206 named bones

[image]

1. axial skeleton
2. appendicular skeleton

[image]

80 bones

they lie around the longitudinal axis of the human body

skull bones, auditory ossicles, hyoid bone, ribs, sternum, and bones of the vertebral column

[image]

126 bones

upper and lower limbs (extremities), bones forming the girdles that connect the limbs to the axial skeleton

[image]

1. long
2. short
3. flat
4. irregular
5. sesamoid

[image]

[image]

-develop in certain tendons where there is considerable friction, tension, and physical stress, such as the palms and soles
-may vary in number from person to person

-are not always completely
ossified

-typically measure only a few millimeters

-notable exceptions are the two patellae (kneecaps),
large sesamoid bones
-functionally, sesamoid bones protect tendons from excessive
wear and tear, and they often change the direction of pull of a
tendon, which improves the mechanical advantage at a joint 

 -have greater length than width, consist of a shaft and a variable number of extremities, and are slightly curved for strength
-A curved bone absorbs the stress of the body’s weight at several different points, so that it is evenly distributed

[image]

-somewhat cube-shaped and are nearly equal in length and width

-consist of spongy bone tissue except at the surface, which has a thin layer of compact bone tissue.
Examples: carpal (wrist) bones, and the tarsal (ankle) bones

-somewhat cube-shaped and are nearly equal in length and width 

-they consist of spongy bone tissue except at the surface, which has a thin layer of compact bone tissue
Examples of short bones are the carpal (wrist) bones (except for
the pisiform, which is a sesamoid bone) and the tarsal (ankle)
bones (except for the calcaneus or heel bone, which is an irregular
bone).

[image]