7. Disorders of the metabolism of lipids. Types of adipose degeneration Flashcards
What are Lipids?
Molecules containing HC
Make up Building Blocks of Structure + Function of Living Cells
E.g Fats / Oils / Waxes / Fat-Soluble Vitamins / Hormone
Make up 30% of Cytoplasm in Normal Cells
How do Lipids Cause Cellular Damage?
Lipid Accumulation in Unusual Locations / Unusual Composition + Unusual Amount
Lipids form Complex Structure with Proteins + Carbs
What are the 3 Types of Lipids?
- Neutral Lipids + Waxes = Triglycerides / Simple Lipids
- Complex Lipids = Phosphatides / Cerebrosides / Gangliosides + Sphingomyelins
- Sterols / Steroids
1| What are the Characteristics of Neutral Lipids + Waxes?
Neutral Lipids = ESTERS of Fatty Acids + Glycerin
The MAIN COMPONENT of Fat Deposits
Waxes = ESTERS of Fatty Acids; Have Movement; RARELY w/ Divalent Alcohols with a LONG STRAIGHT Chain
2| What are the Characteristics of Phosphatides (Complex Lipids)?
AKA Phospholipids = ESTERS of Fatty Acids + Glycerin w/ Nitrogenous Compounds / Inosite + Phosphoric Acid
LARGE Amounts in = Neural Tissue / Liver / Kidneys / Heart
OTHER Complex Lipids = Neural Tissue
3| What are the Characteristics of Steroids?
COMPLEX ESTERS of Fatty Acids w/ CYCLIC Alcohol
Cholesterol + Its Esters = Cholesters
Located in = Adrenal Cortex / CNS / Genital Glands
What are the 7 Physiological Functions of Lipids?
1) Direct Source of Energy
2) Protection + Covering = Eyelids / Heart Valves / Renal Capsules + Mesenterium
3) Maintain Body Temperature
4) Regulate Cell Communication + Neurotransmitter Signals
5) Make up Structural Part of Cell Membrane (Phospholipids + Cholesterol)
6) Energy Depot (85% are Triglycerides)
7) Synthesises = Bile Salts / Hormones / Prostaglandins + Eicosanoids
What is the Solubility of Lipids?
IN-Soluble = In Aqueous Solution + Acetic Acid
Soluble = Alcohol / Acetone / Benzole / Chloroform + Xylol
THEREFORE CANNOT be Studied in Alcohol Fixated Materials / Paraffin Fixatives
How do we Preserve Lipids?
Use Unfixed Tissue / Fixed in Formalin
AND THEN Cut on Freezing Microtome
What are the Staining Methods for Lipids?
(i) Sudan III (Oil Red)
(ii) Scharlactor (Red)
(iii) Sudan IV / Osmic Acid (Black)
(iv) Niblausulfate = Neutral Lipids (Blue)
Which 2 Microscopic Methods are Used to Test for Lipids?
- Polarised = Neutral Lipids are Isotopic; Cholesterol + Esters give Double Refraction of Light
- Electron = Ultrastructural Examination w/ Osmic Acid (Fixative)
- HARDENS Lipids + Forms Lines during Cutting with Ultramicrotome Parallel Stretching
How is Fatty Degeneration Classified?
According to:
- Chemical Composition
- Localisation of Stromal + Parenchymal Cells
- Proliferation
- Acquired or Genetic
- Parenchymatous Fatty Degeneration
- Intracellular Fatty Degeneration
6| What is Intracellular Fatty Degeneration?
ABNORMAL Lipid Accumulation
WITHIN Parenchymal Cells
Organs Damaged = Heart / Liver / Kidneys
What are the 7 Causes of Fatty Degeneration?
MAIN = Hypoxia, which is DUE to
(i) EXCESSIVE Alcohol Intake
(ii) Chronic CV + Pulmonary Insufficiency; Anaemia
(iii) Hepatotoxins = Chloroform / Hepatotoxic Meds / Mushrooms
(iv) Malnutrition
(v) Infections = Sepsis / Diphtheria
(vi) Drugs = Oestrogen / Steroids
(vii) Late Period of Pregnancy
Where does Fat Dystrophy Occur?
Organs where PROTEIN Dystrophy Occur
- Liver
- Myocardium
- Kidneys
What are Lipoproteins AND Lipoprotein Complexes?
Lipoproteins = Complex Particles w/ Central Core (Cholesterol Esters + Triglycerides), Surrounded by Free Chol + Phospholipids (Helping with Formation + Function)
Lipoprotein Complex = MASSIVE Macromolecules w/ Different Stage of Polymerisation
What is Lipophanerosis?
DIVISION of Layers of Protein-Lipid Complex
Via Appropriate Processing
What is the Pathogenesis of Fat Degeneration?
1) Processing w/ Special Methods is SPONTANEOUSLY REALISED in Living Cells, under influence of Agents LEADING to FAT Dystrophy
2) Liphanerosis = MAIN Mechanism for PARENCHYMATOUS Fat Degeneration
3) Infiltration + Absorption (Via PINOCYTOSIS) of Lipids OUTSIDE the Cell LEADS to Fat Degeneration
4) Lipoproteins FROM Blood Plasma / Products of Necrotic Cells GET INTO –> Intercellular Spaces + ENTER Cytoplasm Via PHAGOCYTOSIS
5) Transformation = Triglyceride Synthesis in PATHOLOGIC Conditions INSTEAD OF Carbs + Proteins
What is ‘Fatty Degeneration of the Liver’ also known as?
Liver Steatosis
Happens when MORE THAN 50% Hepatocytes contain NEUTRAL Lipids
What are the 4 Main Causes of Liver Steatosis?
- Alcoholic Steatosis
- Diabetes Mellitus
3 .Alimentary Damages
- Disorder of Small Intestines
1| What is the Pathogenesis of Alcoholic Steatosis?
Fat Accumulation in Hepatocytes of Liver
DUE to Cell Damage from Chronic Alcoholism
1| How does Chronic Alcoholism Cause Cellular Damage?
INCREASED Lipolysis + Free Fatty Synthesis
DECREASED Triglyceride Usage / FA Oxidation to KBs
BLOCKAGE of Lipoprotein Excretion
2| How does Diabetes Mellitus Cause Liver Steatosis?
Complete / Relative DEFICIENCY of Insulin
{Insulin = Anti-Lipolytic Hormone}
LACK of Insulin = INCREASED Lipolysis in Depots + Entry of FAs in Liver
3| How does Alimentary Damages Cause Liver Steatosis?
Inappropriate Diet = PROTEIN Deficiency LEADING to Fatty Liver Disease
LACK of PROTEIN = INHIBITED Lipoprotein Synthesis
E.g. Resections / Gastric Bypass
4| How does Disorders of Small Intestines Cause
Liver Steatosis?
Patients with SI Disorders = Enterocolitis
DEFICIENCY of Proteins + Lipotropic Factors
{Lipotropic Factors are needed for Lipoprotein Synthesis)
What are the MACROSOPIC Changes in Fatty LIVER?
{Morphology}
Enlarged Liver w/ Rounded Margins
Cut Surface = Pale Yellow + Slightly Bulges
Greasy aka Goose Liver
What are the MICROSCOPIC Changes in Fatty LIVER?
{Morphology}
Lipid Vacuoles in Cytoplasm of Hepatocytes = Empty Vacuoles
Vacuoles initially Small (Microvesicular) –> Larger + Push Nucleus to Periphery of Cells (Macrovesicular)
Hepatocytes w/ LARGE Lipid Vacuoles Rupture + Form Fatty Cysts
Lipogranulomas Appear (Rarely)
What are the MACROSOPIC Changes in Fatty HEART?
{Morphology}
Aka Tiger Heart
Enlarged Heart
Stretched + Flabby Chambers
What are the MICROSCOPIC Changes in Fatty HEART?
{Morphology}
Dust-like Vacuoles in Cardiomyocytes
Observed in Papillary Muscles + Trabecules of Ventricles in Form of Bands
Surrounds Veins (Hypoxia is MOST SEVERE)
What are the MACROSOPIC Changes in Fatty KIDNEY?
{Morphology}
Occurs in Nephrotic Syndrome
Large, White Kidney
Enlarged + Flabby
Cortical Substance = Grey w/ Yellow Drops
What are the MICROSCOPIC Changes in Fatty KIDNEY?
{Morphology}
Lipid Accumulates in CYTOPLASM of EPITHELIAL CELLS
OF Convoluted Tubules
What is Stromal Fatty Infiltration?
AKA Lipomatosis
Deposition of Mature Adipose Cells in Stromal CT
Occurs in Obese People
Organs Affected =
- Heart
- Pancreas
1| How does Stromal Fatty Infiltration, affect the Heart?
Subepicardial Fat COVERS Heart
PREVENTING CT from Growing
LEADING to Heart Rupture in Area of Fat Growth
2| How does Stromal Fatty Infiltration, affect the Pancreas?
Atrophy of B-Cells LEADS to Diabetes Mellitus
What Disease does Lipomatosis Occur?
{Lipomatosis = Local Enlargement of Adipose Tissue}
In DEREUM’S DISEASE = Painful Fat Nodules appear in Subcut.Fat of Lower + Upper Extremities / Trunk
What is Obesity?
Lipid Accumulation of Specialized Cells
OF Adipose Tissue
What is Obesity Classified into?
- Depending on Excess of Patient Mass
- According to Etiology (Cause)
- According to Patient’s Appearance
- According to Morphological Peculiarities of Adipose Tissue
1| What are the 4 Degrees of Obesity?
1st Degree = Mass INCREASES by 20 - 29%
2nd Degree = Mass INCREASES by 30 - 49%
3rd Degree = Mass INCREASES by 50 - 99%
4th Degree = Mass INCREASES by 100% + More!
2| What are the 2 Types of Causes of Obesity?
a. Primary (Idiopathic)
b. Secondary
2b| What are the Types of Secondary Obesity
(i) Alimentary
(ii) Cerebral
(iii) Endocrine
(iv) Inheritance in Gierke’s Disease
3| What are the Kinds of Obesity, According to Patient’s Appearance?
a. Symmetrical
b. Upper
c. Medial
d. Lower
4| What are the Types of Obesity, According to Morphological Peculiarities of Adipose Tissue?
a. Hypertrophic Type
b. Hyperplastic Type
4a| What is Hypertrophic Type Obesity?
Tissue Enlargement
DUE to INCREASE VOLUME
OF Fatty Cells
4b| What is Hyperplastic Type Obesity?
Tissue Enlargement
DUE to INCREASE NUMBER
OF Fatty Cells
What Kind of Complication is Obesity?
SEVERE Complication of
Endocrine + Nervous Diseases
What is Another Complication of Obesity?
Alimentary Obesity = Unfavourable for Organism
Patients with Alimentary Obesity DEVELOP Ischaemic Heart Diseases
What is Cachexia?
SHARP REDUCTION in Amount of Adipose Tissue
IN Whole Organism
What does Cholesterol Metabolism Disturbances Lead to?
Atherosclerosis
- Where Vessel Wall is THICKENED DUE to Formation of Atherosclerotic Plaque (Lipids + Fibrotic Tissue)
What are Xantelsmas?
Specific Skin Lesion
Observed in HYPERCHOLESTEROLEMIA
Occurs in Eyelids
Microscopically = Cholesterol Ester Accumulation in Cytoplasm of Skin’s MACROPHAGES –> FOAMY / PSEUDOXANTOMATOUS Cells
