus dorsi runs from the sacrum and thoracic (near the last

3 or 4 ribs) and lumbar vertebrae to the humerus. This contracts to

bring the arm down (adducter) and also to rotate it. This muscle is

used for chopping, paddling, climbing, etc.

Page 12: The Muscular System Objectives: Describe the three types of muscle tissue and their function and location. Explain the function, location, origin, and

The biceps brachii (flexor) have their origin in the scapula and their insertion

in the radius. It flexes (bends) the forearm toward the upper arm and can turn

the arm outward. The biceps femoris (aka the “hamstrings”) is located at the

back of your upper leg. It is a flexor of the lower leg over the thigh and can

rotate the thigh. Its origin is in the femur, its insertion is in the tibia.

The triceps are located on the back of the upper arm. They originate in the

scapula and upper humerus and insert in the ulna. They are extensors of the

forearm.

Page 13: The Muscular System Objectives: Describe the three types of muscle tissue and their function and location. Explain the function, location, origin, and

The rectus femoris muscles are part of the quadriceps. The

quadriceps femoris are located on the front of the thigh. They act as an

extensor of the lower leg but can flex the thigh toward the abdomen

too. The gastrocnemius is the calf muscle of the lower legs. It

originates at the femur and inserts in the calcaneous (heel) via its

Achille’s tendon.

Page 14: The Muscular System Objectives: Describe the three types of muscle tissue and their function and location. Explain the function, location, origin, and

The gluteus maximus, medius, and minimus form most of our

buttocks. They originate in the pelvis area and insert in the femur.

They can work in rotating the thigh and in pulling the thigh backwards

or supporting it upright when standing.

Gluteal muscles and Hamstrings (back of thigh)

Page 15: The Muscular System Objectives: Describe the three types of muscle tissue and their function and location. Explain the function, location, origin, and

1.Galea Aponeurotica 2. Epicranius 3. Orbicularis Oculi 4. Nasalis

5. Levator Labii Superioris 6. Zygomaticus major & minor

7. Orbicularis Oris 8. Risorius 9. Depressor Anguli Oris

10. Depressor Labii Inferioris 11. Mentalis

12. Omohyoid 13. Sternohyoid 14. Sternal Head of Sternocleidomastoid

15. Scalene 16. Trapezius 17. Deltoid

18. Pectoralis Major 19. Serratus Anterior

20. Rectus Abdominis 21. External Abdominal Oblique 22. Biceps Brachii 23. Brachialis

24. Pronator Teres 25. Brachioradialis 26. Flexor Carpi Radialis 27. Extensor

Carpi Radialis 28. Tensor Fasciae Latae 29. Iliopsoas

30. Pectineus 31. Sartorius 32. Adductor Longus 33. Gracilis

34. Rectus Femoris 35. Vastus Intermedius

36. Vastus Lateralis 37. Vastus Medialis 38. Gastrocnemius 39. Peroneus Longus

40. Tibialis Anterior 41. Soleus 42. Peroneus Brevis

43. Extensor Digitorum Longus http://www.google.com/imgres?imgurl=http://www.sport-fitness-advisor.com/images/muscular_system_picture_front.jpg&imgrefurl=http://www.sport-fitness-advisor.com/muscular-system-picture.html&h=138&w=98&sz=53&tbnid=0w6CUrNWOVoJ:&tbnh=138&tbnw=98&prev=/images%3Fq%3Dmuscular%2Bsystem&sa=X&oi=image_result&resnum=1&ct=image&cd=1

Page 16: The Muscular System Objectives: Describe the three types of muscle tissue and their function and location. Explain the function, location, origin, and