This PowerPoint presentation covers the anatomy, physiology and common disorders of the muscular system.

1. The Muscular
System
Prepared by Mickelder Kercy, MD - Instructor

2. Functions of Muscles
O Movement
O Heat production
O Maintain body posture
O Holding bones together
O Breathing,
O Speaking, Eating
O Store and Expel Urine etc….

3. Types of Muscle Tissue
O Skeletal (Voluntary + Striated)
O Smooth (Involuntary + Non Striated)
O Cardiac (Involuntary + Striated)

4. Mechanism of muscle
contraction
O Muscles break down carbohydrates, fats
and proteins with or without oxygen to
create energy called ATP
O Nerves attached to the muscle release
Ach causing the Sarcoplasmic reticulum
to release calcium in the muscle

5. O Calcium attaches to certain parts of the
muscle that will use ATP to make the
muscle contract

7. Structure of Skeletal
Muscles
O Epimysium (Covers the muscle)
O Perimysium (Inside of the muscle
dividing it into sections)
O Endomysium (Inside of the muscle
surrounding each muscle cell)
O Tendons (Attach the muscle to the
bones)

9. Ways to identify Muscles
O Location (eg : Frontalis)
O Direction of fibers (eg : Orbicularis oculi)
O N° of attachments (eg : Sternocleidomastoid)
O Shape (eg : Trapezius)
O Action (eg : Extensor Digitorum)
O Size (eg : Gluteus Maximus, Gluteus Medius,
Gluteus Minimus)

15. How muscles work together
O Agonism/Prime Mover
O Antagonism

17. O Synergism

18. Major Skeletal Muscles
O Muscles that move the Head
*Sternocleidomastoid (Both flex the head
towards the chest, Individually flexes
the head laterally)

22. O Muscles of the Face
*Frontalis (Raises the eyebrows)
*Orbicularis oris (Closes the mouth,
Purses the lips, Kissing)
*Orbicularis oculi (Closes the eyes,
Wrinkles, Blinks)

24. O Muscles that move the arm and forearm
*Pectoralis major (Adducts the arm)
*Deltoid (Abducts the arm) ∆
*Biceps Brachii (Flexes the elbow and
moves the forearm)
*Brachialis (Flexes the elbow)
*Triceps Brachii (Extends the elbow)
etc…..

27. O Muscles that move the wrist, hand and
fingers (key word – carpi / palmaris /
digitorum)
*Flexor carpi radialis
*Flexor carpi ulnaris
*Palmaris longus
*Extensor digitorum etc…..

29. O Muscles of Respiration
*Diaphragm
*Internal Intercostals
*External Intercostals

32. O Muscles of the Abdominal Wall
(Key word – Abdominis)
*Transversus abdmoninis
*Rectus abdominis
*Internal and External Oblique
These muscles help in childbirth, urination,
forced expiration and defecation

34. O Muscle of the Pectoral Girdle/Shoulder
*Rotator cuff muscles
*Deltoid
*Pectoralis Major
*Pectoralis Minor
*Trapezius
*Latissimus Dorsi etc…..
They move the shoulder

35. O Muscles of the pectoral Girdle/Shoulder
*Extrinsic (Suspend scapula from the trunk. Stabilize
and/or actively moves scapula)
-Trapezius, Levator Scapulae, Rhomboid Major &
Minor, Serratus Anterior, Pectoralis minor
*Intrinsic (Attach scapula to humerus)
-Deltoid, Teres Major
*Rotator Cuff (active stabilization of shoulder joint)
-Supraspinatus, Infraspinatus, Teres Minor,
Subscapularis
*Attach trunk to humerus
-Latissimus dorsi , Pectoralis Major

39. O Muscles of the back
*Trapezius (adducts the arm)
*Latissimus Dorsi (adducts, extends &
medially rotates the humerus) etc…

41. O Muscles of the Buttock, Thigh, Leg, Ankle
and Foot
*Gluteus maximus, medius and minimus
*Quadriceps Femoris (Rectus Femoris, Vastus
Lateralis, Vastus Medialis and Vastus
Intermedius)
*Gastrocnemius
*Hamstrings (Biceps Femoris, Semitendinosus
and Semimembranosus)

46. O Sitting and standing are actions performed numerous times
throughout the day by every person. Frail older adults sometimes
have difficulty performing such a fundamental task simply because
they lack the lower body strength. Both sitting down and standing
up require work from the muscles of the lower body as well as
stabilizing work from the upper body. It is important to work the
muscles needed to sit and stand to maintain muscular fitness.
O The quadriceps muscles are on the front of the thigh and are used in
both sitting and standing. They contract to resist gravity when you
lower yourself into a chair. The quadriceps are then contracted to
extend your leg, which allows you to stand
O The hamstring muscles are on the back of the thigh and act to
extend the thigh and flex the knee. The hamstrings are primarily
used to extend your hips when you stand.

47. O The gluteus muscles are comprised of the gluteus maximus, gluteus
medius and gluteus minimus. The gluteus maximus is the major
extensor of the thigh and is responsible for straightening your hips
as you stand. It also works to control downward movement of the
hips when you lower yourself to the chair. The medius and minimus
help to steady the pelvis when sitting or standing from a chair.
O Calves /The gastrocnemius and plantaris muscles of the calf help to
flex the knee when lowering into a sitting position. These muscles,
along with the soleus, act to stabilize the lower leg when rising to a
standing position.
O The tibialis anterior is located laterally to the shin bone. This
muscle works to prevent hyper-flexion of the ankle when you sit
down. It helps to stabilize the lower leg when standing
O The core consists of the muscles of the abdomen and lower back.
These muscles contract to keep your torso upright throughout the
movements. Failure to use these muscles would result in a hunched
posture and rounded back.

48. Common Disorders associated
with the Muscular System
O Atrophy : Loss of muscle mass and strength
with the disuse of muscles

50. O Fibromalgia : Musculoskeletal pain and fatigue at
11 or more sites on the body

52. O Ganglion Cyst : Saclike swelling or cyst

53. O Lyme Disease : Caused by the bacteria
Borrelia Burgdorferi. Causes rash(erythema
migrans), bell’s palsy, muscle weakness, flu-
like sx etc..

54. O Muscular Dystrophy : Genetic diseases causing
progressive weakness and degeneration of the
skeletal or voluntary muscles

55. O Myasthenia Gravis : Chronic autoimmune
neuromuscular disease causing weakness
of the skeletal or voluntary muscles of the
body

56. O Rotator cuff Tears : Make it difficult for the patient to
reach above their heads and lift with the arms

57. O Shin Splints : Inflammation of the
periosteum of the extensor muscles of the
lower leg and surrounding tissues

58. O Sprains : Stretching or tearing of a ligament

59. O Strain : Stretching or tearing of a muscle or a
tendon
Rupture Achilles Tendon

60. O Tendonitis : Inflammation of a tendon due to
overuse

61. O Tetanus : Bacterial Infection causing painful
muscle spasms

62. The End