Lecture 5.1: Axilla and Brachial Plexus Flashcards
Areas of Transition in Upper Limb
- Axilla
- Cubital Fossa
- Carpal Tunnel
What is the Axilla Region?
The axilla is the region that connects the neck to the upper limb
What are the components of the Axilla Region? (5)
- Bordered by pectoral girdle muscles and thoracic cage
- Neurovascular supply to upper limb runs through this region
- Filled with fat
- Tail of breast extends into region
- Contains important lymph node groups
How are Axillary Folds formed?
The axillary folds are formed by muscle covered in skin
Axillary Folds: Posterior Axillary Fold Muscles
- Latissimus dorsi
* Teres major
Axillary Folds: Anterior Axillary Fold Miscles
- Pectoralis major
* Pectoralis minor
Boundaries of the Axilla
Apex
Base
4 Walls (Posterior, Anterior, Lateral, Medial)
What is on the Anterior Border?
- Pectoralis major
* Pectoralis minor
What is on the Posterior Border?
- Subscapularis
- Latissimus dorsi
- Teres major
What is on the Lateral Border?
Intertubecular suculus
What is on the Medial Border?
- Serratus anterior
* Thoracic wall
Functions of the Lymphatic System
• Drain excess extracellular fluid from body & return it to veins of circulatory
system
• Mount immune responses in the body.
• Transports fat and large protein molecules too big for venous transport
• Collects fluid (lymph) from the extracellular spaces in tissues
• This is transported by lymphatic vessels
Lymph
- Typically Clear and Watery
- Foreign Particulates (ie: Bacteria)
- Malignant Cells
What is Lymphoedema?
An accumulation of interstitial fluid
What is a Plexus?
It is is a network of nerves or vessels in the body
Where does the Brachial Plexus originate from?
- Plexus originates from cervical and thoracic spinal cord levels
- C5, C6, C7, C8, T1
5 Main Brachial Plexus Nerves and Root Values
- Musculocutaneous Nerve (C5,6,7)
- Axillary Nerve (C5,6)
- Median Nerve (C5-T1)
- Radial Nerve (C5-T1)
- Ulnar Nerve (C8-T1)
What is a Dermatome?
Area of skin supplied by the cutaneous (sensory) branches from a single spinal nerve
What causes Erb’s Palsy (Erb-Duchenne Palsy)?
- Injury to the Upper Parts of the Brachial Plexus
- Paralysis of muscles of the shoulder/arm supplied by C5-C6
- “Waiter’s Tip” appearance
What is the Appearance of Erb’s Palsy (Erb-Duchenne Palsy)?
1) Arm Medially rotated
2) Adducted Shoulder
3) Extended Elbow
4) Flexion at Wrist
5) Motor and Sensory Deficits
What causes Klumpke’s Palsy (Paralysis)?
- Injury to the Lower Parts of the Brachial Plexus (C8 & T1)
- Often affects the short muscles of the hand
- Claw hand deformity results
What causes Thoracic Outlet Syndrome?
Occurs when blood vessels or nerves in the space between your collarbone and your first rib (thoracic outlet) are compressed
Neurovascular compression can occur due to…? (3)
- Cervical rib
- Hyperabduction of the shoulder (“Saturday night palsy”)
- Poor posture or heavy backpacks
