Download notes on App Skeleton

Lesser tubercle of the humerus - is a smaller raised, roughened area anterior to the to the greater tubercle and
separated from it by a groove.
Intertubercular groove of the humerus - the groove between the greater and lesser tubercles (where the Biceps
brachii muscle's tendon lies).
Deltoid tuberosity of the humerus - warning, students often get confused on this one because it is hard to
locate. This marking is a very low, slightly raised area with a slightly rougher texture. It is on the lateral surface
of the humerus about 1/3 of the way from the proximal to the distal end. It is V-shaped, with the point of the V
being distal.
Capitulum of the humerus - warning, students often get confused between the capitulum and the trochlea. The
capitulum is the distal, lateral condyle where the radius articulates. It is ball-shaped (on most humeruses) which
allows the radius to rotate around it. It can be seen only on the anterior surface.
Trochlea of the humerus - this part is named for and shaped like a pulley. It is all of the joint surface medial to
the capitulum. It is visible on both the anterior and posterior surfaces
Medial epicondyle of the humerus - the capitulum and trochlea
are both condyles (smooth, rounded joint surfaces). The two
epicondyles are named for being superficial to them (like the
epidermis of the skin is superficial to the dermis). The medial
epicondyle is the large, irregular projection near the trochlea on
the medial (head-side) of the bone.
Lateral epicondyle of the humerus - this much smaller,
irregular, projection is near the capitulum on the lateral (greater
tubercle-side) of the bone. Feel the two epicondyles on your
arm. The forearm muscles attach to them.
Radius:
Orientation: the head and neck are
triangular end is distal and joins
proximal; the broadened
with two of the carpals.
Head of the radius - this
than spherical. The proximal
rounded capitulum while the lateral
to rotate against the ulna with
projection is disc-shaped, rather
surface is concave to receive the
circular surface allows the radius
stability.
Neck of the radius - this narrowing
is both an anatomical and surgical
off here.
of the bone is a typical neck. It
neck since the head often snaps
Radial tuberosity - this large
muscle attachment (Biceps brachii).
roughened area is a site of
Styloid process of the radius - a
instrument. The styloid process is a
distal end of the bone.
stylus is a pointed writing
pointed projection from the
Ulna:
Orientation: the larger end is proximal and the narrower end is distal. The large
C-shaped notch is anterior.
Trochlear notch of the ulna - is the scientific name for the large C-shaped
notch. It is named for the trochlea of the humerus with which it articulates.
Olecranon process of the ulna - this roughened area is what we would
commonly call the "elbow". It is on the posterior surface of the bone, opposite
the troclear notch. A large muscle attaches to it (Triceps brachii).
Styloid process of the ulna - is similar in shape and position to the styloid
process of the radius.
HAND: The bones of the hand should be learned only on a complete hand.
Orientation: the carpals are proximal and the phalanges are distal. The thumb is lateral. The anterior surface
(palm-forward in the anatomical position) can be identified by the "hook" found on one of the carpals (hamate).
Carpals: these bones can best be learned as forming two (proximal and distal) rows of four bones each. These
bones are in the wrist region, more than the palm region. Here, they are arranged in lateral to medial order.
Scaphoid - the largest and lateral bone of the
proximal row.
Lunate - the second bone from the lateral side in the
proximal row; named for being moon-shaped (lunar)
when cut in a certain orientation.
Triquetral - the third bone in the proximal row;
named for being approximately triangular in shape.
Pisiform - this small round bone is the fourth bone
in the proximal row. It is named for being round,
small and somewhat pea-shaped.
Trapezium - the bones of the distal row articulate
with the metacarpals; the trapezium is the lateral
bone in the distal row. It articulates with the thumb
metacarpal; its name refers to its four-sided
trapezoid-like shape. You may get it mixed up with
the next metacarpal (trapezoid). Note that the trapezium is associated with the thumb.
Trapezoid - the second bone of the distal row; It is named for a trapezoid-like shape as is the trapezium. Note
that trapezoid ends with a d, like second.
Capitate - the third bone of the distal row is large. It is associated with the middle or third metacarpal. It
commands a position at the middle center of a squad of carpals, like a captain.
Hamate - the easiest bone to recognize; It is the one with the
"hook" on its anterior surface. Perhaps the hook makes it look
like a ham bone
.
Metacarpals:
Metacarpals I to V the carpals and distally to
named with Roman
(thumb-side) to the
make up the palm of the
knuckles when you make
these bones are attached proximally to
the phalanges. They are individually
numerals I to V from the lateral
medial (little finger-side). These bones
hand. Their distal ends form the
a fist.
Phalanges:
Proximal phalanges found in the fingers. Any
thumb has only two and
They are individually
the metacarpals) and the
The proximal phalanges
the phalanges are the 14 little bones
one of them is called a phalanx. The
all the rest of the fingers have three.
identified with a Roman numeral (like
designation proximal, middle or distal.
articulate with the metacarpals.
Middle phalanges - this
one is absent from the thumb.
Distal phalanges - these
of the fingers.
small phalanges are found in the tips
LEG:
Femur:
Orientation: the head is proximal and medial; the rounded, distal condyles are curved back and are more visible
from the posterior.
Head of the femur - is the obvious rounded projection.
Neck of the femur - is the well-defined narrow region next to the head of
the femur.
Greater trochanter of the femur - is the large,roughened area lateral to
the head where a muscle attaches (gluteus medius).
Lesser trochanter of the femur - is a much smaller projection distal to
the head on the medial side of the bone. It is also a point of muscle
attachment.
Medial condyle of the femur - there are two rounded, smooth
condyles where the femur articulates with the tibia. The medial
one is on the head-side of the bone.
Lateral condyle of the femur - is on the greater trochanter side
of the bone.
Linea aspera of the femur part of the femur for students
low, narrow, curved ridge
femur. Several muscles
means line like a snake (asp).
warning, this is often the hardest
to find. It can be described as a
along the posterior surface of the
(adductors) attach to it. It name
Tibia:
Orientation: the larger end of this bone, with the flattened, table-like surface is proximal. The narrower end is
distal. The anterior surface can be identified by a roughened tuberosity (tibial tuberosity) found near the superior
end. The medial side can be identified by a prominent projection on the distal end (medial malleolus).
Tibial tuberosity of the tibia - is the prominent, anterior, roughened bump
just distal to the knee joint. The Quadriceps femoris muscle attaches here.
Medial malleolus of the tibia - is the projection on the distal end of the tibia.
Warning, students often get this part mixed up with the distal end of the fibula
which has a similar name: lateral malleolus. Perhaps it will be useful to you to
remember that the tibia is the medial bone of the lower leg and it has the
medial malleolus, while the lateral bone, the fibula, has the lateral malleolus.
The two malleoli make up the medial and lateral bony projections at the ankle
joint.
Medial condyle of the tibia - the two condyles of the tibia are
not the typical, rounded shape. Instead, they are slightly
depressions on the flat proximal surface of the tibia where the
femur's condyles articulate. The medial one is on the same side
as the distal projection (medial malleolus).
Lateral condyle of the tibia - this second condyle is the lateral
depression.
Fibula:
Orientation: warning, students often get the parts of the fibula mixed up because they do not know how to orient
the proximal and distal ends of the fibula. If you look carefully at the two ends of the bone, the distal end has a
distinct notch, through which a tendon passes to the foot. The notch is on the distal end (near the foot).
Head of the fibula - the proximal end where the fibula attaches to the lateral
surface of the tibia. Note that this end is not involved in the knee joint.
Lateral malleolus of the fibula the distal end of the fibula; the
part with the notch; the lateral
ankle bump. This part is often
snapped off in ankle injuries.
Patella:
Orientation: this basically rounded bone has a slightly triangular shape. The pointed end is distal. The smooth,
slightly-depressed, flat surfaces are posterior. We will learn no parts on this bone.
FOOT:
Orientation: the tarsals are proximal and the phalanges are distal. The big toe is medial (unlike the lateral
thumb). The superior surface of the foot can be identified because it is "arched" upward.
Tarsals:
Talus - is the most proximal tarsal bone. It has a smooth,
rounded joint surface that articulates with the tibia.
Calcaneus - this is the largest, most posterior tarsal, the
one that forms the heel. The Achilles tendon attaches to
this bone
Navicular - is another boat-shaped bone like the carpal of
the same name. It is on the medial surface of the foot, just
distal to the talus.
Cuboid - is a bone that is roughly cube shaped. It lies
lateral to the navicular.
Cuneiforms first, second and third - are three small
stick-like bones. They articulate with the proximal
phalanges of the medial three toes. Their identifying
numbers increase from medial to lateral like the
metatarsals, but don't get their first, second, third
designation mixed up with the I, II, III naming of the
metatarsals.
Metatarsals:
Metatarsals I to V - warning, these bones are numbered differently from the metacarpals. The big toe side
(medial) is I and the little toe side is V (lateral). These bones form the anterior part of the arch of the foot.
Phalanges:
Proximal phalanges - as in the hand, the foot has 14 phalanges. Again, they are individually identified with a
Roman numeral (I-V) and the designations proximal, middle or distal. The proximal phalanges articulate with the
metatarsals.
Middle phalanges - this one is absent from the big toe.
Distal phalanges - these small phalanges are found in the tips of the toes.
PECTORAL GIRDLE:
Clavicle:
Orientation: Warning, students frequently confuse the two ends of the clavicle. The medial end is thicker and
more circular in cross section while the lateral end is thinner and flatter. To help you remember this, it may help
to relate it to the bones with which the clavicle joins. The medial end joins to the thicker sternum and the lateral
end articulates with the thin acromion process of the scapula.
Sternal end of the clavicle - is the thicker, rounder,
medial end which attaches to the sternum.
Acromial end of the clavicle - is the thinner, flatter,
lateral end which attaches to the acromion process of
the scapula.
Scapula:
Orientation: Warning, this bone is one of the most complex. Getting it properly oriented is the key to finding and
learning its parts. To start off, find the joint surface where the humerus joins to the scapula. This surface (the
glenoid cavity) must be lateral since it joins to the arm. Second, note that the scapula is roughly triangular. The
longer pointed part is inferior. The concave (dished in) surface of the scapula is anterior. Now, determine if the
scapula you have fits better as a right or left.
Glenoid cavity of the scapula - is a lateral, shallow fossa which
articulates with the head of the humerus
Spine of the scapula - is on the posterior surface of the scapula.
It is a large ridge of bone which is oriented in a medial to lateral
direction. It divides the posterior surface into upper and lower
compartments.
Acromion process of the scapula - warning, students often
confuse the two large processes on the surface of the scapula, the
acromion and coracoid processes. The acromion process is the
more superior, flatter one that attaches to the clavicle. It is
attached to the scapula through the spine of the scapula. In
common language, the acromion process makes up the
"shoulder", as when we carry something heavy on our shoulder.
Coracoid process of the scapula - is the more anterior, rounder process that attaches to several muscles
(including Biceps brachii). It is attached to the scapula near the glenoid cavity.
Supraspinous fossa of the scapula - is the large depression on
the posterior surface of the scapula superior to the spine of the
scapula. It contains a large scapular muscle (supraspinatus).
Infraspinous fossa of the scapula - is the large depression on
the posterior surface of the scapula inferior to the spine of the
scapula. It contains another large scapular muscle
(infraspinatus).
Subscapular fossa of the scapula - warning, students often have
trouble locating this fossa. Note that the anterior surface of the
scapula (next to the ribs) is concave. This large depression on
the entire anterior surface makes up the subscapular fossa. The
name "subscapular" means "below" or "deep to" the scapula (as a
subcutaneous injection is deep to the surface of the skin).
PELVIC GIRDLE:
Os coxa:
Orientation: Warning, this bone is also very complex. Getting it properly oriented is the key to finding and
learning its parts. First, find the large cup-shaped joint cavity (acetabulum) which accepts the head of the femur.
This region must be oriented laterally. Look at this cavity from the side and note two large masses of bone
projecting out from it. The solid bone mass is superior and the mass with a massive hole (obturator foramen) is
inferior.
Acetabulum of the os coxa - the large cavity for the joint with
the femur. It may help you to remember its spelling to know that
the name means "vinegar cup", and that acetic acid is the main
chemical in vinegar.
Obturator foramen of the os coxa - the large hole through the
inferior portion of the os coxa. In the body this hole is obscured
by a connective tissue membrane, through which nerves and
blood vessels pass. "Obscure" may help you remember the
unfamiliar term "obturator".
Three bones making up the immature os coxa: In a child the developing os coxa is made up if three separate
bones which join at the center of the acetabulum. These three bones are used in naming the parts of the os coxa,
so we will look at their names and locations now.
Ilium - the bone making up the superior part of the os coxa.
Pubis - the bone making up the inferior, anterior part of the os
coxa. (Near the pubic region.)
Ischium - the bone making up the inferior, posterior part of the
os coxa. (Near the "ishy" region.)
Iliac crest of the os coxa - the superior edge of the ilium is
called the iliac crest.
Greater sciatic notch of the os coxa - this large indentation in
the posterior part of the ilium allows the large sciatic nerve to
exit the pelvic cavity to pass down the back of the leg.
Ischial spine of the os coxa - this sharp point on the superior
and posterior part of the ischium is a site of muscle attachment.
Ischial tuberosity of the os coxa - this large roughened area on
the posterior and inferior surface of the ischium is a site of
attachment for muscles of the hamstring group. We sit on the
ischial tuberosities.
Pelvis:
Definition: The word "pelvis" means basin. It is a compound structure made up of the right os coxae, left os
coxae, sacrum and coccyx. It surrounds the pelvic cavity and forms the floor of the abdominal cavity. Note that
this basin of bones consists of part of the axial skeleton (sacrum and coccyx) and part of the appendicular skeleton
(os coxae).
Orientation: You will be expected to know the following parts only on a complete pelvis. The pelvis sits on a
table in a fairly anatomical position, resting on the ischial tuberosities and coccyx. The iliac crests are superior
and the pubic bones are anterior.
Pubic symphysis pubic bones of the
is the anterior joint on the midline where the
right and left os coxae make a strong joint.
Sacroiliac joints joined to the ilia
These are two of
the strongest joints
of the body, since
they must support
the whole weight of
the upper body.
are the two strong joints where the sacrum is
(plural of ilium) of the right and left coxae.
True pelvis - is the smaller, completely-enclosed cavity within the
pelvis.
False pelvis - is the larger, incompletely enclosed cavity between the upper parts of the ilia. This basin is
incomplete because it lacks an anterior wall. It sits on top of the true pelvis.
Pelvic brim - is the superior rim of the true pelvis. The rim
includes the superior edge of the sacrum and a ridge that passes
through the ilium and pubis around to the pubic symphysis.
Pelvic inlet - is the superior opening into the true pelvis. It is
bounded at its edge by the pelvic brim.