in this ppt you will know more about the bones that form the upper limb

1. Dr. Hoda Hassan
Ass. prof. of anatomy & embryology

2. • Ulna
site
general features
special features
• Radius
site
general features
special features

3. Ulna

4. Ulna
Medial Bone of the forearm
Long bone
Formed of:
Upper end
Lower end
Shaft

5. Upper end:
The upper end of the ulna is much larger than the upper end of the
radius
Consists of:
the olecranon, the coronoid processes,
the trochlear notch, the radial notch,
ulnar tuberosity

6. Olecranon process:
is a large projection of bone.
Its anterior surface is articular and contributes to the formation of the trochlear
notch, which articulates with the trochlea of the humerus.
The superior surface is marked by a large roughened impression for the attachment
of the triceps brachii muscle.
The posterior surface is smooth, shaped somewhat triangularly, and can be palpated
as the 'tip of the elbow

7. The coronoid process projects anteriorly from the proximal end of the ulna. Its superior
surface is articular and participates, with the olecranon, in forming the trochlear notch.
The lateral surface is marked by the radial notch for articulation with the head of the radius
Just inferior to the radial notch is a supinator fossa. The posterior margin of this fossa is
broadened to form the supinator crest
The anterior surface of the coronoid process is triangular, with the apex directed distally, and
has a number of roughening's for muscle attachment. The largest of these roughening's, the
tuberosity of ulna, is at the apex of the anterior surface and is the attachment site for the
brachialis muscle

8. Shaft
broad superiorly where it is continuous with the
large proximal end and narrow distally to form a
small distal head
Triangular
Has 3 borders: (interosseous, anterior, posterior)
The anterior border is smooth and rounded.
The posterior border is sharp and palpable along
its entire length.
The interosseous border is also sharp and is the
attachment site for the interosseous membrane,
which joins the ulna to the radius.

9. 3 surfaces: (anterior, medial, posterior)
The anterior surface of the ulna is smooth,
except distally where there is a prominent
linear roughening for the attachment of the
pronator quadratus muscle.
The medial surface is smooth.
The posterior surface is marked by lines,
which separate different regions of muscle
attachments to bone

10. Lower end:
The distal end of the ulna is small and
characterized by a rounded head and the
ulnar styloid process.
1. Head
The anterolateral and distal part of the head
is covered by articular cartilage.
It articulate with ulnar notch of the radius to
form inf radio-ulnar joint,
It does not articulate with carpal bones????
2. Styloid process
The ulnar styloid process originates from
the dorsomedial aspect of the ulna and
projects distally.
Separated from head by a groove

11. How to identify the side of the ulna
• Upper end is larger
• Trochlear notch directed
anteriorly
• Radial notch directed
laterally

12. Ossification
• Cartilaginous
• 4 centers
• Primary center in middle of shaft appears in 8th
week of intrauterine life
• One in head (lower end), one for tip of
olecranon, and one for trochlea
• The lower end of ulna is the growing end of the
bone (complete ossification and join the shaft at
17 years in female and 18years in male

13. Special features

14. Upper end:
Coronoid process
Ant surface including the ulnar
tuberosity: brachialis I
Medial border: flexor digitorum
superficialis & pronator teres O

15. Olecranon process
Post part of superior surface: Triceps I
Lateral surface: anconeus I
Trochlear notch
Articulate with trochlea of humerus
Radial notch
Superior radio-ulnar joint
Supinator crest and fossa: supinator
muscle O

16. Shaft
Anterior surface:
Upper three-fourth of ant
and medial surfaces: flexor
digitorum profundus O
Lower one fourth: pronator
quadratus O
Posterior surface: O of 3
muscles
abductor pollicis longus
extensor pollicis longus
extensor indices
Interosseous border:
interosseous membrane

17. Posterior border
Flexor and extensor
carpi ulnaris O
Lower end
Head: Articulate with
ulnar notch of radius
Groove in the back of
head : tendon of
extensor carpi ulnaris

18. Radius

19. Radius
Lateral bone of the forearm
Long bone
Formed of:
Upper end
Lower end
Shaft

20. Upper end:
Smaller than lower end
Consists of a head, a neck and the radial tuberosity
The head of the radius is a thick disc-shaped structure. The superior surface is
concave for articulation with the capitulum of the humerus. The thick margin of the
disc is broad medially where it articulates with the radial notch on the proximal end
of the ulna
The Neck is a short and narrow cylinder of bone between the expanded head and
the radial tuberosity on the shaft
The radial tuberosity is a large blunt projection on the medial surface of the radius
immediately inferior to the neck. Much of its surface is roughened for the
attachment of the biceps brachii tendon

21. Shaft:
With lateral convexity,
increase in thickness from above
downwards
Throughout most of its length, the shaft of
the radius is triangular in cross-section,
with
Has 3 borders: interosseous, anterior
(upper part form the oblique line)
&posterior
3 surfaces: anterior, lateral, posterior

22. Lower end:
Is larger than upper end
Quadrilateral in cross section
Has 5 surfaces
1. Anterior
2. Posterior (has dorsal
tubercle)
3. Lateral (has styloid process)
4. Medial (has ulnar notch)
5. Inferior (divided by ridge
into lateral triangular and
medial quadrangular areas)

23. How to identify the side of the radius
• Head is upward
• Shaft convex laterally
• Interosseous border
medially
• Lower end showed dorsal
tubercle posteriorly

24. Ossification
• Cartilaginous
• 3 centers
• Primary center in middle of shaft appears in 8th
week of intrauterine life
• One in lower end and one for head
• The lower end of radius is the growing end of the
bone (complete ossification and join the shaft at
17 years in female and 19 years in male

25. Special features

26. Upper end:
Head (upper articulation surface with capitulum, and articular
circumference with the ulnar notch)
Neck surround with annular ligament
Tuberosity: biceps I

27. Shaft
Oblique line: flexor digitorum
superficialis O
Upper third of ant., lateral
and post surface: supinator I
Middle of lat surface:
pronator teres I
Ant. surface:
flexor pollicis longus O,
pronator quadratus I
Interosseous border:
interosseous membrane

28. Posterior surface:
Supinator I
abductor pollicis longus O
extensor pollicis brevis O

29. Lower end
Anterior (smooth, related to flexor
tendons)
Posterior (related to extensor
tendons)
Lateral (brachioradialis I)
Medial (has ulnar notch)
Inferior (lateral triangular area
articulate with scaphoid and
medial quadrangular area
articulate with lunate)

30. • Ulna
site
general features
special features
• Radius
site
general features
special features