Muscles, Faculty of Medicine, Alexandria University, Medical Student: Mohammed Yasir Taha Alkhammas, Under Supervision: Professor Dr. Nancy Mohamed El Sekily

1. Faculty of Medicine
Alexandria University
Mohammed Yasir Taha Alkhammas
Muscles
Under Supervision
Professor Dr. Nancy Mohamed El Sekily

2. Muscles
Muscle tissue is divided into three types:
 Skeletal muscles
 Smooth muscles
 Cardiac muscles

3. Skeletal muscle is called striated muscle, voluntary
innervated by somatic motor nerves
 These muscles are important for movements of the
skeletal system
 Each muscle is composed of cells, each cell is as long
as the muscle
 They vary in shape and size from long and broad to
thick and triangular, or even circular.
Skeletal Muscles

4.  This muscle has origin and insertion and fleshy
portion called belly.
 The origin is less mobile and located more
proximal.
 The insertion is more mobile and located more
distal.
 During contraction the insertion is drawn
proximally toward the origin.
 Tendons are cords of fibrous tissue attach the
ends of a muscle to the supporting structure
(bones, cartilage, ligaments, or other muscles) .
Skeletal Muscles

5. 1. Shape:
 Deltoid for the triangular shape.
 Trapezius for the trapezoid shape.
 Teres for round shape.
 Rectus for straight muscle.
2. Depth:
 Superficialis for superficial muscle.
 Profundus for deep.
 Externus or externi for external.
 Internes or interni for internal.
How Skeletal Muscle are Named ?
The Characteristics Used to Name Muscle are:

6. 3. Position
 Anterior, posterior, medial, lateral, superior, inferior.
 Dorsi (of the back).
 Abdominis for muscle of the abdomen.
 Pectoralis for muscle of the chest.
 Brachii for muscle of the arm.
 femoris for muscle of the thigh.
How Skeletal Muscle are Named ?
The Characteristics Used to Name Muscle are:
 Oris related to the mouth
 Oculi for muscle of the eye.

7. 4. Attachment
Sternocleidomastoid which
attached to the sternum and
clavicle and to the mastoid
process of temporal bone.
How Skeletal Muscle are Named ?
The Characteristics Used to Name Muscle are:

8. 5. Size
 Major for larger
 Minor for smaller
 Longus for long
 Brevis for short
 Latissimus for broadest
 Longissimus for longest
How Skeletal Muscle are Named ?
The Characteristics Used to Name Muscle are:

9. 6. Action
 Flexor :Decreases joint angle
 Extensor: Increases joint angle
 Abductor :Moves bone away from midline
 Adductor: Moves bone closer o mid line
 Levator :Raises or elevate body part
 Depressor: Lowers or depresses body part
 Sphincter :Decreases size of an opening
 Supinator :Turns palm anteriorly
 Pronator :Turns palm posteriorly
How Skeletal Muscle are Named ?
The Characteristics Used to Name Muscle are:

10.  Quadriceps (four heads)
Number of head or bellies
 Biceps (two heads)
 Triceps (three heads)

11. 1. Body movement.
2. Maintenance of posture.
3. Temperature regulation.
4. Storage and movement of materials and support .
Functions of Skeletal Muscle Tissue

12. Gross Anatomy of Skeletal Muscle
 Every skeletal muscle is considered
organ because it is composed of the
four types of tissue: epithelial,
connective, muscle, and nervous tissue.

13. Each skeletal muscle: composed of Multiple
fascicles consist of many muscle fibers and have
covered with connective tissue called Epimysium.
Fascicle: is A bundle of muscle fibers separated
from other bundles of fibers by a dense irregular
connective tissue covering called Perimysium
Muscle Fiber (muscle cell): Elongated, have
multiple nucleus, cylinder-shaped fiber,
contains myofibrils, separated from other
fibers by areolar connective tissue called
Endomysium.
Gross Anatomy of Skeletal Muscle

14. Myofilaments: Two types of short protein
 Thick (myosin).
 Thin (actin, troponin and tropomyosin).
Myofibril: Long, cylinder-shaped
contractile element within muscle
fiber, contain myofilaments, they
exhibit Striations .
Gross Anatomy of Skeletal Muscle

15.  The individual fibers of a muscle are arranged either parallel or
oblique to the long axis of the muscle.
 The Muscles whose fibers attached obliquely to its tendon called
Pennate muscles which classified into:
Arrangement of Skeletal Muscle fibers
 Unipennate muscle: the tendon lies along one side
of the muscle, and the muscle fibers obliquely.
 Bipennate muscle: the tendon lies in the center of the
muscle, and Muscle fibers on both sides of the tendon.
 Multipennate muscle: may be organized as a sequence of
bipennate muscles lying together with one another

16.  It called the myocardium of the heart.
 It arranged in bundles within the
heart wall.
 Its fibers organized in whorls and
spirals, these muscles have rhythmic
and spontaneous contraction .
Cardiac Muscle

17. 1. Short and thick.
2. Striated like skeletal muscle fibers.
3. Have only one or two nuclei.
4. Branches and join to adjacent muscle fibers
at junctions termed intercalated discs.
Cardiac Muscle Fibers Characterized By:
Cardiac Muscle

18. Smooth Muscle
They Found in:
1. The tubes of the body to enhance forcing
the contents through the lumen.
2. The digestive system responsible for
peristalsis movement.
3. The urinary bladder and the uterus (their
contraction is slow and sustained and
brings about expulsion of the contents of
the organs).
Smooth Muscle Cells Characterized By
The Following Properties
 Short and have a fusiform shape.
 Single centrally located nucleus.
 The Thick and thin filaments are not
organized into sarcomeres

19. 1. Muscle Atrophy
 It is a decreasing of tissue due to reduction in muscle size, tone, and power.
 It occurs duo to reduced stimulation of the skeletal muscle, it loses both mass and tone.
 The muscle becomes flaccid.
 Muscle atrophy vary between reversible and irreversible which cause loss of muscle
function.
 Physical therapy is required for patients who suffer transient loss of movement.
Applied Anatomy of Muscle
Example:
 Decrease use of muscle cause muscular
atrophy. the muscle of the limb
reduced in tone and size after limb
immobilization in a cast.
 Persons who have injury to the
nervous system or are have spinal
injury, they gradually lack muscle tone
and size in the areas affected.

20. 2. Aging of the Muscular System
 By decrease the activity due to
aging, a progressive loss of skeletal
muscle mass occurs.
 Diameter of skeletal muscle fibers
and their elasticity reduced by aging.
 Their ability to recover from disease
or trauma also decrease.
 The size and power of all muscle
tissues also decrease.
 Muscular tissue is replaced by either
adipose or fibrous connective tissue.
Applied Anatomy of Muscle

21. 3. Muscle Hypertrophy
 It is increase in muscle size duo to increase in the size of muscle
cells.
 Muscle size may be increased by exercising.
 It occurs duo to increased stimulation of the skeletal muscle results in more
mitochondria, larger glycogen reserves, and an increased ability to produce ATP.
Ultimately, each muscle fiber develops more myofibrils, and each myofibril
contains a larger number of myofilaments.
Applied Anatomy of Muscle
Example
 In athlete and body
builder or weight lifter
exhibits hypertrophied
muscular development .

22. 4. Muscle Tone
 Determining the tone of a muscle
is important in clinical
examination.
 If poliomyelitis has involved the
motor anterior horn cells at a
level in the spinal cord that
innervates the muscle, the
efferent motor neurons will not
function.
 If the muscle is found to be
hypertonic, the possibility exists
of a lesion involving higher
motor neurons in the spinal cord
or brain .
Applied Anatomy of Muscle

23. 5. Muscle Attachments
The main attachments of the muscles are very important, it help the clinicians
knowing the normal and abnormal actions of muscle groups and single muscle,
for example, a patient’s abnormal gait .
Applied Anatomy of Muscle
7. Strain
Tearing or injuring of a
muscle duo to either
overuse or misuse
(improper use).
6. Spasm of skeletal muscle
Sudden, involuntary contraction
of one or more muscles .

24. 8. Cardiac Muscle Necrosis
Myocardium takes its blood supply from the
coronary arteries. Abrupt obstruction of one of
the large branches of a coronary artery will
cause necrosis of the myocardium.
Applied Anatomy of Muscle
9. Cardiomegaly
Radiologically enlargement of the cardiac
muscle in patients with heart failure due to
neurohumoral compensatory effect which
includes sympathetic stimulation, production
of angiotensin II and aldosterone.

25. References
1. Snell's Clinical Anatomy by Regions 10th Edition.
2. Gray's Anatomy, The Anatomical Basis of Clinical Practice.
3. Human Anatomy-3rd-edition.