Cells, Organs, and Molecules: Anatomy and physiology of the immune system Flashcards
How many RBCs are there per uL of blood
about 5 x 10^6/ uL
How many platelets are there per uL of blood?
between 150-400,000/uL
The buffy coat is:
WBCs + platelets
Leukocytes are nucleated, T or F?
T
Which WBCs are mononuclear?
Monocytes and lymphocytes (agranulocytes)
Which cells are polymorphonuclear?
granulocytes- Eosinophils, Basophils (related to mast cells), and Neutrophils.
Monocytes are immature and becoming mature what?
macrophages or dendritic cells.
which type of WBCs have a smooth outlined nucleus?
mononuclear (one nucleus, smooth)
Which cells have a nucleus that is lobulated?
Polymorphonuclear cells.
what color do polymorphonuclear cells generally stain?
Baso- blue
Neutro- colorless
Eosino- Red
Total WBCs per uL of Blood
4500-10500/uL
List the WBCs in descending order of prevalence
Neutrophils Lymphocytes Monocytes Eosinophils Basophils
No Little Monkeys Eat Bananas
Up to 2 years of age what is different about the WBC count?
can have more lymphocytes than Neutrophils
Of Lymphocytes how many are T cells and how many are B cells
T- 70%
B- 20%
What are central lymphoid organs?
The bone marrow and the thymus.
What are peripheral lymphoid organs?
lymph nodes, spleen, Peyer’s patches and mesenteric lymph nodes of the gut, tonsils, and adenoids.
Where are most lymphocytes found in the body at any given moment? Blood and lymph, or peripheral lymphoid organs.
In peripheral lymphoid organs,
How do central and peripheral organs differ in function?
central- lymphocytes develop here
Peripheral- here mature lymphocytes are organized to trap and respond to foreign invaders, which usually arrive through the body surfaces via lymphatics.
In a lymph node what goes through the hilum?
Blood in and out plus efferent lymph
what part of blood flow through the lymph node has high cuboidal endothelium?
venules
What passes through the lymph node periphery (as opposed to the hilum)?
Afferent lymph (comes in through the periphery, everything else goes through the hilum).
The nodes outer region is called the _____ and it is full of tightly packed, highly motile lymphocytes arranged into _____.
cortex, follicles
What is a germinal center? What do theses tend to represent?
Frequent, very crowded areas with many dividing cells within a follicle of the cortex (of a lymph node). They represent visible evidence of an immune response.
what area of the lymph node is less dense than the cortex but still has huge numbers of dividing lymphocytes?
deep or paracortex.
In what regions of a lymph node do B, T, and dendritic cells typically gather (respectively)?
B-cortex (come from bone marrow)
T-paracortex (come from thymus)
Dendritic- in the interface between cortex and paracortex
Follicular helper T cells (Tfh) migrate from where to where and do what?
deep cortex into the follicles and help to activate the B cells there.
how many lymphocytic circulations are there in the body?
2 blood and lymph
in recirculation, a lymphocyte encounters cells lining a _______, in the peripheral lymphoid tissues (especially a lymph node). These cells are ___ and _____ and lymphocytes will bind and pass through these to re-enter the lymph.
postcapillary venule
high and cuboidal
lymphocytes circulate between the blood and the lymph. They cross from the blood into the lymph at _____ and from the lymph back into the blood at the ____ via the ____ duct.
lymph nodes
heart
thoracic
What is the role of red pulp in the spleen?
similar to medulla in the lymph node- lots of phagocytic cells, can make RBCs if necessary. Makes the body’s most important filter of particulates (bacteria or damaged platelets).
the white pulp consists of____.
islands of cells.
What kinds of cells are close to the arteriole? farther away?
The sheath of cells which surrounds the central arteriole is made mostly of T cells. the more diffuse cells, farther away, are mostly B cells (similar to lymph node structure).
What is a Peyer’s patch?
A GALT or MALT (gut or mucosa associated lymphoid tissue). It underlies the mucosa (especially in the small intestine). There specialized M Cells ingest proteins including viruses and transport them to the location of the Peyer’s patch where B cell follicles and T cell zones are located.
What is the difference between an antigen, an immunogen, and a tolerogen?
an antigen is recognized by an antibody, an immunogen is an antigen that triggers an immune response and a tolerogen is an antigen that prevents a immune response to subsequent immunogens containing the same antigenic determinant.
The part of an antigen that fits into the receptor is called:
the antigenic determinant or epitope.
what 3 conditions must be met to activate the T or B cell?
- there must be good fit between antigen and receptor
- several nearby receptors must be simultaneously bound to the antigen
- Accessory or costimulation surface molecules (of the antibody) must also be involved with the antigen.
Once a cell is activated it will differentiate into ____ and _____.
effectors- do the job of killing the foreign particle
memory cells- recirculate efficiently and are easily triggered by a second exposure.
A stimulated T cell becomes a _____
T lymphoblast
A stimulated B cell becomes a____. This second, larger, differentiated type of cell will go on to become a _____.
B lymphoblast; plasma cell
An enormous, specialized cell that makes antibody proteins like nuts. Has a lot of Rough endoplasmic reticulum.
A plasma cell, comes from B lymphoblast.
In mammalian embryos, bone marrow function is first found in the _____.
yolk sac and then later in the liver.