Lecture 10 Flashcards
describe the Integumentary System functions
- Protection
- Thermoregulation
- Sensory
- Synthesis
what are the defense system
•Generally impermeable.
•Openings through it have sphincters or barriers in
place.
•Slightly acidic: Inhibits bacterial growth.
•Sweat/perspiration helps wash invaders out of pores.
•Openings (mouth and anus) have sphincters and
associated mucous membranes (sticky secretions
inhibit entrance of foreign matter).
what are the stages of Superficial
Inflammatory Response
After Damage to Body
Surface
a. first what happens is phagocytosis by nearby macrophages
b. then dialation and increased peambility of capillary
c. containment of bacteria and foreign matter
d. leukocyte proliferation and migration
e. continued activty of recruited leukocytes
what happens during the second step Superficial
Inflammatory Response After Damage to Body
Surface histamine wise
Histamine release causes fluid entry into interstitial space (swelling) (I.e. More fluid moves into extracellular space.)
what happens to the third step of the Superficial Inflammatory Response After Damage to Body Surface?
Defensive proteins from bloodstream help to contain microbes.
what happens to the fourth step of Superficial
Inflammatory Response After Damage to Body
Surface leukocyte proliferation and migration?
Leukocytes help to destroy contained microbes. Remember,
many types of white blood cells are phagocytic.
(Dead or spent leukocytes (white blood cells) near a wound =
“pus”.)
what is phagocytosis? (nonspecific)
removal of cellular debris and general invading micro-organisms.
give examples of microphages- describe them (nonspecific)
neutrophils and eosinophils.
Neutrophils target bacteria and debris. Eosinophils
target both foreign substances and things covered
with antibodies.
what are macrophages (nonspecific)
larger, either fixed in a tissue, or
highly mobile. Can come from remote locations to attack invaders
(nonspecific) natural killer defenses describe NK
-attacks what?
adheres to what? what enzyme?
role in attacking what?
They will attack pretty much any cell that looks
abnormal; i.e. not presenting the surface cell proteins
and other molecules associated with “self”.
• They will generally adhere to abnormal cells and
causes lysis (tear them open) with an enzyme called
PERFORIN.
• Known to have a role in attacking tumor cells
(cancers).
OTHER NONSPECIFIC
DEFENSES
INTERFERONS describe
small proteins released by
lymphocytes and macrophages, or tissues invaded by
viruses.
• Bind to surfaces of normal cells, and stimulates them
to produce anti-viral proteins in their own cytoplasm.
• These antiviral proteins do not prevent entrance of
viruses into a cell, but once in prevent their
reproduction. This slows virus action until other cells
can arrive to help dispose of them.
what is a complement NONSPECIFIC
DEFENSES
• Special proteins, about 30 different kinds.
• They are called complement because they do not act
alone.
• Together with antibodies, they will begin a series of
reactions with other complement proteins to build an
enzyme that will attach to an invader’s cell wall and
lyse it.
describe the non specific defense- FEVER
Creates and environment in which invaders such as
viruses and bacteria do not reproduce well.
• The problem is that very high fevers can interfere with
other body functions.
what does specific defense systems mean?
• Not present at birth
• Immunity that is acquired only when exposed to
a particular antigen (“not self”) or if received
from another source (e.g. from mother, vaccine)
LYMPHOCYTE-BASED
DEFENSE describe what is this function based on?
based on the function of T-lymphocytes which defend against abnormal cells & pathogens in cells.
another word for lymphocyte based defense?
“Antibody-Based Immunity” due to the tight
match (i.e. specificity) between special molecules known as ANTIBODIES which defend against antigens in body fluids.
describe the morphology of LYMPHOCYTES
Slightly larger than red blood cells.
• Large round nucleus; relatively less cytoplasm visible compared
to granulocytes.
• Constitute about 20-40% of circulating white blood cells.
• Fond circulating in cardiovascular system, lymphatic system, and
resident in lymphatic organs and &tissues.
what are the three types of lymphocytes?
T-CELLS – responsible for “cell-mediated immunity” - a specific
defense against invading foreign cells or coordina&ng other immune
responses. Can enter &ssues and aXach foreign cells directly or
coordinate other lymphocytes.
B
-CELLS – responsible for “humoral immunity” – defense by means
of an3bodies.
NATURAL KILLER CELLS (NK Cells) – detect and destroy abnormal
cells. Also important in prevent cancer.
T-CELLS
responsible for “cell-mediated immunity” -a specific defense against invading foreign cells or coordinating other immune responses. Can enter tissues and attach foreign cells directly or
coordinate other lymphocytes.
B-CELLS
responsible for “humoral immunity” – defense by means
of an3bodies
NATURAL KILLER CELLS (NK Cells)
detect and destroy abnormal
cells. Also important in prevent cancer.
what are antigens?
-A foreign substance or organism.
-Any substance against which an antibody
is produced.
-More specifically, antigens are generally
recognized as proteins or polysaccarides
on the cell surface of an invading organism
that do not correspond to “self”.
what are antibodies? what did they bind to?
what can they combine with?
what do they initiate?
•Proteins produced by lymphocytes in response to an
antigen.
•They bind to specific sites on antigen surfaces.
•Antibodies don’t kill organisms. However, they:
•can inactivate an invader, and
•initiate the process of activating phagocytic cells
and other natural killers.
•Can combine with bacterial toxins or viruses to
prevent attachment to target cells (“inactivation”).
•There is a SPECIFIC antibody for any one given type of individual invader.
ANTIBODIES are made up of both
by both B-lymphocytes
and T-lympocytes:
Tlymph- what kind of antibodies
Specific antibodies
Blymph- what kind of anti
Specific antibodies and Natural antibodies
ANTIBODY COMPONENT
STRUCTURE
Made up of four polypeptides (amino acid chains).
Two longer and larger, two shorter and smaller.
Have the shape of a letter “Y”.
Intersection of arms and base of “Y shape” is flexible,allowing deformation of antibody when it attaches toan antigen.
ANTIBODY COMPONENT
STRUCTURE
(Remember, they belong to group of
plasma proteins called “globulins.”)
what are specific regions of the antibodies what does it mean
•At the tip of the arms of the Y-shape.
•Variable region has the potential to bind with
particular classes of antigens.
•Once a raw antibody is stimulated to fit to a
specific antigen, it can then react with ONLY that
antigen. This is known as SINGLE SPECIFICITY.
•Can fit as precisely as a lock-and-key to an
antigen.
Antibodies are anchored in the cell membrane of what does this mean in terms of t cells from the standard Y-shaped antibody see on B-lympocytes.
B-lympocytes
and T—lympocytes.
Note that the receptor sites of
T-cells are slightly different
from the standard Y-shaped
antibody see on B-lympocytes.
what are blymph?
where do they mature?
what does this has to do with other lymphocytes?
•Mature in bone marrow, then carried to lymphoid
tissue via blood stream and lymphatic circulation.
•This process of maturation and migration takes
place throughout life.
•Other lymphocytes can be generated via mitosis
of B lymphocytes resident in lymphoid tissues.
describe tlymph
-immature state?
where do they mature?
what does this mean for other lymphocytes
•Immature lymphocytes leave bone marrow during fetal
and early neonatal life.
•Go to thymus gland.
•Mature there before they go on to other lymphoid
tissues.
•These are T-lymphocytes.
•Any lymphocyte derived from one of these original Tlymphocytes
via mitosis is also a T-lymphocyte.
TC – Cytototoxic T- cells.
Directly attack antigens or
abnormal cells.
Memory T cells.
Respond to antigens that have been
encountered before. Do so by making many copies of self via mitosis.
TH – Helper T cells.
Stimulate activity of both B and T.
lymphocytes. Critical to B lymphocytes because
they are required to stimulate B-cells to make
antibodies.
TS – Supressor T cells.
Can inhibit B and T-cells to
modulate and control immune response
what are the three main points of T-LYMPHOCYTE ROLES
Initiate immune response.
• Maintain immune response.
• Control immune response.
• Cytotoxic T cells will seek out and
what might make the cells become abnormal?
destroy abnormal cells
Cells may become abnormal due to infection/
attack by viruses or bacteria.
Cytotoxic T cells describe attack lol
protein products of their takeover appear in the cell membrane of the affected cells, TC –
Cytototoxic T-cells attack and destroy the
affected cell, and the viruses or bacteria with it.
• Upon activiation of TC – Cytototoxic what is produced??
TMemory cells are also produced.
T Memory cells await the presentation of the same invader again what does this mean?
allow much faster, stronger, more long-lasting second-time or later-time response.
T Helper cells, TH activate??
B-lymphocytes
before they can produce antibodies
themelves.
T Suppressor cells, TS
inhibit T and B cell activities so that immune system doesn’t overreact.
T cells recognize antigens when they are bound to plasma membrane (cell membrane)
of????
another cell
explain no match no activation
how many times must it bind?
Once stimulated, T cells make TC and TM cells for
There must be a specific match between the T cell and the presenting antigen
AND it
must bind twice (COSTIMULATION) to be
sure of such a match.
invader destruction and future
responses respectively.
describe all the genetic codings and significance for B-LYMPHOCYTES
There is genetic coding for millions of different Blymphocyte
types, each with its own particular type of
antibody.
If B cells encounter a matching antigen anywhere in the body, (can or cannot be activated?) describe this process?
can be activated
This could take quite some time between when the antigen gets into the body and it finally encounters one of the few among millions that match.
B cells are mobile- what does this mean??
So encounter is frequently in a
lymph node, or near point of infection.
B-LYMPHOCYTE FUNCTION 5 steps
- Initial binding between a B cell and an antigen (also known as “Sensitization”.
- Antigen brought into the B cell, then presented again
on cell surface of the B cell. - B cell will not undergo complete activation until
facilitated by a Helper T cell. - TH cells secrete chemical called cytokines.
- Cytokines stimulate both B cell activation and
replication (making lots more B cells!). - Cell division makes two kinds of B cells: (1) PLASMA
CELLS, and (2) B MEMORY CELLS. - Plasma cells make huge quantities of antibodies.
This is when the effects of an antigen start to become
knocked down (i.e when you feel less sick!) - B Memory cells are retained for the next time that
same antigen might be encountered. This is also
known as “long term immunity”.
OVERVIEW OF STAGES OF
SPECIFIC IMMUNE RESPONSE
(1) Antigen encounter and recognition by
lymphocytes.
(2) Lymphocyte activation.
(3) Attack.
describe the first step on the specific immune response
Specific lymphocytes are programmed to recognize a specific antigen. This usually happens in a lymphoid organ, bloodstream, or lymph vessel. (This could take quite some time…)
describe the second step 2) LYMPHOCYTE ACTIVATION
Once a lymphocyte has recognized an antigen,
it undergoes numerous cycles of mitotic
divisions, making more of the same.
Each of those has about 100,000 antibodies
embedded in the cell membrane of each cell.
Some of the newly produced cells carry out the
attack; others influence the activation and
function of the attack cells.
3) attack
B-lymphocytes have specific
receptors on their cell membrane –
ANTIBODIES – that bind with
invading materials/organisms.
PRIMARY IMMUNE RESPONSE
B-lymphocyte – antigen contact induces mitosis
(plasma cells) for more antibody carrying cells.
Antibodies released to circulatory systems
SECONDARY IMMUNE RESPONSE
•Some “activated B-lymphocytes” become plasma
cells.
•Some remain smaller, but retain antigen-recognition
ability. (B memory cells)
•Next time similar antigen is encountered, response
is MUCH FASTER due to resident and waiting
memory cells.
UNDERSTANDING VACCINATIONS
• Vaccinations are based on the secondary immune response.
• Some for of dead or deactivated version of an antigen is
injected into an indiivdual
• Because the injection contains a dead version, it doesn’t harm
the person receiving the injection.
• However the cell-surface proteins still induce the process of
recognition, activation, etc. of B cells – including making B
memory cells.
• The B memory cells then stand ready to fight off such an
antigen if ever encountered without having to get sick in the first
place.
NATURAL ANTIBODIES
It has always been thought that antibodies were
programmed to recognize and defend against
“nonself” cells and tissues.
However, a new class of antibodies known as
NATURAL ANTIBODIES have been discovered.
They begin production before birth. Before the
fetus could ever encounter anything that could be
nonself!
what helps natural antibodies attach to
invaders and with the help of molecules called
can hold invaders at bay. But they
can’t kill them on their own.
NATURAL ANTIBODIES are very important in
cleaning up
cellular junk and and debris.
natural antibodies bind to molecules in living or dying cells?
They bind to molecules exposed in dead and
dying cells, and induce macrophages to help
clean them up.
NATURAL ANTIBODIES are part of a waste removal system what does this mean
that helps clean up dead, dying,
and damaged cells of “self”.
They might also clean up dead, or exhausted
macrophages.
Other potential associations:
• Found in great numbers in people with
Alzheimers disease. May signal onset.
• May protect against atheroscleorosis.
what u need to know about HIV
- A retrovirus (RNA-based).
- Once integrated into host, can remain dormant for years.
- Preferentially enters and DISABLES HELPER TLYMPHOCYTES.
•Without these, B-lymphocytes can’t mature to make
antibodies, and natural killer cells can’t function fully.
Thus, an infected person can’t produce antibodies
against even the simples of invaders.
