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Cellular Adaptation the Very Best Way for Most Minds to Remember, Or Identify, Or Understand a Disease Is to Associate It with a Morphologic IMAGE

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Cellular Adaptation the Very Best Way for Most Minds to Remember, Or Identify, Or Understand a Disease Is to Associate It with a Morphologic IMAGE Cellular Adaptation The very best way for most minds to remember, or identify, or understand a disease is to associate it with a morphologic IMAGE. This can be gross, electron microscopic, light microscopic, radiologic, or molecular. In MOST cases it is at the LIGHT MICROSCOPIC LEVEL. The cell is the fundamental unit of disease CELLULAR ADAPTATION: The ability of cells to respond to various types of stimuli and adverse environmental changes. The cell changes chat occur are: . Atrophy(reduction in size and cell number) Hypertrophy (enlargement of individual cells) .Hyperplasia, (increase in cell number) .Metaplasia(transformation from one type of epithelium to another) .Dysplasia(disordered growth of cells) .Anaplasia,,,, Neoplasia. Cellular Changes Then anaplasia/neoplasia HYPERPLASIA Basic description: Increase in the number of cells. Types of hyperplasia 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. proliferation of endometrium due to prolonged estrogen stimulus. Important point regarding hyperplasia: Only cells that can divide will undergo hyperplasia; therefore, hyperplasia of the myocytes in the heart and neurons in the brain does not occur. 1- FOL LICULAR HYPERPLASIA (LYMPH NODE) 2- FOLLICULAR HYPERLASIA (TONSIL) 3- SINUS HYPERPLASIA (LYMPH NODE) LYMPH NODE -FOL LICULAR HYPERPLASIA (LYMPH NODE) -زيادة عدد اﻷجربة، وحجمها، وتكون اﻷجربة بحجوم مختلفة. -ضخامة مركز النتوج ليشمل معظم الجراب. - تزول الجيوب تحت المحفظة نتيجة لتض ّخم اﻷجربة. -تجتاح اﻷجربة معظم العقدة حيث تتجاوز القشر وتصل حتّى اللب، ولكنّها ﻻ تتجاوز المحفظة. 2- FOLLICULAR HYPERLASIA (TONSIL) فرط تصنع جرابي في اللوزة بشر ٌة رصفية مطبّقة مخاطية غير متقرّنة تغطّي اللوزة، وذلك بخﻻف العقدة اللمفاوية التي تحيط بها محفظة من النسيج الليفي)، وهي عﻻمة مميزة( تبدي هذه البشرة انغمادات من السطح للعمق مكوّن ًة أغواراً أولية وثانوية تحت البشرة نرى اﻷجربة اللمفية مفرطة التصنّع حجمها كبير، وذات مركز نتوج ضخم من الممكن أن نرى في المح ّضر جزء من غدد لعابية . SINUS HYPERPLASIA (LYMPH NODE) فرط تصنّع جيبي في العقدة اللمفية تو ّسع الجيوب في العقدة اللمفية وخصوصاً اللبية وذلك يؤدّي إلى تضخم اللب على حساب القشر ولذلك غالباً ما تضمر اﻷجربة ونﻻحظ بقايا لبعضها. المحفظة الليفية والشحم حول المحفظة. القشر: يشاهد فيه بعض اﻷجربة اللمفية التي قد تكون ضامرة أو ﻻ، وربما تتضخم أيضا ً. اللب : حيث تتو ّسع الجيوب الوريدية واللمفية وتمتلئ بالخﻻيا البالعة واللمفية والبﻻزمية HYPERTROPHY Increase in the size of the cell. Types of hypertrophy Physiologic hypertrophy: Occurs due to a normal stressor. For example, enlargement of skeletal muscle with exercise. Pathologic hypertrophy: Occurs due to an abnormal stressor. For example, increase in the size of the heart due to aortic stenosis. Morphology of hyperplasia and hypertrophy: Both hyperplasia and hypertrophy result in an increase in organ size; therefore, both cannot always be distinguished grossly, and microscopic examination is required to distinguish the two ATROPHY •Atrophy is the shrinkage in cell size by loss of cellular substance •With the involvement of a sufficient number of cells, an entire organ can become atrophic •Causes of atrophy include decreased workload, pressure, diminished blood supply or nutrition, loss of endocrine stimulation, and aging •Mechanisms of atrophy : Apoptosis..Autophagy.. 1- Fatty changes,,fatty degenration,,,lymph node. 2- Fatty changes …degenration…thymus. تراجع شحمي في العقدة اللمفية من الطبيعي أن نﻻحظ خﻻيا شحمية خارج العقدة أي خارج المحفظة الليفية) بشكل سوي( ولكن في حال ظهرت خﻻيا شحمية واضحة الحدود ضمن البرانشيم الخلوي للعقدة اللمفية فهذا يدل على حدوث تراجع شحمي في هذه العقدة اللمفية قشر فيه بعض اﻷجربة اللمفية الضامرة. نسيج شحمي يغزو العقدة اللمفية. Histologic Features of the Thymus The cortex is composed primarily of lymphocytes(thymocytes), with a few epithelial and mesenchymal Cells , whereas the medulla is composed of more epithelial cells but fewer lymphocytes. Hassall corpuscles are the characteristic, round, keratinized formations with mature epithelial cells. تراجع شحمي في التايموس نسيج ضام ونسيج شحمي وبقايا النسيج البشروي واللمفي. بقايا جسيمات هاسال موجودة في اللب وهي بنى غير خلوية متقرّنة مكوّنة من صفائح متّحدة المركز تظهر بلون أيوزيني، ويعتبر جسيم هاسال النقطة الع ّﻻمة METAPLASIA REVERSIBLE change in which one mature/adult cell type (epithelial or mesenchymal) is replaced by another mature cell type A protective mechanism rather than a premalignant change Physiological metaplasia: cervical ectopy Pathological metaplasia Occurs as a response to chronic chemical or physical stimuli May completely regress or lead to malignant transformation (considered precancerous) Examples Intestinal metaplasia (Barrett metaplasia) Squamous metaplasia of the bronchi due to smoking → ciliated pseudostratified columnar epithelium is replaced by stratified squamous epithelium Squamous metaplasia of the bladder due to Schistosoma infection, urinary calculi, or indwelling catheters Ciliated columnar cells Stratifiied squamous cells 1. ظهارة تنفسية . .2 ظهارة مالبيكية. 3 طبقة تحت مخاطية تحوي نسيج ضام رخو وغدد. 4 نسيج غضروفي Barrett’s Esophagus Intestinal Metaplasia of the Esophagus THANK YOU .
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