Bones can be classified according to their shapes. Long bones, such as the femur, are longer than they are wide. Short bones, such as the carpals, are approximately equal in length, width, and thickness. Flat bones are thin, but are often curved, such as the ribs. Irregular bones such as those of the face have no characteristic shape. Sesamoid bones, such as the patellae, are small and round, and are located in tendons.
flat bone
thin and curved bone; serves as a point of attachment for muscles and protects internal organs
irregular bone
bone of complex shape; protects internal organs from compressive forces
long bone
cylinder-shaped bone that is longer than it is wide; functions as a lever
sesamoid bone
small, round bone embedded in a tendon; protects the tendon from compressive forces
short bone
cube-shaped bone that is approximately equal in length, width, and thickness; provides limited motion
1. Most of the bones of the arms and hands are long bones; however, the bones in the wrist are categorized as ________.
A) flat bones
B) short bones
C) sesamoid bones
D) irregular bones
B
2. Sesamoid bones are found embedded in ________.
A) joints
B) muscles
C) ligaments
D) tendons
D
3. Bones that surround the spinal cord are classified as ________ bones.
A) irregular
B) sesamoid
C) flat
D) short
A
4. Which category of bone is among the most numerous in the skeleton?
A) long bone
B) sesamoid bone
C) short bone
D) flat bone
A
5. Long bones enable body movement by acting as a ________.
A) counterweight
B) resistive force
C) lever
D) fulcrum
C
1. What are the structural and functional differences between a tarsal and a metatarsal?
Structurally, a tarsal is a short bone, meaning its length, width, and thickness are about equal, while a metatarsal is a long bone whose length is greater than its width. Functionally, the tarsal provides limited motion, while the metatarsal acts as a lever.
2. What are the structural and functional differences between the femur and the patella?
Structurally, the femur is a long bone, meaning its length is greater than its width, while the patella, a sesamoid bone, is small and round. Functionally, the femur acts as a lever, while the patella protects the patellar tendon from compressive forces.