LYMPHATIC SYSTEM
Figures 16.1, 16.2, 16.3 and 16.4
I. General characteristics
A. Separate__________________________system made of:
1. Fluid (lymph)--was ____________________________________ fluid
2. Microscopic blind tubes (lymphatic caps)
3. Lymphatic vessels carrying interstitial fluid (now called _______________ to the heart
4. Nodes (specialized organs ) of reticular tissue containing lymphocytes— filter the fluid
5. Spleen & thymus gland
6. villi of small intestine that contain ___________________________________________
7. Bone marrow -- site of maturation of B lymphocytes
LYMPH == blood in caps ---à
fluid leaks out ---à
interstitial fluid ----à Lymphatic Capillaries
B. Two Collecting Ducts Figure 16.6
1. ________________________ --left lymphatic duct --larger & longer;
a. drains: lower body, left arm, left side of head & neck;
empties into left subclavian vein
2. Right Lymphatic Duct--
a. drains right arm, rt. side of head, rt. side of chest
b. ---------------> ________________________________
C. Fluid enters lymphatic vessels because of high pressure in intercellular spaces
1. proteins do ___________________ go back in
2. therefore, NOT all H2O will be reabsorbed
3. incr. in pressure ---> forces tissue fluid into ______________________
D. Filaments attach to conn. tissue cells---->osmotic pressure of tissue fluid
pushes lymph into vessels
E. What keeps lymph going?
1. _________________________________contraction = == milking action of skeletal muscle
2. Breathing causes pressure changes
3. _____________________________contraction in lymph vessels
4. valves stop back flow
5. EDEMA -- tissue fluid accumulates in spaces -- sit, stand
6. NOTE: lymphatic vessels take particles away from tissues, but at same time, promote spread of cancer cells to other site == ____________________________
II. Structure of lymph node Figure 16.8 & 16.9
A. encapsulated oval node; scattered in groups
1. Hilus -- indented area <======blood vessels, nerves
========> efferent lymphatic vessels leave
2. White Fibrous connective tissue -- divides node into nodules –
these contain the lymphocytes & macrophages
3. Lymphatic sinuses -- chambers & channels for lymph.
a. NOTE: when nodes get full of bacti === swell, painful
4. Lymph enters node by afferent vessels,
a. filtered ( ) exits through ______________________
5. Particles become trapped by nodal reticular fibers
6. Macrophages destroy -----------by _______________________________
7. Lymphocytes destroy -----------by _______________________________
8. Node--site of proliferation of plasma cells & T cells
III. LYMPH NODES ------Figure 16.11
CAN BE IN GROUPS (ORGANS) OR SINGLE
A. Groups == organs
1. Tonsils
a. large nodules in mucous membrane
b. junction of oral cavity & pharynx -- _______________________________
c. protect against foreign invasion
d. participate in immune response
2. Figure 16.12 ________________ largest mass of lymphatic tissue in body
a. in left hypochondriac region between fundus of stomach & diaphragm
a. site of B cell proliferation into plasma cells, phagocytosis of bacteria &
worn-out or damaged RBC & platelets, + storage of blood
3. ____________________________-- between sternum & heart
a. Immunity
b. site of T-cell maturation
4. Peyer's patches -- in ileum of sm. intestines
5. TONSILS + PEYER'S PATCHES== GALT -- gut assoc. lymphatic tissue
B. Single nodes: Figure 16.11
1. __________________________ -- neck, below jawline, behind & in front of heart
2. __________________________-- from arm, mammary gland, upper abdomen
3. __________________________ -- from legs, genitalia, lower abdomen
4. __________________________ -- from viscera -- along path of iliac vessels
5. __________________________ -- along abdominal aorta
6. Thoracic --along trachea & bronchi
7. Supratrochlear -- inner elbow
C. Functions of lymph nodes:
1. Develop lymphocytes that __________________________ specific bacteria & viruses
2. Contain Macrophages (_________________________ foreign substances & debris)
3. _________________________ harmful particles in reticular tissue
D. Thymus
1. Location -- ant. to arch, post. to sternum;
2. Large in child; small in adult; atrophied in Sr. Citizen == fat & connective tissue
3. Inside the thymus -- lymphocytes (from red bone marrow) develop into ---->
a. _____________________---> (leave thymus) & go into combat ==
b. CELL TO CELL COMBAT
2. Thymus produces __________________________________ (hormone) –
a. stimulates T-lymphocytes to mature after leaving thymus
E. Spleen
1. Largest lymphatic organ; under diaphragm, post. to stomach
2. Made of lobules (chamber)
3. Hilus <====== blood vessels enter; sinuses are full of blood when resting
during exercise ---> vasoconstriction ---blood squirts out
4. Contains white pulp of nodules full of lymphocytes & red pulp -- contains
RBC, some lymphocytes & macrophages
a. __________________________________ as they squeeze through capillaries in spleen
b. ___________________________________
5. SPLEEN-- filters blood (takes out dead RBC & BACTERIA)
6. IN EMBRYO--spleen makes RBC
IV. SUMMARY OF FUNCTIONS OF LYMPHATIC SYSTEM:
A. Collects & returns interstitial fluid (includes plasma proteins) ________________________
B. _________________________ against disease (lymphocytes)
C. Absorbs liquids from intestine --->lacteals ---> to blood; lymphatics are NOT
found in__________________ or AVASCULAR TISSUE (epithelial & cartilage)
D. Under skin lymph follows path of _______________; in viscera—follows path of ____________
E. LYMPHATICS from lower body fuse to form ____________________________
F. RIGHT LYMPHATIC --about ______________ in length--empties rt. side of head, rt. arm & rt. side of trunk------->
G. LYMPHANGITIS -- blood poisoning --serious infection extending along lymphatics === _____________________.
H.There are over 100 lymph nodes in mesenteries. WHY?
I. FILARIASIS --parasitic infection of lymphatic system
IV. NON SPECIFIC RESISTANCE - Skin, mucous membranes, products of antimicrobial chemicals, natural killer cells, phagocytosis, inflammation, fever
First line of defense -- _________________________________________
1. Mechanical defenses
a. Epidermal layer of skin
b. Mucous membranes -- line cavities that open to outside--
1). secrete mucus (trap);
2). nose --hairs,
3).trachea has _____________--->cough, sneeze
c. ______________________________________--makes & drains tears --alkaline
d. Saliva, mucus, cilia
e. epiglottis
f. flow of urine
g. defecation, vomiting
2. Chemical factors on skin, loose connective tissue, stomach, vagina
a. _____________________-- oil production by skin) -- acid pH--unsat. fatty acid + lactic acid
b. ____________________________________-- in sweat -- antimicrobial
c. Hyaluronic acid -- in loose connective tissue-- helps contain infections in one area
d. Gastric juice ----pH 1.5-3.0
e. Vaginal secretions -- slightly acidic
B. Second line of defense ----work against colonization by viruses & bacteria
1. ______________________
2. _______________________ -- made in liver 20+ proteins in plasma & cell membrane
a. ATTACKS CELL MEMBRANES
b. CAUSES LESIONS
c. CELL SWELLS, BURSTS, DIES
d. also enhances immune, allergic & inflammatory RXNs
1). causes release of HISTAMINE
3. ______________-- natural killer cells -- kill microbes & tumor cells
a. (AIDS == a decrease in number)
C. ____________________________________ -- THIRD LINE OF DEFENSE involved in both non specific defense & immunity
1. MICROPHAGES MACROPHAGES
2. . FOUR PHASES OF PHAGOCYTOSIS__________________________________
a. Chemotaxis -- chemicals from microbes, WBC, complement & damaged cells attract macrophages
b. Adherence -- attachment of phagocyte to cell membrane of microbe opsonization --antibodies coat microbe == now more susceptible to adherence
c. Ingestion == phagocytosis
d. Killing -lysosome contains dig. enzymes = chemical onslaught -------> 10 -30 min.---DEATH
D. INFLAMMATION ===
1. PAIN, SWELLING, REDNESS, HEAT, LOSS OF FUNCTION
2. Injury == CELLS, CAPILLARIES -------> RELEASE BRADYKININ (a plasma protein)
a. attracts neutrophils; stim mast cells to release histamine; stim nerve endings
b. microphage dilation & permeability of caps; PAIN
c. Loss of function ---> Swelling ---> Heat ---> Redness
3. Neutrophils attack 1st, then macrophages take over ---> swell to 10X snormal size
E. FEVER --
1. intensifies effects of ________________________
2. _________________________ growth of microbes
3. speeds up body's Rxns in _________________
4. Hypothalamus regulates body temperature; keeps it set at 37 C;
5. ______________ reset the hypothalamus
6. PYROGENS --secreted by MACROPHAGES THAT HAVE BEEN EXPOSED TO BACTERIA & FOREIGN SUBSTANCES
7. Liver & spleen hide __________________ during fever;
8. Fever ________ the METABOLIC RATE of cells -- therefore ________ defense & repair
V. SPECIFIC RESISTANCE == ________________-- resistance to
foreign agents & their toxins
A. Cells involved: LYMPHOCYTES & MACROPHAGES
(produced in RED BONE MARROW) –become
a. B-LYMPHOCYTES & T-LYMPHOCYTES
1.) PLASMA CELLS (die in 5-7 days) Develop immunocompetence
a.) Develop ANTIBODIES................develope surface proteins
b.) Antibodies inactivate .............. antigen Killer CD8+ T Cells
B. TWO DIFFERENT KINDS OF IMMUNE RESPONSES - Figure 16.22 & 16.24
1. Cell-mediated immune response _________________
a. CD8+ T Cells -----------> Killer T Cells that attack the antigen
protect against fungi, parasites, viruses, cancers, transplants
2. Antibody mediated (humoral) response ____________________
B -----------> plasma cells ----------------> antibodies protect against antigens dissolved in body fluid & bacteria
C. CD4 cells become _______________ cells. How do B & T cells recognize foreign antigens
1. B cells recognize the ____________________________________, bind to it
2. T cells can recognize only __________________________ that are processed & presented with MHC (major histocompatibility complex) self antigens.
3. Antigen presenting cells: macrophages, B cells, dendritic cells
4. T cells must receive 2 signals: antigen recognition & _________________ by CD4 Cells
Chapter 16 Part B
VI. Antibodies
A. What are antibodies (called immunoglobulins)? See fibure 16.18
1. Soluble, globular proteins
2. Make up the gamma globulin fraction of plasma proteins
3. Each antibody molecule (immunoglobulin molecule) == 4 chains of amino acids linked by pairs of sulfur atoms
a. Two chains == identical light chains (L-chains) – variable region
b. Two chains == identical heavy chains – (H-chains) – constant region
B. What are the major types of antibodies (immunoglobulins)? See Chart 16.5
1. Ig G --- Gee, they are everywhere in the body.
a. Found in plasma & tissue fluid == everywhere in body.
b. Works on bacti, viruses, toxins
c. Activates complement -- Gee, it does a lot.
d. Most numerous -- Gee, there are a lot of these, in a lot of places, doing a lot of things.
e. Prominent in secondary response
2. Ig A
a. Found in secretions from exocrine glands == 1st line of defense
b. Fight bacti & viruses
c. Levels decrease during stress.
3. Ig M
a. Found in plasma
b. Involved in ABO reactions == antibody response
4. Ig D
a. Found on surface of B lymphocyte.
b. Activates B cell
5. Ig E
a. Involved in allergic response. EEEEEEEEEEEEEEEE, it itches.
b. Prominent in worm infestations & allergies.
c. Binds to mast cells & basophils == causes them to release histamine.
C. What do antibodies (immunoglobulins) do? See Chart 16.6
1. Direct attack
a. Agglutination – combines with the antigen to cause clumping.
b. Precipitation – coats the invader to cause precipitation
c. Neutralization – covers invader with toxic particles
d. Activation of complement (a set of enzymes)
D. How does complement (enzymes in the plasma) work?
1. The antigen-antibody complex, as well as the bacteria themselves, can activate complement.
a. A Can of Complement spills OIL
b. These all help complement to COMPLEMENT the immune response
c. Notice that complement is extremely important in defending
VII. Brief summary of types of immunity See Chart 16.8
A. Naturally acquired active immunity
1. Individual has symptoms of a disease
2. Produces T cells, B cells, Memory cells, antibodies
3. Antibodies found after 5-10 days following 1st exposure to the disease.
4. Antibodies found after 1-2 days following 2nd exposure to the disease. Why?
B. Artifically acquired active immunity
1. Individual receives vaccine of weakened or dead pathogens (or their components).
2. Immune response is stimulated, but individual is not sick.
3. Produces T cells, B cells, Memory cells, antibodies.
C. Artifically acquired passive immunity
1. Individual receives injection of gamma globulin containing antibodies.
2. Does not produce T cells, B cells, Memory cells, or self-made antibodies.
3. Immunity lasts for short time == no immune response stimulated.
D. Naturally acquired passive immunity
1. Mom passes antibodies to fetus.
2. Stort-term immunity for infant.
3. No immune response stimulated.
4. Breast feeding continues to impart immunity via antibodies.
"It was no small taskto develop as many as a billion different antibodies against all possible antigens, considering the limited number of genes in the human genome. According to the clonal selection theory, the human immune system, prior to any antigen stimulation, already contains numerous clones of antibody-producing cells, each different clone confined to producing only one specific antibody for one specific antigen. The immune system, thus, prior to being introduced to foreign antigens, already contains the antibody repertoire against all of them. In addition to the enormous amount of information necessary to create such a repertoire, such a strategy had to result in antibodies against only foreign antigens, while leaving the host cell antigens intact." From Clinical Physiology Made Ridiculously Simple by Stephen Goldberg, M.D
Helpful Activities to do after you finish reading this chapter
1. Crossword puzzle on Immune System vocabulary
2. Check out the following web site: