BIO 142 Lymphatic System Learning Objectives/Yost

Define immunology

-the study of the molecules, cells, organs, and systems responsible for the recognition and disposal of foreign (nonself) material -how body components respond and interact -the desirable and undesirable consequences of immune interactions -the ways in which the immune system can be advantageously manipulated to protect against or treat disease

Describe the flow of lymph through a lymph node

1)lymph flows into lymph node through afferent pathway 2) Lymph runs though various cells 3) Exits lymph node through efferent pathway

List and describe the three functions of the lymphatic system

1. It helps the body to get rid of bodily wastes like toxins, dead cells, and unwanted materials 2. The primary function of this system to transport the lymph throughout the body 3. It aids in providing immunity to all the parts of the body through the circulation of white blood cells

List the seven locations of lymph nodes found in the body and the area of the body they are filtering lymph from

1. cervical lymph node (neck) 2. axillary lymph nodes (armpits) 3. thoracic lymph node (thoracic cavity/mediastinum) 4. abdominal lymph nodes (posterior abdominal wall) 5. intestinal lymph node (mesentery appendix) 6. inguinal lymph nodes (groin) 7. popliteal lymph nodes (back of knees)

Differentiate between the three lines of defense

1st line of defense (innate immunity) is a surface protection composed of anatomical and physiological barriers that keep microbes from penetrating sterile body compartments. Response is nonspecific, one size fits all, no memory cells 2nd line of defense (innate immunity) is a cellular and chemical system that comes immediately into play if infectious agents make it past the surface defenses. Examples include - phagocytes that engulf foreign matter Response is nonspecific, one size fits all, no memory cells 3rd line of defense (acquired immunity)- specific immune response; is resistance against infecting foreign substances by releasing certain antibodies tailored made to type of pathogen, has memory cells (so stays in system longer)

Which line(s) of defense have specificity and memory?

3rd line of defense only

Define pathogen

A disease causing agent that can cause death and/or damage to an organism, host, or cell

Which portions of the immune system are responsible for the production of antibodies?

Acquired immune system

What immune cells produce antibodies?

B cells

List the tissue where B cell maturation occurs and the amount of tissue in a child compared to an adult

B cells precursor originate in the red bone marrow. The thymus is larger in children than compared to adults

List and describe the 6 categories of infectious agents

Bacteria - microscopic/unicellular/cell walls (gives them rigidity), lack organelles and organized nucleus. Shape-rounded, rectangular, cork-screw.. Viruses- infectious agents (not cells), acellular, microscopic; has a composition of DNA or RNA and has protein coat around them. Virus attaches to cell or host, penetrates cell membrane, and injects nucleic acid (DNA or RNA) into cell; than replicates host and causes host to replicate the virus's cell. Fungi - microscopic or macroscopic, eukaryotic (similar to human cells); molds, yeast, multicellular, have a cell wall. Responsible for most skins infections; immunocompromised more susceptible to these type of infections Protozoans - generally single cells; microscopic; eukaryotic cells; can move; different shapes; not all are pathogenic; aka "simple animals" Parasites- multicellular; macroscopic; eukarytoic; worms - flatworms (Cestodes), roundworms (nematodes), tapeworms, hookworms; mostly affects GI system Prions- virus-like organisms made up of prion protein. misshaped proteins or misfolded; affects nervous system by attacking nerve cells. Once ingested; will instruct or own prions to fold in different ways which can lead to various diseases as a result

Where do you expect to find lymphatic nodules in a lymph node?

Cortex

Where would you expect to find untrained lymphocytes in the thymus?

Cortex

Which of the following processes occur in the glomerulus of the kidney when material from the blood enters the nephron tubule lumen?

Filtration

Describe the location of the following in lymph nodes: capsule, cortex, medulla and hilum

Lymph enters the node via afferent lymphatic vessels, which are located within the capsule. Lymph from the extracellular space carries antigens and antigen presenting cells such as dendritic cells and macrophages from the tissues to the lymph nodes. The lymphatic vessels contain valves. The subcapsular sinus is lined by a layer of endothelial cells. Beneath the endothelial cells are macrophages that retrieve antigen from the lymph in the subcapsular sinus. Medulla is the middle portion. Capsule is around the afferent lymph vessels. The Hilum is where the Efferent lymphatic vessels are. The Cortex is located at the Germ The body of the lymph node is divided into an outer cortex and an inner medulla. The cortex contains a high concentration of lymphocytes while the inner medulla is less cellular.

List three differences between the cardiovascular and lymphatic systems

Lymphatic - only has one directional type of flow; contains lymph (interstitial fluid); as lymph moves through the vessels it then moves to lymph nodes and makes sure lymph contains no "non-self cells" and no pathogens; has no pump Cardiovascular - two directional flow, to and away from heart; has pump; goes to heart, lungs, tissues and various organs; contains blood

List the location and function of GALT and MALT. Predict what type of cells would found in each, and their function

MALT - mucosal associated lymphoid tissue located in the urinary and respiratory tract, and tonsils under epithelial tissue of mucus membranes. B and T cells have interaction with non-self cells Waddler's Tonsil Ring Galt - gut associated lymphoid tissue found in Peyer's patch (cells found in the mucosa and submucosa of the small intestine and contain CD4, CD8, T and B cells) and appendix

List the location and function of GALT and MALT

MALT - urinary tract, respiratory tract, and female reproductive tract Stimulation of B cells leads to the production of immunoglobulin A (IgA) and immunoglobulin M (IgM) within the Peyer patches, preventing adherence of bacteria and viruses to the epithelium and thus blocking entry to the subepithelial layers of the intestine. GALT -Gut associated lymphoid tissue The intestine and the gut-associated lymphoid tissue (GALT) are essential components of whole body immune defense, protecting the body from foreign antigens and pathogens, while allowing tolerance to commensal bacteria and dietary antigens. The requirement for protein to support the immune system is well established.

Which of the following describes large, phagocytic, pathogen-destroying cells in body tissues?

Macrophages

Multicellular parasite are microscopic or macroscopic? Eukaryotic or Prokaryotic?

Macroscopic, eukaryotic

List the function of mast cells

Mast cells are immune cells that take part in a variety of physiological responses. They are located in the tissues and along blood vessels, and they release substances like histamine to fight infections or allergic reactions.

What infectious agents are visible to the naked eye?

Multicellular parasites

Compare cells and structure found in white and red pulp as well as the function of both

Open Circulation vs Closed Circulation a) open circulation: blood travels in Red Pulp sinuses) closed circulation: blood travels throughout vessels which drain into the splenic vein

Which lymph nodes occur in the back of the knee and receive lymph from the lower legs?

Popliteal lymph node

Describe the mechanisms that ensure that lymph moves along the various lymphatic vessels

Pressure is low, and speed is slow, so mechanisms to return lymph to CV system include: skeletal muscle pump -contraction of skeletal muscle pushes on lymphatic vessels which increases their pressure and moves lymph forward Valves - help ensure one-way flow of lymph fluid through vessels. Respiratory pump - inhaling and exhaling, changes pressure in thoracic cavity. During inhalation, pressure in the thoracic cavity has decreased, but in the abdominal cavity hasn't changed, so because the pressure is higher in the abdominal cavity in compared to the thoracic cavity, cause a pressure gradient which will cause lymph to flow.

Compare the functional differences between primary and secondary lymphoid tissues

Primary lymphoid tissues areas where T and B cells mature. B cells mature in the Bone marrow and T cells mature in the Thymus. The T cells become immunocompetent, where they are able to determine between "self-cells" and "non-self cells". Secondary lymphoid tissues - areas where mature lymphocytes first encounter potential pathogens. This includes the lymph nodes, spleen, MALT (mucosa-associated lymphoid tissue) and diffuse lymphoid tissue

What type of infectious agent is solely a misfolded protein?

Prion

Name the two lymphatic ducts and describe the areas of the body they are draining.

Right lymphatic duct - right arm; right side of head; thorax (right side) Thoracic duct- below diaphragm; left arm; left side of head; left side of neck; thorax (left side)

Describe the location of follicles and germinal center and what is occurring in the germinal centers.

The germinal center (GC) is a specialized microstructure that forms in secondary lymphoid tissues, producing long-lived antibody secreting plasma cells and memory B cells, which can provide protection against reinfection

Describe the anatomical structure of lymphatic capillaries and how those structures facilitate interstitial fluid removal

Transport of lymph begins with lymphatic capillaries -smallest lymphatic vessels open at distal end so lymphatic fluid can be brought into vessels have 3 layers - tunica interna, has endothelium and valves tunica media, has elastic fibers and smooth muscles tunica externa, thin outer layer

What type of infectious agent is composed of genetic material and a protein coat?

Virus

Define lymphatic system

a collection of organs, tissues, ducts, and vessels that help to make or transport lymph

Define lymph

a colorless fluid (like plasma) containing white blood cells (extracellular fluid), that bathes the tissues and drains through the lymphatic system into the bloodstream. Clear, and yellowish, protein poor, non- clotting ability

Define lymphatic tissues

a tube that transports a collection of lymphocytes (B and T cells) and macrophages but is separated from other cells of the tissue by some connective tissue capsule.

List the function of the NK (Natural Killer) cells

a unique group of defensive cells that can lyse and kill cancer cells and virus-infected body cells before the adaptive immune system is activated

Define immunity

ability of the body to resist may (nonliving and living) agents that can cause disease; resistance to disease

List and describe the three layers possible in the large lymphatic vessels

are thin-walled, delicate tubes, become less in number and larger the closer they get to the heart three layers are: tunica interna - endothelium and valves tunica media - elastic fibers and smooth muscles tunica externa - thin outer layer

Describe the blood flow through the spleen

blood enters the spleen via trabecular artery (TA) the TA branches into the central artery (CA) in the white pulp; filtration of blood starts here the CA branches into the penicillar arterioles and these terminate into 2 or 3 sheathed capillaries (SC) SC have fenestrae that allow macrophages to pass; all cells must transverse the wall of macrophages before entering the Red pulp erythrocytes now enter the sinuses of the Red Pulp and must pass through the sinusoid walls with macrophages for more filtration the sinuses drain erythrocytes into progressively larger sinuses until they drain into the splenic vein and to the portal vein

Fungi are microscopic or macroscopic? Prokaryotic or eukaryotic?

both, eukaryotic

Define macroscopic

can be seen by the naked eye

Describe the arrangement of T cells in the thymus

capsule covering, separating it from other connective tissue, separated into lobes by trabeculae, separated into lobules: central medulla - central region of lobes, fully mature immunocompetent T cells; outer cortex - outer portion, has immature T cells Cortex-untrained lymphocytes Medulla - mature lymphocytes Corticomedullary junction : epithelial-reticular cells lines cortex; Hassall's corpuscle/body - junction lined by reticular cells, separates the immature T cells from mature T cells (move through junction). If cells don't mature correctly, macrophages will destroy them

Define immunocompetent cell

cells that have the ability to recognize self cells and non-self cells

What is the name of the blood vessels in the spleen that are completely covered by T cells?

central artery

List the vessels that lymph flows through as it moves from lymphatic capillaries into the cardiovascular system

collecting vessels lymphatic capillaries picking lymphatic fluid, interrupted by lymph nodes, which lymph passes through; then 6 lymphatic trunks which pick up lymphatic fluid from major portions of the body, merge to form two largest lymphatic vessels - Right lymphatic duct - receives lymph from right arm, right side of the head, thorax, and empties into the right subclavian vein. Thoracic duct - starts from the abdomen, receives lymph from parts of body below the diaphragm, left arm, left side of head and neck, and thorax, and empties into the left subclavian veins. Subclavian veins bring lymph back into blood vasculature

Define lymphatic organs

consist of lymphatic cells that are surrounded by a connective tissue capsule

List the function of reticular cells

fibroblast-like cells that produce the reticular fiber stroma, which is a network that supports the other cells types in lymphoid organs and tissues

Describe the two functions of lymph nodes

filters lymph/screens lymph for foreign antigens lymphocytes interact with nonself cells/initiate immune response

List the function of the B cell

helps in making antibodies

Distinguish between innate and acquired immunity

innate defense system - is present from birth, while acquired develops over growth Innate- always prepared, responses within minutes to protect body from foreign substances. Has two differnt lines of defense; nonspecific resistance. Ist line of defense is external body - skin and mucous membranes. 2nd line of defense - Internal defenses are phagocytes; natural killer cells; inflammation; antimicrobial proteins; fever Acquired - requires more time to react; specific immune response/ Humoral immunity - B Cells; Cellular immunity - T Cells; accessory cells; and cytokines They innate and acquired immune system release and recognize may of the same defense molecules, but the innate is not specific, where the acquired is specific. Innate have specific pathways to target certain foreign substances. Proteins are released during innate responses which alerts acquired immune system to the presence of foreign bodies.

Define microscopic

invisible to the naked eye

List the function of dendritic cells

is to present antigens and the cells are therefore sometimes referred to as "professional" APCs. In addition, only the dendritic cells have the capacity to induce a primary immune response in the inactive or resting naive T cells lymphocytes

Characteristics of T cells

made in bone marrow but mature in Thymus do not produce antibodies responsible for cell-mediated immunity can target and selectively destroy virus-infected cells and cancer cells Helper T cells secrete cytokines which release chemicals to regulated the immune response some T cells, Cytotoxic T cells directly kills infected cells or some other intracellular pathogen (non-self antigen-bearing cells) T cells receptors do not recognize whole antigens, but instead react only to small fragments of antigens T cells=Helper T cells, Memory T cells, Cytotoxic T cells, and Cytokines

What is the term for agents that are too small to be visualized with the naked eye?

microscopic

Protozoan are microscopic or macroscopic? Prokaryotic or eukaryotic?

microscopic, eukaryotic

Prions are microscopic or macroscopic? Eukaryotic or Prokaryotic?

microscopic, neither

Viruses are microscopic or macroscopic? Prokaryotic or eukaryotic?

microscopic, neither

Bacteria is microscopic or macroscopic? Prokaryotic or eukaryotic?

microscopic, prokaryotic

Define immune system

not an organ system; a cell population that inhabits organs and defends the body against disease.

Acellular

not consisting of, divided into, or containing cells.

List the function of macrophages

play a role in body protection and the immune response by phagocytizing foreign substances and by helping to activate T cells

The term "primary lymphatic structure" applies

red bone marrow and thymus

Inflammation, fever, complement and phagocytes are all components of the

second line of defense

Although they are not a site of lymphocyte formation, _________ lymphatic structures provide sites where immune responses are initiated

secondary

Define lymphatic capillaries

smallest lymphatic vessels that pick up the fluid that leaks into your tissues from your bloodstream and return it to your circulatory system. Have an opening at their distal end so lymphatic fluid can pass through into the vessels to organs and tissues. The capillaries have endothelial cells which loosely overlap each other and are tethered to surrounding tissue by protein filaments. The endothelium of the capillaries creates valvelike flaps that open when interstitial fluid pressure is high, and close when it is low.

List the function of the T cell

some aide in making antibodies and others aide in other immune responses

Describe the location of the cortex, medulla, capsule, white and red pulp in the spleen

spleen, organ of the lymphatic system located in the left side of the abdominal cavity under the diaphragm, the muscular partition between the abdomen and the chest There is a dense connective tissue capsule that sends conspicuous trabeculae to partially subdivide the organ. Unlike the thymus and lymph nodes, the spleen lacks division into cortex and medulla. The spleen is encased in a thick connective-tissue capsule (the white pulp and red pulp separated). The white pulp is lymphoid tissue that usually surrounds splenic blood vessels. The red pulp is a network of splenic cords (cords of Billroth) and sinusoids (wide vessels) filled with blood, and it is in the red pulp that most of the filtration occurs.

Name the cardiovascular vessels that lymph enters

subclavian vein (right and left)

Define lymphatic vessels

thin-walled, delicate vessels that transport lymph (sporadically interrupted by lymph nodes), converge as move closer to heart

Describe the location of the cortex and medullar in the thymus as well as what process is occurring in each area.

thymus - a pyramid-shaped organ which produces T cells of lymphocytes located in the chest in an area of anterior to your heart and posterior to the sternum The outer cortex is the outer portion of immature T cells, supported by a framework of epithelial reticular cells. A few macrophages are present. A thin connective tissue capsule surrounds the thymus; blood vessels enter the thymus through the capsule and its septa The medulla - the epithelial cells provide structural support to the medulla and negatively select self-reactive T-cells to generate tolerance against self-antigens. A distinguishing feature of the medulla is the presence of Hassall's corpuscles. They are concentric arrangements of flattened epitheloid cells that are acidophilic

Where do T lymphocytes mature?

thymus gland

List the function of Neutrophils

to destroy foreign molecules or materials that enter the body through phagocytosis - including microorganisms that could cause disease.

What is the innermost tunic (layer) of a large lymphatic vessel?

tunica intima

B-lymphocytes are

white blood cells that are generated in red bone marrow.

What portion of the spleen can you find macrophages, dendritic cell, B cells, and T cells responding to microbes and foreign invaders?

white pulp