Copyright Goodheart-Willcox Co., Inc.
Chapter 2 The Skeletal System 37
Bone Processes and Depressions
Joints require processes and depressions in
bones. Bone processes are areas on bones that
extend outward and serve as attachment zones
for muscles and tendons (Figure 2.6). Important
processes include tubercules, trochanters, tuber-
osities, and condyles. A tubercule (TOO-ber-kuhl)
is a small round process found on many bones. A
trochanter is one of two large processes found on r
the femur, or thigh bone. A tuberosity (TOO-buh-
RAHS-ih-tee) is a large, rough process found on
many bones. A condyle (KAHN-DIGH-uhl) is a
rounded-knuckle process at a joint.
A bone depression is an opening or hollow
region in the surface of a bone at which one bone
articulates with another to form a joint (Figure 2.6).
Bone depressions also serve as passageways
for blood vessels and nerves. A commonly seen
depression is a fossa (FAHS-uh), a shallow pit or
cavity in or on a bone. A foramen (foh-RAY-men)
is a passageway for blood vessels and nerves.
A fi ssure fi (FIZH-yer) is a deep, narrow, slit-like
opening. A sulcus (suhl-kus) is a groove or fur-
row, and a sinus is a hollow cavity within a bone.
Axial Skeleton
The axial skeleton consists of the bones along
the axis, or central part, of the human skeleton.
The axial skeleton comprises the skull, thoracic
cage, and vertebral column (spine).
Bones of the Skull
The skull contains the cranial and facial bones.
The cranium is made up of bones that protect the
brain (Figure 2.7). The cranial bones attach to each
Trochanter
Tubercule T
Foramen
Fissure
Sulcus
Tuberosity
Fossa
Fossass Fo
Tubercule
Process
Condyle
Condyle
Femur
Skull
Humerus
Pelvis
Sinus s
Figure 2.6 Examples of bone processes and depressions in the femur, skull, humerus, and pelvis.
MATERIALS NEEDED: Six 8½″ × 11″ ″ sheets ″
of paper; tape; one paper plate; several coins
(any denomination), small rocks, wooden
blocks, paperweights, or stapler
Directions:
1. Roll up three sheets of paper (8½″ × 11″) ″
about 1 inch wide into a cylinder. Tape the
cylinder closed so that it doesn’t unroll. The
sheets of paper represent hollow bones.
2. Test the strength of the paper bones by
standing the “bones” on their ends and
placing a paper plate on top of the bones.
3. Add weight to the paper plate using rocks,
wooden blocks, coins, or household items
such as a stapler or paperweights.
4. Observe how much weight the hollow paper
bones can handle before they collapse.
5. Now roll up three more sheets of paper,
as tightly as you can, so that there is no
hollow section.
6. Repeat steps 2–4.
7. Record your observations. Then share
them with the class.