Redo 8.3 Flashcards
What is the lymphatic circulatory system?
A network of vessels, with associated glands or nodes that extends throughout the body
What does the lymphatic system collect?
A fluid called lymph
What is lymph made of?
Interstitial fluid
What is interstitial fluid?
Fluid that surrounds all cells in the body
What color is lymph?
Colorless or pale yellow
What does the lymphatic system do?
Helps to maintain the balance of fluids in the body
How does plasma enter the lymph vessels?
As blood circulates the capillaries, some plasma escapes and become part of interstitial fluid. It is then absorbed into lymph vessels
How does plasma rejoin the main circulatory system?
Through ducts that empty into large veins near the heart
Why isn’t the lymphatic system a continuous circuit?
Because lymph forms in close ended tubes in capillary beds
What do specialized lymph vessels do in the intestines?
Some lymph capillaries are found in intestinal villi, they carry digested fats throughout the body
What does the lymphatic system work with white blood cells to do?
Protect the body against infection
Where do lymphocytes mature?
In the lymph nodes
What are lymph nodes?
Glands that are found throughout the lymphatic system
What are lymphocytes?
A type of white blood cell
Where are macrophages found?
In the lymph nodes
What do macrophages do?
Trap and destroy bacteria
What can an infection do to the lymphatic system?
Cause the number of macrophages and lymphocytes to increase
What is a pathogen?
A biological agent that causes disease or illness to its host
How does the human body defend itself against pathogens?
By preventing entry or destroying them when they enter
What are the 3 defences of the body?
- Barriers to keep pathogens out
- General/non-specific against a wide variety of pathogens
- Specific defenses against particular pathogens
What is the first line of defence?
The physical and chemical barriers of the body
What are examples of the physical and chemical barriers of the body?
Eyelashes Cilia of the respiratory tract Tears Stomach Acid The skin
What is the largest first defence against pathogens?
The skin
Why is the skin a hostile environment for microorganisms?
The outer layer is dry and contains large amounts of keratin which is tough and indigestible
What does the skin’s oil contain?
Bactericides
What does perspiration do to the skin?
Forms an inhospitable layer for microbial growth
What is the second line of defense for the body?
Non-specific defenses
What types of white blood cells does the non-specific defenses contain?
Macrophages
Neutrophils
Monocytes
What is cell mediated immunity?
A non-specific defense that involves activation of macrophages, neutrophils, and monocytes
What do neutrophils, monocytes and macrophages do?
They are white blood cells that kill bacteria using phagocytosis
Where do macrophages develop from?
Monocytes
Where are macrophages found?
Liver Spleen Brain Lungs Blood and interstitial fluid
Which defense are natural killer cells found in?
Non-specific defense
What do natural killer cells do?
Target body cells that have become cancerous or infected by viruses
What are the names for the 3rd line of defense?
Specific Defenses or Immunity
What is immunity developed by?
The actions of the specific defenses using antibodies
What is antibody-mediated immunity?
A component of the immune system that involves the activation of lymphocytes and the secretion of antibodies specific to a specific antigen
What are antibodies?
Proteins that recognize foreign substances and act to neutralize or destroy them
Why does each person develop an immune system?
Because of exposure to foreign substance overtime and variations in genetic makeup
What is an immune system?
The unique ability to deal with a wide variety of possible infections
What is the function of the specific immune system primarily a function of?
Lymphocytes in the circulatory system
What are the 2 groups that lymphocytes divided in the specific immune system?
B lymphocytes (B cells) or T lymphocytes (T cells)
What criteria are lymphocytes divided by in the specific immune system?
Where they mature
Where do B cells mature?
In bone marrow
Where do T cells mature?
In the thymus gland, which is located near the heart
Why does the body catalogue the molecules that are already present in the body?
So your body could recognize proteins and other as part of the self
What are antigens?
Molecules found on the surface cells and on pathogens.
What do antigens do?
They create an identification system
What do antigen receptors T and B cells do?
Allow them to recognize foreign antigens and begin responding to invasion
What do antibodies have that help them?
Antibodies have the same shape antigen receptor for a specific antigen so they can bind with and neutralize the antigen
What do different B cells produce?
Different antibodies
Why do B cells produce produces different antibodies?
The variation increases the possibility that the body will have an antibody that can recognize and bind to an invading pathogen
What happens once a B cell is activated?
It enlarges and divides to produce memory B cells and plasma cells
What does a plasma cell created by a B cell do?
They produce enormous amounts of the same antibody created by the B cell and release the antibodies into the bloodstream to fight infection
What do memory B cells do after being created by B cells?
Remain in the blood ready to trigger another immune response when necessary
When are helper T cells activated?
After a pathogen has been destroyed by phagocytosis and the antigens from the pathogen move to the surface of the macrophage that destroyed it
What it the process called when T cells are activated?
Cellular immunity
What are the 4 types of T cells in cellular immunity?
Helper T cells
Killer T cells
Suppressor T cells
Memory T cells
What do helper T cells do in cellular immunity?
When a helper T cell recognizes an antigen from a dead pathogen, it gives off chemical signals that stimulate the actions of macrophages (B cells) and the other T cells
What do killer T cells do?
After being called to action by helper T cells, they bind with infected cells and destroy them by puncturing a hole in their cell membranes
What can killer T cells be activated by?
By chemical signals from a helper T cells or directly by the presence of an invading pathogen and the associated antigen
What do suppressor T cells do in cellular immunity?
They slow and suppress the process of cellular immunity to ensure normal tissue is not destroyed
What do the T cells that do not respond to invading antigens do?
They turn into memory T cells
What do memory cells do?
They remain in the bloodstream and are able to act quickly if the antigen is encountered again
What is another name for killer T cells?
Cytotoxic cells
What is a blood transfusion?
The transfer of blood from one person to another
Why are only certain types of blood compatible with each other?
Because red blood cells carry specific antigens and plasma carries certain antibodies
What determines a person’s blood type in the ABO system?
The presence or absence of type A and type B antigens
What determines the type of antigens a person has?
It is an inherited characteristic
What type of antigens does a person with type A blood have?
Type A antigens
What type of antigens does a person with type B blood have?
Type B antigens
What type of antigens does a person with type AB blood have?
Both A and B antigens
What type of antigens does a person with type O have?
They have no antigens
What type of antibodies does a person with type A blood have?
Anti-B antibodies in the plasma
What type of antibodies does a person with type B blood have?
Anti-A antibodies in the plasma
What type of antibodies does a person with type O blood have?
Anti-B antibodies and Anti-A antibodies in the plasma
When do antibodies appear?
Within several months after birth
What type of antibodies does a person with type AB blood have?
They have no antibodies
What is another antigen found in red blood cells called?
The Rh factor
What does it mean to be Rh+?
This means a person has the Rh factor on their RBC
What does it mean to be Rh-?
This means a person does not have the Rh factor on their RBC
What type of antibodies do people who are Rh- have?
People who are Rh- usually don’t have antibodies to the Rh factor but may develop them when they are exposed to the Rh factor during a blood transfusion or pregnancy
What can happen during pregnancy that makes a mother develop Rh antibodies?
If a mother is Rh- and the Child is Rh+, the RBCs of the child can leak into the mothers blood stream. This causes her to develop Anti Rh antibodies
What can cause Hemolytic disease of a newborn?
When a mother has Anti-Rh antibodies and they leak across the placenta and attack the RBCs of an RH+ baby
What happens in Hemolytic disease of a newborn?
A mothers anti-Rh antibodies destroy the RBCs of the baby causing them to burst
What can HDN lead to?
Brain damage
Deafness
Death
What happens with the liver in HDN?
As the red blood cells break down the liver produces bilirubin in excess that it ends up in the blood and tissues of a babies blood. Causing jaundice
What is the treatment for HDN?
Blood transfusions for the child or inducing early labour
How is the Rh problem prevented?
By injecting Rh negative women with an antibody preparation (Anti-Rh antibodies) against the Rh factor within 72 hours after the birth of an Rh+ child
What do the injections do for the mother do?
The anti-Rh antibodies in the injection attack any of the babies RBCs in the blood before it can stimulate her immune system to produce its own antibodies
What autoimmune disorder?
When T cells or antibodies mistakenly attack the body’s own cells as if they had foreign antigens
When does a autoimmune disorder tend to begin?
After recovery from an infection
What is rheumatoid arthritis?
An chronic autoimmune disorder that is characterized by inflammation of the lining of the joints
What is rheumatoid arthritis caused by?
The body’s own immune system attacking the joints, causing pain, stiffness, swelling, fever, fatigue, and decreased apetite
What are treatments for rheumatoid arthritis?
Aspirin, anti-inflammatory medications. Disease modifying antirheumatic drugs work to slow the immune system
What is an allergy?
An exaggerated response by the immune system to a harmless material
what are the 2 major type of allergic reactions?
Immediate (acute) and Delayed
What is an immediate reaction?
The most common type of reaction, occurs within seconds of exposure and usually disappears within 30 minutes
What happens in an immediate reaction?
Specialized antibodies trigger certain cells to release histamines, which increase the permeability of blood vessels making the area red and swollen. Can also trigger the release of cellular fluids which result in water eyes and runny nose
What type of reaction is asthma?
Immediate reactions
What happens in an asthma reaction?
Inhaled allergens trigger a massive release in histamines which sets off spasms in the bronchioles. Can also be triggered by stimuli such as cold air and fatigue
What are delayed allergic reactions set off by?
T cells that have be sensitized by previous contact with allergens
What are delayed reactions characterized by?
Slower reactions that last for a longer period of time. Ex. reactions to jewelry
What can immediate reactions to food allergies look like?
Runny nose
Vomiting
Diarrhea
Asthma attack
What can delayed reactions to food allergies look like?
Skin problems
Wheezing
Aches or pains
