1. Muscular tissue Mrs. Dalia Kamal Eldien MSC in Microbiology Lecture NO 7

2. Objectives  Function of muscles  Properties of Muscle  Classification of muscles  Types of muscles

3. MUSCULAR TISSUE

4. INTRODUCTION Muscular tissue makes the main bulk of the body. Functions of Muscles 1.Movement(but can only pull) 2.Production of heat 3.Protect the bones and internal organs MUSCULAR TISSUE

5. 1- Contractility Ability of a muscle to shorten or contract with force. 2- Excitability Ability to stretch in response to a force 3- Elasticity Ability of muscle to recoil to original resting length after stretched Properties of Muscle

6. MUSCULAR TISSUE IFUNCTIONALLY 1.Voluntary-can be moved by will( skeletal muscle) 2.Involuntary- cannot be moved by will (cardiac and smooth muscles) HISTOLOGICALLY 1.Striated --have striations (skeletal, cardiac muscles) 2.Non striated—no striations (smooth muscles) Muscles can be classified in two ways

7. Functional classification Voluntary (skeletal muscles) Involuntary (cardiac and smooth muscles) Histological classification Striated muscles (cardiac and skeletal ) Non-striated muscles (smooth muscles)

8. Due to its high degree of specialization, unique terms are used for certain structures in muscle cells: 1.Individual muscle is called muscle fibers. are the functional units of the tissue 2. The cytoplasm of muscle fibers is called sarcoplasm. 3.The muscle fiber plasma membrane is called the sarcolemma.

9. 4.The smooth endoplasmic reticulum is called the sarcoplasmic reticulum. 5. The functional unit of a muscle tissue consist of protein filaments called myofilaments which consists of thin filaments, actin and thick filaments, myosin.

10. MUSCULAR TISSUE TYPES OF MUSCLES 1.Cardiac muscle ( striated, involuntary) 2. Skeletal muscle (striated, voluntary) 3. Smooth muscle (non striated, involuntary)

11. MUSCULAR TISSUE 1.SKELETAL MUSCLES Under microscope –Long, cylindrical cells –Multinucleate (nucleus on periphery) –Obvious striations

12. MUSCULAR TISSUE Function –Voluntary movement –Facial expression Location –Skeletal muscles attached to bones (occasionally to skin) – 40% of body weight

13. MUSCULAR TISSUE Each skeletal muscle consists of two kinds of tissue Connective tissue, and Muscle tissue. The 3 LAYERS OF CONNECTIVE TISSUES IN SKELETAL MUSCLE : 1.Epimysium-Exterior collagen layer Separates muscle from surrounding tissue 2.Perimysium- Surrounds muscle fiber bundles (fascicles) Contains blood vessel and nerve supply to fascicles 3. Endomysium surrounds each single muscle fiber.

15. MUSCULAR TISSUE Level4: Muscle Fascicle

16. MUSCULAR TISSUE 2. CARDIAC MUSCLE Function –Contracts to propel blood into circulatory system UNDER MICROSCOPE –Branching cells –Uni-nucleate –Intercalated discs Location –Occurs in walls of heart

17. MUSCULAR TISSUE 3. SMOOTH MUSCLE UNDER MICROSCOPE –Spindle-shaped cells with central nuclei –Arranged closely to form sheets –No striations

18. MUSCULAR TISSUE Function –Propels substances along internal passageways –Involuntary control Location –Mostly walls of digestive tract, blood vessels, reproductive system.

19. Recognize the three types of muscles ?

20. Thank you