Muscle tissue

Muscle tissue general characteristics

• Made up of elongated cells (muscle cells/fibres, myocytes), that use energy from the hydrolysis to generate force for movements

• Due to contraction of muscle tissue, movement generated, posture maintained, heat generated

Skeletal muscle general characteristics

• Are ~650 skeletal muscle in human body

• Attached to bond through tendons

• Striated

• Multi-nucleated

• Voluntary movement

Why is muscle tissue striated?

Arrangement of myofibrils in cells composed of actin and myosin

Epimysium

Surrounds anatomical muscle

Perimysium

Connective tissue that surrounds bundles of muscle fibers (fascicles) within a muscle, providing support and facilitating blood supply.

Endomysium

Layer for capillaries and nerves, surrounds muscle fibres

Sarcolemma

Cell plasma membrane that surrounds the muscle fibres and facilitates transmission of signals for muscle contraction

Sarcoplasm

Cytoplasm of a muscle fibre

A band

Dark, middle part of myofibril that contains all thick filaments and overlapping thin filament

I band

Thin filament, but no thick filament

H band

Thick filament, but no thin filament

M line

Middle of sarcomere, holds thick filament together

Z disc

Passes through the I line between sarcomeres, made of actinins that link filament of adjacent sarcomeres

Cardiac muscle general characteristics

• Striated

• Branched

• Single central nucleus

• Fibres joined together end to end by intercalated discs (gap junction + desmosome)

What are Purkinje fibres?

Specialized fibers in the heart that conduct electrical impulses, facilitating coordinated heart contractions.

Smooth muscle general characteristics

• Located in walls of hollow internal structures

  • Intestines (peristalsis)

  • Blood vessels (constriction)

  • Urinary

  • Skin erector pill

• Involuntary control

• Non-striated

• Single central nucleus