chapter 22 lymphatic bio 211 lab. copyright © 2009 pearson education, inc., publishing as pearson...
TRANSCRIPT
Chapter 22 Lymphatic
Bio 211 lab
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Structures of Body Defenses
• Lymphocyte Circulation – Fluid from blood enters interstitial fluid through capillaries– (Excess interstitial) fluid returned to venous blood through
lymphatic vessels• Lymph = interstitial fluid that has entered a lymphatic vessel• Often contains ___________, lymphocytes and ____________.
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Structures of Body Defenses• Lymphatic Vessels – Are vessels that carry lymph – Lymphoid system begins with smallest vessels• Lymphatic capillaries (terminal lymphatics)
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Structures of Body Defenses• Lymphatic Capillaries – Differ from blood capillaries in 4 ways
1. Start as pockets rather than tubes2. Have larger diameters3. Have thinner walls4. Flat or irregular in section
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Structures of Body Defenses
Figure 22–2a Lymphoid Capillaries.
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Structures of Body Defenses• Lymphatic Capillaries – Endothelial cells loosely bound together with
overlap– Overlap acts as one-way ________• Allows fluids, solutes, lymphocytes, viruses, and
bacteria to enter• Prevents return to intercellular space
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Structures of Body Defenses• Lymph Flow– From lymphatic capillaries to larger lymphatic vessels
containing valves– Lymphatic vessels travel beside ___________
• Lacteals– Are special lymphatic capillaries in small intestine– Transport __________ from digestive tract
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Structures of Body Defenses
Figure 22–3 Lymphatic Vessels and Valves.
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Structures of Body Defenses
Figure 22–4 The Relationship between the Lymphatic Ductsand the Venous System.
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Structures of Body Defenses• Lymphedema – Blockage of lymph drainage from a body limb– Causes severe swelling
– Interferes with immune system function • Lymphocytes– Make up 20–30% of circulating leukocytes– Most are stored, not circulating
• Refer to Collection of Anatomy Images for additional lymphatic structures (pp. 48-49, 71).