CHapter 3 Skeletal System Key Terms

ossification

process where a newborn skeleton’s fragile membranes and cartilages turns into bone

periosteum

tough, fibrous tissue that forms the outermost covering of bone

compact bone

(also known as cortical bone) the dense, hard, and very strong bone that forms the protective outer layer of bones

spongy bone

(also known as cancellous bones) porous bones where red bone marrow is located

medullary cavity

central cavity located in the shaft of long bones, where it is surrounded by compact bone; where red and yellow bone marrow are stored

endosteum

tissue that lines the medullary cavity

hematopoietic

pertaining to the formation of blood cells

cartilage

smooth, rubbery, connective tissue that acts as a shock absorber between bones; more elastic than bones, it also makes up the flexible parts of the skeleton such as outer ear and the tip of the nose

articular cartilage

covers surfaces of bones where they articulate (come together to form joints); makes smooth joint movement possible and protects bones from rubbing against each other

meniscus

an interarticular fibrocartilage of crescent shape found in some joints, such as the knee and the temporomandibular joint of the jaw

diaphysis

shaft of a long bone

epiphyses

the wider ends of long bones

foramen

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

process

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

joints

(also known as articulations) the place of union between two or more bones; classified either to their construction or based on the degree of movement they allow

fibrous joints

joints connected by fibrous tissue that hold the bones tightly together and allow little to no movement

fontanelles

(also known as the soft spots) any of the tough, fibrous membranes lying between the bones of the cranial vault of a fetus or infant; allows for the passage of an infant through the birth canal and the growth of the skull in its initial year before the child matures and the fontanelles harden

cartilaginous joints

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

pubic symphysis

the junction of the pubic bones on the anterior midline that allows for some movement to facilitate childbirth

synovial joint

a joint where two bones articulate to permit a variety of motions

synovial capsule

the outermost layer of strong fibrous tissue that encloses the synovial joint

synovial membrane

thin layer of CT that lines the inner surface of the joint capsule

synovial fluid

fluid flowing within the synovial cavity that acts as a lubricant to make the smooth movement of the joint possible

ligaments

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

bursa

a 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

axial skeleton

consists of bones along the axis, or central line, of the human body; PROTECTS MAJOR ORGANS OF THE NERVOUS, RESPIRATORY, AND CIRCULATORY SYSTEMS

appendicular skeleton

contains the bones in the appendages of the body, as well as the structures that connect appendages to the axial skeleton; MAKES BODY MOVEMENT POSSIBLE AND PROTECTS ORGANS OF THE DIGESTIVE AND REPRODUCTIVE SYSTEMS

skull

the bony framework of the head, composed of 8 cranial bones, the 14 bones of the face, and the teeth

cranium

the portion of the skull that encloses the brain, consisting of a single frontal, occipital, sphenoid, and ethmoid bones and the paired temporal and parietal bones

external auditory meatus

the opening of the external auditory canal of the outer ear

meatus

the external opening of a canal

costals

(also known as the ribs) 12 pairs of bones that attach posteriorly to the thoracic vertebrae

26

The spinal column has __ vertebrae

lamina

the posterior portion of a vertebra where the transverse and spinous processes extended and serve as attachments for muscles and tendons

vertebral foramen

the opening in the middle of the vertebra that allows the spinal cord to pass through

intervertebral disks

disks made of cartilage and pads of tissue that separate and cushion the vertebrae from each other and allow for movement of the spinal column