Ulna Flashcards Preview

ESA 2- Musculoskeletal System > Ulna > Flashcards

Flashcards in Ulna Deck (50):
1

What is the ulna?

A long bone in the forearm

2

Where does the ulna lie?

Medially and parallel to the radius, and second of the forearm bones

3

What does the ulna act as?

The stabilising bone, with radius pivoting it to produce movement

4

What does the ulna articulate with?

Proximally, the humerus 
Distally, the radius

5

What is formed when the ulna articulates with the humerus?

The elbow joint

6

What is formed when the ulna articulates with the radius?

The distal radio-ulnar joint

7

What does the proximal portion of the ulna articulate with?

The trochlea of the humerus

8

What enables movement at the elbow joint?

The specialised structure of the ulna, with bony prominences for muscle attachment

9

What are the important landmarks of the proximal ulna?

The olecranon 
Coronoid process
Trochlear notch
Radial notch 
Tuberosity of ulna

10

What is the olecranon?

A large projection of bone

11

Where does the olecranon extend?

Proximally

12

What does the olecranon form?

Part of the trochlear notch

13

Where can the olecranon be palpated?

As the ‘tip’ of the elbow

14

What attaches to the olecranon?

The triceps brachii, at its superior surface

15

What is the coronoid process?

A ridge of bone that projects outwards in an anterior manner

16

What does the coronoid process form?

Part of the trochlear notch

17

What is the trochlear notch formed by?

Olecranon
Coronoid process

18

What shape is the trochlear notch?

Wrench shaped

19

What does the trochlear notch do?

Articulates with the trochlea of the humerus

20

Where is the radial notch located?

On the lateral surface of the trochlear notch

21

What does the radial notch do?

Articulates with the head of the radius

22

What is the tuberosity of the ulna?

A roughening immediately distal of the coronoid process

23

What is the purpose of the tuberosity of the ulna?

It is where the brachialis muscle attaches

24

What shape is the ulnar shaft?

Triangular

25

What does the ulnar shaft have?

Three borders and three surfaces

26

What happens as the ulnar shaft moves distally?

It decreases in width

27

What are the three surfaces of the ulnar shaft?

Anterior 
Posterior 
Medial

28

What is the importance of the anterior surface of the ulnar shaft?

It is the site of attachment for the pronator quadratus muscle distally

29

What is the importance of the posterior surface of the ulnar surface?

It is the site of attachment for many muscles

30

What are the three borders of the ulnar shaft?

Posterior
Interosseous 
Anterior

31

Where is the posterior border of the ulnar shaft palpable?

Along the entire length of the forearm posteriorly

32

What is the importance of the interosseous border of the ulnar shaft?

It is the site of attachment for the interosseous membrane

33

What does the interosseous membrane do?

Spans the distance between the two forearm bones

34

How does the distal portion of the ulna differ from the proximal end?

It is much smaller in diameter

35

How does the distal portion of the ulna terminate?

In a rounded head, with a distal projection

36

What is the distal projection on the rounded head of the ulnar called?

The ulnar styloid process

37

What does the ulnar head articulate with?

The ulnar notch of the radius

38

What is formed when the ulnar head articulates with the ulnar notch?

The distal radio-ulnar joint

39

How does a fracture of the ulnar alone usually occur?

As a result of the ulna being hit by an object

40

Where is the most likely site of ulnar fracture?

The shaft

41

What happens in a shaft fracture of the ulna?

The normal muscle tone will pull the proximal ulna posteriorly

42

What can less commonly be fractured in the ulna?

The olecranon process

43

What causes olecranon process fractures?

The patient falling on a flexed elbow

44

What happens when the olecranon process fractures?

The triceps brachii can displace part of the fragment proximally

45

How are the ulna and radius attached?

Interosseous membrane

46

What is the result of the interosseous membrane regarding fractures?

The force of trauma to one bone can be transmitted to the other via the membrane, and therefore fracture of both the forearm bones are not uncommon

47

What are the two classical fractures of both forearm bones?

Monteggia’s fracture
Galeazzi’s fracture

48

What causes Monteggia’s Fracture?

Force from behind the ulna

49

What happens in Monteggia’s Fracture?

The proximal shaft of the ulna is fractured, and the head of the radius dislocates anteriorly at the elbow

50

What is Galaezzi’s fracture?

A fracture to the distal radius, with the ulna head dislocating at the distal radio-ulnar joint