Hyperplasia (1)

1. HYPERPLASIA
Presented By
Maryam Manzoor
Lecturer Pharmacology
Rashid Latif College of Pharmacy

2. DEFINITION
“Hyperplasia is an increase in the number of cells in an
organ that stems from increased cell proliferation”

3.  Hyperplasia takes place if the tissue contains cell
populations which is capable of replication.
 It may occur concurrently with hypertrophy and often in
response to the same stimuli.

4. TYPES

5. MECHANISM
 In both situations, cellular proliferation is stimulated by
growth factors that are produced by a variety of cell types.

6. CAUSES
 Increased local production of hormones.
 Increased growth factor response on receptor cells.
 Activation of particular intracellular signaling pathway.

7. PHYSIOLOGICAL HYPERPLASIA
 The two types of physiologic hyperplasia are:
 Hormonal hyperplasia
Proliferation of the glandular epithelium of the
female breast at puberty and during pregnancy.
 Compensatory hyperplasia
In which residual tissue grows after removal or loss of
part of an organ. For example, when part of a liver is resected,
mitotic activity in the remaining cells begins as early as 12 hours
later, eventually restoring the liver to its normal size.

8. The growth and multiplication of milk secreting glandular epithelial
cells in response to pregnancy for future lactation

9. Compensatory Hyperplasia

10. PHYSIOLOGICAL HYPERPLASIA
 The stimuli for compensatory hyperplasia in case of liver
resection is polypeptide growth factors produced by
uninjured hepatocytes.
 After restoration of the liver mass, various growth
inhibitors turn off cell proliferation

11. PATHOLOGICAL HYPERPLASIA
 Most forms of pathologic hyperplasia are caused by excessive
hormonal or growth factor stimulation.
1- For example, after a normal menstrual period there is a burst of
uterine epithelial proliferation. A disturbance in this process can lead
to increased estrogenic stimulation causes endometrial hyperplasia,
which is a common cause of abnormal menstrual bleeding------------
--- endometrial hyperplasia

13. PATHOLOGICAL HYPERPLASIA
2- Benign prostatic hyperplasia -------------induced in responses to
hormonal stimulation by androgens.
3- Certain viral infections; for example, papillomaviruses cause skin
warts and mucosal lesions that are composed of masses of
hyperplastic epithelium.
4- wound healing.
5- Thyroid Hyperplasia

15. THYROID HYPERPLASIA

16.  In all of these situations, the hyperplastic process remains
controlled; if the signals that initiate it abate, the hyperplasia
disappears.