Lymphatic system lecture

Question 1

What is the pathway of the lymphatic system starting with the capillaries?

Answer 1

Lymph capillaries
Afferent lymphatic vessels
Lymph nodes
Efferent lymphatic vessels
Lymphatic trunks
Collecting ducts
Subclavian veins
Into the cardiovascular system

Question 2

What are the lymphatic capillaries within the villi of small intestines? What is their function?

Answer 2

Lacteals

Absorb fats

Question 3

What makes up the lymphatic system?

Answer 3

Lymph vessels, nodes

Thymus and spleen

Question 4

How do lymph vessels compare to veins?

Answer 4

They have 3 layers but are thinner

Lymph is moved via skeletal muscle contractions like blood through veins

They have valves

Question 5

What drains the lymph from the lymphatic vessels?

What are the 6 trunks?

Answer 5

Lymphatic trunks

Lumbar
Intestinal
Intercostal
bronchomediastinal
subclavian
Jugular

Question 6

What is a large storage area for lymph stores

Answer 6

Cisterna chyli

Question 7

What drains the lymph from trunks?
What are the names?
Which duct is the most important and why?

Answer 7

Lymphatic ducts

Right lymphatic duct and Thoracic Duct

Thoracic duct is most important because it drains 75% of the body’s lymph

Question 8

What is lymph fluid?

Answer 8

Tissue fluid that has entered a lymphatic capillary

that has been absorbed into lymphatic capillaries

Question 9

How is fluid formed in the tissues and what does it contain?

What does it not contain?

Answer 9

capillary pressure filters water and small molecules from the plasma leaving a fluid in the tissues with similar consistency as plasma

The fluid contains water and dissolved substances like smaller proteins that create plasma colloid osmotic pressure

Large proteins

Question 10

How is lymph formed and how is it absorbed?

Why is this important?

Answer 10

The fluid filtered from the plasma normally exceeds reabsorption leading to the net formation of tissue fluid

The increase in tissue fluid increases the hydrostatic pressure within the tissues forcing fluid into lymphatic capillaries forming lymph.

This is important because it prevents edema

Question 11

How does lymph move throughout the lymphatic vessels?

Answer 11

Actions of skeletal muscles
Respiratory movements
Smooth muscle in the larger vessels
Valves in the lymphatic vessels

Question 12

Where are lymph nodes located?

What do they contain?

Answer 12

Along the lymphatic pathway

Contain lymphocytes and macrophages to fight invading pathogens

Question 13

Where does the Afferent vessel enter a lymph node?
Efferent?

What would you expect to find in the Germinal Center of a lymph node?

Subcapsule?

Answer 13

The convex side
The concave with the Hilum

B cells

Macrophages, B cells

Question 14

What is the function of a lymph node?

Answer 14

Filter harmful particles from lymph

Act with Immune function provided by macrophages and lymphocytes

Also centers for lymphocyte production along with red bone marrow

Question 15

What is the thymus for?

What is a special characteristic of the thymus?

What implications does this have?

Answer 15

Site of T lymphocyte production and secretes protein hormones called thymosins

Larger in infancy and puberty than in an adult, and the thymus is replaced by fat and connective tissue in the elderly

As we get older, our ability to fight infection decreases

Question 16

What is the largest lymphatic organ?

What areas make it up and what are the contents?

Answer 16

Spleen

White pulp - lymphocytes

Red Pulp - red blood cells, lymphocytes, and macrophages

Question 17

What are the main types of defense the body has against pathogens and what are they?

Answer 17

Innate defenses : General defenses that protect against many pathogens

Adaptive defenses: Immunity, specific and targets antigens. Carried out by lymphocytes

Question 18

What is species resistance?

Answer 18

Refers to a given type of organism, or species, that develops diseases unique to it

Question 19

What is the first line of defense and is it innate or adaptive?

Answer 19

Mechanical barriers like skin, mucus membranes.

Innate

Question 20

What is the second line of defense and is it innate or adaptive?

Answer 20

All Innate

Chemical barriers “ Interferons, Defensins, collectins

Nk Cells

Inflammation

Phagocytosis

Fever

Question 21

What are the chemical barriers and what is their function?

Answer 21

Interferons - hormone like peptides that stimulate phagocytosis

Defensins - peptides produced by neutrophils and other granulcytes that make holes in bacteria cell walls

Collectins - proteins with a broad protection against yeasts, bacteria, and some viruses

Question 22

What are NK cells and what do they do?

Answer 22

Natural killer cells a re lymphocytes and defend against viruses and cancer by secreting perforins that destroy and infected cell

Can also increase inflammation

Question 23

How does inflammation assist with defense?

What is pus?

Answer 23

Produces local redness, swelling, heat and pain

White blood cells are invading the region, lots of phagocytes to destroy all the dead cells, bacteria, and debris

Form as white blood cells, bacterial cells, and debris accumulate

Question 24

What is phagocytosis?

What are the most active phagocytes?

What attracts phagocytes?

Answer 24

removing foreign particles from lymph

neutrophils and monocytes

chemical called chemotaxis

Question 25

What causes a fever to begin?

Answer 25

When a viral or bacterial infection stiumlates lymphocytes to proliferate, producing cells that secrete a substance called interleukin 1

Question 26

What is the complement cascade?

Answer 26

A group of proteins in plasma and other body fluids that stimulate inflammation, attract phagocytes and enhance phagocytosis. Engulfs and slows down pathogens as well.

Question 27

What is a phagocytic rage?

Answer 27

When the hypothalamus increases the body tempurature in to start a fever. The lymphocytes work over time. Specifically monocytes and neutrophils.

Question 28

What is the 3rd line of defense? What is it based on?

Answer 28

Adaptive immunity Resistance to pathogens or their toxins or biproducts the bodies ability to distinguish molecules that are self from non self

Question 29

What kind of molecules can elicit an immune response? What are they? example

Answer 29

Antigens and Haptens Antigens are like markers on a cell, they can be proteins, polysaccharides, glycoproteins, and glycolipids Haptens are not antigenic by themselves but in combination with another larger molecule, they can cause an immune response A penicillin reaction is cause by haptens as well as dust and pet dander

Question 30

What is required before t-cell activation? What are the types of T cells and their function? What can T-cells synthesize and secrete?

Answer 30

The DC cell must present an antigen via the major histocompatibility complex Helper T-Cells: (CD4) stimulate B cells to produce antibodies Cytotoxic T Cells (CD8) release perforins Memory T cells - dont attack initially, but wait for a later encounter. They create helper T cells and Cytotoxic T cells the second time around Cytokines

Question 31

What are some types and functions of cytokines?

Answer 31

Colony-stimulating factors- stimulate bone marrow to make lymphocytes Interferons - stimulate B cells to produce antibodies, and attack cancer cells and prevent viral replication Interleukins - control lymphocyte growth Tumor necrosis factor - stops tumor growth, causes fever

Question 32

When can B cells be activated? What do they do?

Answer 32

When an Antigen fits the shape of its receptor, usually requires T cell activation and cytokines to stimulate B cells Some become memory, some become differentiate into plasma cells and produce and secrete large globular proteins called antibodies or immuno globins

Question 33

Why would a higher response be seen the second time someone comes in contact with a pathogen?

Answer 33

Because there are already memory B cells and T cells

Question 34

What is the mechanism and result of these types of immunity? Naturally acquired active immunity? Artificially acquired active immunity? Artificially acquired passive immunity? how long does it last? Naturally acquired passive immunity? How long does it last?

Answer 34

exposure to live pathogens (immune response with symptoms) Vaccine containing weakened pathogens (immune response without symptoms of a disease) Injection of gamma globulin with antibodies or antitoxin (short-term immunity without immune response) couple of weeks Antibodies passed to fetus from pregnant woman with active immunity or through breast milk (short term immunity for newborn without stimulating an immune response) 6 months to a year

Question 35

What are the characteristics of these allergic reactions? Type 1 Type 2 Type 3 Type 4

Answer 35

Immediate reaction symptoms are hives, asthma, eczema, gastric disturbances and anaphylactic shock antibody-dependent cytotoxic reaction 1-3 hours to develop transfusion reaction Immune-complex reaction takes 1-3 hours to develop antibody complexes cannot be cleared from body causes damaged tissues delayed-reaction allergy results from repeated exposure to allergen causes eruptions and inflammation of the skin takes about 48 hours to occur

Question 36

how does a basic allergic reaction work?

Answer 36

B-cells come in contact with the allergen and plasma cells secrete antibodies the antibodies attach to mast cells that not release allergy mediates like histamine etc. causing a reaction

Question 37

What is a tissue rejection reaction? | How is it stopped?

Answer 37

when a donors tissues are recognized as foreign resembles a cellular immune response against antigens Immunosuppressive drugs used (forever) to prevent rejection

Question 38

What are the transplant types? Donor and example

Answer 38

Isograft - identical twin- bone marrow for leukemia Autograft - self - skin graft Allograft - same species- kidney transplant Xenograft - different species - heart valves from pig

Question 39

What are some lifespan changes?

Answer 39

Immune system declines later in life as thymus shrinks to only 25% potency higher risk of infection antibody response to antigens becomes slower elderly may not be candidates for cetrain medical treatments that suppress immunity