Skeletal System - Penn Foster

Ossification

Repairs minor damage that occurs during normal activity and repairs bone after injuries like fractures

Osteoclasts

Break down old & damaged bone

Osteoblasts

Help rebuild the bone

Periosteum

tough, fibrous tissue that forms the outermost covering of bone

Compact bone (or Cortical bone)

dense, hard, very strong bone that forms the protective outer layer of bones; when measured by weight, its >75% of the body’s bone matter

Spongy bone (or Cancellous bone)

porous, making it lighter & weaker than compact bone; red bone marrow often located here

Medullary Cavity

“inner section”, central cavity in shaft of long bones, where it is surrounded by compact bone; red & yellow marrow stored here

Endosteum

tissue that lines the medullary cavity

Red bone marrow

a hemopoietic tissue that makes red blood cells, white blood cells, hemoglobin, and thrombocytes

Yellow bone marrow

functions as a fat storage area; composed of fat cells & is located in medullary cavity of long bones

Hemopoietic

pertaining to formation of blood cells

Cartilage

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

Articular Cartilage

covers surface of bones where they articulate (come together) to form joints; makes smooth joint movement possible & protects bones from rubbing against eachother

Meniscus

the curved, fibrous cartilage found in some joints (ex- knee, TMJ)

Diaphysis

the shaft of a long bone

Epiphyses

wider ends of long bones; each is covered with articular cartilage

Proximal epiphyses

end of bone nearest to the midline of the body

Distal epiphyses

end of bone farthest from the midline of the body

Foramen

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

Process

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

Joints

the place of union between 2 or more bones; classified according to either their construction or based on degree of movement they allow

Fibrous joints

consisting of inflexible layers of dense connective tissue, hold the bones tightly together

Fontanelles (or soft spots)

normally present on the skull of a newborn; they facillitate passage of the infant through the birth canal and also allow for growth of the skull during the first year

Cartilaginous joints

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

Pubic symphysis

allows some movement to facilitate childbirth

Synovial joints

created where two bones articulate to permit a variety of motions; described based on their type of motion

Ball-and-socket joints

synovial joints that allow a wide range of movement in many directions (ex- hips & shoulders)

Hinge joints

synovial joints that allow movement primarily in one direction or plane

Synovial Capsule

Synovial membrane

Synovial fluid

Ligaments

Bursa

206

amount of bones in the typical human skeleton

Axial skeleton

Appendicular skeleton

Extremity

Appendage

Appendicular

Lower extremeties

Upper extremeties

28

amount of bones that form the cranium

Cranium

Frontal bone

Parietal bones

Occipital bone

Temporal bones

External auditory meatus

Sphenoid bone

Ethmoid bone

Auditory ossicles

14

the amount of bones in the face

Nasal bones

these 2 bones are the upper part of the bridge of the nose

Zygomatic bones (or cheekbones)

these 2 bones articulate with the frontal bone (forehead)

Maxillary bones (maxilla, maxillae)

these 2 bones form most of the upper jaw

Palatine bones

these 2 bones form the anterior (front) part of the hard palate of the mouth, and the floor of the nose

Lacrimal bones

these 2 bones make up part of the orbit at the inner angle

Inferior conchae

these 2 bones are thin, scroll-like bones that form part of the interior of the nose

Vomer bone

this bone forms the base for the nasal septum

Mandible (or jawbone)

the only movable skull bone; attached to the skull at the TMJ

Nasal septum

cartilage wall that divides the two nasal cavities

Temporomandibular joint

also known as TMJ, is a dental arch that is formed at the back of the mouth where the maxillary and mandibular arches come together

Thoracic cavity (rib cage)

the bony structure that protects the heart and lungs; consists of the ribs, sternum, and upper portion of the spinal column extending from the neck to the diaphragm, but not including the arms

Ribs (or costals)

12 pairs; attach posteriorly to the thoracic vertebrae

True ribs

the first 7 pairs of ribs, attach anteriorly to the sternum

False ribs

the next 3 pairs of ribs, attach anteriorly to cartilage that connects them to the sternum

Floating ribs

the last 2 pairs of ribs, only attached posteriorly to the vertebrae

The sternum (or breast bone)

a flat dagger-shaped bone in the middle of the chest; by joining with the ribs, it forms the front of the rib cage

Manubrium

bony structure that forms the upper portion of the sternum

Body of the sternum (gladiolus)

bony structure that forms the middle portion of the sternum

Xiphoid process

structure made of cartilage that forms the lower portion of the sternum; comes from the greek word for a straight sword

Shoulders form the …

pectoral girdle

Pectoral girdle (or shoulder girdle)

supports the arms and hands

girdle

a structure that encircles the body

Clavicle

a slender bone that connects the manubrium of the sternum to the scapula; aka collar bone

Scapula

shoulder blade

Acromion

an extension of the scapula that forms the high point of the shoulder

Humerus

the bone of the upper arm

Radius

the smaller & shorter bone in the forearm; runs up the thumb side of the forearm

Ulna

the larger & longer bone of the forearm

Olecranon process

a large projection on the upper end of the ulna; forms the point of the elbow & exposes a nerve that tingles when struck

Funny bone

Olecranon process

Carpals

the 8 bones that form the wrist; they form a narrow bony passage known as the ____ tunnel

Carpal tunnel

A narrow bony passage formed by carpals; the median nerve & the tendons of the fingers pass through this tunnel to reach the hands

Metacarpals

the 5 bones that form the palms (one in each finger)

Phalanges

the 14 bones of the fingers

(also the name of the bones of the toes)

The amount of bones in each of the 4 fingers

3 bones - proximal, middle, and distal phalanges

The amount of bones in the thumb

2 bones - distal and proximal phalanges

Distal phalanx

The outermost phalanx from the hand

Middle phalanx

between the distal and proximal phalanges

Proximal phalanx

the phalanx nearest to the hand