Anatomy – Additions and Notes

I. Upper Limb:

1. Adductor Canal:

• Boundaries:
  • Anteromedial: Sartorius muscle, medial fascial septum
  • Anterolateral: Vastus medialis muscle
  • Posterior: Adductor longus & Adductor magnus muscles
• Contents:
  • From lateral to medial: VAN: N (Saphenous nerve), A (Femoral artery), V (Femoral vein).
  • While the mnemonic VAN is convenient, the actual position of these structures can vary.
• Adductor muscles: This is the strongest muscle group in the thigh, innervated by the femoral nerve (L2-L4).

2. Femoral Triangle:

• Boundaries:
  • Medial: Adductor longus muscle
  • Lateral: Sartorius muscle
  • Inferior: Medial border of the sartorius muscle
• Contents:
  • From lateral to medial: NAVL: N (Femoral nerve), A (Femoral artery), V (Femoral vein), L (Lymphatic nodes).
• The femoral triangle is a crucial area for examining and intervening in the femoral vessels and nerve.

3. Popliteal Fossa:

• Boundaries:
  • Superior: Adductor longus & semitendinosus muscles
  • Inferior: Biceps femoris & gastrocnemius muscles
  • Medial: Adductor magnus muscle
  • Lateral: Short head of the biceps femoris
• Contents:
  • From lateral to medial: NVA: N (Common peroneal nerve), A (Deep femoral artery), V (Deep femoral vein).
• The popliteal fossa is the access point for the deep femoral vessels and the common peroneal nerve.

4. Saphenous Nerve:

• Branch of: Femoral nerve (L2-L3-L4)
• Type of branch: Purely sensory peripheral nerve
• Termination: Medial side of the foot

5. Deep Femoral Artery:

• Branch that does not contribute to the genicular anastomosis: Medial circumflex femoral artery.
• The genicular anastomosis plays a crucial role in supplying blood to the knee joint.

6. Arm:

• Posterior wall: Medial intermuscular septum.
• Intermuscular septa are fibrous connective tissue membranes that separate muscle groups, creating distinct compartments.

7. Brachial Plexus:

• Composition: Anterior branches of C4 — T1.
• The brachial plexus innervates the motor and sensory functions of most of the upper limb.

8. Lateral branches of the Brachial Artery:

• List:
  • Deep brachial artery
  • Superior ulnar collateral artery
  • Inferior ulnar collateral artery
  • Radial artery
  • Ulnar artery
• The lateral branches of the brachial artery supply blood to the surrounding muscles and bones.

9. Bicipital Groove:

• Lateral bicipital groove: Superficial branch of the radial nerve.
• Medial bicipital groove: Median nerve and brachial artery.

10. Supracondylar Process of the Humerus:

• Structure: Ulnar nerve.

11. “Companion” Muscles:

• Ulnar artery: Flexor carpi ulnaris muscle.
• Radial artery: Brachioradialis muscle.
• Axillary artery: Coracobrachialis muscle.

12. Anterior Forearm:

• Innervated by the ulnar nerve:
  • Flexor carpi ulnaris muscle
  • Medial half of the flexor digitorum profundus muscle
• The ulnar nerve innervates the flexor muscles of the forearm.

13. Sensation in the Posterior Forearm:

• Innervated by:
  • Posterior cutaneous nerve of the forearm
  • Radial nerve
  • Musculocutaneous nerve
• These nerves provide sensation to the skin on the posterior forearm.

14. Elbow Flexion:

• Inability to perform with damage to: Musculocutaneous nerve.
• The musculocutaneous nerve innervates the elbow flexors.

15. Axillary Suspensory Ligament:

• Composition: Superficial layer of the clavipectoral fascia.
• The axillary suspensory ligament helps to secure the vessels and nerves passing through the axilla.

16. Axillary Artery:

• Passes through the clavipectoral triangle: Midpoint of the anterior margin of the clavicle.
• The axillary artery is the continuation of the subclavian artery.

II. Lower Limb:

1. Sciatic Nerve:

• Branch of: Sacral plexus (L4-L5-S1-S2-S3)
• Branch of: Common peroneal nerve (L4-L5-S1-S2)
• Position in the buttock: Lateral to the posterior cutaneous nerve of the thigh
• Lateral branch in the buttock: None
• Function: Innervates motor and sensory functions of most of the lower limb.

2. Superior Gluteal Nerve:

• Branch of: L4; L5; S1
• Position: Passes through the greater sciatic foramen, emerging above the superior border of the piriformis muscle.
• Function: Motor: Tensor fasciae latae, gluteus medius, gluteus minimus muscles.

3. Posterior Cutaneous Nerve of the Thigh:

• Branch of: S1; S2; S3
• Position: Posterior (medial) to the sciatic nerve.
• Branches: Inferior gluteal nerve, sensory branch innervating the skin on the lateral leg.

4. Obturator Nerve:

• Branch of: L2; L3; L4
• Position: Travels with the obturator artery (branch of the internal iliac artery) into the obturator canal.
• Branches: Two branches that wrap around the adductor brevis muscle.
• Function:
  • Sensory: Medial thigh.
  • Motor: All muscles in the anterior thigh {rectus femoris}.

5. Saphenous Nerve:

• Purely sensory branch of: Femoral nerve.

III. Cardiovascular:

1. Coronary Arteries:

• Left marginal branch: Branch of the left coronary artery (LCA).
• Coronary arteries supply blood to the heart muscle.

2. Interatrial Groove:

• Position: On the base of the heart.
• The interatrial groove separates the left and right atria.

3. Apex of the Heart:

• Position: Where the anterior and posterior interventricular grooves meet.

4. Posterior Interventricular Groove:

• Position: On the diaphragmatic surface of the heart.

5. Coronary Sulcus:

• Runs from: Anterior to diaphragmatic surfaces of the heart.
• The coronary sulcus separates the atria from the ventricles.

6. Right Atrium:

• Anatomical details:
  • Fossa ovalis and the limbus of the fossa ovalis
  • Crista terminalis (external surface)
  • Opening of the coronary sinus
  • SA node, AV node
• The right atrium receives blood from the superior and inferior vena cava.

7. Valves:

• Between right atrium and ventricle: Tricuspid valve.
• Valves prevent backflow of blood from the ventricles to the atria.

8. Cardiac Veins:

• The smallest cardiac veins: Drain blood directly into the ventricles and atria = Thebesian veins.
• Anterior cardiac vein: Drains directly into the right atrium.

9. Bronchial Veins:

• Drain into: Azygos vein.

IV. Respiratory:

1. Lung:

• Anterior border: The border between the costal and medial surfaces.
• Lungs are the primary respiratory organs.

2. Mediastinal Pleura:

• Sensation: Phrenic nerve.

3. Hilum of the Lung:

• Topmost structure: Main bronchus (root).
• Relationship of the pulmonary artery and bronchus:
  • Right lung: Pulmonary artery lies anterior to the main bronchus.
  • Left lung: Pulmonary artery lies superior to the main bronchus.
• The hilum of the lung is where the vessels and bronchus enter the lung.

4. Mediastinum:

• Boundary between superior and inferior mediastinum: Plane passing through the sternal angle and the midpoint between the T4 & T5 vertebrae.
• Largest mediastinum: Middle mediastinum.
• Mediastinum with the most structures passing through: Posterior mediastinum.
• The mediastinum is the compartment between the two pleural sacs, containing the cardiovascular and respiratory organs.

5. Thoracic Duct:

• Position: Posterior to the descending thoracic aorta.
• Direction: T4 to empty into the left subclavian vein.
• The thoracic duct is the largest lymphatic vessel in the body.

6. Foramina:

• Aortic hiatus: Transverse level of T12 vertebra.
• Inferior vena cava hiatus: Transverse level of T8-T9 vertebrae.
• Esophageal hiatus: Transverse level of T10 vertebra.

7. Structures passing through the foramina:

• Aortic hiatus: Aorta, thoracic duct.
• Inferior vena cava hiatus: Inferior vena cava, phrenic nerve.
• Medial compartment of the esophageal hiatus: Greater splanchnic nerve & lesser splanchnic nerve.
• Lateral compartment of the esophageal hiatus: Azygos vein, hemiazygos vein, sympathetic trunk.

General Notes:

• Adding Illustrations: Using anatomical diagrams enhances learning and memory retention.
• Practice: Practice on anatomical specimens, models, or virtual reality applications to gain a deeper understanding of the position, structure, and function of body parts.
• Connecting Knowledge: Connect anatomical knowledge with pathology, diagnosis, and treatment.

Good luck with your studies!