human anatomy & physiology! This time, I'm going

to continue where I left off in a previous

presentation in which I provided a shortcut to

learning the bones and bone features of the

vertebrate skeleton by focusing on the meaning

their names. In our previous episode, I advised that the

best

way—and the quickest way—to learn a long list of

specific skeletal features like those illustrated

here is to think of the human skeleton as having

geographic features like those on the surface of

the earth. If you know what a river is, then finding

a

specific river in a map or satellite image is not

that hard. You just ignore all the bumps and

holes and look only at the sharp, squiggly lines.

Likewise, in the skeleton if you know that a

foramen is a hole, then you can ignore the bumps

and depressions and only look at the holes until

you find the one you are looking for. And

knowing the meanings of these descriptive terms

also helps you remember these features more

easily. In this presentation, I'm going to very quickly

run through the meaning of each major descriptive

term used to describe various geographical

features of the skeleton. This is so that you

form a picture in your mind and can get started

learning skeletal features right away. Some skeletal features are the outer edges

or

boundaries of a bone. A straight edge or boundary

of a bone is called a BORDER. Here, we can see

the medial border and lateral border of the

scapula, or shoulder blade. An edge of a flat bone or flat area can

also be

called a MARGIN, as in the margins around the

socket or orbit of the eye. An ANGLE is an inside or outside corner along

the

boundary of a bone. A NOTCH is V-like "cut" out of the margin

or edge

of a flat area. It looks a little like a bite has

been taken out of the bone. The main or central portion of a bone is called

the BODY of the bone. As in the main part of the

lower jaw bone (the mandible) identified here.

In a long bone, the shaft portion is the also

called the body of the bone. The HEAD of a bone is a distinct epiphysis

(or

"endpiece") on a long bone, separated from the

shaft by a narrowed portion (or neck). The NECK is a narrowed portion of a bone,

usually

at the base of a head. The neck of the femur (or

thigh bone) can be seen here. The long bone of

the arm, the humerus, has an anatomical neck

where the head joins the body of the bone. 8 But

there is also a narrowing below that, where

fractures may occur, called the surgical neck. A ramus or ramus is a curved portion of a

bone,

like a ram's horn. Here, we see the part of the

lower jaw bone (the mandible) that curves upward.

The word ramus literally means "branch." We often identify features on the surface

of a

bone. A FACET or facet, for example, is a flat

surface that forms a joint with another facet or

flat bone. Facet literally means "little face."

A FOSSA is a depression. A fossa is often an

indentation that receives an articulating bone.

The word fossa literally means "ditch." An elongated depression or groove may be called

a

SULCUS. The word sulcus literally means

"trench." A CREST is a moderately raised ridge. It is

generally a site for muscle attachment. The term

crest literally means "tuft" or "comb." A LINE is similar to a crest but not raised

as

much. It is often rather faint, as in these lines

seen along the back of the femur and along the

side of the skull. A PROCESS is the general name for any bone

projection or significantly raised area. A sharp, pointed process may be called a SPINE

or

spinous process. A spine can be similar to a

crest but raised more. A spine is for muscle

attachment. Spine literally means "thorn." A CONDYLE is a rounded bump. It usually fits

into a fossa on another bone to form a joint.

Condyle literally means "knuckle." An EPICONDYLE is a bump near a condyle. An

epicondyle often gives the appearance of a "bump

on a bump." An epicondyle is usually for muscle

attachment, not for direct connection to another

bone. Epicondyle literally means "upon a

knuckle." A TROCHANTER is kind of like a huge epicondyle.

A trochanter is a very large bump for muscle

attachment. It is larger than either a tubercle

or tuberosity, both of which we'll look at in a

moment. Trochanter literally means "runner." A TUBEROSITY is an oblong, raised bump, usually

for muscle attachment. It may also be called a

tuber. A small tuberosity is called a tubercle. The

word part tuber literally means "bump" or "lump."

Here are a couple tubercles. A TUBERCLE is a

small tuberosity—that is, a small oblong bump.

Tubercle literally means "small bump" or "small

lump." A FORAMEN or foramen is a rounded hole for

vessels and nerves. The plural of foramen is

foramina. A MEATUS is like a foramen, but is more tube-

like, forming an elongated opening or channel.

The plural of meatus is same as the singular

form, meatus. Or you can say "meatuses." Meatus

literally means "passage." A long, crack-like hole—a kind of split

in the

bone—to allow blood vessels and nerves to pass

through is called a FISSURE. And lastly, one that you probably already

know.

A SINUS is cavity or hollow space within a bone,

such as any of the large sinuses found in some of

the skull bones. Where can you find a list of these skeletal

descriptive terms, their meanings, and examples

of each one? One source is my Survival Guide for

Anatomy & Physiology. You'll find a lot more

shortcuts there, too. Another place to look is

my online web guide to human anatomy and

physiology, where you can download a free list

of these terms. For more videos, shortcuts, tips, and practical

advice for learning human structure and function,

visit theAPstudent.org and sign up for the free

newsletter.