(second midterm) Lecture 10 (5/9/16) PT. 1 Flashcards
Functions of integumentary system (general):
protection
thermoregulation
sensory
synthesis
True or false:
If the skin is acidic, we are experiencing a chemical imbalance and we should get it back to neutral.
false;
the skin is is usually a little acidic. generally is about 5.5 pH
*acid inhibits (doesn’t kill) bacterial growth
Is sweat good or bad? How?
good; helps wash invaders out of pores
What is the largest organ of our bodies?
skin
Review:
exocrine vs. endocrine
exocrine: secretes into tubes
endocrine: secretes into bloodstream
What is the biggest WBC?
macrophages
What do the macrophages release?
histamines
What are histamines?
they cause cells and cardiovascular vessels to release fluid and other WBCs out of the vessels and into surrounding tissues
What comes from the bloodstream and helps contain microbes when a cut is healing?
defensive proteins
What are granulocytes (general)?
WBCs not including lymphocytes
Types of phagocytes:
microphages
macrophages
Microphages:
types of phagocytes;
neutrophils and eosinophils
Neutrophils:
type of microphage; they target bacteria and debris
Eosinophils:
type of microphage; they target both foreign substances and things covered with antibodies
Macrophages:
larger, either fixed in a tissue, or highly mobile
can come from remote locations to attack invaders
Natural killer cells (NK cells):
will attack pretty much any cell that looks abnormal
Natural killer cells will generally adhere to abnormal cells and cause lysis (tears them open) with an enzyme. What is the enzyme?
perforin
What kind of cells are known to have a roll in attacking cancer cells?
natural killer cells
Small proteins released by lymphocytes and macrophages or tissues invaded by viruses:
interferons
What do interferons do?
bind to surfaces of normal cells and stimulate them to produce anti-viral proteins in their own cytoplasm
What do interferons produce? What does it/do they do?
anti-viral proteins
- they do not prevent entrance of viruses into a cell, but can prevent their reproduction
- slows virus action until other cells can arrive to help dispose of them
Complement:
special proteins
30 different kinds
What are they called “complement”?
they do not act alone
What do complement proteins work with? To do what?
antibodies
to begin a series of reactions with other complement proteins to build an enzyme that will attach to an invader’s cell wall and “lyse” (break) it
Why are fevers important? What is a drawback?
they create an environment in which invaders such as viruses and bacteria do not reproduce well
they can interfere with other body functions
When do specific defensive systems work?
NOT at birth but when you are exposed to a particular antigen (“not self”) or if received from another source (mother, vaccine, etc.)
Specific defenses are sometimes called ________________. Why?
lymphocyte-based defense
-the WBCs used are lymphocytes
Review:
What type of WBC is a lymphocyte?
agranulocyte
What defends against antigens in body fluids?
antibodies
Lymphocytes constitute about _______% of circulating WBCs.
20-40%
Types of lymphocytes:
T-Cells
B-Cells
Natural Killer Cells (NK Cells)
T-Cells:
responsible for “cell-mediated immunity” (defense against invading foreign cells)
-can enter tissues and attach foreign cells directly or coordinate other lymphocytes
Where do T-cells mature? B-cells?
T = thymus B = bone
B-Cells:
responsible for “humoral immunity” (defense by means of antibodies)
What is an antigen?
- a foreign substance or organism
- any substance against which an antibody is produced
How are antigens generally recognized?
-generally recognized as proteins or polysaccharides on the cell surface of an invading organism that do not correspond as “self”
What are antibodies?
Where do they bind?
proteins produced by lymphocytes in response to an antigen
-bind to specific sites on antigen surface
Antibodies don’t kill organisms, but they CAN…
- activate an invader
- initiate the process of activating phagocytic cells and other natural killers
Antibodies can attach to _____________ to prevent attachment to target cells (“inactivation”).
bacterial toxins or viruses
There is a specific antibody for any what?
for any one given type of individual invader
