Necrosis Cell Injury | Apoptosis | General Pathology🦠
HTML-код
- Опубликовано: 11 сен 2024
- #necrosis #apoptosis #cellinjury #cellinjury #generalpathology #drnajeeb #pathology
Necrosis Cell Injury | Apoptosis | General Pathology🦠
Like this video?
Sign up now on our website at www.DrNajeebLe... to access 1000+ Exclusive videos on Basic Medical Sciences & Clinical Medicine. These are premium videos (NOT FROM RUclips). All these videos come with English subtitles & download options. Sign up now! Get Lifetime Access for a one-time payment of $59 ONLY!
Sign up now on our website at members.drnaje...
---------------------------------------------------------------------------------------------------------------------------
Why sign up for premium membership? Here's why!
Membership Features for premium website members.
1. More than 1000+ Medical Lectures.
2. Basic Medical Sciences & Clinical Medicine.
3. Mobile-friendly interface with android and iOS apps.
4. English subtitles and new videos every week.
5. Download option for offline video playback.
6. Fanatic customer support and that's 24/7.
7. Fast video playback option to learn faster.
8. Trusted by over 2M+ students in 190 countries.
---------------------------------------------------------------------------------------------------------------------------
▬▬▬▬▬▬▬▬▬▬ Contents of this video ▬▬▬▬▬▬▬▬▬▬
Necrosis (from Ancient Greek νέκρωσις (nékrōsis) 'death') is a form of cell injury which results in the premature death of cells in living tissue by autolysis. The term "necrosis" came about in the mid-19th century and is commonly attributed to German pathologist Rudolf Virchow, who is often regarded as one of the founders of modern pathology. Necrosis is caused by factors external to the cell or tissue, such as infection, or trauma which result in the unregulated digestion of cell components. In contrast, apoptosis is a naturally occurring programmed and targeted cause of cellular death. While apoptosis often provides beneficial effects to the organism, necrosis is almost always detrimental and can be fatal.
Cellular death due to necrosis does not follow the apoptotic signal transduction pathway, but rather various receptors are activated and result in the loss of cell membrane integrity and an uncontrolled release of products of cell death into the extracellular space. This initiates an inflammatory response in the surrounding tissue, which attracts leukocytes and nearby phagocytes which eliminate the dead cells by phagocytosis. However, microbial damaging substances released by leukocytes would create collateral damage to surrounding tissues. This excess collateral damage inhibits the healing process. Thus, untreated necrosis results in a build-up of decomposing dead tissue and cell debris at or near the site of the cell death. A classic example is gangrene. For this reason, it is often necessary to remove necrotic tissue surgically, a procedure known as debridement.
---------------------------------------------------------------------------------------------------------------------------
Join this channel to get access to the perks:
Sign up now on our website at members.drnaje...
Follow us on Facebook:- / drnajeeb
Follow us on Instagram:- / drnajeeblectures
0:00 - 29:40
When a cell is irreversibly damaged, either it undergoes necrosis or apoptosis. Necrosis always follows pathological cell injury by toxins, radiations, trauma, hypoxia. Apoptosis may be physiological (during embryogenesis) or pathological.
NECROSIS:
Necrosis is a series of morphological changes in a lethally and irreversibly injured cell.
These changes may be recognized by light microscope only after a few hours.
When cell is lethally injured, it cannot produce ATPs. Reserve of ATPs run out.
In case of hypoxia, pyruvic acid produced from glucose cannot enter Krebs cycle. So they get converted into lactic acid. So intracellular environment becomes acidic. And structural and functional proteins get denatured. This will translate into morphological changes in cell.
There is also enzymatic digestion of severely injured cell.
a. These enzymes are from burst lysosomes.(autolysis)
b. And also may be from inflammatory cells like neutrophils and macrophages. These enzymes also may be from proliferating microbes (Heterolysis)
So causes of morphological changes:
a. Enzymatic digestion
b. Denaturation of proteins
c. Loss of integrity of plasma membrane. Intracellular components leaks out and injure surrounding cells. This causes inflammation at the site. This will summon the leucocytes. This process does not happen in apoptosis.
The summoned leucocytes eat the cell debris and produce factors that cause proliferation of cells at the site for repair or conversion of fibrocyte into fibroblast.
DEATH OF PATIENT IMMEDIATELY AFTER LETHAL CELL INJURY:
For example, a person dies within an hour of severe myocardial ischemia. The section of heart under light does not show necrotic changes. Because necrotic changes take some hours to manifest and can happen only in a live person. Other sign like plaque in coronary artery sections and past MI scars may be seen in dead person.
However, in this case, because of loss of membrane integrity, intracellular myocardial proteins may leak in to blood and act as evidence of myocardial death. These proteins may be cardia Troponin T, cardiac Troponin I, CK-MB.
These markers are also used to diagnose MI in live persons. ECG can also be used.
If the person were to live, local inflammation would be produced and leucocytes would be summoned forming a necrotic picture and later fibrosis would have occurred at the site of necrosis.
29:40 - 49:30
MORPHOLOGICAL CHANGES IN NECROSIS:
Normally cytoplasmic proteins bind eosinophillic stain. Ribosomes binds hemotoxyllin. DNA is basophilic and binds hematoxyllin.
After irreversible injury, light microscopic changes seen are
1. Cell becomes intensely eosinophillic because
a. Denatured intracellular proteins unfold and bind more eosinophil and cell becomes intensely eosinophillic.
b. Disintegration of basophilic ribosomes.
2. Moth eaten appearance due to digestion of organalles and unstained pockets.
3. Granularity present in normal because of glycogen granules.
4. During necrosis, glycogen granules are lost and cell appearance becomes glassy and homogenous
5. Myelin figures are formed which are whorled phospholipid membrane formed from disintegrated membrane of organelles and cell. These will be ultimately be cleared by macrophages or undergo dystrophic calcification since they are difficult to digest.
Ultra structural changes under Electron Microscope:
1. Plasma and organelle membrane discontinuity
2. Mitrochondrial swelling.
3. Amorphous bodies inside mitochondria
4. Intracellular myelin figures
5. Cytoplasmic amorphous deposits which are denatured proteins.
DNA is also digested by DNAases
Nuclear changes during necrosis may be any one of the following types
1. Karyolysis: Gradual disappearance of nucleus by gradual digestion of nuclear material
2. Pyknosis: Nucleus becomes intensely condensed and
3. Karyorrhexis: Nucleus becomes condensed and fragmented
49:30 - 1:20:12
DIFFERENT TYPES OF NECROSIS
Coagulative necrosis: Hallmark: Maintenance of cellular architecture for few days but nucleus is lost within 1 or 2 days. Both structural and functional proteins undergo denaturation simultaneously. So enzymes are also denatured. So enzymatic digestion does not occur. So autolysis cannot occur. Example: Myocardial Infarction, Severe hypoxic injury of Spleen, Kidney, Liver Localised areas of coagulative necrosis is called infarct. After a few days, heterolysis by neutrophils and macrophages occurs. Brain cannot undergo coagulative necrosis.
Liquefactive Necrosis: Severe hypoxia of brain causes liquefactive necrosis. Cellullar architecture not maintained. Enzymatic digestion occurs here( autolysis). Also heterolysis occurs by leucocytes and microbes. Other examples: necrosis by infection.
Why do neutrophils come early than mcrophages?
a. The chemotactic factors produced at first attract neutrophils. That which attract monocytes are produces later.
b. Neutrophils are abundant
c. Neutrophils are mobile
In the later part of inflammation, macrophages are abundant than neutrophils.
PUS: It is a product of liquefactive necrosis constitutes of alive, dead and dying local cells, microbes and neutrophils all covered with protein rich inflammatory exudates.
ABCESS: Localised pus formation. Center of the collection consists of dead local cells, microbes, neutrophils. This is surrounded by active and alive local cells, microbes and neutrophils. This is further surrounded by blood vessels that is dilated and permeable. And finally, the periphery is made of fibrotic tissue and proliferating local tissue
Thanks man
It really helps🤩
Very very useful...
Thank you so... much mam..
Thanks man it's really helpful
Tqs a lot....Mam 🙏🙏🙏
Where are u study bro
I watched the video because I thought it was about studying apoptosis in detail, but the wonderful explanation of necrosis prevented me from leaving until the end!❤
Glad you enjoyed it!
Thank you for videos. I am a nursing student who just wants to know more and I really appreciate your in-depth videos and much respect.
You're a good professor. You make each point in lecture clear
I'm Egyptian medical student
Thank you for all the love and support❤ Stay blessed ❤
The best teacher l have ever seen , Allah protects you Dr. Najeeb .
We are waiting for the rest of necrosis types 🙏🏻
Thank you for your kind words❣️ Stay blessed ❣️
Zindagi se yahi gila hai mujhey
Tu bahot der se mila hai mujhe...❤❤❤
Fantastic teacher being a physiotherapist i also like watch dr najeeb sir lectures brilliant teacher✌👍💞
Dr Nejeeeb Thankyou my Lecture and My senior Faithfulness
Best teacher in world,god bless you sir
Thank you so much 🥰
There is no need of further explanation after Dr Najeeb lecture 👏👏
Sir, i am watching your lectures from class 9th....today I am in class 11th and I am still watching your lectures.Your lectures helps me a lot... especially in my 11th class.....
Sir, I am very thankful to you....💜💜...
All the best for your future endeavors ❤️
Hello dear doctor !
Really exceptional ❤️ lectures, God bless you !
Love from Iran 🇮🇷
🙏🌹
Love you more dear💖Keep supporting💖
Thank you so much Sir for your support 💯☺️😊❣️❤️💖
I always search for dr najeeb sir lecture if am not clear with some concept. God bless u dr❤
You are the father of medicine as I think
Thank you for your love
It is literally best explanation i have studied in my whole 2nd year ❤
Keep watching keep supporting ❤
I humbly Thank you Respected Sir💕..May Allah Almighty bless U with His uncountable blessings.Ameen
You are most welcome❤ Stay blessed❤
Thanks alot for the Lectures .
Glad you like them! HAPPY LEARNING ❤️
It's a blessing to be able to listen to your class dear Sir😊❣️
Are u in ist year mbbs
Sir my big wish in my whole life is that I want to meet you in my life sir you are really legend
I sir still waiting for your new lecture 😘
So nice of you. Stay blessed ❤️
Best teacher in the world❤
Thank you for your love and support❤ Stay blessed ❤
I find your basic lectures of medical science free where should I search for it: please help me sir
Please Visit at www.DrNajeebLectures.com
You can find lectures on Basic Medical Sciences & Clinical Medicine.
MASTER OF MEDICAL SCIENCES💝DR NAJEEB WE LOVE U💝💝
Thank you for all the love and support❤️ Keep supporting❤️
Love you sir you are excellent teacher.
You are best teacher for we all student.... Thanks for this best lecture 😊 ..
It's my pleasure❤ Keep supporting ❤
Love And Respect for you Sir 💖
Thank you for all the love and respect dear❤ Stay blessed ❤
Thank you sir
You are welcome ❤
Too much love from Delhi guru ji🙏🏻❤
Thank you for your love and support❤
Thank you so much Dr.Najeeb and happy holidays, where can I find the other part of necrosis (caseous, gangrenous, fibroid)?
Please Visit at www.DrNajeebLectures.com
You can find lectures on Basic Medical Sciences & Clinical Medicine.
@@DoctorNajeebsir can't find it
Did you find the video? Pls let me know
Thanks you sir, from Nigeria
You are most welcome❤️
Is it true that Necrotic cells do not generate ATP in the intracellular space?
Love from Kashmir sir u are the best
Love you more ❤️
Watching from kashmir ... love you so
Love you more ❤️ Stay blessed 💖
Thanku sir ji
You are welcome❤
Best lecture
thank you doctor my negrosis has been acting up lately this has helped me out with that pesky negrosis
Nice lecture sir.watching from mardan
Thanks and welcome 💝
Thank you sir 💝.....
Most welcome
Thank you so much Sir😍
Most welcome
Perfect👍🏻
Excuse me is there are videos for all general pathology chapters?
Please visit the website to get full video library access.
www.drnajeeblectures.com/
Love you dear sir 😘 ❤️
Love you more dear❤ Keep supporting❤
Happy holidays professor
Happy holidays!
Health and wealth for you❤
Very good👍👍👍 teaching...
Thank you❤ Stay blessed ❤
May Allah Give you 100 year lifespan 🤲
Thank you for your love and support❤ Stay blessed ❤
thank you so much for your best videos🙏I want lecture videos about typhoid Fever 🙏
The best forever ❤❤
Thanks for the love and support 💖
My GREAT TEACHER
Thank you❤ Stay blessed ❤
Tnxkiyou sir ji u are the great ❤❤❤
Sir 🔥
Happy teachers day ....dear sir.....may almighty god bless you and your family endlessly....
Thank you for your kind words❤
@@DoctorNajeeb sir, i have a doubt...is the following stem T/F
- The light microscopy changes precede ultra structural changes during necrosis
thank you Dr.
Thank
Please allow the subscription for one year only and reduce the price...
We want to leaen truely from sir and we cant afford this price though it is life time
contact at Support@drnajeeblectures.com
@@DoctorNajeeb form is restricted on website and can’t contact you! What should we do ?
Sir .may Allah protect you from evil eyes Amin suma amin
Thank you so much for kind prayers. ❤️
Nice class
Thanks 🙏
Thankyou 100%
You are welcome❤
What is inflammation
Very very thanks sir... 🙏❤❤
Most welcome❤
What is necrosis❤
The meaning of life
🌹🌹🌹🌹🌹
❤❤
Thank you so much sir,god bless you 👍🙏👌😊🤗
Most welcome❤
Sir cancer pe lectures hai aapka
You can find lectures at our website at : www.drnajeeblectures.com
🙏👍
❤❤
Waw
Thank you ❤❤
❤❤🙏🙏🙏🙏
❤❤
Thank you sir
Most welcome❤ Stay blessed ❤
thank you sir
Most welcome❤ Stay blessed ❤