Exam 1 Flashcards
skipped slide 27, 29, 32, 37, 40, 44, 46, 50
Collection of cells & biochemicals that travel in lymphatic vessels
* Contains network of vessels that assist in circulating fluids
* Closely associated w/ Cardiovascular system
“Immune system” refers to many cells of the system providing both a defense against a disease & permanent immunity against future infections
Lymphatic system
What are 3 functions of the lymphatic system?
Transports excess interstitial fluid away from interstital saces & returns it to bloodstream
Absorbs lipids from digestive system & transports them to bloodstream
* Accomplished by lymphatic capillaries (Lacteals)
Defends body against diseases & allows humans to live with other organisms
List the lymphatic pathway in order:
1) Lymphatic capillaries
2) Afferent lymphatic vessel
3) Lymph nodes
4) Efferent Lymphatic vessels
5) Lymphatic trunks
6) Lymphatic collecting ducts
7) Subclavian veins in thorax
Microscopic, thin walled, closed-ended tubes merged into the lymphatic vessels
* Walls formed from simple squamous epithelium
Networks parellel blood capillaries throughout body
Tissue (Interstitial) fluid enters lymphatic capillaries (Lymph)
Lymphatic capillaries
Walls similar to veins but thinner
Contain semilunar valves to allow 1-way flow
Composed of 3 layers:
* Inner: Endothelial lining
* Middle: Smooth muscle & elastic fiber
* Outer: Connective tissue
Larger vessels lead to lymph nodes, then to larger lymphatic trunks
Lymphatic vessels
What is the difference between a lymphatic trunk & a lymphatic collecting duct?
Lymphatic trunk:
* Drains lymph from lymphatic vessels
* Drains into lymphatic collecting ducts
* Named from location (Lumbar, intestinal, intercostal, bronchomediastinal, subclavian, jugular)
Lymphatic collecting duct:
* Drains lymph from trunk
* Thoracic duct (Longer/wider; drains majority of body; begins as sac (“Cisterna chyli”) empties into L subclavian vein)
* R Lymphatic Duct (Smaller than thoraic duct, drains into upper R portion of body; Begins in R thorax & empties into R subclavian vein)
Capillary BP filters water & small molecules from plasma
Has same composition as blood plasma
Contains water & dissolved nutrients, gases, or hormones
Exception: Tissue fluid doesn’t contain large plasma protein, which remain in blood plasma to maintain osmotic pressure to draw back fluid into capillaries
* Tissue fluid = Blood plasma - plama protein
Tissue Fluid Formation
Increased tissue fluid hydrostatic pressure w/in interstitial space, forcing fluid into lymphatic capillaries forming lymph
Process prevents accumulation of excess tissue fluid or edema
* Ex of edema: Axillary lymph node removed during breast cancer surgery, lymphatic drainage obstructed from upper limb
Lymph formation
Has low hydrostatic pressure
Muscle activity influence movement of lymph through lymphatic vessels
* Contraction of skeletal muscles compress lymphatic vessels, moving lymph
* Resp. process creates low pressure in thorax & high pressure in abd. during inspiration (sends lymph from abd. to thorax)
* Smooth muscles in larger lympahtic vessels contract to aid in flow of lymph
Valves in lymphatic vessels prevent backflow
Lymph flow
What are the roles of lymphatic capillaries?
Absorb. of dietary fats in small intestine & delivery to bloodstream
Return small proteins filtered by blood capillaries to bloodstream
Collection of excess interstitial fluid
Delivery of excess fluid to bloodstream
Delivery of foreign particles to lymph nodes
Flap like valves between cells of lymphatic capillaries allow easy entry to tisue fluid
Unencapsulated lymphatic tissue of digestive, resp, urinary, & reproductive tracts
Tonsils & appendix composed of lymphatic nodules (Compact masses of lymphatic tissue)
Peyer’s patches are aggregates lymphatic nodules found in ileum (distal part of small intestine)
Mucosa-Associated Lymphoid Tissue (MALT)
List 3 lymphatic organs:
Encapsulated lymphatic tissue
Spleen
Lymph nodes
Thymus
Bone marrow
Contain macrophages to engulf/destroy foregin substances, damaged cells & cellular debris
* Contain lymphocytes to attack viruses, bacteria & parasite cells
Located along lymphatic vessels
* Filter pathogens from lymph
Found in groups/chains along paths of larger lymphatic vessels through the body
* Not found in Central Nervous System (CNS)
Lymph nodes
What major locations of the body have lymph nodes?
Cervical & pelvic Regions
Abd. cavity
Axillary region
Thoracic cavity
Supratrochlear region
Inguinal region
What are the primary functions of lymph nodes?
Filter harmful particles away from lymph
Immune surveillance
* Monitor body fluids via macrophages & lymphocyte production
Centers for lymphocyte production (like RBC)
Lymphocytes attack pathogens in lymph nodes
Macrophages engulfs & digests foreign substances, damaged cells & debris
Divided into lobules that contain lymphocytes derived from progenitor cells in red bone marrow
* Soft bilobed gland located in mediastinum
* Most are innactive (Thymocytes)
T lymphocytes (T cells) leave thymus to provide immunity
* Thymosin: Hormone produced in thymus to stimulate T cell maturation
thymus
Largest lymphatic organ that resembles larger lymph node
* Located in upper L abd. cavity, inferior to diaphragm & posterior & lateral to stomach
Contains venous sinuses filled w/ blood
* Filters blood
* Breaks down RBCs
2 tissue types:
* White Pulp: Contains lymphocytes & macrophages
* Red Pulp: RBC & many macrophages
Spleen
How does the lymphatic system defend the body against infections by pathogens?
Disease causing agents:
* Bacteria
* Viruses
* Protozoa (microorganism)
* Spores (Fungi)
To prevent pathogen entry or destroy any pathogen that enters the body
Mechanisms:
* Innate (Nonspecific) defense: General defense, Protect against many types of pathogens
* Adaptive (Specific) defense: More specific & precise, targeting specific antigens, carried out by lymphocytes that recognize certain foreign molecules
Immunity
What is the difference between Innate Defense Species Resistant & Innate Defense Mechanical Barriers?
Innate Defense Species Resistant:
* Contains species resistent to diseases that affect other species
* Certain species lack recpetors, temp, or chemical enviorment for a particular pathogen
Innate Defense Mechanical Barriers:
* Skin & mucous membranes form barriers & prevent enterance of pathogens
* Ex: As epidermis sloughs off, removes superficial bacteria; Ciliated epithelium in respiratory tract traps and sweeps away pathogens;Tears, saliva, and urine wash away microorganisms
Produces local redness, swelling, heat, & pain
* Redness d/t vasodilation
* Swelling results from increases capillary permeability and fluid entry into tissue spaces
* Heat is derived from blood arriving from deep areas of body
* Pain is d/t stimulation of pain receptors
White blood cells gather in area, and destroy pathogens by phagocytosis
* Inhibits spread of infection
Exudates (fluids) that contain fibrinogen and other clotting factors may form fibrin network
Following control of infection, phagocytes engulf and destroy dead cells
* Cells that were lost are replaced by cell division
Innate Defenses: Inflammation
List some Major Actions of an Inflammation Response:
Blood vessels dilate. Capillaries permeability increases & fluid leaks into tissue space
Tissues become red, swollen, warm, & painful
WBC invade region, Pus may form as WBC, bacteria cells & cellular debris accumulate
Tissue fluids containing clotting factors seep into the area, clot containing fibrin may form
Fibroblasts arrive, connective tissue may form around injured tissue
Phagocytes are active, Bacteria, dead cells & other debris are removed
Cells divide, newly formed cells replace injured ones
Enzymes in body fluids provide a chemical barrier to pathogens
* Ex: Pepsin in gastric juice; lysozyme in tears destroy microorganisms
Interferons block viral replication, act against growth of tumors, stimulate phagocytosis
Defensins are peptides produced by neutrophils and other granulocytes
* Cripple microbes by making opening in cell membranes or walls
Collectins are proteins that protect against many bacteria, yeast, and some viruses
Complement system: Group of inactive proteins in plasma and other body fluids that becomes activated by binding to surface of foreign cells
* Once activated, begins a cascade of reactions that stimulates inflammation, attracts phagocytosis, enhances phagocytosis, and causes cell lysis
Innate Defenses: Chemical Barriers
Phagocytes in the blood vessels and the tissues of the spleen, liver, or bone marrow remove particles from blood
Most active cells are neutrophils & monocytes
Chemicals from damaged tissue attract phagocytic cells to injury via chemotaxis
Monocytes that leave the bloodstream become macrophages, which can be free or fixed in tissues
Mononuclear phagocytic system (reticuloendothelium) consists of monocytes and macrophages of the body
Innate Defenses: Phagocytosis
Based on the ability to distinguish molecules that are part of the body (“self”) from “non-self”
* Third line of defense
Antigens: Non-self molecules that can evoke an immune response
Carried out by lymphocytes and macrophages that can recognize specific antigens
Adaptive (Specific) Defenses
Name two types of adaptive defenses:
Cellular immune response (performed by immune cells)
Humoral immune response (performed by antibodies)
Receptors on the surface of lymphocytes enable the cells to recognize non-self antigens
Lymphatic system responds to non-self antigens, but not self antigens
Most effective are large and complex molecules
Ex:
* Proteins
* Polysaccharides
* Glycoproteins
* Glycolipids
Antigens
Red bone marrow releases unspecialized lymphocyte precursors into blood
Half of cells settle in thymus, specialize, and are then released (become T cells)
Other half of cells differentiate in red bone marrow, and are then released (become B cells)
Lymphocyte (Orgins)
Name & describe the 2 main types of lymphocytes:
T lymphocytes (T cells, thymus-derived lymphocytes):
* Specialize in thymus
* Make up 70 to 80% of circulating lymphocytes
* Some settle in lymphatic organs, such as lymph nodes, thoracic duct, white pulp of spleen
B lymphocytes (B cells, B = Bursa of Fabricius in chickens):
* After release from bone marrow
* Make up 20 to 30% of lymphocytes in blood
* Abundant in lymph nodes, spleen, bone marrow, intestinal lining
List & describe the 4 types of Specialized T Cells:
Helper T cells (TH cells):
* Activate other cells by secreting cytokines
* Stimulate B cells to produce antibodies
* Stimulate activity of cytotoxic T cells
Cytotoxic T cells (TC cells):
* Attack virally infected, cancerous, or transplant cells
Memory T cells (TM cells):
* Provide future immune protection
Regulatory T cells (TR cells):
* Suppress immune responses after defeat of pathogens, which lowers chance of developing an autoimmune disease
List & describe the 4 types of Cytokines:
Colony-stimulating factors:
* Stimulate bone marrow to produce lymphocytes
Interferons:
* Block viral replication, stimulate macrophages to engulf viruses, stimulate B cells to produce antibodies, attack cancer cells
Interleukins:
* Control lymphocyte differentiation and proliferation
Tumor necrosis factor:
* Stops tumor growth, releases growth factors, causes fever that accompanies bacterial infection, stimulates lymphocyte differentiation
What are the 5 steps in B cell antibody production?
1) Antigen-bearing agents enter tissue
2) Encounters an antigen that fits its antigen receptors
3) Either alone or in conjunction w/ helper T Cells, B cell is activated
4) Some newly formed cell differentiate to become plasma cells
5) Plasma cells synthesize & secrete antibodies
* Molecular structure is similar to the activated B cell’s antigen receptors
What are the 7 steps in T cell antibody production?
1) Antigen-bearing agents enter tissues
2) Antigen-presenting cell, such as a macrophage, phagocytizes the antigen-bearing agent, and the macrophage’s lysosomes digest the agent.
3) Antigens from the digested antigen-bearing agents are displayed on the membrane of the antigen-presenting cell.
4) Helper T cell becomes activated when it encounters a displayed antigen that fits its antigen receptors.
5) Activated helper T cell releases cytokines when it encounters a B cell that has previously combined with an identical antigen-bearing agent.
6) Cytokines stimulate the B cell to proliferate, enlarging its clone.
7) Some of the newly formed B cells give rise to cells that differentiate differentiate into antibody-secreting plasma cells.
List and describe the 5 Major Types of Antibodies or Immunoglobulins (IG):
IgG:
* 80% of antibodies
* Acts on bacteria, viruses, toxins
* Occurs in Plasma and tissue fluid
IgA:
* 13% of antibodies
* Found in exocrine gland secretions
* Defends against bacteria & viruses
IgM:
* 6% of antibodies
* Acts on antigens in food and bacteria
* Occurs in plasma
* Reacts with antigens on some RBC membranes following mismatched blood transfusions
* Activates complement
* Reacts w/ antigens on RBC membranes
IgD:
* <1% of antibodies
* Found on B cells surfaces
* Activates B cell
* Common in infants
IgE:
* <1% of antibodies
* Found in exocrine gland secretions
* Promotes inflammation and allergic responses
What is the difference between Naturally acquired active Immunity & Artificially acquired active Immunity?
Naturally acquired active immunity: Obtained by a natural process, such as getting and recovering from the disease, or given from mother to fetus or infant
* Exposure to live pathogens
* Stimulation of an immune response with symptoms of a disease
Artificially acquired active immunity:Obtained by an injection, instead of a natural process
* Exposure to a vaccine containing weakened or dead pathogens or their components
* Stimulation of an immune response without symptoms of a disease
What is the difference between Naturally Acquired Passive Immunity & Artificially Acquired Passive Immunity?
Naturally Acquired Passive Immunity: Temporary immunity obtained via antibodies
* No antigen exposure
* No immune response is evoked in person’s immune system
Artificially Acquired Passive Immunity: Permanent immunity obtained via antigen contact
* Immune response is evoked, and memory B cells are produced
Which of the following are part of the first line of defense against pathogens?
A) Microorganisms are washed away by tears, saliva, and urine.
B) Particles trapped by the ciliated epithelium of the respiratory tract are swept out of the airways.
C) Bacteria are engulfed by macrophages.
D) The site of an infection is walled off by an inflammatory response.
E) Viral replication is blocked by interferon.
F) Bacteria are removed from the skin by
the sloughing off of epidermal cells.
A) Microorganisms are washed away by tears, saliva, and urine.
B) Particles trapped by the ciliated epithelium of the respiratory tract are swept out of the airways.
Match the following signs of inflammation with the correct description:
Pain, Heat, Redness, Edema
A) Greater blood volume enters area d/t vasodilation
B) Blood enters area from deeper body parts
C) Appropriate receptors are stimulated in area of injury or infection
D) Capillaries in area of injury or infection have increased permeability (leakiness).
Pain:
* C) Appropriate receptors are stimulated in area of injury or infection
Heat:
* B) Blood enters area from deeper body parts
Redness:
* A) Greater blood volume enters area d/t vasodilation
Edema:
* D) Capillaries in area of injury or infection have increased permeability (leakiness).
Which two of these factors are examples of chemical barriers important in innate defense?
A) lysozyme found in tears
B) mucus membranes
C) natural killer (NK) cells
D) pepsin and hydrochloric acid of gastric juice
A) lysozyme found in tears
D) pepsin and hydrochloric acid of gastric juice
Which of the following is an example of first line of defense of innate immunity?
A) interferon
B) lysozyme
C) mucous membranes
D) T and B lymphocytes
C) mucous membranes
Select three reasons why a given species may be resistant to diseases that affect other species (“species resistance”).
A) Cells/tissues lack lymphocytes and macrophages that a particular pathogen requires.
B) Cells/tissues lack receptors that a particular pathogen requires.
C) Cells/tissues lack the chemical environment that a particular pathogen requires.
D) Cells/tissues lack the temperature that a particular pathogen requires.
B) Cells/tissues lack receptors that a particular pathogen requires.
C) Cells/tissues lack the chemical environment that a particular pathogen requires.
D) Cells/tissues lack the temperature that a particular pathogen requires.
Which are characteristics of interferons?
A) plasma proteins that help with blood clotting
B) block viral replication
C) act as pyrogens
D) produced by lymphocytes and fibroblasts
B) block viral replication
D) produced by lymphocytes and fibroblasts
The redness and swelling associated with inflammation are both due to changes in …
A) excessive growth of capillaries in injured tissue
B) bleeding due to damage to blood vessels
C) blood vessel diameter and permeability
C) blood vessel diameter and permeability
What is the defense function of stomach acid and the gastric enzyme called pepsin?
A) promote the absorption of vitamins necessary for cell production
B) activate interferons and complement
C) kill pathogens that are swallowed
C) kill pathogens that are swallowed
Fill in the blank
The group of plasma proteins called (x) is involved in a cascade of reactions that defend against pathogens. The result is inflammation, the attraction of phagocytes, and enhancement of phagocytosis.
A) Albumin
B) Enzymes
C) Collagen
D) Complement
D) Complement
* involved in a cascade of reactions that defend against pathogens
* result is inflammation, the attraction of phagocytes, and enhancement of phagocytosis
Which mechanism increases phagocytic activity and indirectly inhibits microbial growth through an elevation of body temperature?
A) interferon activity
B) hypothermia
C) complement activation
D) fever
D) fever
Fill in the blank
Fever is part of the (x) defense of the body.
A) Innate (nonspecific) defense
B) Adaptive (Specific) defense
A) Innate (nonspecific) defense
What is the 3rd line od defense against a pathogen?
A) a mechanical barrier such as the skin
B) resistance to specific pathogens or to the toxins or metabolic products they release
C) a chemical barrier such as gastric juice
B) resistance to specific pathogens or to the toxins or metabolic products they release
Fill in the blank
Any large molecule capable of triggering an immune response is called a(n) (x).
A) Pathogen
B) Antigen
B) Antigen
What is the role of fever in innate defense?
To make the body less hospitable to certain pathogens.
Where do B cell precursors fully differentiate into B lymphocytes?
A) Spleen
B) Thymus
C) Yellow bone marrow
D) Red bone marrow
D) Red bone marrow
Fill in the blank
The ability to distinguish molecules that are part of the body from those that are foreign is integral to the
(x) line of defense against pathogens.
A) First
B) Second
C) Third
C) Third
Fill in the blank
An antigen is a molecule that can (X).
A) cause cell lysis by forming pores in a cell membrane
B) provoke an immune response
C) bind to and neutralize a pathogen
D) inhibit viral replication
B) provoke an immune response
Fill in the blank
T lymphocytes originate in the red bone marrow, then finish their maturation in the (x).
A) lymph node
B) yellow bone marrow
C) spleen
D) thymus
D) thymus
Why does a fever indirectly counters microbial growth?
Because higher body temperature cause the liver and spleen to sequester iron needed for microbial growth
What is a role of helper T cells?
A) release perforin, which destroys targeted cell
B) trigger activation of the complement system
C) stimulate B cells to make antibodies
D) phagocytize, digest, and present foreign antigens
C) stimulate B cells to make antibodies
The adaptive immune response includes which two of the following?
A) chemical Barriers
B) humoral immune response
C) mechanical barriers
D) natural Killer Cells
E) cellular immune response
B) humoral immune response
E) cellular immune response
What do Plasma cells produce and secrete in order to recognize nonself molecules?
A) Antigens
B) Antibodies
C) Haptens
D) Interferons
B) Antibodies
Fill in the blank
The release of IgM followed by IgG is associated with the (x) immune response.
A) Primary
B) Secondary
C) tertiary
A) Primary
During a primary immune response, in which order do the plasma cells release the first two types of antibodies?
A) IgM followed by IgG
B) IgA followed by IgG
C) IgM followed by IgB
D) IgG followed by IgM
A) IgM followed by IgG
Proteins that are present in plasma and body fluids that bind to antigens
Antibodies
Fill in the blank
During a (X) immune response, antibodies are produced more rapidly than during a (x) immune response.
A) primary; secondary
B) secondary; primary
B) secondary; primary
By which means does artificially acquired passive immunity occur?
A) normal exposure to a pathogen, leading to a primary immune response
B) receiving antibodies via placenta or breast milk
C) receiving a vaccine that triggers a primary immune response
D) receiving an injection containing antibodies produced by another individual
D) receiving an injection containing antibodies produced by another individual
