Deck 10: The Lymph Vessels and Lymph Tissue

Question 1

A 23-year-old woman is treated in the emergency department for an infected right index finger. Three days previously, she had got a rose thorn in her finger while gardening. On examination, the finger is red, tender, and very swollen. After removing the thorn and applying a dressing, the physician prescribes a course of antibiotics. He asks the nurse to put the patient's right arm in a sling, and warns the patient not to move the arm excessively. Explain why the patient's arm has been placed in a sling.

Answer 1

The immobilization of the patient's arm in a sling reduces the muscular activity and, thus, the rate of lymph flow from the limb. This serves to limit the spread of toxins and bacteria from the site of infection.

Question 2

A 54-year-old man visits his doctor complaining of a skin infection of the auricle of the right ear. The patient had scratched his ear 4 days previously and since then his ear has become greatly swollen, and his wife has noted that the right side of his neck is also swollen. The physician's assistant made the diagnosis of impetigo and gave the patient an antibiotic to be taken orally. She advised the patient to place a warm compress over the ear twice daily to reduce the auricular swelling. Using your knowledge of anatomy and physiology, explain the following: (a) Why is the ear swollen? (b) Why is the right side of the neck swollen? and (c) Why will the application of a warm compress to the ear reduce the swelling?

Answer 2

(a) The auricle of the ear is swollen by inflammatory edema. Edema is an abnormal accumulation of tissue fluid in the intercellular spaces. The fluid dynamics of inflammatory edema includes the vasodilatation of the arterioles and capillaries at the site of infection with an outpouring of protein-rich plasma into the tissue spaces along with the outpouring of neutrophils. (b) The right side of the neck is swollen because the bacteria have spread from the right auricle via the lymphatic vessels to the right superficial and deep cervical lymph nodes, which are enlarged as a result of the proliferation of the contained lymphocytes. (c) In the early stages of infection, heat causes arteriolar vasodilatation, which in turn raises blood flow through the infected skin, hastening the arrival of neutrophils, antibodies, and antibiotics to the site of infection. Once the infection is controlled, the increased vascular and lymphatic flow will help reduce the local accumulation of tissue fluid and cause the swelling of the ear to diminish.

Question 3

A 58-year-old woman following a right radical mastectomy (which involves the removal of the right breast and the right axillary lymph nodes) has lymphatic edema of the right arm because of obstruction of the normal lymph flow. Describe the main factors responsible for lymph flow.

Answer 3

The factors responsible for lymph flow are summarized in the CD paragraph under Lymph Flow in Clinical Medicine.

Question 4

Explain the mechanism of allograft rejection. What form of immunity is lacking in a patient who has a congenital absence of the thymus?

Question 5

A 70-year-old man complaining of a small painless swelling below his chin visited his physician. On questioning, he said that he had first noticed the swelling 4 months earlier and that it was gradually increasing in size. Because it had not caused any discomfort, he had chosen to ignore it. On examination, a single, small, hard swelling could be palpated in the submental triangle. It was mobile on the deep tissues and not attached to the skin.

-The following statements suggest that the hard swelling is a secondary malignant deposit in a lymph node except which?

A) The submental lymph nodes are located in the submental triangle just below the chin.
B) The submental lymph nodes drain the tip of the tongue, the floor of the mouth in the region of the frenulum of the tongue, the gums and incisor teeth, the middle third of the lower lip, and the skin over the chin.
C) A small, hard-based carcinomatous ulcer was found on the right side of the tongue near the tip.
D) The deep cervical group of lymph nodes beneath the sternocleidomastoid muscle receive lymph from the submental lymph nodes.
E) The submental lymph nodes lie deep to the superficial part of the submandibular salivary gland.

Question 6

An 8-year-old boy was examined by a pediatrician and found to have a painful swelling below and behind the angle of the jaw on the left side. The skin over the swelling was red and hot. Palpation of the neck revealed a tender firm swelling beneath the anterior border of the sternocleidomastoid muscle on the left side. The right side of the neck was normal. Examination of the pharynx and palatine tonsils showed marked redness of the mucous membrane and enlargement of both tonsils, especially the one on the left. The left tonsil also showed a yellow exudate draining from the tonsillar crypts.

-Using your knowledge of anatomy, name the group of lymph nodes involved in the disease.An 8-year-old boy was examined by a pediatrician and found to have a painful swelling below and behind the angle of the jaw on the left side. The skin over the swelling was red and hot. Palpation of the neck revealed a tender firm swelling beneath the anterior border of the sternocleidomastoid muscle on the left side. The right side of the neck was normal. Examination of the pharynx and palatine tonsils showed marked redness of the mucous membrane and enlargement of both tonsils, especially the one on the left. The left tonsil also showed a yellow exudate draining from the tonsillar crypts.

Question 7

An 8-year-old boy was examined by a pediatrician and found to have a painful swelling below and behind the angle of the jaw on the left side. The skin over the swelling was red and hot. Palpation of the neck revealed a tender firm swelling beneath the anterior border of the sternocleidomastoid muscle on the left side. The right side of the neck was normal. Examination of the pharynx and palatine tonsils showed marked redness of the mucous membrane and enlargement of both tonsils, especially the one on the left. The left tonsil also showed a yellow exudate draining from the tonsillar crypts.

-The following symptoms and signs in this patient were consistent with a diagnosis of an acute bacterial infection under the nail folds (paronychia) of the right thumb except which?

A) Some tender lymph nodes could be palpated in the infraclavicular fossa.
B) The patient's temperature was raised.
C) The infection had spread into the lymph vessels draining the finger.
D) The red streaks on the front of the forearm were caused by the local vasodilatation of the blood vessels along the course of the lymph vessels.
E) The lymph vessels from the thumb drain into the supratrochlear node, which was inflamed and enlarged.

Question 8

A 45-year-old woman having her yearly physical examination was found to have a hard, painless lump in the upper lateral quadrant of the left breast. On examination with her arms at her sides, the left nipple was seen to be higher than the right, and a small dimple of skin was noted over the lump. On examination of the left axilla, three small, hard discrete nodules could be palpated below the lower border of the pectoralis major muscle. The right breast was normal. A diagnosis of carcinoma of the left breast was made, with secondary deposits in the axilla.

-The following statements concerning this patient are correct except which?

A) The contracting fibrous tissue of the malignant tumor had pulled on the lactiferous ducts of the nipple, raising it above the level of the opposite nipple.
B) The dimpling of the skin was caused by the fibrous tissue pulling on the suspensory ligaments of the breast.
C) The upper lateral quadrant of the breast is drained into the pectoral or anterior axillary lymph nodes.
D) The enlarged pectoral lymph nodes could be palpated against the surgical neck of the humerus.
E) The malignant tumor had spread by way of the lymph vessels to the pectoral lymph nodes.

Question 9

A 45-year-old man complaining of a lump in the groin was seen by his physician. The lump, which caused him no pain or discomfort, was first recognized 3 months previously. On examination, a large discrete hard lump was found about 2 in. $(5 \mathrm{~cm}$ ) below and lateral to the pubic tubercle on the front of the right thigh.

-The following signs indicated that this patient had a melanoma of the right big toe with secondaries in the inguinal lymph nodes except which?

A) Two smaller hard swellings were found immediately below the large swelling.
B) On flexing the right knee joint, three small hard swellings could be palpated in the popliteal fossa.
C) The external genitalia were found to be normal.
D) Examination of the anal canal revealed nothing abnormal.
E) A small pigmented mole was discovered beneath the nail of the right big toe.

Question 10

A senior medical student taking a surgical examination was asked to look at a 55-year-old man. On examination of the abdomen, he found a hard, fixed mass in the midline, about 4 in. $(10 \mathrm{~cm})$ in diameter, lying on the transpyloric plane. On questioning, the patient said that he had recently lost $20 \mathrm{lb}$ and had a poor appetite. The student told the examiner that the patient was suffering from a carcinoma of the stomach and should have an immediate gastrectomy. The examiner then asked the student if he had examined the patient's scrotum, and the student admitted he had not. On examination, the scrotum was found to contain a large, hard mass on the right side that was not tethered to the skin. The inguinal lymph nodes on the right side were normal. Explain the connection between the abdominal swelling and the scrotal swelling. Why were the inguinal lymph nodes normal?