1. Cellular Adoption & Tissue Response Chapter # 10 Abasyn University Peshawar Campus

2.  Cellular adaptation is the ability of cells to respond to various types of stimuli and adverse environmental changes.  Cellular adoption is, Reversible changes of cells in,  Size, number, phenotype,  metabolic activity and function  To give in response to change in their environment Cellular Adoption

3.  These adaptations include;  Hypertrophy (enlargement of individual cells),  Hyperplasia (increase in cell number),  Atrophy (reduction in size and cell number),  Metaplasia (transformation from one type of epithelium to another), and  Dysplasia (disordered growth of cells).  Cells must constantly adapt, even under normal conditions, to changes in their environment. Cellular Adoption

4.  Hypertrophy (enlargement of individual cells)  It’s the increase in the size of cells lead to caused increased in size of organ.  No new cells generation, just increased the size of the cells.  Synthesis of more structural components.  Due to increased demand or stimulation by hormones & growth factors.  Example, as in the enlargement of the breast and induction of lactation by pregnancy. 1. Hypertrophy

5.  Causes of Hypertrophy Could be Physiologic and pathologic  Enlargement of uterus pregnancy, action of estrogenic hormones.  Hypertrophy of heart the most common stimulus is chronic hemodynamic overload 1. Hypertrophy Hypertrophy Physiologic Pathologic  Hypertrophy of cardiac muscle,  Hypertrophy of smooth muscle,  Hypertrophy of cardiac muscle,  Hypertrophy of smooth muscle, Pregnancy

6.  Hyperplasia (increase in cell number)  It’s the increasing of cells numbers, lead to caused increased in size of tissue / organ.  Generation of new cells, and increased the size of the cells.  Synthesis of more structural components. 2. Hyperplasia

7.  Causes of Hyperplasia Could be Physiologic and pathologic  Physiologic hyperplasia: Occurs due to a normal stressor.  For example, increase in the size of the breasts during pregnancy  Increase in thickness of endometrium during menstrual cycle  and liver growth after partial resection.  Pathologic hyperplasia: Occurs due to an abnormal stressor. 2. Hyperplasia

8. Atrophy (reduction in size and cell number)  Shrinking in size of the cell by the loss of cell substance is known as Atrophy  Atrophy (Reduced size of an organ or tissue, resulting from a decrease in cell size and number)  Atrophy is the progressive degeneration or shrinkage of muscle or nerve tissue.  Mostly occurred in fetus in infants 3. Atrophy

9. Nutritional (starvation) atrophy Caused by starvation or malnutrition Seen in proteins calorie malnutrition (marasmus), due to utilization of muscle protein as an energy source. 3. Atrophy

10. Loss of endocrinal stimulation After menopause: Loss of estrogen stimulation Menopause is the time that marks the end of menstrual cycles. Physiological atrophy of endometrium, (female reproductive part) epithelium and breast. 3. Atrophy

11. Brain atrophy Senile atrophy due to progressive developing atherosclerosis

12.  Metaplasia (transformation from one type of epithelium to another)  Metaplasia is the replacement of one differentiated somatic cell type with another differentiated somatic cell type in the same tissue.  Metaplasia is a process whereby one type of mature tissue is replaced by another type of mature tissue not indigenous to that organ or tissue.  Example; Squamous metaplasia 4. Metaplasia

13.  A term used to describe the presence of abnormal cells within a tissue or organ.  Dysplasia is not cancer, but it may sometimes become cancer.  Dysplasia can be mild, moderate, or severe, depending on how abnormal the cells look under a microscope and how much of the tissue or organ is affected. 5. Dysplasia

14. Thank You 20 h December, 2021