ANATOMY OF THE ARM
BY
Mrs. STEPHANIE ABAH
1
, ARM
• The arm is also called
brachium,it extends from the
shoulder joint till the elbow
joint. The skeleton of the arm
is a 'solo' bone, the humerus.
• Medial and lateral
intermuscular septa divide
the arm into an anterior or
flexor compartment and a
posterior or extensor
compartment, to give each
compartment its individuality
and freedom of action.
2
, Surface landmark of the arm
• The arm extends from the shoulder joint to the elbow joint
• The greater tubercle of the humerus is the most lateral bony point in the shoulder
region. It can be felt just below the acromion
• The shaft of the humerus is felt only indistinctly because it is surrounded by muscles
• The medial epicondyle of the humerus is a prominent bony projection on the medial
side of the elbow. It is best seen and felt in a mid-flexed elbow.
• The lateral epicondyle of the humerus is less prominent than the medial. It can be felt
in the upper part of the depression on the posterolateral aspect of the elbow in the
extended position of the forearm.
• The medial and lateral supracondylar ridges are better felt in the lower one-fourth of
the arm as upward continuations of the epicondyles.
• The deltoid forms the rounded contour of the shoulder. The apex of the muscle is
attached to the deltoid tuberosity located at the middle of the anterolateral surface of
3
the humerus.
, COMPARTMENTS OF THE ARM
• The arm is divided into anterior and posterior compartments by extension
of deep fascia which are called the medial and lateral intermuscular septa.
• These septa has the following functions: provides additional surface for
the attachment of muscles, also form planes along which nerves and blood
vessels travel.
• The septa are well defined only in the lower half of the arm and are
attached to the medial and lateral borders and supracondylar ridges of the
humerus.
• The medial septum is pierced by the ulnar nerve and the superior ulnar
collateral artery;
• The lateral septum is pierced by the radial nerve and the anterior
descending branch of the profunda brachii artery.
4
BY
Mrs. STEPHANIE ABAH
1
, ARM
• The arm is also called
brachium,it extends from the
shoulder joint till the elbow
joint. The skeleton of the arm
is a 'solo' bone, the humerus.
• Medial and lateral
intermuscular septa divide
the arm into an anterior or
flexor compartment and a
posterior or extensor
compartment, to give each
compartment its individuality
and freedom of action.
2
, Surface landmark of the arm
• The arm extends from the shoulder joint to the elbow joint
• The greater tubercle of the humerus is the most lateral bony point in the shoulder
region. It can be felt just below the acromion
• The shaft of the humerus is felt only indistinctly because it is surrounded by muscles
• The medial epicondyle of the humerus is a prominent bony projection on the medial
side of the elbow. It is best seen and felt in a mid-flexed elbow.
• The lateral epicondyle of the humerus is less prominent than the medial. It can be felt
in the upper part of the depression on the posterolateral aspect of the elbow in the
extended position of the forearm.
• The medial and lateral supracondylar ridges are better felt in the lower one-fourth of
the arm as upward continuations of the epicondyles.
• The deltoid forms the rounded contour of the shoulder. The apex of the muscle is
attached to the deltoid tuberosity located at the middle of the anterolateral surface of
3
the humerus.
, COMPARTMENTS OF THE ARM
• The arm is divided into anterior and posterior compartments by extension
of deep fascia which are called the medial and lateral intermuscular septa.
• These septa has the following functions: provides additional surface for
the attachment of muscles, also form planes along which nerves and blood
vessels travel.
• The septa are well defined only in the lower half of the arm and are
attached to the medial and lateral borders and supracondylar ridges of the
humerus.
• The medial septum is pierced by the ulnar nerve and the superior ulnar
collateral artery;
• The lateral septum is pierced by the radial nerve and the anterior
descending branch of the profunda brachii artery.
4
