Understanding Muscle Histology: Types, Structure, and Function
This exercise explores the histology of muscle tissue, focusing on three primary types: skeletal, cardiac, and smooth muscle. Skeletal muscle, responsible for voluntary movements, is connected to bones by tendons and exhibits striations due to the arrangement of myofibrils. Cardiac muscle, found only in the heart, forms a branched network and is interconnected via intercalated discs. Smooth muscle, located in the walls of internal organs, has a tapered shape and single nucleus. The exercise includes details on connective tissue layers, muscle fiber structure, and the neuromuscular junction.
Understanding Muscle Histology: Types, Structure, and Function
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Presentation Transcript
Exercise 10 Muscle histology
Muscle Types • Skeletal – attached to bone by tendons is responsible for voluntary movements. • Cardiac- located in heart • Smooth- located in the walls of internal organs, blood vessels, and airways
Skeletal muscle fibers • Connective tissue layers: • Epimysium- around the entire muscle • Perimysium surrounds bundle of muscle fibers (fascicle) • Endomysium-surrounds each muscle fiber
Skeletal muscle cont. • Striations in appear because of alternating light and dark bands from the arrangement of the thick and thin protein filaments called myofibrils.
Cardiac muscle • Forms branching networks. • Striated • Linked together by intercalated discs
Smooth Muscle • Widest in middle and tapered toward each end. • Single nucleus
Cell structure of skeletal muscle • Actin- main component of thin filaments. • Myosin- main component of thick filaments • Together these are called myofilamentswhich are packaged into parallel bundles called myofibrils.
Structure of a skeletal muscle fiber • Sarcolemma or cell membrane • T-tubules-continuous with the sarcolemma and travel into the cytoplasm • Sarcoplasmicreticulum-SER • Cisternae- saclike extensions of the SR
Neuromuscular Junctions • Synaptic terminal- the expanded knob at the end of the nerve fiber • Motor end plate-the region of the sarcolemma associated with the neuromuscular junctions. • Synaptic cleft- narrow space between the cell membrane
The End • View the different types of muscle under the microscope. • Be able to ID the various terms on models, pictures or on slides
