All CTT Flashcards
What are the two regions of the platelet?
The granulomere and the hyalomere
What is the granulomere?
Platelet: the central region, containing mitochondria, glycogen, and three types of cytoplasmic granules functionally related to its role in blood clotting,
What is the hyalomere
Platelet: the clear peripheral region, which contains an encircling ring-shaped marginal band of microtubules that serve to maintain the lens-shape of the platelet. The high concentration of actin and myosin in the hyalomere play a role in the retraction of the platelet after the clot has served its function. Two tubular systems, a dense tubule and a surface-opening set of tubules assist in the delivery of the contents of the granules to the exterior.
What are the granules in the platelet? Where are they located?
Alpha granules: fibrinogen, pdgf, coagulation factors,
lambda granules: lysosomes (hydrolytic enzymes)
delta granules: dense bodies - adp, atp, ca2+, serotonin
What types of granules do all granulocytes have?
primary granules: lysosomes
secondary/cell-specific granules
What granules do neutrophils have?
What else do they secrete? what is it?
primary granules: lysosomes
secondary/cell-specific granules: kill bacteria with enzymes and reactive oxygen compounds (antimicrobial)
tertiary: facilitate migration to target
IL-1; a pyrogen
What is the internum
It is the dense core of an eosinophilic granule - it contains major basic protein
What is an externum
It is the surrounding part of an eosinophilic granule
exists with IgE antibodies bound to its surface
basophil (mast also has these in CT, they bind to mast and cause Ca2+ signal for degranulation.)
What do basophil granules contain? (cell specific)
The granules contain pharmacologically active agents such as histamine and heparin, as well as eosinophil chemotaxic factor and neutrophil chemotaxic factors
responsible for vascular disturbances, such as widespread vasodilation, associated with hypersensitivity and anaphylaxis.
basophil
What is the order of layers in an uncoagulated centrifuged tube of blood?
Top: plasma, platelets, WBCs, RBCs
When fresh blood coagulates, what is the order of layers?
blood serum, blood clot
In coagulated blood, the clot of blood consists of:
blood cells in a tangle of fibers, and includes large proteins as well as all the coagulation proteins that are normally present in blood plasma.
What is the buffy coat?
WBCs, constitutes 1% of total volume
Besides water, what else is in plasma? What percentage total is this other stuff?
9% proteins, which include albumen, globulins, clotting proteins (fibrinogen and prothrombin), electrolytes, glucose, and other molecules that are in balance with the tissue fluid.
Usually occurs as a result of transfusion reactions or Rh-incompatability. cells may also lyse in the circ in response to some toxins
intravascular hemolysis
RBC lysis within the phagocytes
extravascular hemolysis
Antibodies in a Type A or B mother
IgM (not taken up by placenta)
Antibodies in a type O mother
IgG (taken up by placenta)
Assessment of Extrinsic Pathway
average time?
Prothrombin time
10-14s
Assessment of Intrinsic Pathway
average time?
Partial thromboplastin time
30-50 secs
Prothrombin time measures the integrity of ____________ It is independent of defects in factors, _______ or
_____.
the extrinsic systems, factors VII, X, II,
V and I (fibrinogen).
XII, XI, VIII, or platelets
Partial thromboplastin time measures the integrity of factors ____________ It is unaffected by defects in factors, _______ or
_____.
XII, XI, IX, VIII, X, V, II and I but is unaffected
by defects in VII or platelets.
When caretaker genes are inactivated, what occurs re: mutations?
the rate at
which additional mutations accumulate is accelerated
Caretaker genes are genes involved in:
DNA repair
inactivation of _______ genes is often an early event that creates genome
instability, and subsequently promotes carcinogenesis
Caretaker or tumor suppressor?
caretaker
How can gain-of-function mutations lead to the dysregulation of oncogenic activity (cell cycle dysregulation and possibility of oncogenesis)?
interfere with proper regulation
of proto-oncogenic activities or that amplify the number of copies of protooncogenes
What kinds of proteins are encoded by oncogenes (proto-oncogenes)? (4)
How are they different? How are they the same?
growth factors,
growth factor receptors, signal transduction molecules, and nuclear transcription
factors
involved in different aspects of the
cell growth cycle and have different modes of oncogenesis.
disruption of any of these components yields essentially the same result:
disregulation of the cell cycle and the possibility of oncogenesis
miRNA molecules that are
responsible for the post-transcriptional regulation of upwards of 200 unique
genetic targets per miRNA gene
Give one example of how they can act as oncogenes
onco-miRs
by inhibiting large numbers of tumor suppressor genes
most oncogene-based tumors are ______ in
nature and often result from acquired mutations in oncogenes such as: (3)
sporadic;
ras, myc, src
At the cellular level, oncogenes act in a ______ fashion.
Tumor suppressor genes at the cellular level act in a _______ fashion
dominant; recessive