Muscular tissue

Mrs. Dalia Kamal Eldien

MSC in Microbiology Lecture NO 7

Objectives

Function of musclesProperties of MuscleClassification of muscles Types of muscles

MUSCULAR TISSUE

INTRODUCTIONMuscular tissue makes the main bulk of the body.

Functions of Muscles1. Movement(but can only pull)

2. Production of heat

3. Protect the bones and internal organs

MUSCULAR TISSUE

1- ContractilityAbility of a muscle to shorten or contract with force.

2- ExcitabilityAbility to stretch in response to a force

3- ElasticityAbility of muscle to recoil to original resting length after stretched

Properties of Muscle

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

Functional

classification

Voluntary

(skeletal muscles)

Involuntary

(cardiac and smooth muscles)

Histological classification

Striated muscles

(cardiac and skeletal)

Non-striated muscles

(smooth muscles)

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.

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.

MUSCULAR TISSUE

TYPES OF MUSCLES

1. Cardiac muscle

( striated, involuntary)

2. Skeletal muscle

(striated, voluntary)

3. Smooth muscle

(non striated, involuntary)

MUSCULAR TISSUE

1. SKELETAL MUSCLES• Under microscope

– Long, cylindrical cells – Multinucleate (nucleus on periphery)– Obvious striations

MUSCULAR TISSUE

• Function – Voluntary movement– Facial expression

• Location– Skeletal muscles attached to bones (occasionally

to skin)– 40% of body weight

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.

MUSCULAR TISSUE

Level4: Muscle Fascicle

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

MUSCULAR TISSUE

3. SMOOTH MUSCLE

• UNDER MICROSCOPE

– Spindle-shaped cells with

central nuclei

– Arranged closely to form

sheets

– No striations

MUSCULAR TISSUE

• Function

– Propels substances along

internal passageways

– Involuntary control

• Location

– Mostly walls of digestive tract , blood vessels,

reproductive system.

Recognize the three types of muscles ?

Thank you