What are Myofibres?
Muscle tissue is a highly specialized type of tissue, made up of cells that have as their fundamental properties excitability and contractility. The cellular elements that make up this type of tissue are called muscle fibers, or myofibers, because of the elongated shape they have.
What is muscle fasciculus?
Each bundle of muscle fiber is called a fasciculus and is surrounded by a layer of connective tissue called the perimysium. Within the fasciculus, each individual muscle cell, called a muscle fiber, is surrounded by connective tissue called the endomysium.
Where is perimysium found?
The perimysium is the connective tissue support surrounding each fiber bundle within the muscle belly and the endomysium represents sheets of connective tissue surrounding each independent muscle fiber.
What is the A band?
The A band is the region of a striated muscle sarcomere that contains myosin thick filaments. In fact, the A band is the entire length of the thick filament of the sarcomere. Its length is approximately 1 μm. The center of the A band is located at the center of the sarcomere (M line).
What is the a band?
What is Multipennate?
multipennate (not comparable) (anatomy) Of a muscle: having the fibers arranged at multiple angles in relation to the axis of force generation.
What is perimysium made of?
The perimysium comprises collagen fibres, types I, III, VI and XII, and many elastic fibres (Figs 3.42 and 3.43). Compared to the epimysium, the percentage of collagen type I decreases and that of collagen type III increases (Sakamoto 1996).
What is the H Zone?
H zone. Definition: The H zone is in the center of the A band where there is no overlap between the thick and the thin filaments. Therefore, in the H zone, the filaments consist only of the thick filament. The H zone becomes smaller as the muscle contracts and the sarcomere shortens.
What is Z disc?
Z-discs (Z-disk, Z-line, Z-band) delineate the lateral borders of sarcomeres and are the smallest functional units in striated muscle. The core of a Z-disc consists of actin filaments coming from adjacent sarcomeres which are crosslinked by α actinin molecules .
Where do myoblasts come from?
Paraxial mesodermal cells adjacent to the neural tube form blocks of cells called somites. Skeletal muscles, excluding those of the head and limbs, develop from mesodermal somites, whereas skeletal muscle in the head and limbs develop from general mesoderm. Somites give rise to myoblasts.
What is a Myotube?
Medical Definition of myotube : a developmental stage of a muscle fiber composed of a syncytium formed by fusion of myoblasts.
What does Unipennate mean?
Medical Definition of unipennate : having the fibers arranged obliquely and inserting into a tendon only on one side in the manner of a feather barbed on one side a unipennate muscle.
What does Bipennate mean?
Medical Definition of bipennate : having the fibers arranged obliquely and inserting on both sides into a central tendon The biceps brachii is a bipennate muscle with two heads of origin.—