The appendicular skeleton consists of the bones that make up the upper and lower limbs, including the shoulder girdle, arm, leg, and pelvic girdle. It is comprised of the scapula, clavicle, humerus, radius, ulna, carpals, metacarpals, phalanges, femur, patella, tibia, fibula, tarsals, metatarsals, and phalanges. The document provides details on key features and anatomical positioning of many of these bones to aid in identification.

1. The Appendicular skeleton

3. The appendicular skeleton
consists of
Arm + Shoulder
Leg + Pelvic Girdle
Girdle
• Scapula • Os Coxa
• Clavicle • Femur
• Humerus • Patella
• Radius • Tibia
• Ulna • Fibula
• Carpals • Tarsals
• Metacarpals • Metatarsals
• Phalanges • Phalanges

4. Your body is your cheat
sheet.
To remember what whole bones look like, think about where they are,
and what they do – how they move.
Let’s start with some simple examples.

5. What’s This?

6. What’s This?
Cranial or postcranial?
Axial or appendicular?

7. Humerus
• Where is it? Upper arm
(anatomically, the arm; the
lower part is the forearm)
• What does it do? It
rotates at the shoulder, and
it flexes at the elbow.
• You now know everything
you need to know to orient
and side the intact
humerus.

8. Humerus
• The shoulder is a highly
mobile joint, so logically its
anatomy must permit free
movement.
• The elbow’s motion is more
restricted. It’s a hinge, with
a limited range of
motion, so its anatomy is
consistent of that.
• This enables you to
distinguish proximal from
distal.

9. Terminology
• The humerus is a long bone. It
has a shaft, called a
diaphysis, and two ends, called
epiphyses.
• The proximal end is smooth
bone that’s rounded, like a ball.
This is called a head.
• The distal end has rounded
projections of smooth bone
where the humerus articulates
with other bones. These areas
of articulation are called
condyles.
• Projections of bone next to
condyles are called
epicondyles.

10. HUMERUS
• The head is proximal and
medial.
• The condyles are
distal, and the rounded one
(called the capitulum) is
lateral.
• The epicondyles are distal
and the medial epicondyle
is bigger than the lateral
epicondyle.
• Now you can tell proximal
from distal and medial from
lateral.

11. humerus
• The proximal humerus has
two rough projections
below the head anteriorly.
These are called tubercles
(the greater and lesser).
• The distal humerus has
depressions on the anterior
and posterior surfaces. A
depression on bone is
called a fossa. There are
two shallow ones
anteriorly, and one deep
one posteriorly.

12. Humerus
• Head is proximal and
medial.
• Tubercles are proximal and
anterior.
• Condyles are distal and
project more anteriorly.
• The olecranon fossa is deep
and posterior, and there’s
only one of it.
• The coronoid and radial
fossae are shallow, and
there are two of them.

13. What are these?
Cranial or postcranial?
Axial or appendicular?

14. RADIUS AND ULNA
• Where are they? The
radius and ulna are the
bones of the forearm.
• What do they do? They
flex at the elbow and they
pivot right below it.
• This tells you what you
need to know to distinguish
the radius from the
ulna, and how to side
them.

15. RADIUS and ulna
• The ulna is the medial
bone of your forearm.
When you bend your
forearm, you’re using your
ulna.
• The radius is the lateral
bone of your forearm.
When you pronate or
supinate your
forearm, you’re using your
radius.

16. Radius and ulna
• Remember, medial and
lateral refers to being
toward or away from the
midline in standard
anatomical position.
• So when we say “the
radius is lateral,” we mean
that it’s on the lateral side
of the forearm when the
skeleton is in standard
anatomical position.

17. Radius and ulna
• Another way to remember
the position of the bones is
that the radius is on the
thumb side of your forearm.
• When you rotate your
forearm, your thumb
moves. That’s your radius
rotating around your ulna.
The ulna stays still, the
radius moves around it.

18. RADIUS AND ULNA
RADIUS ULNA
• Round head proximally • Olecranon process (hook
for the elbow) proximal and
• Major articulation with concave anteriorly
wrist distally (large
concavity) • Makes minimal
articulation with wrist
• Ulnar notch is medial and distally (small head with
distal styloid process)
• Distal end: concave • Radial notch is lateral and
anteriorly, small tubercles proximal
posteriorly

19. The hand
• The hand consists of
carpals (the wrist),
metacarpals (the palm),
and phalanges (the
fingers).
• We’ll skip the hand for now
and talk about it in the
Anthropology section.

20. Clavicle and scapula

21. Clavicle
• Where is it? Anterior part of
the pectoral girdle.
• What does it do? Stabilizes
shoulder joint.
• smoother superiorly than
inferiorly
• thick and rounded medially
• broad and flat laterally
• anterior surface is convex
medially and concave
laterally. (You can feel this
on yourself.)

22. Scapula
• Where is it? The
shoulderblade.
• What does it do?
Articulation between
humerus and torso.
• Point of triangle is inferior
• Concave surface is anterior
• Spine is posterior and
superior
• Fossa for articulation with
head of humerus is lateral

23. What’s this?

24. femur
• Where is it? The thigh.
• What does it do? Mobile
hip joint proximally, flexes
at knee distally.
• Head and neck proximal
and medial.
• Trochanters proximal and
lateral/posterior.
• Condyles and
epicondyles distal.

25. Patella
• Where is it? The
kneecap.
• What does it do?
Improves functionality of
knee joint.
• Anatomical siding: anterior
surface is rough.
Superior/proximal surface
is flat (you can feel this on
yourself). Lateral facet is
the larger.
• Siding trick: put on table
with rough surface up and
point away from you. It
falls to the side it’s from.

26. Tibia
• Where is it? Large bone
of the lower leg.
• What does it do? Flexes
at the knee proximally and
at the ankle distally.
• On the medial side of the
lower leg.
• Two flat condyles
proximally. The medial is
longer.
• Tuberosity anteriorly.

27. Tibia
• The medial face of the
anterior shaft is convex
and lies close to the skin
(you can feel it on
yourself).
• The lateral face of the
anterior shaft is concave
(you feel muscle on
yourself when you touch
there).
• The distal end has an
articulation for the fibula
laterally and a malleolus
(large bone projection)
medially.

28. Fibula
• Where is it? Smaller bone
of the lower leg.
• What does it do?
Stabilizes the lower leg and
ankle.
• The fibula shaft is complex,
so we’ll avoid the detail on
that for now.
• To side, hold it with either
end up with the articular
facet towards you. The
facet is on the side the
bone is from.

29. Foot
• The foot consists of tarsals
(ankle), metatarsals
(arch), and phalanges
(toes).
• It’s complex, so we’ll talk
about it in detail in the
anthropology section.

30. Os Coxa
• The two os
coxae, combined with the
sacrum, make up the
pelvis.
• The os coxa consists of
three parts, which start out
as individual bones: the
ilium, the ischium, and the
pubis.
• The pubis is anterior. The
ilium is superior. The
ischium is inferior.

31. Os Coxa
• On the anterior os
coxa, there’s a large hole.
A hole in bone is called a
foramen. This particular
one is called the obturator
foramen.
• One more word to learn:
ramus. The obturator
foramen is bordered by the
iliopubic and ischiopubic
rami. (Rami is plural of
ramus).

32. Os Coxa
• The ilium is large, flat, and
curved. It makes up the
crest of your hip.
• The ischium is
smaller, thick, and very
dense. Its inferior margin
is marked by ischial
tuberosities. You sit on
them.
• The pubis is relatively
gracile, and it’s anterior.

33. Os Coxa
• Iliac crest is superior
• Sciatic notch is posterior
and inferior
• Auricular surface
(articulates with sacrum) is
posterior and medial
• Acetabulum (articulates
with femur) is lateral and
opens anteriorly.

34. What to remember
• Know the names of the
bones.
• Know where they are, and
what they do. That will
enable you to side them.
• How a bone moves is the
biggest help to identifying it
when you’re new to
osteology.

35. REVIEW

36. REVIEW

37. FINIS
Next: the axial skeleton.