muscles Flashcards
Vertebrate Skeletal Muscles Pull on
tendons
connective tissue, attaches muscles to bones
Muscle contraction
pulls bone
toward or away from the bone with
which it articulates
the skeletal system ______ forces generated by
muscles
mechanical`
Hydrostatic Skeleton
Fluid in closed body compartment
transmits forces generated by contractile cells
or muscle
Exoskeletons
________ skeleton and
Nonliving, does not grow
Arthropod skeleton
composed partly of chitin
jointed for flexibility
adapted for many lifestyles
Endoskeletons
Consist of ______ ______
can grow
Found in …
living tissue,echinoderms and chordates
Axial skeleton
skull
vertebral column
rib cage
sternum
Appendicular
skeleton
limbs
pectoral girdle
pelvic girdle
Skeletal systems, whether they are hydrostatic skeletons, exoskeletons, or endoskeletons, \_\_\_\_\_\_\_ and \_\_\_\_\_\_ body and transmit \_\_\_\_\_\_ \_\_\_\_\_\_ important in movement
support and protect mechanical forces
joints
Junctions of two or more bones
Ligaments
connective tissue bands
connect bones
limit movement in join
Immovable joints
sutures of the skull
Slightly movable joints
joints between vertebrae
Freely movable joint
enclosed by joint capsule lined with
membrane that secretes synovial fluid
Skeletal muscles act _________ to
one another
antagonistically
Agonist
muscle that produces a particular action
Antagonist
produces the opposite movement
Skeletal muscle (such as biceps)
organ made up of hundreds of muscle fibers
Muscle fiber consists of
threadlike myofibrils
composed of smaller myofilaments (filaments)
Striations of skeletal muscle fibers
overlapping actin and myosin filaments
Sarcomere
contractile unit of actin (thin) and myosin
(thick) filaments
immediate energy source for muscle contraction
Creatine phosphate,ATP Glycogen
ATP _______ provides energy to “cock” myosin
hydrolysis
Creatine phosphate for muscles
intermediate energy storage compound
Glycogen in muscles
fuel stored in muscle fibers
During muscle contraction, energy from
___ is used to _____ muscle _______ so
that the muscle shortens
ATP,slide,filaments
Contraction of a whole muscle depends on
(1) number of muscle fibers contracting
(2) tension developed by each fiber
All skeletal muscle fibers stimulated by a
single motor neuron
Motor recruitment
messages from brain activate motor neurons
The more motor units recruited,
the stronger the contractions