Chapter 2: Adaptations of Cellular Growth and Differentiation Flashcards
What are the four different cellular adaptations to stress?
Hypertrophy, hyperplasia, atrophy, and metaplasia
What is hypertrophy?
an increase in the size of cells that results in an increase in the size of the affected organ
what is the mechanism for hypertrophy?
increased production of cellular proteins
what is an example of pathologic hypertrophy?
left ventricular hypertrophy secondary to increased hemodynamic load
what is an example of physiologic hypertrophy?
the uterus during pregnancy
What is hyperplasia?
an increase in the number of cells in an organ or tissue in response to to a stimulus
what causes physiologic hyperplasia?
hormones or growth factors occur in several circumstances: when there is a need to increase the functional capacity of hormone sensitive organs; and when there is need for compensatory increase after damage or resection
what is an example of pathologic hyperplasia?
endometrial carcinoma in response to prolonged estrogen exposure; benign prostatic hyperplasia
What is an example of physiologic hyperplasia?
proliferation of the glandular epithelium of the female breast at puberty and during pregnancy
what is an example of compensatory hyperplasia?
liver regeneration and bone marrow
hyperplasia is a characteristic response to what?
certain viral infections, such as papillomavirus, which causes skin warts and several mucosal lesions composed of masses of hyperplastic epithelium
what is atrophy?
the reduction in size of an organ or tissue due to a decrease in the cell size and number
what are 2 examples of physiologic atrophy?
common during normal development-notochord and the thyroglossal duct; decrease in the size of the uterus ofter birth
What are 6 etiologies for pathologic atrophy?
decreased workload (atrophy of disuse), loss of innervation (denervation atrophy), diminished blood supply (senile atrophy), inadequate nutrition, loss of endocrine stimulation, and pressure
What is the mechanism of atrophy?
it results from decreased protein synthesis and increased protein degradation in cells
