Studied by 29 peoplewhat is bone
A type of connective tissue that is hard and inflexible
5 purposes of bone
1.serve as sites of attachment for skeletal muscles and work as levers that make body parts move when these muscles contract
2.give the body its general shape and support body structures
3.protect delicate structures(brain, spinal cord, heart and lungs)
4.serve as storage places for minerals such as calcium and phosphorus
5.serve as the places where red blood cells and some white blood cells are produced
what is bone made up of
living bone cells, connective tissue fibers, and inorganic compounds
bone is an ______ ______
active tissue
what is collagen
a protein mineral with great strength
what do osteoblasts do
secrete collagen and certain polysaccharides
what does the collagen do
forms fibers that are bound together by the polysaccharides which act like cement
when is bone formed
when calcium and phosphate ions from the body fluids combine, forming calcium phosphate
why are bones hard and heavy
because of the calcium phosphate
what forms the bone cell osteocytes
osteoblasts that are trapped in small cavities inside the bone substance
how are osteocytes arranged
a series of smaller and smaller circles with a common center
what is in the center of each series of circles
a cavity called the haversian canal which contains blood vessels and nerves
what do the blood vessels with haversian canals carry
oxygen and nutrients to the bone cells and remove wastes
what happens to the osteocytes if a bone is broken
they become active and produce new bone tissue to heal the wound
what is the tough membrane that is on the outside of the bone except for the ends called
periosteum
what is the purpose of periosteum
make new bone for growth and repair
what is the point at which muscles are fastened to
the periosteum
what does periosteum contain
blood vessels and nerves that enter the bone
what are the 2 types of bony tissue
compact bone and spongy bone
both of the bony tissues are made out of the same material so what is the difference between them
compact bone is very dense and strong while spongy bone is more porous
what are the spaces in spongy bone filled with
soft tissue called marrow
what are the 2 types of marrow
red marrow and yellow marrow
what does red marrow do
makes red blood cells, platelets and some types of white blood cells
where is red marrow found in adults
in the spongy bone of the vertebrae, ribs, breastbone, cranium, and long bones
what is yellow marrow made of
fat cells
where is yellow marrow found in adults
in the hollow center of long bones
what is cartilage
type of connective tissue that bends easily
in the embryo most of the skeleton is cartilage, as the embryo develops minerals are laid down and the cartilage begins to change into bone. What is this process called?
ossification
True or false: the bones of children contain more cartilage than the bones of adults
true
where is cartilage found in adults
ends of ribs, at joints, in the nose and outer ear
what is the purpose of cartilage
gives the bones support while still allowing some bending motion and allows bones to bend more easily at joints and cushions against impact or pressure
what are the 2 main parts of the skeleton
the axial skeleton and the appendicular skeleton
what is the axial skeleton made up of
the skull, vertebrae, ribs, and breastbone
what is the upper part of the skull called and what does it do
it is called the cranium and it houses and protects the brain
what is the rest of the skull made up of
facial and jaw bones
what is another word for the backbone
spinal column
the backbone has 33 bones called _______
vertebrae
how are the vertebrae separated from each other
by disks of cartilage that act as shock absorbers and allow the spine to bend
what is the space that is enclosed by the sternum, ribs and back bone
chest cavity
what do the ribs and sternum protect within the chest cavity
heart and lungs
what is the appendicular skeleton made up of
arm and leg bones, and the pectoral girdle and pelvic girdle
what makes up the pectoral gridle
shoulder blades (scapula) and collar bones (clavicle)
what is the pelvic gridle made up of
hip bones and connect to legs and spine
what are the points in the skeleton where bones meet called
joints
what are immovable joints
joints in which bones are tightly fitted together (example: in cranium)
what are hinge bones and where are they located
allow back and forth movement in the elbow and knee
what are ball and socket joints and where are they located
allow movement in all directions in the shoulder and hip
how do ball and socket joints work
the ball shaped end of a bone fits into a cuplike hollow(socket) of another bone
what are pivot joints and where are they located
joints that allow side to side as well as up and down movement at the base of the skull
what are gliding joints and where are they located
joints that allow some bending and twisting movement like in the wrist joints and joints between the vertebrae
how are bones at movable joints held together
by tough, fibrous bands of connective tissue called ligaments
what fluid is secreted to act as a lubricant and reduce friction at a joint
synovial fluid
what type of muscles are fastened to the bones of the skeleton
skeletal/striated muscles
how is skeletal muscle tissue made
during development, cells fuse together, forming individual muscle fibers. all these fibers are bound together by connective tissue
what is a bundle of small fibers called
myofibrils
each myofibril is made up of still finer protein filaments, one thin and one thick what are the called
thick=myosin
thin=actin
what does the sliding filament theory of muscle contraction say
the muscle fibers shorten when the actin slides over the myosin
by what is voluntary movement started and coordinated
impulses from the brain and spinal cord
what does voluntary movement include
any action that is under conscious control
how are skeletal muscles fastened to bones
by strong fibers of connective tissue called tendons
muscles can ___ when they contract, but they cannot ____ when they relax
1.pull
2.push
muscles always work in _____ pairs
antagonistic
when the bicep muscle on the front of the upper arm contracts what does the arm do
bends
whenever the biceps contract what happens to the triceps
they relax allowing the arm to bend
when the triceps muscle contracts, what does the biceps muscle do
relaxes causing the arm to extend
True or false: as long as you are conscious your skeletal muscles are never completely relaxed
true
what is muscle tone
the fact that your brain always keeps your muscles slightly contracted
what is involuntary muscle tissue called
smooth muscle
where is smooth muscle found
walls of digestive organs, in the walls of arteries and veins, in the diaphragm, and other internal organs
smooth muscle does not form bundles of fiber like skeletal muscle what does it do instead
the cells of smooth muscle are long and overlap to form sheets of muscle
what type of muscle is only found in the heart
cardiac
Note
Flashcard