230
UNIT 2
Covering, Support, and Movement of the Body
7
respectively (Figure 7.27c and d). Te condyle pair is flanked by
the
medial
and
lateral epicondyles
(muscle attachment sites).
Directly above these epicondyles are the
medial
and
lateral su-
pracondylar ridges
. Te ulnar nerve, which runs behind the
medial epicondyle, is responsible for the painful, tingling sensa-
tion you experience when you hit your “funny bone.”
Superior to the trochlea on the anterior surface is the
coro-
noid fossa
; on the posterior surface is the deeper
olecranon
fossa
(o-lek
9
rah-non). Tese two depressions allow the corre-
sponding processes of the ulna to move freely when the elbow
is flexed and extended. A small
radial fossa
, lateral to the coro-
noid fossa, receives the head of the radius when the elbow is
flexed.
a tendon of the biceps muscle of the arm to its attachment point
at the rim of the glenoid cavity (the supraglenoid tubercle). Just
distal to the tubercles is the
surgical neck
, so named because it is
the most frequently fractured part of the humerus. About midway
down the sha± on its lateral side is the V-shaped
deltoid tuberos-
ity
, the roughened attachment site for the deltoid muscle of the
shoulder. Nearby, the
radial groove
runs obliquely down the pos-
terior aspect of the sha±, marking the course of the radial nerve, an
important nerve of the upper limb.
At the distal end of the humerus are two condyles: a medial
trochlea
(trok
9
le-ah; “pulley”), which looks like an hourglass
tipped on its side, and the lateral ball-like
capitulum
(kah-pit
9
u-
lum). Tese condyles articulate with the ulna and the radius,
Greater
tubercle
Lesser
tubercle
Inter-
tubercular
sulcus
Lateral
supracondylar
ridge
Radial
fossa
Capitulum
Head of
humerus
Anatomical
neck
Radial groove
Deltoid
tuberosity
Coronoid
fossa
Olecranon
fossa
Medial
epicondyle
Trochlea
Surgical
neck
Deltoid
tuberosity
Greater
tubercle
Lateral
epicondyle
Medial
supracondylar
ridge
(a) Anterior view
(b) Posterior view
Coronoid
fossa
Radius
Radial
tuberosity
Head of
radius
Capitulum
Trochlea
(c) Anterior view at the elbow region
Humerus
Medial
epicondyle
Coronoid
process of
ulna
Ulna
Radial notch
Olecranon
fossa
Ulna
Olecranon
Medial
epicondyle
(d) Posterior view of extended elbow
Humerus
Lateral
epicondyle
Head
Radius
Neck
Figure 7.27
The humerus of the right arm and detailed
views of articulation at the elbow.
(For a related image, see
A Brief Atlas of the Human Body
, Figure 25.)
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