STRIATED SKELETAL MUSCULAR TISSUE. FUNCTIONS Movement Heat Stabilization.

STRIATED SKELETALMUSCULAR TISSUE

FUNCTIONS

• Movement

• Heat

• Stabilization

TYPES

Striated Skeletal

Voluntary

Striated Cardiac

Involuntary

Visceral Smooth

Involuntary

PROPERTIES

• Contractibility

• Excitability

• Extensibility

• Elasticity

FASCIA

• Tendon of Origination

• Epimysium

• Perimysium

• Endomysium

• Tendon of Insertion

MYOFIBER STRUCTURE

• Sarcolemma• Sarcoplasm• Sarcoplasmic Reticulum

– Transverse Tubule

– Triad

– T Tubule

– Terminal Cisterna

• Multinuclear• Mitochondria• Myofibrils

MYOFIBER MYOFILAMENTS• Contractile Proteins

Actin

Myosin

• Regulatory ProteinsTroponin

Tropomyosin

• Structural ProteinsTitin

Nebulin

Myomesin

Dystrophin

SARCOMERIC AREAS

• Z Disc

• I Band

• A Band

• H Zone

• M Line

• I Band

• Z Disc

METABOLISM OF MYOFIBER

• Anaerobic Respiration– Glycolysis

• 2 ATP’s / Glucose• 2 Trioses / Glucose• 2 NADH2 / Glucose

AEROBIC RESPIRATION

• Transition Reaction– 2 Pyruvic Acid / Glucose– 2 NADH2 / Glucose

• Citric Acid Cycle– 2 ATP’s– 2 FADH2 / Glucose– 6 NADH2 / Glucose

• Electron Chain Transport

BLOOD SUPPLY

• Myofiber– Capillary

• Arterial• Venous

NEUROMUSCULAR JUNCTION

• Somatic Motor Neuron– Dendrites– Cell Body– Axonic Hillock– Teleodendria– Synaptic End Bulb– Synaptic Vacuole– Exocytosis– ACH– Synapsis– Diffusion

NEUROMUSCULAR JUNCTION

• Myofiber– Sarcolemma– Ach Receptor– Transverse Tubule – Na+ Gates Open– Na+ Influx– Transverse Tubule– Triad

NEUROMUSCULAR JUNCTION

• Myofiber– Triad– Terminal Cisternae– Ca+2 Gates Open– Ca+2 Sarcoplasmic Diffusion– Activated Troponin– Activated Tropomyosin– Troponin Tropomyosin Complex– Exposed Actin

NEUROMUSCULAR JUNCTION

• Myofiber– Ca+2 Sarcoplasmic Diffusion– Myosin Cross Bridges– ATP Myosinases– Dephosphorylation of ATP– Diphosphate Bonds Broken– Energy Released– ADP and Free High Energy

NEUROMUSCULAR JUNCTION

• Myofiber– Actin-Myosin Lock Up– Myomesin Pulls on Myosin– Myosin Pulls Actin– Myosin and Actin in H Zone– H Zone Disappears– Sarcomere Shortens– Z Disc– All Sarcomeres Shorten

NEUROMUSCULAR JUNCTION

• Myofiber– Dystrophin– Sarcolemma– Endomesium– Perimesium– Epimesium– Tendon of Insertion

NEUROMUSCULAR JUNCTION

• Remove Threshold Stimulus– Na+1 Gates Close– K+1 Gates Open– Repolarization– Refractory– AChE– Actin-Myosin unlock– Troponin-Tropomyosin Complex unlock

NEUROMUSCULAR JUNCTION

• Remove Threshold Stimulus– H Zone Reappears– Sarcomeres Return – Ca+2 Transported to Organelle of Storage– Calsequestrin– Ca+2 Gates Closed– Expenditure of Energy

MOTOR UNIT

• One Somatic Motor Neuron

• 150 Myofilbers

• Epimesium

• Tendon of Insertion

TWITCH CONTRACTION

• Response to One Stimulus

• Latent Period

• Contraction Period

• Summation Period

• Refractory Period

• Relaxation Period

APPLICATION OF STIMULI

• Treppe

• Complete Tetanic

• Incomplete Tetanic

• Wave Summation– Smooth Summation– Rough Summation

MUSCULAR TONUS

• Partial Contraction

• Involuntary Contraction

TYPES OF MOVEMENTS

• Isotonic– Examples:

• Isometric– Examples:

TYPES OF MUSCLES

• Red Muscles– # Myoglobin– Slow– Examples:

• White Muscles– # Myoglobin– Fast– Examples:

TYPES OF MUSCLES

• Red and White Mixture– # of Myoglobin– Examples: