Rasmussen College. NURSING 3 Cancer Notes. A+ RATED.CANCER
Principles of Cancer Development Chapter 21
Pathophysiology:
Cells continue to grow and
... [Show More] replace old and dead cells after maturation through cellular
regulation.
Cellular regulation: the process to control cellular growth, replication and differentiation
(maturation into a specific cell type) to maintain homeostasis.
Tissues that continue to grow by undergoing MITOSIS in adulthood include:
Skin
Hair
Mucous Membranes
Bone marrow
Linings of organs: lungs, stomach, intestines, bladder, and uterus.
These tissues are located in areas in which constant damage or wear is likely and continued cell
growth is needed to replace dead tissues.
NEOPLASIA: any new or continued cell growth not needed for normal development or
replacement of dead and damaged tissues.
o This cell growth is considered to be abnormal even if it causes no harm (benign).
o Whether or not the cell growth is cancerous or benign, neoplastic cells develop
from normal cells (parent cells).
This means CANCEROUS CELLS WERE ONCE NORMAL CELLS,
but went through genetic mutations that prevents them from functioning
normally.
Biology of Normal Cells
Specific morphology: the feature in which each normal cell type has a distinct and recognizable
appearance, size, and shape.
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Smaller nuclear to cytoplasmic ratio: the nucleus of a normal cell occupies a relatively
small amount of the pace inside the cell.
Differentiated Function: every normal cell has least one function it performs to contribute
to whole body function.
Skill cell make keratin
Liver cells make bile
Cardiac muscle cells contract
Red Blood Cells make hemoglobin
Tight Adherence: occurs when normal cell make proteins that protrude from the membranes,
allowing the cells to bind closely and tightly together.
Fibronectin: this keeps most normal tissues bound tightly to each other. Exceptions are
blood cells. RBCs and WBCs produce no fibronectin and do not usually adhere together.
Nonmigratory: when normal cells do not wander throughout the body (except for RBCs).
This is because normal cells are tightly bound together, which prevents cells from wandering
from one tissue into the next.
Cellular Regulation: cells divide (MITOSIS) for only 2 reasons:
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To make normal tissue
To replace damaged normal tissue.
***NORMAL CELLS ARE GO THROUGH MITOSIS, ONLY WHEN CONDITIONS
WITHIN THE BODY ARE JUST RIGHT. ***
CELL DIVISION (MITOSIS):
Occurs in a cell cycle which progresses through various stages in production and
maturation.
Cells that are NOT actively reproducing, remain in a reproductive resting stage known as
G0. During this stage, cells carry out their normal functions but do not divide.
o Normal cells spend most of their existence in this stage.
Mitosis: division of one cell into 2 separate, but identical cells.
o This process is tightly controlled. It depends on the presence of cellular regulation
proteins. Proteins that promote cells to enter and complete division, are
produced by oncogenes and are known as cyclins.
Cyclins are activated by external or internal signaling, they allow a cell to
leave the G0 (reproductive resting), and enter the cell cycle. This will result
in the process of division.
Proteins produced by suppressor genes control the amount cyclins present,
and ensure that cell division occur only when needed. [Show Less]