Muscle Tissue 🏋️♀️ Flashcards
Muscle Tissue
Consists of contractile cells and responsible for movement. Derived from the mesoderm.
Myofibrils
Bundles of myofilaments and the structural and functional subunit of the muscle cell.
Actin/thin filaments
Composed mainly of F-actin, with associated proteins like tropomyosin, troponin complex, and nebulin for regulation and stabilization.
I-band
Region of the sarcomere where only thin (F-actin) filaments are present.
Sliding Filament Hypothesis of Huxley
Theory explaining muscle contraction where myofilaments slide past each other without changing length.
Sarcoplasmic reticulum
Membranous network around myofibrils that stores calcium ions and communicates with T-tubules in muscle cells.
Muscle Spindle
Encapsulated sensory receptor in muscle belly that senses changes in muscle length or stretch, containing modified muscle fibers.
Smooth Muscle Cells
Cells that secrete connective tissue matrix, synthesize various types of collagens and elastin, and possess well-developed rER and golgi.
Sarcomere
The specific organization of contractile proteins of the myofibril observed in all striated muscle types.
Sarcomere
Basic contractile unit of striated muscles containing thick (myosin II) and thin (F-actin) filaments.
H-band
Central region of the sarcomere made up of thick filaments (myosin II) only.
Golgi Tendon Organ
Encapsulated proprioceptor located at myotendinous junction that senses tension in muscles and is part of the Golgi tendon reflex.
Peripheral protein
Proteins found on the periphery of membranes or structures, serving various functions such as structural support or cell signaling.
T tubules
Extensions of the cell membrane that help transmit action potentials deep into muscle fibers, facilitating muscle contraction.
Gap junctions
Specialized protein channels that allow direct communication and passage of ions and small molecules between adjacent cells.