Chapter 3 - The Skeletal System

• 1. Bones act as the framework of the body
• 2. Bones support and protect the internal organs.
• 3. Joints work in conjunction with muscles, ligaments, and tendons, making possible the wide variety of body movements.
• 4. Calcium, which is required for normal nerve and muscle function, is stored in bones.
• 5. Red bone marrow, which has important function in the formation of blood cells, is located within spongy bone.

the tough, fibrous tissue that forms the outermost covering of bone

aka cortical bone, the dense, hard, and very strong bone that forms the protective outer layer of bones

aka cancellous bone, lighter and no as strong as compact bone

commonly found in the ends and inner portions of long bones such as femur & red bone marrow

the central cavity located in the shaft of long bones where it is surrounded by compact bone

red and yellow bone marrow are stored

the tissue that lines the medullary cavity

located within the spongy bone

a hempoietic tissue that manufactures red blood cells, hemoglobin, white blood cells, and thrmbocytes

formation of blood cells

functions as a fat storage area

composed chiefly of fat cells and located in the medullary cavity of long bones

smooth, rubbery, blue-white connective tissue that acts as a shock absorber between bones

more elastic than bone, also makeup the flexible parts of the skeleton such as the outer ear and the tip of the nose

covers the surfaces of bones where they come together to form joints.

makes smooth joint movement possible and protects the bones from rubbing against each other

the curved fibrous cartilage found in some joints, such as the knee and the temporomandibular joint of the jaw

the shaft of a long bone

the wider ends of long bones such as the femur of the legs

each epiphysis is covered with articular cartilage to protect it

proximal is the end of the bone located nearest to the midline of the body

distal is the end of the bone located farthest away from the midline of the body

an opening in a bone through which blood vessles, nerves, ligaments pass

ex: spinal cord passes through the foramen magnum of the occipital bone at the base of the skull

a normal projection on the surface of a bone that most commonly serves as an attachment for a muscle or tendon

ex: mastoid process is the bony projection located on temporal bones just behind the ears

aka articulations, the place of union between two or more bones

classified according to their construction or based on the degree of movement they allow

aka sutures, consiist of inflexible layers of dense connective tissue, hold the bones tightly together

aka soft spots, are normally present on the skull of a newborn

• facilitates the passage of the infant through the birth canal
• allow for the growth of the skull during the 1st  year

allow only slight movement and consist of bones connected entirely by cartilage

ex: where the ribs connect to the sternum (breast bone), these joints allow movement during breathing

pubic symphysis allows some movement to facilitate childbirth, located between the pubic bones in the anterior (front) of the pelvis

created where two bones articulate to permit a variety of motions

ball-and-socket joints, such as the hips and shoulders, allow a wide range of movement in many directions

hinge joints, such as the knees and elbows, are synovial joints that allow movement primarily in one direction or plane

the outermost layer of strong fibrous tissue that resembles a sleeve as it surrounds the joint

lines the capsule and secretes synovial fluid

flows within the synovial caovity, act as as a lubricant to make the smooth movement of the joint possible

bands of fibrous tissue that form joints by connecting one bone to another bone or by joining a bone to cartilage

fibrous sac that acts as a cushion to ease movement in areas that are subject to friction, such as the shoulder, elbow, and knee joints where a tendon passes over a bone

protects the major organs of the nervous (spinal cord), respiratory (lung), and circulatory systems (heart)

makes body movement possible and protects the organs of digestion, excretion, and production

consists of 8 bones that form the cranium, 14 bones that form the face, and 6 bones in the middle ear.

the anterior portion of the cranium that forms the forehead

houses the frontal sinuses and forms the roof of the ethmoid sinuses, the nose and part of the socket that protects the eyeball

two of the largest bones of the skull and form most of the roof and upper sides of the cranium

forms the back part of the skull and the base of the cranium

form the sides and base of the cranium

the opening of the external auditory canal of the outer ear

located within the temporal bone on each side of the skull

3 tiny bones: malleus, incus, and stapes

aka cheekbones, articulate with the frontal bone that makes up the forehead

form most of the upper jaw

form the anterior (front) part of the hard palate of the mouth and the floor of the nose

make up part of the orbit (socket of the eye) at the inner angle

thin, scroll-like bones that form part of the interior of the nose

forms the base for the nasal septum

aka jawbone, the only movable bone of the skull

attached to the skull at the temporao-mandibular joint

first set of 7 vertebrae and form the neck

second set of 12 vertebrae

make up the third set of 5 vertebrae