Biology Questions and Answers
a blood sample is above the normal
level for the individual ldefined. When the leukocyte coueukocytosisnt is is
lower than the expected normal level
leukopenia is defined. The multiplicationof these defense cells, leukocytosis,
generally takes place when the body is
suffering infectionsthese cells. The lowering of these or in cancers o f
defense cells, or leukopenia, occurs
when some like in AIDS, or diseases attackwhen the cells,
immunosuppressor drugs are used.
In general the body creates leukocytosis
as a defense reactioninfectious or pathogenic agents. The when it is facin g
clinical condition of leukocytosis is thus
a sign of infection. Lwhen there is a deficiency in eukopenia occursthe
production (for example, in bone
marrow diseases) destruction of leukocytesor excessive (for exam (^) ple,
in case of HIV infection).
- What are the mechanisms
of hemorrhage contention
called?
The physiologicalhemorrhage contention mechanisms of(one of them is (^)
blood clotting) arhemostasis, or hemostatice generically named processes.
- How are platelets formed?
What is the function of
platelets? What consequences
does the clinical condition
known as thrombocytopenia
yield?
Platelets, also known as thrombocytes,
are fragments of giant cells of marrow called megakaryocytes. Withthe bone
their properties of aggregation and
adhesiveness thblood clotting aney play a d they also libdirect role inerate
substances that activate other
hemostatic processes.
Thrombocytopenia is a clinical condition
in which tis lower than he platelet counormal. In this situationnt of the blood
the person becomes susceptible to
hemorrhages.- How does the organism
understand that a clotting
process must begin?
When there is some tissue winjury of blood vessel the plateletsound with and (^)
endothelial cells of the wall of the
damaged vessel liberate su(respectively platelet factors anbstancesd tissue (^)
factors) that trigger the clotting
process.
- How can the blood
coagulation (clotting) process
be described?
Blood clotting eof chemical reactionsncompasses a s whose respectiveequence
products are enzymes that catalyze the
following clotting reactionsreactions (that is why are called cascadethe (^)
reactions). In the plasma
thromboplastinogethromboplastin, a reaction trin transforms intoggered by (^)
tissue and platelet factors liberated after
injury of the blood vessel.Thromboplastin then catalyzes alon (^) g
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