Flashcards in biology chapter 10 Deck (45):
1
muscoskeletal system
forms the basic internal framework of the vertebrate body
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flagella
achieve movement by means of the power stroke, a thrusting movement generated by the sliding action of microtubules
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exoskeleton
is a hard skeleton that covers all muscles and organs of some invertebrates
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endoskeleton
serves as the framework within all vertebrate organisms. Also provides protection by surrounding delicate vital organs in bone
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cartilage
is a type of connective tissue that is softer and more flexible than bone.
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bone
is a specialized type of mineralized connective tissue that has the ability to withstand physical stress
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compact bone
is dense bone that does not appear to have any cavities when observed with the naked eye
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spongy bone
is much less dense, and consists of an interconecting lattice of bony spicules (trabeculae); the cavities in between the spicules are filled with yellow and/or red bone marrow
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yellow marrow
is inactive and infiltrated by adipose tissue
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red marrow
is involved in blood cell formation
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osteoblasts
synthesize and secrete the organic constituents of the bone matrix; once they have become surrounded by their matrix, they mature into osteocytes
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osteoclasts
are large multinucleated cells involved in bone resorption
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bone formation
occurs by either endochondral ossification or by intramembranous ossification
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endochondral ossification
existing cartilage is replaced by bone
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intramembranous ossification
mesenchymal (embryonic, undifferentiaated) connective tissue is tranformed into, and replaced by, bone
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axial skeleton
is the basic framework of the body, consisting of the skull, vertebral column, and the rib cage
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appendicular skeleton
which includes the bones of the appendages and the pectoral and pelvic girdles
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sutures
or immovable joints hold the bones of the skull together
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movable joints
bones that do move relative to one another
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ligaments
serve as bone to bone connectors
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tendons
attach skeletal muscle to bones and bend the skeleton at the movable joints
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origin
the point of attachment of a muscle to a stationary bone (the proximal end in limb muscles)
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insertion
the point of attachment of a muscle to the bone that moves (distal end in limb muscles)
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extension
indicates a straightening of a joint while flexion refers to a bending of a joint
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skeletal muscle
is responsible for voluntary movements and is innervated by the somatic nervous system. Has striations of light and dark bands, and is therefore also referred to as striated muscle
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myofibrils
are enveloped by a modified endoplasmic reticulum that stores calcium ions and called the sarcoplasmic reticulum
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sarcoplasm
the cytoplasm of a muscle fiber
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sarcolemma
cell membrane . Is capable of propagating an action potential, and is connected to a system of transverse tubules (T system) oriented perpendicularly to the myofibrils
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sacromere
is composed of thin and thick filaments
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thin filaments
are chains of actin molecules
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thick filaments
are composed of organized bundles of myosin molecules
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Z line
define the boundaries of a single sacromere and anchor the thin filaments
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M line
runs down the center of the sarcomere
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I band
is the region containing thin filaments only
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H zone
is the region containing thick filaments only
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A band
spans the entire length of the thick filaments and any overlapping portions of the thin filaments
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neuromuscular junction
the link between the nerve terminal (synaptic bouton) and the sarcolemma of the muscle fiber
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simple twitch
is the response of a single muscle fiber to a brief stimulus at or above the threshold stimulus, and consists of a latent period, a contraction period, and a relaxation period
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latent period
is the time between stimulation and the onset of contraction
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relaxation period
in which the muscle is unresponsive to a stimulus
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tonus
is a state of partial contraction. Muscles are never completely relaxed and maintain a partially contracted state at all times
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smooth muscle
is responsible for involuntary actions and is innervated by the autonomic nervous system. Is found in the digestive tract, bladder, uterus, and blood vessel walls, among other places
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cardiac muscle fibers
possess characteristics of both skeletal and smooth muscle fibers.
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creatine phosphate
energy can be temporarily stored in a high energy compound called creatine phosphate
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