Science Chapter 17

Front 1

skeletal system

Back 1

all the bones in your body

Front 2

five major functions of skeletal system

Back 2

1. Your skeleton gives shape and support to your body.

2. Your bones protect your internal organs.

3. Major muscles are attached to your bones.

4. Blood cells are formed in the marrow in the center of your bones.

5. Calcium and phosphorus compounds are stored in your skeleton for later use.

Front 3

Periosteum

Back 3

a tough, tight-fitting membrane that covers the bone’s surface, Contains small blood vessels that carry nutrients into the bone, Contains cells involved in the growth and repair of bone

Front 4

Compact bone

Back 4

the hard, strong layer under the periosteum, Gives bone its strength, Has a framework containing deposits of calcium phosphate

Front 5

Spongy bone

Back 5

found toward the ends of long bones, Has many small, open spaces that make bones lightweight, Filled with marrow, which produces blood cells

Front 6

Cartilage

Back 6

Cartilage acts as a shock absorber and reduces friction between bones when they rub together, People with damaged cartilage feel pain when they move their joints, Your skeleton begins before birth as cartilage, which is gradually broken down and replaced by bone

Front 7

Osteoblasts

Back 7

build up bone by depositing calcium and phosphorus, which make bone tissue hard

Front 8

Osteoclasts

Back 8

break down bone tissue

Front 9

Joints

Back 9

any place where two or more bones come together, Bones must be kept just far enough apart so they don’t rub against each other

Front 10

Ligament

Back 10

a tough band of tissue that holds bones in place

Front 11

Immovable joint

Back 11

Allows little or no movement, Example: the joints of the bones in your skull

Front 12

Pivot joint

Back 12

One bone rotates in a ring of a stationary bone, Turning your head is an example of a pivot movement

Front 13

Ball-and-socket joint

Back 13

The rounded end of one bone fits into a cuplike cavity on another bone, Example: hips

Front 14

Hinge joint

Back 14

Back-and-forth movement, Example: elbows

Front 15

Gliding joint

Back 15

One part of a bone slides over another bone, Example: wrists, Used the most in the body

Front 16

muscle

Back 16

A muscle is an organ that can relax and contract, and provides the force to move your body parts

Front 17

Voluntary muscles

Back 17

muscles that you are able to control

Front 18

Involuntary muscles

Back 18

muscles that you cannot control

Front 19

skeletal muscles

Back 19

Skeletal muscles move bones, Most common type of muscle, Voluntary muscles, Contract quickly and tire more easily, Look striped, or striated

Front 20

tendons

Back 20

Tendons are thick bands of tissue that attach muscle to bones

Front 21

Cardiac muscle

Back 21

found only in the heart, Cardiac muscle is striated, like skeletal muscle

Front 22

Smooth muscles

Back 22

found in internal organs, Example: Intestines, Smooth muscles are involuntary muscles, Contract and relax slowly

Front 23

pairs of muscles

Back 23

You move because pairs of muscles work together, When one muscle of a pair contracts, the other relaxes, Muscles always pull, Over time, muscles can become larger or smaller, depending on whether or not they are used, Blood carries energy-rich molecules to the muscles so they can do their work

Front 24

skin

Back 24

Your skin is the largest organ of your body, Skin is made up of three layers of tissue

Front 25

Epidermis

Back 25

the outer, thinnest layer, The outermost cells of your skin are dead and rub off when you touch anything, New cells are constantly produced at the base of the epidermis, Cells produce melanin, which is a pigment that protects your skin and gives it color

Front 26

Dermis

Back 26

the middle layer, The dermis is thicker than the epidermis, The dermis contains blood vessels, nerves, muscles, oil, sweat glands, and other structures

Front 27

Fatty layer

Back 27

insulates the body

Front 28

Protection

Back 28

forms a protective covering over the body that prevents injury, Many disease-causing organisms cannot pass through the skin, Prevents excess water loss

Front 29

Sensory response

Back 29

nerve cells in the skin detect and relay information to the brain

Front 30

vitamin D

Back 30

Formation of vitamin D, which helps your body absorb calcium

Front 31

Regulation of body temperature

Back 31

Blood vessels in the skin help release or hold heat, Perspiration from the sweat glands eliminates excess body heat by evaporation

Front 32

sweat glands

Back 32

Elimination of wastes through sweat glands

Front 33

when injured

Back 33

When injured, the skin produces new cells and repairs tears

Front 34

bruises

Back 34

Bruises happen when tiny blood vessels beneath the skin burst and leak into surrounding tissues

Front 35

cuts

Back 35

When you have a cut, a scab forms to prevent bacteria from entering your body, Cells in the surrounding blood vessels fight infection, Skin cells beneath the scab grow to fill in the gap of the torn skin

Front 36

Doctors are able to repair severe skin damage

Back 36

Doctors sometimes use skin from cadavers to prevent infections until a victim’s skin heals, Doctors are beginning to grow large sheets of epidermis from small pieces of the victim’s healthy skin

Front 37

skin grafts

Back 37

Skin grafts are pieces of skin that are cut from one part of a person’s own body and moved to the injured area