CH. 22 - LYMPHATIC SYSTEM & IMMUNITY
I. FUNCTION
A. FLUID BALANCE - Interstitial fluid Û Circulation
B. FAT ABSORPTION - from intestines - LACTEALS, later. . .
C. DEFENSE - Immunity
II. COMPONENTS (Fig. 22.1, p. 780)
A. LYMPH - fluid
B. LYMPHOCYTES - Agranular WBCs
C. LYMPH VESSELS - 1 Way valves & flow, AWAY from tissuesè veins
1. LYMPH CAPILLARIES (Fig. 22.2, p. 780)
a. Blind-ended
b. Cells overlap loosely - porous, permeable
c. No basement membrane
2. LYMPH VESSELS
a. Movement via muscles & respiration
D. LYMPH NODES
1. Filter
2. Groin, axilla, neck
E. THORACIC DUCT (Fig. 22.3, p. 781)
1. Drains 3/4 of bodyèL. Subclavian v.
F. RIGHT LYMPHATIC DUCT
1. Drains 1/4 of body, R. head, thorax & armèR. Subclavian v.
III. LYMPHATIC ORGANS
A. DIFFUSE LYMPH TISSUE - Reticular C.T. + Lymphocytes
B. LYMPH NODULES (Fig. 22.4, p. 782)
1. Larger grouping of lymph tissue
2. No C.T. capsule
3. In loose C.T. of Dig, resp, urin & spleen
4. Peyer’s patches - group in wall of intestine
5. Tonsils - Adenoids = enlarged pharyngeal tonsils (Fig. 22.5, p. 783)
C. LYMPH NODE (Fig. 22.6, p. 784) – in neck, axilla & groin
1. Capsule, cortex & medulla
2. Phagocytosis
3. Stim. lymphoctye division
D. SPLEEN (Fig. 22.7, p. 785)
1. Works like a big node, filters
2. Blood reservoir
3. Destroys old RBCs
E. THYMUS (Fig. 22.8, p. 787)
1. Produces lymphocytes
2. Function & size ê as age é
F. OVERVIEW - (Fig. 22.9, p. 788)
IV. IMMUNITY - Resist damage from foreign substances, 2 types
A. INNATE or NON-SPECIFIC
- Same response, NO “MEMORY”
1. MECHANICAL
a. Prevent entry - Skin & mucous membranes
b. Wash away - tears & saliva
c. Cough & sneeze
2. CHEMICAL (KNOW Tab. 22.1, p. 789)
a. Destroy cells/invaders
b. Stim. inflammation, pain, fever
c. Prevent spread
3. CELLS (KNOW Tab. 22.2, p. 791)
a. All WBCs except Lymphocytes
b. Phagocytosis
4. INFLAMMATORY RESPONSE (Fig. 22.11, p. 793)
a. Local - boils, acne, sore throat, sty, etc.
b. Systemic - often w/fever
B. ADAPTIVE or SPECIFIC - stim. by ANTIGENS & HAPTENS
- RECOGNIZE, RESPOND & REMEMBER
- LYMPHOCYTES, 3 kinds
1. ANTIBODY-MEDIATED/HUMORAL (Tab 22.3, p. 794)
a. B-CELLS è PLASMA cells è Antibodies
(red marrow) (against 100,000,000 diff. antigens!)
b. Protection from EXTRACELLULAR antigens
c. Antibodies work 2 ways: (Fig. 22.20, p. 804)
i. Direct: - 1. Inactivate antigen
- 2. Clump
ii. Indirect - 1. Activate complement è é lysis (p. 790)
- 2. é Inflammation
- 3. Opsonin è é Phagocytosis
d. Activated by:
i. T-Helpers & Interleukin 2
2. CELL-MEDIATED (Fig. 22.23, p. 807)
a. T-CELLS - 1. CYTOTOXIC T-cells - contact killing
(Thymus) - é inflam, phago.
- 2. T-HELPER - é response, I.D. targets
- 3. T-SUPRESSOR - ê response
b. Protection from INTRACELLULAR antigens & tumors
c. NO ANTIBODIES
d. 5X as many T as B cells
3. MEMORY CELLS - both produce (Fig. 22.21, p. 805)
a. Lifespan - probably lifetime for most
b. 10 response - 1st, slow
c. 20 response - 2nd, Faster & stronger
4. AIDS - T-Helpers destroyed, no recognition
5. NATURAL KILLER cells - 3rd type of lymphocyte
a. Destroy tumor & virus-infected cells
b. up to 15% of lymphocytes
c. Innate or Non-specific - no memory
V. ACQUIRED IMMUNITY (Fig. 22.24, p. 808)
YOUR immune system makes its own antibodies:
A. ACTIVE NATURAL - Natural exposure to an antigen = get sick, recover
B. ACTIVE ARTIFICIAL - Deliberate exposure to antigen = Vaccination
Preformed antibodies TRANSFERRED to your body:
C. PASSIVE NATURAL - Antibodies from mother è fetus/child
D. PASSIVE ARTIFICIAL - Antibodies from immune animal è
non-immune animal (ANTISERUM or ANTIVENOM)