Chapter

15

Key Terms

Active immunity.......... 359 .. Immunoglobulin D (IgD)...... 359 Macrophage.......... 360 .....

Afferent lymphatic vessels.... 353 Immunoglobulin E (IgE)..... 359. Memory cells............. (^). 360.
Antibodies/immunoglobulins.. 358 Immunoglobulin G (IgG)...... 359 Monokines............... 360 ..
Antigens............ 358 .... .Immunoglobulin. M (IgM)..... 359 Palatine tonsils.......... 357 ...
B cells................... 360 .. Intercostal trunk........... 356. Passive immunity........ 359 ...
B lymphocytes............. 358. Interstitial fluid............ 350. Pathogens.............. 358 ...
Bronchomediastinal trunk.... 356 Intestinal trunk............ 356. Peyer’s patches........... 358 ..
Cellular immunity.......... 358. Jugular trunk.............. 356. Pharyngeal tonsils/adenoids.. 357
Chyle................ 350 .. (^).. Killer. T cells.............. 360 .. Plasma cells............... 360.
Complement............ 359 ... Lacteals.............. 350 .... Right. lymphatic duct......... 353
Cortical nodule/lymph nodule. 353 Lingual tonsils............. 357. Spleen.............. 357 ......
Edema............... 350 .... Lumbar. trunk.............. 356. Subclavian trunk........... 356.
Efferent lymphatic vessels.... 353 Lymph.............. 350.... Suppressor.. T cells.......... 360.
Germinal center............ 353. Lymphatic capillaries..... 351 ... Thoracic duct/left
Helper T cells.............. 360. Lymph nodes/glands........ 353. lymphatic duct......... 353.
Hilum.................. 353 ... Lymphatic sinus............ 353. Thymus gland............ 358 ..
Humoral immunity......... 358. Lymphatic trunks....... 353 .... T lymphocytes............ (^358) ..
Immunity................ 358 .. Lymphatics............... 353 .. Trabeculae............... 353 ..
Immunoglobulin A (IgA)...... 359 Lymphokines............. 360 ..
Introduction
The lymphatic system is intimately associated with the
blood and the cardiovascular system. Both systems
transport vital fluids throughout the body, and both have a
system of vessels that transport these fluids. The lym-phatic
system transports a fluid called lymph through special
vessels called lymphatic capillaries and lymphat-ics. This
lymph eventually gets returned to the blood from where it
originated. In addition to fluid control, our lym-phatic
system is essential to helping us control and de-stroy a
large number of microorganisms that can invade our bodies
and cause disease and even death. The lym-phatic system
consists of lymph, lymph vessels, lymph nodes, and four
organs. The organs are the tonsils, the
spleen, the thymus gland, the vermiform appendix, and
Peyer’s patches. See Concept Map 15-1: The Lymphatic
System. Figure 15-1 shows the vessels and organs of the
lymphatic system.
The Functions of the System
and the Structure and Functions
of the Lymphatic Vessels
The primary function of this system is to drain from tis-sue
spaces protein-containing fluid that escapes from the blood
capillaries. Other functions are to transport fats from the
digestive tract to the blood to produce lym-phocytes and to
develop immunities.
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