* Chapter 37 Flashcards
What is involved in the non-specific resistance first line of defense
- intact skin: Upper layer of skin is stratified squamous, tightly bound so it blocks out microbs, Skin is arid (dry) and acid (low pH) does not support micro organisms.
- Microbial inhabitants: Ecoli covers our skin to keep pathogenic bacteria from entering system, Good bacteria lives in our body cavities –> their presence discourages pathogenic bacteria (the gut and vagin)
- Mucous Membrane: consists of cells that release/ produce mucous, Mucous trap and immobilizes microbs from entering system
- exocrine glands: secrete lysosomes (tears and saliva) which degrade bacterial cell wall
- Urine: low pH (acidic) flushes out bacteria, the quicker the process of urination bacteria get eliminated
- Diarrhea: if there are substances that shouldnt be in the digestive tract (pathogens), body will sacrifice water to flush it out
What are the stem cells in bone marrow?
- monocyte
- basophil
- neutrophil
- eosinophil
- lymphocyte (3rd line of defense)
Monocytes–>_____—-> Phagocytosis
Monocytes–> macrophages (can recognize any microb/cell that should not be in our system, called “search and destroy cells,” shreds cells into pieces)—> Phagocytosis: process of eating cell and using digestive enzymes to shred cell
Lymphatic vessel function in the lymphatic system
to collect plasma fluid that leak into your tissues from the bloodstream and return it to the circulatory system
The second line of defense includes nonspecific substances and cell activities, the 2nd line is activated when….
microbs cross the 1st line of defense and start affecting tissue
The molecules include interferons and proteins of the complement system. What are interferons and what do they do?
interferons interfere with the life cycle of the virus by limiting the rate of infection
What is included in the 2nd line of defense?
compliment proteins (which travel as single plasma)
What are complement proteins (second line of defense)
the complement system is a set of plasma proteins that enhance nonspecific and specific defenses
About 20 kinds of complement proteins circulate in the blood in inactive form: what are their characteristics?
- these proteins are activated in a cascading fashion *
- Some form pore complexes which cause the pathogen to lyse and die
- some activate proteins which promote inflammation
- some attract phagocytes to the scene to ingest the invaders
what are viruses?
all are parasites. They have infectious particles. They also have nucleic acids but do not know what to do. They cannot transcribe/ translate. They have no machinery. They kill cells/ infect cells by puncturing them. Infect cells by making cells replicate them.
Function of histamine?
to orchestrate inflammation, and makes capillaries “leaky”
What are neutrophils
the most abundent leukocytes, phagocytize bacteria, detect bacterial invaders–> kills by phagocytosis.
what are Eosinophils
they secrete enzymes that punch holes in parasitic worms, detect single and multicelled parasites
What are basophils
they secrete histamine which promotes leakage of fluid out of capillaries, which sustains inflammation, tiny leukocytes.
Where are macrophages formed?
they are formed from immature cells called monocytes
What are macrophages
these leukocytes are slower to act but can engulf and digest just about any foreign agent or damage tissue
The inflammatory response starts when microbs start affecting tissue.
What do the inflammatory response results include?
-Localized warming,redness,swelling, and pain are signs of inflammation that occur at the site of damage or invasion
-Microorganisms invade a tissue and kill and damage cells
-Mast cells release histamine(makes capillary leaky) and heparin (makes plasma more fluid), which stimulates vasodialation and capillary permeability
- fluid seeps from blood vessels causing swelling and delivery of infection-fighting proteins
-complement proteins attack invaders as clotting factors wall off inflamed area
- some leukocytes are also squeezed out of the “leaky” capillaries
Macrophages secrete interleukins and prostaglandins which are communication signals among leukocytes, but in addition prostoglandins can signal the brain the reset its “thermostat” to cause fever
What are mast cells made up of?
Loose connective tissue
What are the lymphatic organs?
- tonsils: give quick local response
- lymph node: expands when there is infection, projector cells go through mitosis to protect
- Thymus gland: houses leukocytes
- Spleen: largest lymphatic organ & *filters dead or mutated red blood cells
Interleukin-1 induces ____
drowsiness
Macrophages secrete
interleukins and prostaglandins-> which communicate with white blood cells
What are the function of prostoglandins
- Increase the temperature
- to signal messages to white blood cells
- High temperature can cause denaturation of proteins, hence must bring down temp. –> more WBC produced to get rid of microbs
- once concentration of microbs go down-> bod returns to normal temperature
What are the functions of specific responses-> immune system?
- goes after the very microb that causes the infection
- creates memory, for the next time you get infected by a microb so it can kill them fast
- memory cell: immunization
T lymphocytes arise from stem cells in the bone marrow and then travel to the ______ where the helper T and _____ cells complete their development by aquiring T-cell receptors (TCRs)
Thymus gland; Cytotoxic T (natural killer) cells
Virgin T cells ignore both unadorned ___ markers and ____ antigen, but they do recognize and bind with _____ complexes on antigen- presenting cells; this causes them to dived repeatedly to form clones
MHC; Free; antigen-MHC complexes
Any cell that displays antigen with a suitable MHC marker is known as …..
an antigen-presenting cell and will be noticed by lymphocytes
What are MHC markers?
if a cell has MHC makers communicate with macrophages. it says–> do not destroy us, we belong here.
What happens if an MHC marker is not on the cell or mutated?
the macrophages are given the OK to destroy the cell
What are antigens ?
Antigens are foreign protein to the system.
These are also destroyed by macrophages because they do not belong
How do leukocytes find infection?
finding an antigen-> cells are identified by surface protein*
Specific surface protein for each microb
Helper T cells (CD4) and Cytotoxic T cells (CD8) go through a process called ____?
T-Cell education. This is where t cell gets exposed to MHC markers
- T cells that attack cell normal cell with MHC marker <– kept
Helper T cells attach to ____
antigen/MHC complexes
Virgin T cells have not encountered microbs therefore will….
- ignore free antigens and MHC
- will recognize antigen/MHC complexes
What are antibodies?
they attach to microbs to get attention (they function as a flag) of phagocytic cells
How are MHC-Antigen complexes created
when an antigen enters the body, they are engulfed and destroyed by macrophages but not completely- the antigen becomes attached to the MHC marker to form an MHC-Antigen complex, which is then displayed on the macrophages surface
HIV kills ____
Helper T cells.
Without Helper T cells -> patient becomes immune deficient. Hence, no more activation of interleukins.
The body then begins to collect various and viruses and cancers because the bod cannot protect itself (AIDS)
Helper T cells produce interleukins-> which activate the production of B cells (generate antibodies) and cytotoxic (kill infected cells like tumors)
What are AIDS
A collection of diseases brought upon HIV infected individual
What is the function of effector T cells
The effector T cells (clones) secrete interleukins which stimulate further cell divisions and differentiation
how do the clones of cytotoxic T cells recognize the antigen MHC complexes on infected cells?
by punching holes in their cell membranes with proteins called perforins*
what are the structures of antibodies?
they have a globular structure, and are Y-shaped with the tail embedded in the B cell membrane and the 2 arms (bearing the antigen receptors) sticking outward
What happens when a virgin B cell makes contact with an antigen?
it becomes sensitive to communication signals by helper T cells that have been activated by antigen-presenting cells
what are the main targets of antibody-mediated responses are
extracellular pathogens and toxins
B cells produce 4 classes of antibodies known as :
immunoglobulins IgM -IgC -IgA -IgE -IgD
What is IgM
hint: Mama feed the fetus
- it is the first antibody to be secreted during immune response, to trigger the complement cascade. (first to respond to microbs)
- involved in incompatible transfusion (A blood-> B blood)
- **- only type of antibody fetus can produce on its own
what is IgG
Hint: Igg y did you eat the placenta
antibodies that can cross the placenta to protect the fetus
What is IgA
Hint: A tit
antibody present in breast milk
What is IgE?
hint: histaminEEEEE
antigen of inflammation. Stimulate basophils and mast cells to secrete histamine
IgD
Hint: Where Dey At Doe?
we dont know what they do
________ is the basis of the secondary immune response to a previously encountered agent
“immunological memory”
What do some B and T cells do after primary immune response?
they will continue to circulate for years as memory cells, which can divide when they meet the antigen again
** the secondary response is more rapid, of greater magnitude and of longer duration
What does immunization do?
it tricks the system to produce antibodies/ memory cells to protect the system
What is active immunity and give an example.
Active immunity is when your system produces memory cells and antibodies on its own
Example: a fetus producing IgM (the only antigen a fetus can produce on its own)
What is passive immunity and give an example.
passive immunity is getting antibodies from outside source by injecting antibodies
Example. Fetus receiving IgG antibodies from across the placenta
