muscle Flashcards
Movement in the body is accomplished by specialized cells called
muscle fiber
responsible for locomotion or movement of the body
muscle tissue
muscle tissue is highly specialized to contract because muscle cells contain ____
contractile myofilaments in cytoplasm
muscle tissue is present in
walls of tubular organs, muscle organs, heAART
a basic tissue specialized for contraction and transmission of impulses in aid of that contraction.
muslce
an extreme example of specialization and differentiation
muscle
things common to all muscle types
contraction is due to actin and myosin filaments and it is an all or none response
origin is from embryonic mesoderm
specialization caused the loos of ability to divide
the force of contraction of muscles is transmittes through
a network of collagenous fibers
Anatomic MUSCLES are bundles of individual cells called
myofibers
what composes myofibers
contractile myofibrils
organizational classification that make up muscle
sarcomere-myofilaments-myofibril-myofiber-muscle
myofilaments are organized into ___
sarcomeres
s the basic unit of contraction
sarcomere
major component of muscle tissue
cells
a term used for the combined plasmalemma and basal lamina
sarcolemma
the cytoplasm of myofiber
sarcoplasm
the endoplasmic reticulum of a myofiber
sarcoplasmic reticulum
a form of smooth ER, is associated with the release of calcium ions needed for contraction
sarcoplasmic reticulum
comprised of contractile proteins such as
actin and myosin.
myofilaments
Connective tissue proper which
immediately surrounds a muscle fiber
forming a “basketwork” around individual
cells is
endomysium
surrounds a bundle of fibers within a
muscle.
perimysium
dense irregular connective tissue which surrounds the entire muscle.
epimysium
classification of muscle cell based on function
voluntary and involuntary
a muscle cell under the control of the conscious will
voluntary
intrinsically contractile, involuntary where it responds to autonomic and hormonal stimuli and specialized for slow, prolonged contraction
smooth myocytes
this type of muscle cell is surrounded by a basal lamina except at its junction with another cell
smooth myocyte
smooth muscle cells uses this to communicate
gap junctions
It has fusiform or spindle-shaped cell with tapered ends and wide middle containing a centrally located oval nucleus with 15-20 microns wide and 0.2-0.5 mm in length
smooth myocyte
Sarcoplasm does not show a banding pattern like the skeletal and cardiac myocytes because the
myofilaments are arranged differently.
smooth muscle
One distinguishing physiological feature of smooth myocyte is
its ability to secrete ct matrix
In the walls of blood vessels and the uterus in particular, smooth muscle fibers secretes ____
large amount of collagen and elastin
are long (up to 50 cm) and cylindrical (about
100um um diameter) with blunt ends
skeletal muscle cell
the middle nad terminal part of this cell have the same size, and individual cells are surrounded by a basement membrane
skeletal muscle cell
contains many small dark oval nuclei located in the peripheral area of the cytoplasm
skeletal muscle cell
the muscle cell where the cytoplasm presents cross-stiations oriented perpendicular to the longitudinal axis of the cell
skeletal muscle cell
the primary distinguishing feature of muscle tissue
convertion of chemical to mechanical energy and heat (atp to enrgy and heat)
the surrounding cell membrane of muscle is called the
sarcolemma
the intercellular substance of the muscle is composed of
collagenous ct with some elastic fiber
the force of contraction is transmitted through ____
connective tissue
this is composed of A (dark) bands which contains thick myosin and thin actin filaements
sarcometre
it contains thin actin filaments that are located on both ends of a bands
i band (light or isotropic)
a narrow light zone that bisects the a bands represents the gap between the free ends of the actin filaments
h band
dark lines that bisect i bands and represents the peripheral limits of one sarcomere and the site where the actin filaments of one sarcomere are attached t
z band
what connects one sarcomere to another sarcomere
cross bridges
3 classification of the functional state of the sarcomere
relaxed, contracted, stretched
these sarcomeres have myosin filaments (a band) in the middle and the actin filaments (i band) eztends from z line to the middle of the sarcomere
relaxed
describe the relaxed state of sarcomeres in transverse
1 myosin is surrounded by a hexagon of actin filaments
contraction accdg to the sliding filament hypothesis occurs when
the cross bridges alternately disconnects and reconnect the myosin filaments to a new sites along the actin filaments
have actin filament overextend from their original relaxed position and almost slide away from myosin filaments
stretched sarcomeres
the distinct clumps of fine pink dots in the cytoplasm that represent the cut surface of myofibrils
fields of cohnheim
processes that involves some degree of mobility or contraction
mitosis, phagocytosis, amoeboid migration of wbc into extravascular tissue
state of sarcomere where the i band diminishes in length but a band does not
contracted
the energy for contraction is provided by
atp breakdown to adp
the h band is almost wide almost obliterating a banf
stretched
transverse section o fstretched sarcomere
skeletal myocyte is polygonal in outline with dark blue, triangular nuclei at the periphery
3 types of myocyte
cardiac, red skeletal, white skeletal
red, smaller, and has more mitochondrial s
red skeletal
slow twitch, less tension and high endurance
red skeletal
white, larger, dast twitches, more tension but easily fatigued
white skeletal myocyte
involuntary and striated with more mitochondria
cardiac myocytes
cardiac myoscyte is found in the
myocardium of the heart
ordinary vs special cardiac myocyte
ordinary is much smaller, elongated and branched. has one or two centrally located oval nuclei. while special is larger and wider
transverse of ordinary cardiac
polygonal with centrally located round or ovoid nucleu and cytoplasm shows fields of cohnheim
