What is Axilla? The Armpit which is pyramidal in shape situated in between the upper part of the arm and the chest wall is known as the Axilla. The Axilla is a important structure through which pass various structures supporting the Upper limb, and has:
1. Apex
2. Base
3. Walls - Anterior, Posterior, Medial and Lateral.
Here,
1. Anterior means the front side of a part
2. Posterior means back side of a part
3. Medial means the side towards the centre of the body
4. Lateral means the side away from the body which is considered by a standard followed in Medical science dealing with the structure of the body (Anatomy); in The Anatomical Position.
The apex of the Axilla is having its direction as such that it faces upwards and towards the centre of the body, towards the neck and the base of the Axilla faces downwards.
The Apex of Axilla Direction: - Upwards, medially towards the base (root) of neck. The apex is not a pointed and is actually truncated which is bounded
1. Anteriorly by the Clavicle
2. Posteriorly by the Superior border of the Scapula
3. Medially, by the outer border of the First Rib
This part is also known as the Cervico-Axillary Canal. The Brachial Plexus and the Axillary Artery enter the Axilla through this canal.
The Base (Floor) of Axilla Direction: - Downwards and is formed by Skin and Fascia.
1. Anteriorly by: -
a. Pectoralis Major Muscle
b. Clavipectoral Fascia which covers Pectoralis Minor Muscle and the Subclavius Muscle.
2. Posteriorly by: -
a. Subscapularis Muscle above
b. Teres Major Muscle and Latissimus dorsi Muscle below
3. Medially by: -
a. Upper four ribs with their intercostals muscles
b. Upper part of Serratus anterior Muscle
4. Laterally by: -
a. Upper part of shaft of Humerus bone in region of bicipital groove
b. Coracobrachialis Muscle and short head of Biceps Muscle
This area is very narrow because the anterior wall and Posterior walls unite on to it.
The Contents of the Axilla
1. Axillary artery and its branches
2. Axillary vein and its branches
3. Infraclavicular part of Brachial nerve plexus
4. Five Groups of Axillary lymph nodes and the associated lymphatics
5. The long thoracic and intercostobrachial nerves
6. Axillary fat and areolar tissue which embed the contents of the Axilla
Applied Anatomy of the Axilla
The most common pathology that can occur in the Axilla is Suppurations (pus formation). The pus once formed spreads according to the epicenter of the origin site of the pus and the arrangement of the Fascia of Axilla. Such an Axillary abscess (pus formation/suppuration) needs frequently to be incised through the floor of Axilla from in between the Anterior and Posterior Axillary folds, nearer to the Median wall to avoid injury to the main blood vessels running along the anterior, posterior and lateral walls of the Axilla.
Syllabus of General Human Anatomy, Embryology and Histology at IndiaStudyChannel - http://www.indiastudychannel.com/resources/54520-Syllabus-General-Human-Anatomy-Embryology-AND-HISTOLOGY.aspx/.
Expert Health Topics at IndiaStudyChannel - http://www.indiastudychannel.com/experts/ExpertType-5-Health.aspx/
Dr. Apurva Tamhane
1. Apex
2. Base
3. Walls - Anterior, Posterior, Medial and Lateral.
Here,
1. Anterior means the front side of a part
2. Posterior means back side of a part
3. Medial means the side towards the centre of the body
4. Lateral means the side away from the body which is considered by a standard followed in Medical science dealing with the structure of the body (Anatomy); in The Anatomical Position.
The apex of the Axilla is having its direction as such that it faces upwards and towards the centre of the body, towards the neck and the base of the Axilla faces downwards.
The Apex of Axilla Direction: - Upwards, medially towards the base (root) of neck. The apex is not a pointed and is actually truncated which is bounded
1. Anteriorly by the Clavicle
2. Posteriorly by the Superior border of the Scapula
3. Medially, by the outer border of the First Rib
This part is also known as the Cervico-Axillary Canal. The Brachial Plexus and the Axillary Artery enter the Axilla through this canal.
The Base (Floor) of Axilla Direction: - Downwards and is formed by Skin and Fascia.
1. Anteriorly by: -
a. Pectoralis Major Muscle
b. Clavipectoral Fascia which covers Pectoralis Minor Muscle and the Subclavius Muscle.
2. Posteriorly by: -
a. Subscapularis Muscle above
b. Teres Major Muscle and Latissimus dorsi Muscle below
3. Medially by: -
a. Upper four ribs with their intercostals muscles
b. Upper part of Serratus anterior Muscle
4. Laterally by: -
a. Upper part of shaft of Humerus bone in region of bicipital groove
b. Coracobrachialis Muscle and short head of Biceps Muscle
This area is very narrow because the anterior wall and Posterior walls unite on to it.
The Contents of the Axilla
1. Axillary artery and its branches
2. Axillary vein and its branches
3. Infraclavicular part of Brachial nerve plexus
4. Five Groups of Axillary lymph nodes and the associated lymphatics
5. The long thoracic and intercostobrachial nerves
6. Axillary fat and areolar tissue which embed the contents of the Axilla
Applied Anatomy of the Axilla
The most common pathology that can occur in the Axilla is Suppurations (pus formation). The pus once formed spreads according to the epicenter of the origin site of the pus and the arrangement of the Fascia of Axilla. Such an Axillary abscess (pus formation/suppuration) needs frequently to be incised through the floor of Axilla from in between the Anterior and Posterior Axillary folds, nearer to the Median wall to avoid injury to the main blood vessels running along the anterior, posterior and lateral walls of the Axilla.
Syllabus of General Human Anatomy, Embryology and Histology at IndiaStudyChannel - http://www.indiastudychannel.com/resources/54520-Syllabus-General-Human-Anatomy-Embryology-AND-HISTOLOGY.aspx/.
Expert Health Topics at IndiaStudyChannel - http://www.indiastudychannel.com/experts/ExpertType-5-Health.aspx/
Dr. Apurva Tamhane
