Lymphatic System

McQ pass year -30 questions, 9 questions about immune ((not much for cell mediated and antibody mediated 

Saq fill in blank some from book, true false about immune 

Lymph flow @ node 

(a) Define innate and adaptive immunity (4 marks)

innate - naturally occurring response to wide range of pathogen

adaptive - activation of specific lymphocytes to combat particular foreign substances

(b) List the differences between innate and adaptive immunity (6 marks). 

innate - rapid, non specific, no specific recognition of pathogen, no memory, low diversity 

adaptive 倒反来，记啥记

(c) Explain the functions of lymphatic system

vessel drain excess interstitial fluid from tissue spaces & return it back to blood 

transport dietary lipid from GIT to blood - lipid soluble vitamin这种

carry out immune response 

(d) How is the lymphatic capillary different from a blood capillary?

LC- conduct lymph, larger diameter, 1 closed end 1 open, low plasma protein, more permeable, larger pore

BC- 2 open end 倒反，不用记太多

(e) Briefly explain how disruption of lymphatic flow can lead to edema

excess interstitial fluid accumulate between cells cause swelling - system can't return lymph into bloodstream - interstitial fluid unable drain to capillaries due to lower concent gradient than accumulated lymph

A: first exposure

B: primary response

C: IgM 

D: second exposure

E: secondary response

F: IgG

G: latent period

(f) According to the graph, estimate how many folds increase of the IgG level circulating in the blood in the secondary response than in the primary response and explain why.

10 folds 

immunological memory 

memory B activated faster 

rapid production of IgG 

Ab has higher affinity - bind more effective to Ag 

IgG maintain high for long duration to maintain extended protection

(g) Review the primary and secondary responses to an antigen and how it works as the basis of vaccination.

(h) Define how vaccination works to enhance immunity.

vaccine has specific pathogen w specific Ag - inactive/weak 

1st exposure - primary - activated B clonal selection - plasma & memory B - Ab, store 

2nd exposure - memory B differ into more memory B & plasma - more Ab, higher affinity 

(i) at peak secretion, approx 1000 times more IgG produced 

Reviewing Terms and Facts
1. The complement system can be activated only by antibodies. (True or false?) F
2. Specific adaptive immune responses are accomplished by neutrophils. (True or false?) F
3. Damaged tissue is always replaced by scar tissue. (True or false?) F
4. Active immunity against a particular disease can be acquired only by actually having the disease. (True or false?) F
5. A secondary response has a more rapid onset, is more potent, and has a longer duration than a primary response. (True or false?) T

6. are receptors on the plasma membrane of phagocytes that recognize and bind with telltale molecular patterns present on the surface of microorganisms but absent from human cells. -toll like receptor
7. The complement system’s forms a doughnut-shaped complex that embeds in a microbial surface membrane, causing osmotic lysis of the victim cell. -membrane attack complex
8. is a collection of phagocytic cells, necrotic tissue, and bacteria. -pus
9. is the localized response to microbial invasion or tissue injury that is accompanied by swelling, heat, redness, and pain. -inflammation
10. A chemical that enhances phagocytosis by serving as a link between a microbe and the phagocytic cell is known as a(n). -opsonin
11. All the chemical messengers other than antibodies secreted by lymphocytes that regulate immune process are categorized as . -cytokines
12. molecules released by killer cells form pore like channels that punch holes in a victim cell, and released by killer cells trigger apoptosis of victim cells. -perforin, granzymes

13. Which of the following statements concerning leukocytes is/are incorrect?
a. Monocytes are transformed into macrophages.
b. T lymphocytes are transformed into plasma cells that secrete antibodies. F
c. Neutrophils are highly mobile phagocytic specialists. 
d. Basophils release histamine.
e. Lymphocytes arise in large part from lymphoid tissues.

14. Match the following:
1. a family of proteins that nonspecifically defend against viral infection -IFN
2. a response to tissue injury in which neutrophils and macrophages play a major role -inflammation

3. a group of plasma proteins that, when activated, bring about destruction of foreign cells by attacking their plasma membranes -complement system
4. lymphocyte like entities that spontaneously lyse tumor cells and virus-infected host cells -NK 

15. Using the answer code on the right, indicate whether the numbered characteristics of the adaptive immune system apply to antibody-mediated immunity or cell-mediated immunity (or both):
1. involves secretion of antibodies -Ab

2. mediated by B cells -Ab
3. mediated by T cells -cell
4. accomplished by and cell-mediated thymus-educated immunity lymphocytes -cell
5. triggered by the binding of specific antigens to complementary lymphocyte receptors -both
6. involves formation of memory cells in response to initial exposure to an antigen -both
7. primarily aimed against virus-infected host cells -cell
8. protects primarily against bacterial invaders -Ab
9. directly destroys targeted cells -cell
10. involved in rejection of transplanted tissue -cell
11. requires binding of a lymphocyte to a free extracellular antigen -Ab
12. requires dual binding of a lymphocyte with both foreign antigen and self-antigens present on the surface of a host cell -cell

16. Using the answer code on the right, indicate whether the numbered characteristics apply to the epidermis or dermis:
1. is the inner layer of skin -dermis 
2. has layers of epithelial cells that are dead and flattened -epidermis

3. has no direct blood supply -epidermis
4. contains sensory nerve endings -dermis
5. contains keratinocytes -epidermis
6. contains melanocytes -epidermis
7. contains rapidly dividing cells -epidermis
8. is mostly connective tissue -dermis

Understanding Concepts (Answers at www.cengagebrain.com)
2. Summarize the functions of each of the lymphoid tissues

primary - form lymphocyte & mature, T/B, red BM-B&pre-T, thymus-T mature, thymic involution (shrink) low T, memory T, capable of clearing new infections, loss competent T (immune aging)

capsule + outer cortex - iDC, T, epithelial, macrophage

medulla - mature T , DC, ET, macrophage, clusters of thymic corpuscles 

secondary - maintain maturation, initiate adaptive - both T & B, increase size with age, nodes nodules spleen 

nodes - stroma, outer cortex - B, inner cortex - T&DC, medulla - B, plasma, macrophage 

route: afferent vessel, subcapsular sinus, trabecular, medullary, efferent 

spleen - stroma, white pulp, red pulp

red pulp - removal by macrophage, store >1/3 plat supply, hemopoiesis during fetal life  

route: splenic artery, red pulp, central artery within white pulp, vein - splenic macrophage remove blood-borne pathogen - T&B immune 

left lymphatic duct - trunk involved:

lumbar - drain lymph from abdominal wall, kidney, adrenal gland, pelvis, lower limb 

intestinal - stomach, pancreas, spleen, intestine

bronchomediastinal - thoracic wall, lung, heart

subclavian - upper limb

jugular - head neck 

right:

bronchomediastinal

subclavian

jugular 

pump

skeletal muscle: flow of lymph driven by milking action of skeletal muscle contractions compress lymphatic vessel, force lymph to jx of jugular & sc vein

respiratory: flow of lymph driven by pressure change during inhalation

1 line: skin & mucous membrane 

Physical - epidermis, mucous membrane, nose hair

Fluid - lacrimal apparatus of eye, urine, vomit, vaginal secretion 

Chemical - sebaceous gland secrete sebum inhibit pathogen & fungal growth 

2: antimicrobial substances 

Interferon released by infected cells to synthesize antiviral protein 

Complement system 

Iron binding protein 

Antimicrobial proteins 

NK cells 

Phagocytosis: chemotaxis, adherence, ingestion, phagolysosome digestion, digestive enzymes and lysozyme killing and produce residual body 

Inflammation: vasodilation & increase BV permeability, emigration, tissue repair 

4. Compare the life histories of B cells and T cells.
5. Describe the structure of an antibody. List and describe the five subclasses of immunoglobulins.

2 light 2 heavy chains linked by disulfide bond 

variable region = antigen binding site 

constant region = specificity & determine Ab class

IgG - bacteria, enhance phagocytosis, neutralize toxins, trigger complement - can cross placenta

IgM - activate complement, cause agglutination, microbe lysis
IgE - allergy, hypersensitivity, parasite 
IgA - localized protection of mucous membrane 
IgD - activation of B 

6. In what ways do antibodies exert their effect? Ab action

antigens neutralizing toxins

immobilizing bacteria

agglutinating & precipitating antigens 

activating complement - initiate classical pathway

enhancing phagocytosis 

7. Describe the clonal selection theory.

cell-mediated: begins w activation of small no of T by specific Ag, T, intracellular microbe, no Ab production

helper TCR + exogenous Ag on MHC2 molecules of APC + co stimulation = active T secrete cytokines & memory T 

cytotoxic T + Ag on MHC 1 + co stimulation by helper T  = clonal selection = effector or active & memory cytotoxic T

Ab-mediated: begins w activation of B by specific Ag, B, extracellular microbe, Ab production

Ag + BCR + MHC2 + co stimulation by helper T = clonal selection = plasma cell & memory B

8. Compare the functions of B cells and T cells. What are the roles of the three types of T cells?
9. Summarize the functions of macrophages in immune defense.
10. What mechanisms are involved in self-tolerance?
11. What is the importance of class I and class II MHC glycoproteins?
12. Describe the factors that contribute to immune surveillance against cancer cells.
13. Distinguish among immunodeficiency disease, autoimmune disease, immune complex disease, immediate hypersensitivity, and delayed hypersensitivity.
14. What are the immune functions of the skin?