1. Muscle Tissues
Prof. Dr. ASHRAF M.
Prof. of Histology

2. Muscle Tissues muscle cells called muscle fibers three types skeletal
General characteristics
muscle cells called muscle fibers
contractile
three types
skeletal
smooth
cardiac
Skeletal muscle
attached to bones
striated
voluntary
Smooth muscle
walls of organs
skin
walls of blood vessels
involuntary
not striated
Cardiac muscle
heart wall
involuntary
striated
intercalated discs

3. Types of Muscle Tissue Cardiac: only in the wall of the heart
Skeletal
Attach to and move skeleton
40% of body weight
Fibers = multinucleate cells (embryonic cells fuse)
Cells with obvious striations
Contractions are voluntary
Cardiac: only in the wall of the heart
Cells are striated
Contractions are involuntary (not voluntary)
Smooth: walls of hollow organs
Lack striations
Contractions are involuntary (not voluntary)

4. Muscle Tissues
Skeletal Muscle
Smooth Muscle
Cardiac Muscle

5. types 0f the muscles A- Skeletal, Striated and Voluntary.
B- Cardiac, Striated and Involuntary.
C- smooth non-striated &Involuntary

6. Connective Tissue Coverings
epimysium
perimysium
fascicles
endomysium
muscle
fascicles
muscle fibers
myofibrils
thick and thin filaments

7. Type of skeletal muscle fibres
Red muscle fibres
White muscle fibres :
Intermediate muscle fibres

8. Red muscle fibres irregular striations . abundant cytoplasm .
rich in myoglobin , mitochondria .
can contract for long time without fatigue

9. less myoglobin , mitochondria . quick , short contractions ,
White muscle fibres
regular striations .
less myoglobin , mitochondria .
quick , short contractions ,
easily fatigued .

10. Intermediate muscle fibres :
have intermediate characters between red and white fibres .
*Skeletal muscle contain the 3 type but usually the white fibres predominate .
* The diaphragm muscle of mastication contain red fibres only .

11. Structure of a Skeletal Muscle
organ of the muscular system
skeletal muscle tissue
Skeletal muscle is also called
voluntary muscle since it is under voluntary control.

12. Skeletal muscle fibers
1-The skeletal muscle is formed of elongated cells with two rounded ends and usually termed muscle fibers.

13. Skeletal muscle fibers
The myofibrils appear as deep acidophilic dots
within the fiber.
-Each muscle fibers is about 1-40 mm in length
and um in diameter.
-The muscle fiber is surrounded by delicate
embrane known as Sarcolemma, which enclose
the sarcoplasm of the fiber.
-Each muscle fiber contain multiple, flat and
peripheral nuclei.

14. Skeletal muscle fibers

15. Skeletal muscle fibers

17. The dark bands are Anisotropic
( A-bands ) .
The light bands are Isotropic
( I – bands ) .
The ( A ) band show a pale area in its center = H- zone divided by a dark line = M .
The ( I ) band show a dark line in its center = Z- line .

19. Triad of tubular system
It plays an important role in conducting the nerve impulse during muscle contraction .
It includes :
T-tubule :
Formed by a invagination of thes arcolemma in to sarcoplasm , its cavity is continuous with the extensor .
It extends transversely into sarcoplasm at the level between the A and I bands .

20. Triad of tubular system
Sarcoplasmic reticulum :
Modified longitudinal parts of sarcoplasmic reticulum and continuous slit .
Each 2 sarcoplasmic tubules surround one t.v. T . tubule forming a triad . As the nerve impulse reaches the sarcolemma , it passes through T.tubules then sarcoplasmic tubules which pump Ca E , ATP , ADP gliding of actin over myosin Muscle contraction .

23. Cardiac Muscle

24. Cardiac Muscle located only in the heart
muscle fibers joined together by intercalated discs
fibers branch
network of fibers contracts as a unit
self-exciting and rhythmic
longer refractory period than skeletal muscle

26. cardiac sarcoplasmic reticulum
Cardiac T-tubules are present at the Z lines and not at the A band, I band junctions.
-The cardiac sarcoplasmic reticulum is not well developed, and consequently Diads and not Triads are common in cardiac muscle.
-Cardiac T-tubules are associated with only one expanded terminal sarcoplasmic reticulum cisterna.

27. Smooth muscle

29. smooth muscle
1-Smooth muscle cells are fusiform or spindle-shaped, large at the middle part and taper towards the ends.
2-Each smooth muscle cell has a centrally located elongated nucleus which becomes cork screw-shaped during contraction.
3-The smooth muscle is surrounded by an external lamina and reticular fibers.

30. Sites and functions of smooth muscle
1-In the walls of hollow viscera such as the uterus, vas deferens and ureters, smooth muscle regulate the size of the lumen.
2-In the walls of the intestine, smooth muscle generate rhythmic peristaltic movements
3- In the iris of the eye, smooth muscle produce precise and graded contractions.
4-In the blood vessels, smooth muscle can synthesize collagen, elastin and proteoglycans