Muscles and locomotion Flashcards
musculoskeletal system
forms the basic internal framework of the vertebrate body. Muscles and bones work in close coordination to produce voluntary movement in addition to other functions. the skeletal system are the physical support and locomotion, the muscles generate force.
unicellular locomotion
protazoans and primitive algae may move by beating cilia or flagella.
cilia and flagella
each contain a cylindrical stalk of 11 microtubules- 9 paired arranged in a circle with 2 single microtubules in the center.
power stroke
how flagella achieve movement, a thrusting motions generated by the sliding action of microtubles
recovery stroke
the return of the cillium or flagellum to its original position
amoeba movement
they use pseudopodia for locomotion, the advancing cell membrane extends forward allowing the cell to move.
flatworms worms hydrostatic skeletons
the muscles within the body wall of advanced flatworms, such as planaria are arranged in two antagonistic layers. longitudinal and circular. The muscles contract against the resistance of incompressible fluid within the animals tissues. circular layers lengthen the animal and the longitudinal layer shortens the animal.
segmented worms hydrostatic skeleton
has the same skeleton seen in flatworms, each segment can expand or contract independently. the bristles in the lower part of each segment, called setae, anchors it into the ground while muscles push it ahead.
Exoskeleton
a hard skeleton that covers all muscles and organs of some invertebrates. found principally in arthropods.
Insect skeleton
composed of chitin. all exoskeletons are composed of noncellular material secreted by the epidermis. offers protections yet shunts growth.
molting
periodic formation and deposition of a new exoskeleton are necessary to permit body and growth.
endoskeleton
serves as the framework within all vertebrae organisms. also provides protection by surrounding delicate vital organs in bone.
two components of skeleton
cartilage and bone
cartilage
type of connective tissue that is softer and more flexible then bone. retained in adults in places where firmness and flexibility are needed.
bone
specialized type of mineralized connective tissue that has the ability to withstand physical stress. designed for body support, bone tisssue is hard and strong while elastic and lightweight. two types
-compact bone and spongy bone
compact bone
dense bone that does not appear to have any cavities when observed by the naked eye. the boney matrix is deposited in structural units called osteons.
Osteons
(haversian systems) each osteon consists of a central microscopic channel, called Haversian canal, surrounded by a number of concentric circles of bony matrix called lamellae.
spongy bone
much less dense and consists of an interconnecting lattice of bony spicules (trabeculae): the cavities between the spicules are filled with yellow and or red bone marrow.
yellow marrow
is inactive and infiltrated by adipose tissue
red marrow
is involved in blood cell formation.
osteocytes
two other types of cells found in the bone tissue are osteoblasts and osteoclasts.
Osteoblasts
synthesize and secrete the organic constitutents of the bone matrix; once they have become surrounded by their matrix they mature into osteocytes
Osteoclasts
are large multinucleated cells involved in bone resorption or breakdown.