Chapter 14 Lymphatic System and Immunity

Question 1

What are the general functions of the lymphatic system?

Answer 1

Get fluid back to the bloodstream and kill shit.

Circulating body fluids, transport excess fluid away from interstitial spaces and return it to the bloodstream. Secondary function is to enable the body to live with organisms. Cells and biochemicals of the lymphatic system launch generalized and targeted attacks against foreign particles….

Question 2

Distinguish between the thoracic duct and the right lymphatic duct.

Answer 2

Thoracic duct, collects lymph from the legs, abdominal regions, left upper limb, and left side of the thorax, head, and neck, and empties into the left subclavian vein near the junction of the left jugular vein.
The right lymphatic duct, receives lymph from the right side of the head and neck, right upper limb, and right thorax, and empties into the right subclavian vein near the junction of the right jugular vein.

Question 3

What is the relationship between tissue fluid and lymph?

Answer 3

Lymph is tissue fluid that has entered a lymphatic capillary.

Question 4

How do plasma proteins in tissue fluid affect lymph formation?

Answer 4

Plasma protein is too large to pass through blood capillaries. So it maintains osmotic pressure and draws fluid back into the capillaries by osmosis.

Question 5

What are the major functions of lymph?

Answer 5

Lymph returns most of the small proteins to the bloodstream, and it transports foreign particles, such as bacteria or viruses to lymph nodes.

Question 6

What factors promote lymph flow?

Answer 6

Contracting skeletal muscles moves lymph through out the body and breathing squeezes lymph out of the abdominal cavity.

Question 7

What is the consequence of lymphatic obstruction?

Answer 7

edema - fluid accumulation in interstitial spaces, or swelling.

Question 8

Distinguish between a lymph node or a lymph nodule.

Answer 8

Lymph nodule’s are masses of B cells and macrophages in the cortex of the lymph nodes.

Question 9

What are the major functions of the lymph nodes?

Answer 9

to fight off invading microorganisms

Question 10

Why are the thymus and the spleen considered part of the lymphatic system?

Answer 10

They function similarly to lymph nodes.

Question 11

What are the major functions of the thymus and the spleen?

Answer 11

Thymus - houses many lymphocytes, most of which mature into T lymphocytes, which leave the thymus and provide immunity.
Spleen - is the largest lymphatic organ. It resembles a large lymph node, however it’s venous sinuses are filled with blood instead of lymph. It is filled with lymphocytes and macrophages.
The spleen filters blood the way that other lymph nodes filter lymph.

Question 12

What is an infection?

Answer 12

The presence and multiplication of a disease-causing agent or pathogen.

Question 13

Explain seven innate defense mechanisms.

Answer 13

• Species resistance -when a species is incompatible with a pathogen.
• Mechanical barriers - skin and mucous membranes that line passage ways of the body are the first line of defense.
• Chemical barriers - enzymes in body fluid.
• Natural killer cells (NK) - Small population of lymphocytes that provide adaptive defense mechanisms.
• Inflammation - blood and tissue fluid fill the area, stimulating white blood cells to the sites.
• Phagocytosis - cells remove foreign particles.
• Fever - pathogens cannot survive the higher temperature, and phagocytic cells attack more vigorously.

Question 14

What is immunity?

Answer 14

resistance to specific pathogens or toxins.

Question 15

What is the difference between an antigen and a hapten

Answer 15

Antigen - a marker in the body that cells identify as either part of yourself of foreign.
Hapten - A small molecule, similar to an antigen, but it is too small for your body to recognize it.

Question 16

How do T cells and B cells originate?

Answer 16

T cells - in fetal development unspecialized cells are released from the bone marrow and go live in the thymus, where they become T lymphocytes.
B cells - lymphocytes stay in the red bone marrow until they differentiate and become B lymphocytes.

Question 17

How do T cells become activated?

Answer 17

When a macrophage phagocytes a bacterium and digests it into lysosomes. Some of the antigens exit the lysosome and move to the surface, where they are displayed on the membrane. When a T cells comes into contact it is activated.

Question 18

What are some functions of cytokines?

Answer 18

enhance cellular responses to antigens.
ex. - interleukins and colony-stimulating factors, which stimulate leukocyte production in red gone marrow and activate macrophages.

Question 19

Name three types of T cells.

Answer 19

helper T cell, becomes activated when its antigen receptor combines with displayed foreign antigens.
Cytotoxic T cell, recognizes and combines with non self antigens that cancerous cells or virally infected cells display on their surfaces.
memory cells - remember past threats and immediately become t cells and helper t cells upon subsequent exposure.

Question 20

How do cytotoxic T cells destroy cells bearing foreign antigens?

Answer 20

combines itself with non self antigens on cancerous cells or virally infected cells, then it PROLIFERATES (splits itself into more cells). Then they release perforin protein that cuts pore like openings/ destroys the cells.

Question 21

How are B cells activated?

Answer 21

when it encounters an antigen whose molecular shape fits the shape of its antigen receptors.

Question 22

How does the antibody response protect against diverse infections?

Answer 22

An individual B cells can produce and estimated 10 mill to 1 bill different varieties of antibodies.

Question 23

Which immunoglobulins are most abundant, and how do they differ from each other?

Answer 23

Most abundant are immunoglobulin A, immunoglobulin G, and immunoglobulin M.
A - in exocrine gland secretions, breast milk, tears, nasal fluid, gastric juice, intestinal juice, bile, and during.
G - in plasma and tissue fluids
M - antibody in plasma respones to contact with certain antigens in foods or bacteria.

Question 24

In what general ways do antibodies function?

Answer 24

Direct attacks, activate complement, or stimulate localized changes.

Question 25

How is complement activated?

Answer 25

IgG or IgM combine with antigens, which triggers reactions that activates the complement protein.

Question 26

What is the function of complement?

Answer 26

Coating the antigen, making it more susceptible to phagocytosis, attracting macrophages and neutrophils into the region, rupturing membranes, clumping antigen-bearing cells, and altering the molecular structure of viruses, making them harmless.

Question 27

Distinguish between a primary and a secondary immune response.

Answer 27

primary - Activation of B or T cells after they meet the antigens the will kill.
secondary - if the antigen is encountered again, the memory cells produce the secondary response.

Question 28

How are allergic reactions and immune reactions similar yet different?

Answer 28

Allergy - immune response to a non harmful substance, however it can damage tissue.

Question 29

How does tissue rejection reaction involve an immune response?

Answer 29

The body recognizes a foreign substance and attacks it.

Question 30

How is autoimmunity an abnormal functioning of the immune response.

Answer 30

The body is attacking (self) antigens instead of (foreign) antigens.