bones of the upper limbs and muscles of the arm Flashcards
between the rounded head of the
humerus and the shallow, pear-
shaped glenoid cavity of the
scapula
shoulder joint
covered by hyaline articular
cartilage
synovial ball-and-socket joint
shoulder joint
Capsule of the SHOULDER JOINT
• attached medially to the margin of
the _____
• attached laterally to the _____
• ___ and ___
• strengthened by the ______
• glenoid cavity
• anatomic neck of the humerus
• thin, lax
• rotator cuff muscles
Ligaments of the SHOULDER JOINT
• Glenohumeral Ligaments (3)
• Transverse Humeral Ligament
• Coracohumeral Ligament
• Coracoacromial Ligament
Movements of the SHOULDER JOINT:
Flexion:
about 90°
performed by the
anterior fibers of the deltoid, pectoralis major, biceps, and coracobrachialis muscles
Movements of the SHOULDER JOINT:
Extension:
about 45°
performed by the
posterior fibers of the deltoid, latissimus dorsi, and teres major muscles
Movements of the SHOULDER JOINT:
Abduction:
performed by the
middle fibers of the deltoid, assisted by the supraspinatus
Movements of the SHOULDER JOINT:
Adduction:
can swing 45° across the front of the chest
performed by the
pectoralis major, latissimus dorsi,
teres major, and teres minor muscles
Movements of the SHOULDER JOINT:
Lateral rotation:
40° to 45°
performed by the
infraspinatus, teres minor, and
posterior fibers of the deltoid muscle
Movements of the SHOULDER JOINT:
Medial rotation:
about 55°
performed by
subscapularis, latissimus dorsi, teres major, and anterior fibers of the deltoid muscle
Movements of the SHOULDER JOINT:
Circumduction:
combination of the above movements
articulates with the scapula at
the SHOULDER JOINT and with
the radius and ulna at the
ELBOW JOINT
humerus
lateral bone of the forearm
- proximal:
humerus at elbow joint
ulna at proximal radioulnar joint
- distal:
ulna at the distal radioulnar joint
scaphoid and lunate bones of the
hand at the wrist joint
radius
- medial bone of the forearm
- proximal:
humerus at the elbow joint
radius at the proximal radioulnar joint - distal:
radius at the distal radioulnar joint
but it is excluded from the wrist joint
by the articular disc
ulna
Strong membrane that unites
the shafts of the radius and
the ulna
INTEROSSEOUS MEMBRANE
Fibers run obliquely downward
and medially; taut when
forearm is in midprone
position (function)
Provides attachment for
neighboring muscles
INTEROSSEOUS MEMBRANE
Enclosed in a sheath of deep fascia
upper arm
2 fascial septa:
- on the medial side
- on the lateral side
- Medial Supracondylar Ridge of the Humerus
- Lateral Supracondylar Ridge of the Humerus
2 fascial compartments:
- Anterior fascial compartment
- Posterior fascial compartment
Anterior Fascial Compartment of the Upper Arm:
Muscles
Biceps brachii, coracobrachialis, & brachialis
Anterior Fascial Compartment of the Upper Arm:
BLOOD SUPPLY
Brachial artery
Anterior Fascial Compartment of the Upper Arm:
NERVE SUPPLY
Musculocutaneous nerve
Long head
origin:
insertion:
Supraglenoid tubercle of scapula
Tuberosity of radius and bicipital aponeurosis into deep fascia of forearm
short head
origin:
Coracoid process of scapula
coracobrachialis
origin:
insertion:
Coracoid process of scapula
Medial aspect of shaft of humerus
brachialis
origin:
insertion:
Front of lower half of humerus
Coronoid process of ulna
begins at the lower border of the
teres major muscle as a
continuation of the axillary artery
brachial artery
provides the main arterial supply to
the arm
terminates opposite the neck of the
radius by dividing into the radial and
ulnar arteries.
brachial artery
from the lateral cord of the brachial
plexus (C5, 6, and 7) in the axilla
→ coracobrachialis muscle
→ biceps and brachialis muscles
→ lateral aspect of the forearm
(lateral cutaneous nerve of the
forearm)
MUSCULOCUTANEOUS NERVE
has branches to the muscles, skin of
front and lateral aspects of forearm,
and elbow joint
MUSCULOCUTANEOUS NERVE
Posterior Fascial Compartment of the Upper Arm:
MUSCLES
Triceps muscle
Posterior Fascial Compartment of the Upper Arm:
BLOOD SUPPLY
Profunda brachii and ulnar collateral arteries
Posterior Fascial Compartment of the Upper Arm:
NERVE SUPPLY
Radial nerve
triceps
long head
origin:
infraglenoid tubercle of scapula
triceps
lateral head
origin:
insertion:
Upper half of posterior surface of shaft of humerus
Olecranon process of ulna
triceps
medial head
origin:
Lower half of posterior surface of shaft of humerus
a triangular depression that lies in front of the elbow
CUBITAL FOSSA
Boundaries of the Cubital Fossa:
• Laterally:
• Medially:
• Base:
• Floor:
• Roof:
•Brachioradialis muscle
•Pronator teres muscle
•2 epicondyles of the humerus
•Supinator muscle laterally and the Brachialis muscle medially
•Skin and fascia reinforced by the bicipital aponeurosis
