Muscle Tissue

Myology

The scientific study of muscles

Orthopedics

Branch of medicine concerned with the prevention or correction of disorders of the musculoskeletal system

Characteristics of Muscle Tissue

Excitability – the ability to respond to a stimulusContractility – the ability to shorten when stimulatedExtensibility – the ability to be stretchedElasticity – the ability to return to the original size

Functions of Muscle Tissue

Motion – body movements as well as moving substances within the bodyPosture – postural muscles continuously contract when awake to hold the body uprightHeat Production – muscular contraction produces 85% of the body’s heat

Skeletal Muscle

Location – attached to bonesAppearance – striatedNervous Control - Voluntary

Cardiac Muscle

Location – The HeartAppearance – striatedNervous Control - involuntary

Smooth Muscle

Location – walls of hollow organsAppearance – non-striatedNervous Control - involuntary

Connective Tissue

Fascia – sheets or bundles of fibrous connective tissue Superficial Fascia – just beneath the skin Deep Fascia – Holds muscles together

Epimysium – covers the entire muscle Perimysium – covers a bundle of muscle

fibers Endomysium – covers individual muscle

fibers

More connective tissue

Tendon – cord-like extension of deep fascia that connects muscle to boneAponeurosis – a sheet of connective tissue, similar to a tendon that attaches muscles

Nerve and Blood Supply

Highly vascular and highly innervated Need to respond to stimuli (nerves) Uses lots of energy (ATP) so needs

blood

Histology of Muscle Tissue

Myofibers – muscle fiber (cell) Sarcolemma – plasma membrane Sarcoplasm – cytoplasm Sarcoplasmic Reticulum – ER Transverse Tubules (T-Tubules) –

tubes that extend across the myofiber and open to the outside.

Myofibril – structures that make up the fibers

Myofilaments – structures that make up the fibrils

Sarcomeres – basic functional unit of skeletal muscles

http://www.brookscole.com/chemistry_d/templates/student_resources/shared_resources/animations/muscles/muscles.html

SARCOMERES

Z-line – end of a sarcomereA-band – dark area made of think and thin filamentsI-band – light area made of only thin filamentsH-zone – light area made of only thick filaments

http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter10/animation__sarcomere_contraction.html

Proteins

Actin – protein that makes the thin filamentsMyosin – protein that makes the thick filaments

Myology Resourceshttp://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter10/