Introduction to Pathology - Cell Injury - A New Pathology Series

Summary

This video from Medicosis Perfectionalis delves into pathology, the study of diseases, and their causes. The host explains key concepts like cell injury and cell death, highlighting the reversible nature of cell injury and the irreversible nature of cell death. They discuss various causes of cell injury, including hypoxia, chemical agents, and genetic conditions, and elaborate on conditions like myocardial infarction, COPD, and heavy metal poisoning. The video also touches on treatments and how medicine 'makes sense' when thoroughly understood. It's an engaging, detailed breakdown of disease processes with practical applications.

Takeaways

• 🦠 Pathology studies diseases, their nature, causes, and risk factors, with biopsy as the gold standard for diagnosis.
• 🔬 Gross examination refers to inspecting organs with the naked eye, while microscopic examination involves using a microscope.
• 💀 Cell injury is reversible, but cell death is irreversible, with apoptosis and necrosis being types of cell death.
• 😷 Causes of cell injury include hypoxia (lack of oxygen), chemical agents (e.g., alcohol, acetaminophen), physical agents, free radicals, and inflammatory or immunological conditions.
• 🫁 Organs like the lungs and heart are key to preventing hypoxia. Lung disease or heart disease can lead to oxygen deprivation and cell injury.
• 💊 Acetaminophen overdose is dangerous, leading to liver damage through the depletion of glutathione, which normally neutralizes free radicals.
• 🧬 Genetic conditions (e.g., phenylketonuria) and metabolic disorders (e.g., diabetes) can cause cell injury by disrupting normal metabolic pathways.
• 🍽️ Nutritional deficiencies, such as in protein energy malnutrition (e.g., kwashiorkor or marasmus), can cause cell injury, leading to conditions like edema due to low oncotic pressure.
• 🦠 Bacterial, viral, fungal, and parasitic infections can cause cell injury, with treatments including antibiotics, antivirals, and antifungals.
• 💡 The Fenton reaction describes how free iron or copper generates harmful hydroxyl radicals, leading to further cellular damage.

Q & A

What is the gold standard for diagnosing diseases according to the video?

The gold standard for diagnosing diseases is biopsy, which involves examining the organ through gross (naked eye) and microscopic examination.

What is the difference between cell injury and cell death?

Cell injury is a reversible process, meaning the cell can recover, while cell death is irreversible, and the cell cannot be restored.

What are some of the causes of hypoxia or anoxia mentioned in the video?

The causes of hypoxia or anoxia include lung disease (such as COPD), heart disease (such as myocardial infarction), and chemical factors like cigarette smoking and alcohol.

What are the main categories of agents that can cause cell injury?

The main categories of agents that cause cell injury include hypoxia, chemical agents, physical agents, free radicals, inflammatory conditions, immunological conditions, microbiological causes, genetic or metabolic factors, nutritional deficiencies, and aging.

How does acetaminophen cause cell injury, and how can it be treated?

Acetaminophen is metabolized into a toxic compound called NAPQI, which depletes glutathione, leading to cell damage. It can be treated by replenishing glutathione using N-acetylcysteine.

What is the Fenton reaction, and why is it harmful?

The Fenton reaction occurs when free iron or copper generates hydroxyl free radicals, which cause oxidative damage to cells. This is why iron is normally bound to transferrin in the blood and ferritin in tissues.

What is the difference between gram-positive and gram-negative bacteria?

Gram-positive bacteria have a thick peptidoglycan cell wall and stain purple, while gram-negative bacteria have a thinner cell wall and stain pink in a Gram stain.

What is phenylketonuria (PKU), and how can it be treated?

Phenylketonuria (PKU) is a genetic condition caused by a deficiency in the enzyme phenylalanine hydroxylase, which prevents the conversion of phenylalanine into tyrosine. It can be treated with a special diet rich in tyrosine and low in phenylalanine.

What are the signs of protein-energy malnutrition, and how do they affect the body?

Protein-energy malnutrition, such as kwashiorkor, leads to low protein levels in the blood, causing edema due to low oncotic pressure. Signs include pitting edema and poor wound healing.

How does cyanosis in a newborn indicate the difference between lung and heart disease?

If oxygen administration improves cyanosis, it indicates a lung problem, but if it does not, it suggests a heart condition, such as congenital heart disease.

Outlines

00:00

📚 Introduction to Pathology and Cell Injury

The speaker introduces the study of pathology, which covers diseases, their causes, and the processes behind them. A brief explanation of how biopsies and tissue examination are key to understanding diseases is provided, alongside a comparison of gross and microscopic examinations. The video will focus on cell injury, its causes, and how it differs from cell death. Key causes of cell injury are introduced, including hypoxia, chemical agents, free radicals, and immunological causes, highlighting that some injuries are reversible, but others, like cell death, are irreversible.

05:01

🫁 Hypoxia and Anoxia in Cell Injury

The paragraph focuses on hypoxia (reduced oxygen) and anoxia (lack of oxygen) as major causes of cell injury. It explains how lung and heart diseases can lead to hypoxia and uses the example of cyanotic heart diseases in newborns. The distinction between lung and heart-related hypoxia is made by observing whether oxygen therapy improves the condition. Other causes of cell injury are discussed, such as alcohol and acetaminophen toxicity, heavy metals, and free radicals.

10:03

🦠 Microbial, Genetic, and Nutritional Causes of Cell Injury

This paragraph delves into the microbial, genetic, and nutritional causes of cell injury. It highlights bacteria, viruses, fungi, and parasites as sources of infection that can damage cells, leading to diseases. The paragraph also touches on genetic conditions like phenylketonuria (PKU) and metabolic issues like diabetes mellitus. Nutritional deficiencies, especially those involving proteins, can also harm cells, with examples like Kwashiorkor (protein malnutrition) and marasmus (severe malnutrition). It briefly mentions intracellular accumulations, such as lead from external sources or triglycerides from within the body.

15:04

🧬 Aging, Oxidative Stress, and Heavy Metal Toxicity

Aging is introduced as a factor that affects cell injury by slowing down cell replication, making it harder for the body to recover from damage. The text discusses oxidative stress from free radicals and the toxicity of heavy metals like iron and copper, which produce harmful hydroxyl radicals through the Fenton reaction. It also references medications like statins, radiocontrast agents, and antibiotics as potential sources of kidney damage.

Keywords

💡Cell Injury

Cell injury refers to the damage caused to cells due to various stressors or harmful conditions. It is reversible, meaning the cell can recover if the harmful condition is removed. The video emphasizes that understanding cell injury is essential as it distinguishes reversible processes from irreversible ones like cell death.

💡Cell Death

Cell death occurs when a cell reaches a point beyond repair, making the process irreversible. The video contrasts it with cell injury, explaining that once a cell dies, recovery is impossible. Apoptosis and necrosis are discussed as forms of cell death.

💡Hypoxia

Hypoxia is a condition where there is a deficiency of oxygen reaching the tissues, leading to potential cell injury. The video discusses how lung or heart diseases can cause hypoxia, affecting the body's oxygen supply, and leading to conditions like cyanosis (blue baby syndrome).

💡Apoptosis vs Necrosis

These are two forms of cell death. Apoptosis is a programmed, orderly process, while necrosis is uncontrolled and typically caused by external factors like toxins or injury. The video differentiates between the two to highlight how cells die under different circumstances.

💡Biopsy

A biopsy is the gold standard for diagnosing diseases by examining tissue samples. The video explains that a biopsy involves both gross (macroscopic) and microscopic examination of the tissue, providing insights into disease processes and conditions.

💡Free Radicals

Free radicals are highly reactive molecules that can cause cellular damage. The video mentions them as a cause of cell injury, specifically highlighting reactive oxygen species (ROS) and conditions like iron overload (hemochromatosis) that can lead to free radical formation.

💡Autoimmune Diseases

Autoimmune diseases occur when the immune system attacks the body’s own tissues. The video lists diseases like lupus, rheumatoid arthritis, and scleroderma as examples where the body’s immune response causes cell injury, leading to chronic conditions.

💡Inflammation

Inflammation is a biological response to harmful stimuli, such as infections or injuries. It can lead to cell injury if chronic or excessive. The video discusses how abscesses, cellulitis, and other inflammatory conditions contribute to cell damage.

💡Phenylketonuria (PKU)

Phenylketonuria (PKU) is a genetic disorder caused by a deficiency in the enzyme phenylalanine hydroxylase, leading to the accumulation of phenylalanine. The video explains that early diagnosis and dietary management can prevent severe developmental issues, making it a key example of reversible cell injury.

💡Kwashiorkor

Kwashiorkor is a form of protein-energy malnutrition caused by a lack of dietary protein. The video uses it as an example of nutritional deficiency leading to cell injury, describing how low protein levels result in edema due to decreased oncotic pressure.

Highlights

Introduction to the new pathology playlist, focusing on the study of diseases, their nature, causes, risk factors, and precipitating factors.

Biopsy is the gold standard in diagnosing diseases by examining organs at both gross and microscopic levels.

Explanation of reversible cell injury versus irreversible cell death, with causes such as hypoxia, chemical agents, and physical agents.

Free radicals, such as reactive oxygen species, and their role in cell injury and disease processes.

Hypoxia and anoxia as major causes of cell injury, with conditions like myocardial infarction and chronic obstructive pulmonary disease (COPD) leading to oxygen deprivation.

Discussion of chemical factors like polycyclic hydrocarbons from cigarette smoke, alcohol, and heavy metals that cause cell injury.

Acetaminophen (Tylenol) toxicity and its effects on the liver, leading to depletion of glutathione and free radical damage.

Iron overload (hemochromatosis) and copper toxicity, resulting in harmful free radicals through the Fenton reaction.

The role of inflammation, autoimmune diseases (like lupus and rheumatoid arthritis), and infections in causing cell injury.

Nutritional deficiencies, including protein-energy malnutrition (kwashiorkor) and total energy malnutrition (marasmus), leading to cell injury.

The importance of intracellular accumulation, like triglycerides and bilirubin, in contributing to disease.

Explanation of cyanosis and how it helps differentiate between lung and heart diseases in newborns with oxygen deprivation.

Heavy metals such as mercury, lead, and arsenic, along with their toxic effects on kidneys and overall cell injury.

Staphylococcus versus Streptococcus infections, their cellular effects, and how coagulase enzymes influence the spread of infection.

Phenylketonuria (PKU), its genetic basis, and dietary treatments that reverse cell injury.

Protein malnutrition leading to pitting edema due to low oncotic pressure from reduced plasma proteins like albumin.

Transcripts

hey guys it's medicosa's perfect net is

where medicine makes perfect sense

welcome to a brand new playlist

pathology baby the study of diseases and

their nature and their causes or risk

factors and precipitating factors biopsy

is the gold standard look at the organ

look at it and then respect it how the

organ looks to the naked eye is called

gross examination grows here means big

not disgusting and then you put the

tissue under the microscope and that's

called microscopic examination in this

series you will learn about the

different types of stains different

techniques to prepare the tissue and

resilient diseases did you know that

medicine has more than 10 000 conditions

to study and learn and devour let's

start at the beginning cell injury first

you gotta understand the difference

between cell injury and cell death cell

injury is reversible but cell death it's

over there is no going back irreversible

here your cell is just hurt but here

your cell is gone she gone man she gone

and if you are familiar with this

pathology playlist you know that we

talked about cell death before apoptosis

versus necrosis what can cause cell

injury which is irreversible condition

it could be hypoxia less oxygen or

anoxia no oxygen chemical agents

physical agents free radicals like the

reactive oxygen species inflammatory

causes immunological causes

microbiological causes genetic or

metabolic causes nutritional

deficiencies intracellular accumulation

of some Gunk sometimes the gunk is

coming from outside and sometimes it's

coming from your body from the inside

and then aging or senescence where

everything in your body literally

becomes like a country song what are the

most famous causes of hypoxia or anox

see it let's think about that what are

the organs that are responsible for

supplying your body with oxygen lungs of

course so lung disease can lead to this

and who should Supply that oxygen to all

tissues of your body the hot so heart

disease can also lead to hypoxia or

anoxia so causes of cell injury can

include myocardial infarction and

chronic obstructive pulmonary disease

how about chemical factors we have the

polycyclic hydrocarbons such as

cigarette smoking do not just say

hydrocarbons because literally you are

made of hydrocarbons we say polycyclic

hydrocarb next was that oh that's the

alcohol group yep alcohols can lead to

cell injury medications especially

acetaminophen or paracetamol Tylenol

heavy metals such as mercury poisoning

lead poisoning arsenic toxicity Etc

physical agents such as radiation or

frostbite or Burns or more skin wounds

then free radicals also acetaminophen so

you can imagine that acetaminophen is

dangerous especially if you overdose and

iron overload state known as

hemochromatosis what does osis mean

condition what does chroma mean color

because if I have hemochromatosis my

skin will acquire a bronze color Chromo

color and hemo because iron is in the

heme which is part of your hemoglobin of

the blood inflammatory conditions can

injure my cells such as abscess fironco

carbuncle cellulitis folliculitis sepsis

Etc immunological conditions like the

famous autoimmune diseases lupus

rheumatoid arthritis Scleroderma AKA

systemic sclerosis sjogren syndrome and

much more microbiological which include

bacteria viruses fungi and parasites

they can lead to cell injury of course

genetic or metal all the conditions like

phenylketin urea and diabetes mellitus

nutritional deficiencies can injure my

cell such as if I am deficient just in

proteins this is called protein energy

malnutrition a famous example is quite

sure core disease but if I live in the

desert and I'm not eating or if I live

in abject poverty I am deficient in all

three what do you call that total energy

malnutrition such as a disease known as

merasmus and the patient will have

cachexia which we talked about before in

this pathology playlist intracellular

accumulation of stuff coming from the

outside lead or anthracotic pigment

remember my video on Anthrax I've told

you Anthrax is not the same as anthracos

anthracosis is a pigment no big deal but

Anthrax oh it can kill you next we have

endogenous intracellular accumulation

coming from within you so as

triglycerides or bilirubin The Starry

heavens above me and the moral law

within me who said that let me know the

answer in the comment section and then

aging because if I age as I age the cell

replication decreases which means when

the cell gets injured it's not repairing

itself as it used to now let's have some

of these as examples and elaborate

starting with hypoxia this is cyanosis a

blue baby a blue baby is born what do

you think is going on well it's either a

lung disease or a heart disease of

course how can you tell the difference

easy give oxygen if oxygen treated the

problem then it was a lung issue because

when I give oxygen I am replacing the

lungs function if it corrects then it

was a lung disease but if it does not

correct no significant Improvement then

it's a heart issue even if you give

oxygen to the body the heart still has

to pump it to all the tissues when the

heart cannot do it this is the heart

condition such as the famous cyanotic

congenital heart diseases all of them

start with a t trachos paid atresia

tetralogy of follow tea a PVR

transposition and truncus don't you know

next let's talk about alcohol methanol

can lead to formic acid toxic to your

eye ethanol metabolize into acetic acid

normal doses usually not toxic high

doses it can lead to toxicity especially

because of the elevated nadh level which

will trigger many enzymatic reactions in

your body and you will end up with

outcomes that you do not like example

lactic acidosis to name just one how

about ethylene glycol it can be

metabolized into glycolic acid not good

for your kidney it causes kidney stones

next let's talk about acetaminophen

acetaminophen or paracetamol will be

metabolized in your liver over by the

liver p450 enzyme system cytochrome into

something called napkey what does napkey

mean it's an acronym it stands for an

acetyl P benzoquinone amine in case

you're wondering this snapkey is evil

it's gonna deplete the glutathione

glutathione was the good guy glutathione

is a free radical scavenger gluthion is

the good guy it gets rid of the bad guys

the free radicals how do you think we

should treat acetaminophen well try to

replenish the good guy how do I

replenish glutathione by an

acetylcysteine we were just scratching

the surface on acetaminophen if you want

to learn more about acetaminophen and

the other non-steroidals like aspirin

ibuprofen ketoprofen oxyprosyn if you

want to learn about serotonin

pharmacology the antihistamines and the

H2 blockers the medications that we use

for peptic ulcer disease and for

migraine download my utakoids

pharmacology course at

medicosisperfectsnellis.com next let's

talk about heavy metals if you have

watched my kidney failure videos

especially my video on acute kidney

failure I've told you that acute renal

asotemia has three types pre-renal intra

renal and post renal pre-renal the

problem is here in the blood that's

reaching the kidney renal the problem

starts inside the kidney post reading of

the problems in the outflow from the

kidney two from inside what are the

things that can damage the kidney itself

I.E intraenal exotemia hypoxic and toxic

hypoxic ischemia oh like anoxia hypoxia

exactly and toxic what are these could

be medications or could be heavy metals

look at this all of these agents can

injure your kidney these include a radio

contrast agents like iodine that we use

in contrast city scan heavy metal

poisoning many antibiotics Platinum is

chemotherapy immunosuppressive

medications like cyclospore and

tachrolymers Methotrexate but not

serolimus because usually seralimus is

good for the kidney seralimus spares the

kidney lipid lowering agents like

statins cocaine ethylene glycol and

tolene next let's talk about iron and

copper why are they toxic because of

something called the fentan reaction if

iron is left free if copper is left free

they will give me hydroxyl free radicals

so here's how I remember the Phantom

reaction it's the F me mnemonic if Fe is

left free by the Fenton reaction it will

give me hydroxyl free radicals freaking

bad and that's why if you remember your

physiology someone has to be carrying

that iron all the time we do not leave

that iron to be free because if it

becomes free it causes disasters who's

gonna bind the iron in your blood it's

bound to transferrin in in your tissue

it's bound in the form of ferritin see

medicine makes so much sense once you

understand what the flip you're talking

about next let's talk about some

cellulitis and some abscess action

remember that microbes are bacteria

fungi viruses or parasites that's why

the field of microbiology studies

bacteriology fungality or mycology

virology and parasitology we use the

Gram stain to differentiate between many

types of bacteria if they stain purple

we call them gram-positive because they

have a thick peptidoglycan cell wall but

if they stay in pink because they do not

have a thick peptidoglycan cell wall

they are called gram negatives gram

positives could look like this spherical

we call them cocci or like this bacilli

we call them rods and then if you are a

gram-positive caucus the next question

is do you have catalase enzyme or do you

not have catalase enzyme if you do you

are staphylococcus and then do you have

coagulase if yes it's a a staff Aureus

this Steph lukakis Aureus as we have

discussed in my microbiology and

infectious diseases playlist is

coagulate is positive why is that

important coagulase is an enzyme that

coagulates by making fibrant fibers you

coagulate the infection will be

localized in a small area relatively

speaking so you get a tiny folliculitis

or can get bigger furunco or even bigger

carbuncle but we're still limited to a

certain Locale in your body conversely

if you're talking about streptococcus

pyogenes which is coagulase negative

there is nothing to clot it and keep it

in one place that's why streptococcus

pergines will spread all over the area

giving you

cellulitis sepsis necrotizing fasciitis

all of these are widespread areas of

infection medicine makes so much sense

if you understand standard next let's

talk about phenylketon urea if you have

watched my video on it look at this

doctor my child is acting strangely not

learning smells forgive me like a rat

low birth weight low head circumference

and a lighter skin tone Oh by the way I

married my cousin this is fennel

kittenuria a deficiency in an enzyme

known as phenylalanine hydroxylase

normally this enzyme should convert

phenylalanine into tyrosine but in cases

of phenylketonuria phenylaline

hydroxylase stose which means

phenylalanine cannot become tyrosine

who's gonna pile up everything that is

before the enzyme so phenylalanine will

accumulate and who will decrease in my

blood tyrosine will be very low

therefore how can I treat this patient a

special diet rich in tyrosine and poor

in phenylalanine I.E try to reverse the

symptoms and when the doctor did just

that look what happened hey doctor do

you remember me I am the mother of the

PKU child this is a True Story by the

way he has caught up with other kids

he's leading a normal life now thank you

you changed our lives see what a good

doctor can do not the doofuses with the

stethoscope that we have today running

around the hospital and this proves to

you that PKU is a cell injury because it

was reversible not a cell death if your

wonderful Professor explains like this I

will retire from YouTube and work for a

garbage company NeXT let's talk about

kwashir core which is protein energy

malnutrition look what are the causes of

low protein in my blood maybe I'm not

eating it and this is called kwasher

core syndrome due to malnutrition of

proteins or maybe because my liver is

not making it we see this in chronic

liver disease like cirrhosis or maybe

because I am eating it I am making it

it's just I am losing it I'm wasting too

much protein I could be wasting their

protein through skin in third degree

burns or through the gut maybe I should

blame my stomach Miniatures disease or

blame my intestines male absorption

syndrome such as celiac disease or

should I blame the kidneys this is

nephrotic syndrome whatever the case

might be all of these patients with low

protein and Darren will have low oncotic

pressure because remember that's in the

vessel what's the name of the pressure

that pushes hydrostatic pressure which

depends on the volume of the blood and

what's the name of the pressure that

pulls fluid to the inside of the vessel

it's called oncotic pressure who's

responsible for the oncotic pressure

plasma proteins namely albumin if I am

not eating enough protein I will have

less albumin and I will be unable to

pull fluid to the vessel in instead the

fluid will escape and go to the outside

accumulation of fluid in the

interstitial space is the definition of

Edema this edema is pitting when you

touch it when you push your finger in

and then pull your finger for the next

few seconds you will still see the

indentation this is called pitting it is

dependent which means gravity will pull

it down that's why we speak of ankle

edema next this edema is made of clear

fluid known as a Transit versus the

edema of infection and inflammation

which is known as an exudator you see

this in cases of abscesses pus formation

this edema is not caused by the high

hydrostatic pressure instead it's caused

by the low on cardiac pressure whether

it's due to quasher core or cirrhosis or

burn or celiac disease or minutes

disease or nephrotic Center drone this

is medicine as it should be not the

trash that you're taught in school well

I saw the kind of ish read my

professor's PowerPoint and I got all of

this medicine thing figured out kiss my

calcaneus so today you learn about a

variety of causes of cell injury which

is a reversible process if this video

gets 3 000 likes I will make a special

video on hypoxia and the different

causes of hypoxia and the difference

between hypoxia and hypoxemia and what

the flip is hypoxic hypoxia and much

more so please subscribe hit the like

button and share my videos with others

today we talked about abscesses

cellulitis for your uncle carbuncle all

kinds of infection how do we treat

bacterial infections antibiotics if you

download my entire parents course it

will teach you not only of

antibacterials but also

anti-virals anti-fungals and

anti-parasitic medications downloaded

today at medicosisperfect snails.com

myocardial infarction can lead to

hypoxia in the body and this can lead to

cell injury of course you can learn

about angina and myocardial infarction

many cardiac arrhythmias ischemic

Strokes hemorrhagic strokes and much

more if you download my emergency

medicine high yields course at

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cases be safe stay happy study hard this

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medicine makes perfect sense