Chapter 10 and 11: Muscles and Muscle Tissues Flashcards
4 properties and that distinguish muscle tissue from other tissues
contractility, excitability, extensibility, and elasticity
contractility
muscle tissue contracts forcefully
excitability
nerve signals or other stimuli excite muscle cells
extensibility
muscle tissue can be stretched
elasticity
muscle tissue can recoil passively and resume its resting length
functions of muscle tissue
produce movement, open and close body passageways, maintains posture and stabilize joints, and heat generation
skeletal muscle tissue
skeletal muscles that are striated; innervated by voluntary division of nervous system
cardiac muscle tissue
striated muscles only in walls of heart; innervated by the involuntary division of the nervous system
smooth muscle tissue
walls of hollow organs; lack striations; innervated by involuntary division of nervous system
epimysium
dense irregular connective tissue surrounding entire muscle
perimysium
surrounds each fascicle (group of muscle fibers)
endomysium
fine sheath of loose connective tissue wrapping each muscle cell
muscle attachments
most skeletal muscles run from one bone to another, crossing 1 moveable joint
insertion
more moveable
origin
less moveable
skeletal muscle fiber
long, cylindrical fibers; huge cells; each cell formed by the fusion of hundreds of embryonic cells; nuclei are peripherally located
myofibrils
rodlike bundle of contractile myofilaments in the cytoplasm of a skeletal muscle cell; made of repeating segments called sarcomeres
Z disc (Z line)
boundaries at the two ends of each sarcomere