musculoskeletal (textbook) Bio 30s

what 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