Mod 2: Lecture 3 - Arm, Elbow and Cubital Region Flashcards
1
Q
Cubital means
A
elbow
2
Q
Distal Humerus
A
- Condyles: articulating surfaces
- — Capitulum: articulates with the radius
- — Trochlea: articulates with the ulna
- Epicondyles
- — Two: Medial and Lateral
- — primarily sites of muscle attachment
- Fossae
- — Three: radial, coronoid, olecranon
3
Q
Radius and Ulna
- proximal ends
- distal ends
A
- both articulate with the distal humerus
- ulna is longer proximally
- end of ulna is much bigger, has a hook
- end of radius is a flat little cap
- both articulate with the distal humerus
- radius is longer distally
- radius has a slanted triangular end
- ulna has a little bumpy end
- radius is longer distally
4
Q
Radius and Ulna
- rotation
- joined by
A
- radius rotates around the ulna
- — supination and pronation
- radius rotates around the ulna
- they are joined by interosseus membrane
- — syndesmosis joint
- proximal and distal radial-ulnar joints
- they are joined by interosseus membrane
5
Q
Features of the Radius
A
- Head: little flat cap
- Neck: short, skinny area under the head
- Radial Tuberosity: bump right under the neck, site of biceps attachment
- Shaft of Radius
- Styloid Process: the tip of the triangular distal end, pointed projection
- Ulnar notch: the tip of the other side of the distal radius, where the radius meets the ulna
6
Q
Features of the Ulna
A
- Olecranon Process
- Trochlear (Semilunar) Notch
- Coronoid Process
- Tuberosity
- Radial Notch
- Shaft of Ulna
- Head of Ulna
- Styloid Process
7
Q
Features of the Ulna:
- Olecranon Process
- Trochlear Notch
- Coronoid Process
A
- the superior tip of the hook at the proximal end
- the inside curve of the hook, where the ulna joins the trochlea of the humerus
- the inferior tip of the hook at the proximal end
8
Q
Features of the Ulna:
- Tuberosity
- Radial Notch
A
- a bump a little below the hook on the same side as it, site of attachment for the brachialis muscle
- bump on the lateral side (in anatomical position), right underneath the hook, where the radius meets the ulna on the proximal ends
9
Q
Features of the Ulna:
- Shaft
- Head
- Styloid Process
A
- the long middle part
- the distal end
- the little pointy bump off of the distal end
10
Q
Articulations
A
- Three which share a joint capsule
- — Humeroulnar
- — Humeroradial
- — Proximal Radioulnar
- Distal Radioulnar
11
Q
- Humeroulnar Joint
- Humeroradial Joint
- Proximal Radioulnar
A
- these three share a joint capsule
1. - Hinge - Flexion/Extension of the elbow
- medial side
2. - Modified hinge - flexion/extension
- supination/pronation - some spinning of radial head
- lateral side
3. - Pivot - supination/pronation
- between the radius and ulna on the proximal ends
12
Q
Distal Radioulnar
A
- Pivot
- supination/pronation
- between the radius and ulna on the distal ends
13
Q
Arthrokinematics of the Elbow
- In extension…
- In flexion…
A
- the olecranon process is in close approximation to the distal humerus in the olecranon fossa
- the olecranon process pulls away from the distal humerus, as the coronoid process and radius approach their respective fossae
- – the radius and coronoid process get closer to the the humerus
14
Q
Arthrokinematics: supination/pronation
A
- Supination occurs as the radial head spins on the capitulum of the humerus
- the radius rotates around the ulna
- the radius is the only bone that moves, the ulna is fixed
- includes these joints:
- — humeroradial
- — proximal and distal radioulnar
15
Q
Supporting Structures: Elbow Region - Annular Ligament
A
- Encircles the head of the radius
- — forms 4/5 of a circle
- — the radial notch of the ulna forms the other 1/5
- Attaches to the margins of the radial notch
- Holds the head of the radius against the ulna
- Protects against the distal dislocation of the radius
- — holds the radius up so it stays in its place at the joint
- — distal dislocation is down toward the wrist
- Stabilizes the proximal radioulnar joint
- — holds the radius to the ulna