Muscle Tissue Flashcards
What is the difference between connective tissue and muscle tissue?
Connective tissue:
Fibers are extracellular
Non contractive
What is the function of muscle tissue?
To move parts of the body by contracting and to change the size and shape of internal organs and the vascular system
What are the two types of myofilaments found in muscle tissue?
Actin (thin filament)
Myosin (thick filament)
How is muscle classified ?
What are those classifications?
Muscle is classified according to its appearance of their contractile cells.
Two principle types of muscles are
Smooth Muscle: no cross striations
Striated Muscle: cross striations
Striated muscle is further unclassified on the basis of its location:
skeletal muscle: usually attached to bone
visceral striated muscle: morphologically identical to skeletal muscle but restricted to soft tissue mainly the tongue, pharynx, diaphragm, and esophagus.
Cardiac Muscle: type of striated muscle found in the wall of the heart and in the base of the large veins that empty into the heart.
What is myofilament interaction responsible for?
muscle cell contraction
The muscle cell is referred to as ?
Muscle Fiber
Muscle Cells can be : what and are located where?
Muscle cells can be multinucleated or have a single nucleus
They are located in the sarcoplasm beneath the sarcolemma. (i.e. intracellular)
Tell me about skeletal muscle:
Voluntary muscle
Multinucleated, located near the periphery
The myoblasts of skeletal muscle are derived from the mesoderm.
Consists of striated muscle fibers held together by connective tissue.
The connective tissue then continues on as a tendon or some other type of arrangement that attaches to bone.
The connective tissue associated with muscle is name according to its relationship with the fibers:
What are the three connective tissues associated with muscle?
Endomysium: a layer of reticular fibers that surrounds individual fibers
Perimysium: thicker layer of connective tissue that surrounds a group of fibers to forma bundle or “fascicle”
Epimysium: sheath of dense connective tissue that surrounds a collection of fascicles that constitutes a muscle.
What is a myofibril?
The structural and functional subunit of the muscle which extends the entire length of the fiber.
What are myofibrils composed of?
Bundles of myofilaments which are myosin and actin which are the contractile elements of the striated muscle
Motor Innervation:
What is the neuromuscular junction or motor endplate?
Axons of neurons branch as they near the muscle giving rise to terminal branches that end on individual muscle fibers…This area is called the neuromuscular junction or motor endplate.
Motor Innervation:
At the neuromuscular junction the myelin sheath of the axon ends and the terminal portion of the axon is covered by
Schwann Cells
Motor Innervation
What does the axon release that causes depolarization of the plasma membrane which starts the muscle fiber contraction?
The axon releases EACh
