Lecture Exam 2 (muscle tissue) Flashcards
three types of muscle tissue
skeletal, cardiac, and smooth
tissue moves the body by pulling on bones of the skeleton
skeletal muscle
tissue pushes blood through the arteries and veins of the circulatory system
cardiac muscle
tissues push fluids and solids along the digestive tract and perform varied functions in other systems
smooth muscle
4 basic properties of muscle tissue
excitability, contractibility, extensibility and elasticity
the ability to respond to stimulation
excitability
the ability to shorten actively and exert a pull or tension that can be harnessed by connective tissues
contractibility
the ability to continue to contract over a range of resting
extensibility
the ability of a muscle to rebound toward its original length after a contraction
elasticity
functions of skeletal muscle
produce skeletal movement, maintain posture and body position, support soft tissues, regulate entering and exiting of material and maintain body temperature
skeletal muscle has three concentric layers of connective tissue
epimysium, perimysium nad endomysium
dense irregular connective tissue layer that surrounds the entire skeletal muscle. separates muscle from surrounding tissues and organs. connected to deep fascia.
epimysium
divide muscle into series of internal compartments, each containing a bundle of muscle fibers called a fascicle. contains numerous blood vessels and nerves that branch to supply each individual fascicle
perimysium
fascicle
bundle of muscle fibers
delicate network of reticular fibers that surround each skeletal muscle fiber
endomysium
endomysium 2 functions
binds each muscle fiber to its neighbor and supports capillaries that supply individual fibers
repair damaged muscle tissue, lie between the endomysium and muscle fibers
satellite cells
end of muscle collagen fibers of the epimysium, perimysium, and endomysium often converge to form a fibrous connection of muscle to bone, skin, or another muscle known as
tendons
tendons that form thick flattened sheets are called
aponeuroses
muscle fiber =
muscle cells
length of the whole muscle, long and tubilar, are multi-nucleated.
muscle fibers/muscle cells
contains hundreds to thousands of cylindrical myofibrils
sacroplasm (cytoplasm)
surrounds sarcoplasm
sarcolemma (cell membrane)
network of tubules, vesicles, and cisternae in cells. plumbing of cells. stores calcium ions for muscle contraction. surrounds myofibrils
sarcoplamic reticulum
scattered among myofibrils within fiber. glycogen is used to power the cell
mitochondria and glycogen granules
process by which new mitochondria are formed in the cell. activated by numerous different signals during times of cellular stress or in response to environmental stimuli
mitochondrial biogenesis
two types of skeletal muscle fibers
extra-fusal muscle fibers and intra-fusal muscle fiber
standard skeletal muscle fibers. make up most of the large mass of skeletal muscle tissue that contract
extra-fusal muscle fiber
serve as specializes sensory organs called proprioceptors that detect the amount and rate of change in length. (muscle spindle)
intra-fusal muscle fiber
protein filaments consisting primarily of the proteins actin and myosin
myofilaments
bundles of myofilaments
myofibrils
thin filaments. consists of a twisted strand of several interacting proteins
actin filament
thick filaments. heads are known as cross-bridges
myosin filaments
actin and myosin filaments are organized in repeating hexagonal units. give muscles a striated appearance. responsible for skeletal muscle fiber contractions. smallest functional units of muscle fiber.
sarcomeres
ends of sacromere.
z-line
thick filaments in the center of sacromere
m-line
myosin filaments
h-zone
includes m-line, h-band and zone overlap
a-band
region between a band and z line only contains actin filaments part of
i band
associated proteins in thin filaments
tropomyosin and troponin
form a long chain that covers the active sites, preventing actin-myosin interaction
trpomyosin
holds the tropomyosin strand in place
troponin
sarcopenia
age related loss of muscle mass and function
increase in the amount of cell subunits of actin and myosin otherwise known as myofilaments
muscle hypertrophy
group of muscles that a single spinal nerve root innervates
myotomes
releases stored calcium ions increasing the calcium concentration of the sarcoplasm in and around the sarcomeres
sarcoplasmic reticulum
