Skeletal System 7.5

skeletal organization

two major divisions of the skeletal system

axial skeleton and appendicular skeleton

condyle

rounded process that usually articulates with another bone

ex: occipital condyle of the occipital bone

crest

narrow, ridgelike projection

ex: iliac crest of the ilium

epicondyle

projection situated above a condyle

ex: medial epicondyle of the humerus

facet

small, nearly flat surface

costal facet of the thoracic vertbra

fontanel

soft spot in the skull where membranes cover the space between bones

ex: anterior fontanel between the frontal and parietal bones

foramen

opening through a bone that usually is a passageway for blood vessels, nerves, or ligaments

ex: foramen of the occipital bone

fossa

relatively deep pit or depression

ex: olecranon fossa of the humerus

fovea

tiny pit or depression

ex: fovea capitis of the humerus

head

enlargement on the end of a bone

ex: head of the humerus

meatus

tubelike passageway within a bone

external acoustic meatus of the temporal bone

process

prominent projection on a bone

ex: mastoid process of the temporal bone

sinus

cavity within a bone

ex: frontal sinus of the frontal bone

spine

thornlike projection

ex: spine of the scapula

sulcus

furrow or groove

ex: intertubercular sulcus of the humerus

suture

interlocking line of union between bones

ex: lambdoid suture between the occipital and parietal bones

trochanter

relatively large process

ex: greater trochanter of the femur

tubercle

small, knoblike process

ex: greater tubercle of the humerus

tuberosity

knoblike process usually larger than a tubercle

ex: radial tuberosity of the radius

axial skeleton

support and protect the organs of the head, neck, and trunk. includes:

1. skull (composed of the cranium and facial bones)

2. hyoid bone (supports tongue and located in neck between lower jaw and larynx)

3. vertebral column

   1. thoracic cage (12 pairs of ribs + sternum)

appendicular skeleton

bones of the upper and lower limbs + bones that anchor the limbs to the axial skeleton. includes:

1. pectoral girdle (formed by scapula and collarbone)

2. upper limbs (humerus, radius, ulna, carpals, metacarpals, phalanges)

3. pelvic girdle (hip bones, sacrum, coccyx)

4. lower limbs (femur, tibia, fibula, tarsals, metatarsal, phalanges)

how many vertebrae fuse to form the coccyx?

four

which bones compose a pectoral girdle?

clavicle, scapula