リンパ節試験
Q1: What are the main functions of the lymphatic system?
The lymphatic system has two primary functions: returning extracellular fluid back to the venous circulation and exposing antigenic substances to the immune system. As lymph travels through lymphatic channels toward systemic circulation, it encounters multiple lymph nodes containing highly concentrated clusters of lymphocytes that play a critical role in maintaining immunity.
Q2: Which lymph nodes can be assessed during a physical examination?
Most lymph channels and nodes reside deep within the body and are inaccessible to physical examination. However, superficial nodes larger than one centimeter in diameter can be palpated, primarily in the head and neck region, axillae, and inguinal areas. These nodes normally appear as soft, smooth, movable, non-tender, bean-shaped structures embedded in subcutaneous tissue.
Q3: What does lymphadenopathy indicate, and how does it present?
Lymphadenopathy, the enlargement of lymph nodes, usually indicates an infection or less commonly cancer in the area of lymph drainage. Affected nodes may become enlarged, fixed, firm, and tender depending on the underlying pathology. For example, soft tender nodes near the mandible may suggest infection, while firm enlarged non-tender nodes in the axilla may indicate malignancy.
Q4: How should you palpate lymph nodes during examination?
Use the pads of your index and middle fingers to palpate nodes bilaterally, assessing size, shape, number, pliability, texture, mobility, and tenderness. Begin with inspection for noticeably enlarged nodes, then systematically palpate each region. Press fingers against the chest wall and slide downward to feel central nodes, working methodically through all accessible lymph node groups.
Q5: What are the key lymph node groups in the head and neck region?
Head and neck lymph nodes include preauricular and posterior auricular nodes near the ears, mastoid and occipital nodes at the base of the skull, and nodes around the mandible including tonsillar, submandibular, and submental nodes. Additional groups surround the sternomastoid muscle, including superficial and deep cervical nodes, plus supraclavicular and infraclavicular nodes near the clavicle.
Q6: How do you examine axillary lymph nodes in a patient?
Position yourself in front and to the left of the seated patient. Gently grasp the patient's wrist or elbow and slightly abduct the arm. Move your hand high into the axilla behind the pectoralis muscle, pointing fingers toward mid-clavicle, then press against the chest wall and slide downward to feel central nodes. Repeat on the opposite side using your opposite hand.
Q7: What characterizes the superficial inguinal lymph nodes and how are they palpated?
Superficial inguinal lymph nodes are located high in the anterior thigh and drain various regions of the legs, abdomen, and perineum. They subdivide into horizontal nodes just below the inguinal ligament and vertical nodes medial to the horizontal group below the femoral artery pulse. Ask the patient to lie supine with hips extended or slightly flexed, then palpate along the entire length of the ligament, noting size, shape, and firmness.