Apoptosis Intrinsic And Extrinsic Pathway Ppt To Pdf

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In molecular biology, the words extrinsic pathway may refer to both the extrinsic pathway of apoptosis and the extrinsic pathway of blood coagulation.

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Copy embed code:. Automatically changes to Flash or non-Flash embed. WordPress Embed Customize Embed. URL: Copy. Presentation Description No description available. It may occur in the living body as a local or focal change i.

These pathologic processes involved in the cell death are as follows. It occurs in the living body in places surrounded by inflammatory reaction or it may occur as post-mortem change in which there is complete absence of surrounding inflammatory response. Tissues rich in hydrolytic enzymes such as in pancreas and gastric mucosa autolysis is rapid.

It is accompanied by inflammatory reaction. Generally heart , kidney and spleen are affected. It occurs due to degradation of tissues by the action of powerful hydrolytic enzymes eg : infarct brain and abscess cavity. Caseous necrosis: Caseous necrosis It is found in the centre of foci of tuberculous infections. These are acute pancreatic necrosis and traumatic fat necrosis commonly in breast. It is encountered in various examples of immunologic tissue injury Eg in immune complex vasculitis , autoimmune disease, Arthurs reaction etc..

Significance of apoptosis. Apoptosis Vs Necrosis. Morphological features. Molecular Mechanism. Serves to eliminate cells with irreparable faulty DNA produced as a result of mutation etc, thereby preventing proliferation of defective cells.

Helps in cessation of immune response. During development many cells are produced in excess which eventually undergo programmed cell death and thereby contribute to sculpturing many organs and tissues.

Necrosis :: Apoptosis vs. Preservation of organelles and cell membranes Rapid engulfment by Macrophages preventing inflammation. Cell begins to shrink following the cleavage of lamins and actin filaments of the cytoskeleton. Cells continue to shrink. C , packaging themselves into a form that allows for their removal by macrophages. D Small vesicles called apoptotic bodies are also sometimes observed. DNA breakdown : Ca-Mg dependant exonucleases breakdown DNA into fragments of kilobasepieces with further intranucleosomal cleavage of DNA into oligonucleosomes in multiples of basepairs.

Flow cytometry : to visualize rapid cell shrinkage. Gel electrophoresis : to detect DNA fragmentation DNA laddering test Annexin V dye : marker for phosphatydyl serene on cell membrane of apoptotic bodeis. Cell deletion in proliferating cell population : ex intestinal crypt epithelial cells, to maintain a steady cell count. Atrophy in parenchymal organs ex :duct obstruction of pancreas, parotid gland, kidney, prostatic atrophy orchidectomy. Activation of TNF death rec : extrinsic pathway.

The mitochondria release of cytochrome C from mitochondria can lead to the activation of caspase 9, and then of caspase 3. This effect is mediated through the formation of an apoptosome , a multi-protein complex consisting of cytochrome C, Apaf-1, pro- caspase 9 and ATP.

They can activate a caspase cascade within seconds of ligand binding. Induction of apoptosis via this mechanism is therefore very rapid. This ceramide release is thought to promote clustering of the death receptors. The large scale receptor clustering is important because it helps amplify the apoptotic signalling. In the absence of receptor clustering some cells, such as lymphocytes, are still able to trigger apoptosis. The final step in this process is the recruitment of one of the caspases , typically pro- caspase 8, to the DISC.

This results in activation of caspase 8 and the inititation of apoptosis. TRADD has the ability to recruit a number of different proteins to the activated receptor.

Capase cascade follows. Binding of the ligand promotes receptor clustering. In addition the Fas receptor is generally though to only activate apoptosis. Rapid fragmentation of the nuclear DNA follows. Oligonucleosomes nucleosomal units exist in multiples of basepairs.

Follow us on:. Go to Application. US Go Premium. PowerPoint Templates. Upload from Desktop Single File Upload. Post to :. URL :. Related Presentations :. Add to Channel. The presentation is successfully added In Your Favorites. Views: Category: Education. Like it 0. Dislike it 0. Added: January 22, Posting comment Premium member. Presentation Transcript. PHARM 1. Necrosis is caused by various agents such as hypoxia, chemical and physical agents, microbial agents and immunological injury Two essential changes bring about irreversible cell injury in necrosis-cell digestion by lytic enzymes and denaturation of proteins 5.

Fat necrosis: Fat necrosis It is a special form of cell death occurring at two anatomically different locations but morphologically similar lesions. Fibrinoid necrosis: Fibrinoid necrosis It is characterised by deposition of fibrin like material which has the staining properties of fibrin.

Significance of apoptosis:: Significance of apoptosis: It serves to eliminate unwanted, worn out potentially harmful cells which have outlived their usefulness. Apoptosis vs. Necrosis Nuclear swelling Cell swelling Disruption of organelles Rupture of cell and release of cellular contents Inflammatory response Image below shows a trophoblast cell undergoing apoptosis.

Identifying apoptotic cells :: Identifying apoptotic cells : Staining of condensed chromatin : by haematoxylin , feulgen , acridene orange. Apoptosis in Physiologic Situations :: Apoptosis in Physiologic Situations : Hormone-dependent involution in the adult ex: endometrial shedding , regression of lactating breast, involution of thymus in adults, involution of appendix.

The Apoptosome : The Apoptosome Granzyme B delivered into cells by cytotoxic T lymphocytes and is able to directly activate caspases 3, 7, 8 and Apoptotic signalling from the death receptors: : Apoptotic signalling from the death receptors: Binding of the ligand to its receptor can lead to a the generation of ceramide , produced by hydrolysisof sphingomyelin.

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Intrinsic and Extrinsic Pathways of Apoptosis

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Cell Death Signaling

These changes include blebbing , cell shrinkage , nuclear fragmentation , chromatin condensation , chromosomal DNA fragmentation , and global [ vague ] mRNA decay. The average adult human loses between 50 and 70 billion cells each day due to apoptosis. In contrast to necrosis , which is a form of traumatic cell death that results from acute cellular injury, apoptosis is a highly regulated and controlled process that confers advantages during an organism's life cycle. For example, the separation of fingers and toes in a developing human embryo occurs because cells between the digits undergo apoptosis.

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Apoptosis: A Review of Programmed Cell Death

The process of programmed cell death, or apoptosis, is generally characterized by distinct morphological characteristics and energy-dependent biochemical mechanisms. Apoptosis is considered a vital component of various processes including normal cell turnover, proper development and functioning of the immune system, hormone-dependent atrophy, embryonic development and chemical-induced cell death. Inappropriate apoptosis either too little or too much is a factor in many human conditions including neurodegenerative diseases, ischemic damage, autoimmune disorders and many types of cancer.

Intrinsic and Extrinsic Pathways of Apoptosis

In multicellular organisms, cell death is a critical and active process that maintains tissue homeostasis and eliminates potentially harmful cells. There are three major types of morphologically distinct cell death: apoptosis type I cell death , autophagic cell death type II , and necrosis type III. All three can be executed through distinct, and sometimes overlapping, signaling pathways that are engaged in response to specific stimuli.

Intracellular cues, such as damage to the cell's DNA, drive apoptosis primarily through the intrinsic pathway. The intrinsic apoptosis pathway, which involves conserved signaling proteins, is physically associated with mitochondria, and in vertebrates is sensitive to mitochondrial oxidative stress. The pathway is influenced by members of the Bcl family bound to the mitochondrial membrane, including Bax and Bcl-2 gene, which act as pro- or anti-apoptotic regulatory proteins, respectively. It is activated by a range of exogenous and endogenous stimuli, such as DNA damage, ischemia, and oxidative stress. Moreover, it plays an important function in development and in the elimination of damaged cells.

Быстрее. Хейл выслушал все это, не сдвинувшись с места и не веря своим ушам. Хватка на горле Сьюзан слегка ослабла. Стратмор выключил телефон и сунул его за пояс. - Твоя очередь, Грег, - сказал. ГЛАВА 81 С мутными слезящимися глазами Беккер стоял возле телефонной будки в зале аэровокзала. Несмотря на непрекращающееся жжение и тошноту, он пришел в хорошее расположение духа.


Mechanisms of Apoptosis. • Death receptor (Extrinsic) pathway. • Mitochrondrial (​Intrinsic) pathway. • Execution Phase. • Removal of dead cells. This slide.


What is the difference between intrinsic and extrinsic pathway of apoptosis?

 В чем дело? - спросил Фонтейн.  - Вы что-то нашли. - Вроде.  - У Соши был голос провинившегося ребенка.  - Помните, я сказала, что на Нагасаки сбросили плутониевую бомбу. - Да, - ответил дружный хор голосов. - Так вот… - Соши шумно вздохнула.

Сьюзан плюхнулась обратно в ванну. - Ох! - Она не могла скрыть разочарование.  - Здравствуйте, шеф. - Думала, кое-кто помоложе? - засмеялся Стратмор. - Да нет, сэр, - попыталась она сгладить неловкость.

2 Response
  1. TeГіfilo S.

    The intrinsic and extrinsic pathways of apoptosis are both naturally occurring processes by which a cell is directed to programmed cell death.

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