7. Disorders of the metabolism of lipids. Types of adipose degeneration

Question 1

What are Lipids?

Answer 1

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

Question 2

How do Lipids Cause Cellular Damage?

Answer 2

Lipid Accumulation in Unusual Locations / Unusual Composition + Unusual Amount

Lipids form Complex Structure with Proteins + Carbs

Question 3

What are the 3 Types of Lipids?

Answer 3

1. Neutral Lipids + Waxes = Triglycerides / Simple Lipids
2. Complex Lipids = Phosphatides / Cerebrosides / Gangliosides + Sphingomyelins
3. Sterols / Steroids

Question 4

1| What are the Characteristics of Neutral Lipids + Waxes?

Answer 4

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

Question 5

2| What are the Characteristics of Phosphatides (Complex Lipids)?

Answer 5

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

Question 6

3| What are the Characteristics of Steroids?

Answer 6

COMPLEX ESTERS of Fatty Acids w/ CYCLIC Alcohol

Cholesterol + Its Esters = Cholesters

Located in = Adrenal Cortex / CNS / Genital Glands

Question 7

What are the 7 Physiological Functions of Lipids?

Answer 7

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

Question 8

What is the Solubility of Lipids?

Answer 8

IN-Soluble = In Aqueous Solution + Acetic Acid

Soluble = Alcohol / Acetone / Benzole / Chloroform + Xylol

THEREFORE CANNOT be Studied in Alcohol Fixated Materials / Paraffin Fixatives

Question 9

How do we Preserve Lipids?

Answer 9

Use Unfixed Tissue / Fixed in Formalin

AND THEN Cut on Freezing Microtome

Question 10

What are the Staining Methods for Lipids?

Answer 10

(i) Sudan III (Oil Red)
(ii) Scharlactor (Red)
(iii) Sudan IV / Osmic Acid (Black)
(iv) Niblausulfate = Neutral Lipids (Blue)

Question 11

Which 2 Microscopic Methods are Used to Test for Lipids?

Answer 11

1. Polarised = Neutral Lipids are Isotopic; Cholesterol + Esters give Double Refraction of Light
2. Electron = Ultrastructural Examination w/ Osmic Acid (Fixative)
   - HARDENS Lipids + Forms Lines during Cutting with Ultramicrotome Parallel Stretching

Question 12

How is Fatty Degeneration Classified?

Answer 12

According to:

1. Chemical Composition
2. Localisation of Stromal + Parenchymal Cells
3. Proliferation
4. Acquired or Genetic
5. Parenchymatous Fatty Degeneration
6. Intracellular Fatty Degeneration

Question 13

6| What is Intracellular Fatty Degeneration?

Answer 13

ABNORMAL Lipid Accumulation

WITHIN Parenchymal Cells

Organs Damaged = Heart / Liver / Kidneys

Question 14

What are the 7 Causes of Fatty Degeneration?

Answer 14

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

Question 15

Where does Fat Dystrophy Occur?

Answer 15

Organs where PROTEIN Dystrophy Occur

• Liver
• Myocardium
• Kidneys

Question 16

What are Lipoproteins AND Lipoprotein Complexes?

Answer 16

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

Question 17

What is Lipophanerosis?

Answer 17

DIVISION of Layers of Protein-Lipid Complex

Via Appropriate Processing

Question 18

What is the Pathogenesis of Fat Degeneration?

Answer 18

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

Question 19

What is ‘Fatty Degeneration of the Liver’ also known as?

Answer 19

Liver Steatosis

Happens when MORE THAN 50% Hepatocytes contain NEUTRAL Lipids

Question 20

What are the 4 Main Causes of Liver Steatosis?

Answer 20

1. Alcoholic Steatosis
2. Diabetes Mellitus

3 .Alimentary Damages

4. Disorder of Small Intestines

Question 21

1| What is the Pathogenesis of Alcoholic Steatosis?

Answer 21

Fat Accumulation in Hepatocytes of Liver

DUE to Cell Damage from Chronic Alcoholism

Question 22

1| How does Chronic Alcoholism Cause Cellular Damage?

Answer 22

INCREASED Lipolysis + Free Fatty Synthesis

DECREASED Triglyceride Usage / FA Oxidation to KBs

BLOCKAGE of Lipoprotein Excretion

Question 23

2| How does Diabetes Mellitus Cause Liver Steatosis?

Answer 23

Complete / Relative DEFICIENCY of Insulin

{Insulin = Anti-Lipolytic Hormone}

LACK of Insulin = INCREASED Lipolysis in Depots + Entry of FAs in Liver

Question 24

3| How does Alimentary Damages Cause Liver Steatosis?

Answer 24

Inappropriate Diet = PROTEIN Deficiency LEADING to Fatty Liver Disease

LACK of PROTEIN = INHIBITED Lipoprotein Synthesis

E.g. Resections / Gastric Bypass

Question 25

4| How does Disorders of Small Intestines Cause | Liver Steatosis?

Answer 25

Patients with SI Disorders = Enterocolitis DEFICIENCY of Proteins + Lipotropic Factors {Lipotropic Factors are needed for Lipoprotein Synthesis)

Question 26

What are the MACROSOPIC Changes in Fatty LIVER? {Morphology}

Answer 26

Enlarged Liver w/ Rounded Margins Cut Surface = Pale Yellow + Slightly Bulges Greasy aka Goose Liver

Question 27

What are the MICROSCOPIC Changes in Fatty LIVER? {Morphology}

Answer 27

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)

Question 28

What are the MACROSOPIC Changes in Fatty HEART? {Morphology}

Answer 28

Aka Tiger Heart Enlarged Heart Stretched + Flabby Chambers

Question 29

What are the MICROSCOPIC Changes in Fatty HEART? {Morphology}

Answer 29

Dust-like Vacuoles in Cardiomyocytes Observed in Papillary Muscles + Trabecules of Ventricles in Form of Bands Surrounds Veins (Hypoxia is MOST SEVERE)

Question 30

What are the MACROSOPIC Changes in Fatty KIDNEY? {Morphology}

Answer 30

Occurs in Nephrotic Syndrome Large, White Kidney Enlarged + Flabby Cortical Substance = Grey w/ Yellow Drops

Question 31

What are the MICROSCOPIC Changes in Fatty KIDNEY? {Morphology}

Answer 31

Lipid Accumulates in CYTOPLASM of EPITHELIAL CELLS OF Convoluted Tubules

Question 32

What is Stromal Fatty Infiltration?

Answer 32

AKA Lipomatosis Deposition of Mature Adipose Cells in Stromal CT Occurs in Obese People Organs Affected = 1. Heart 2. Pancreas

Question 33

1| How does Stromal Fatty Infiltration, affect the Heart?

Answer 33

Subepicardial Fat COVERS Heart PREVENTING CT from Growing LEADING to Heart Rupture in Area of Fat Growth

Question 34

2| How does Stromal Fatty Infiltration, affect the Pancreas?

Answer 34

Atrophy of B-Cells LEADS to Diabetes Mellitus

Question 35

What Disease does Lipomatosis Occur?

Answer 35

{Lipomatosis = Local Enlargement of Adipose Tissue} In DEREUM'S DISEASE = Painful Fat Nodules appear in Subcut.Fat of Lower + Upper Extremities / Trunk

Question 36

What is Obesity?

Answer 36

Lipid Accumulation of Specialized Cells OF Adipose Tissue

Question 37

What is Obesity Classified into?

Answer 37

1. Depending on Excess of Patient Mass 2. According to Etiology (Cause) 3. According to Patient's Appearance 4. According to Morphological Peculiarities of Adipose Tissue

Question 38

1| What are the 4 Degrees of Obesity?

Answer 38

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!

Question 39

2| What are the 2 Types of Causes of Obesity?

Answer 39

a. Primary (Idiopathic) | b. Secondary

Question 40

2b| What are the Types of Secondary Obesity

Answer 40

(i) Alimentary (ii) Cerebral (iii) Endocrine (iv) Inheritance in Gierke's Disease

Question 41

3| What are the Kinds of Obesity, According to Patient's Appearance?

Answer 41

a. Symmetrical b. Upper c. Medial d. Lower

Question 42

4| What are the Types of Obesity, According to Morphological Peculiarities of Adipose Tissue?

Answer 42

a. Hypertrophic Type | b. Hyperplastic Type

Question 43

4a| What is Hypertrophic Type Obesity?

Answer 43

Tissue Enlargement DUE to INCREASE VOLUME OF Fatty Cells

Question 44

4b| What is Hyperplastic Type Obesity?

Answer 44

Tissue Enlargement DUE to INCREASE NUMBER OF Fatty Cells

Question 45

What Kind of Complication is Obesity?

Answer 45

SEVERE Complication of Endocrine + Nervous Diseases

Question 46

What is Another Complication of Obesity?

Answer 46

Alimentary Obesity = Unfavourable for Organism Patients with Alimentary Obesity DEVELOP Ischaemic Heart Diseases

Question 47

What is Cachexia?

Answer 47

SHARP REDUCTION in Amount of Adipose Tissue IN Whole Organism

Question 48

What does Cholesterol Metabolism Disturbances Lead to?

Answer 48

Atherosclerosis - Where Vessel Wall is THICKENED DUE to Formation of Atherosclerotic Plaque (Lipids + Fibrotic Tissue)

Question 49

What are Xantelsmas?

Answer 49

Specific Skin Lesion Observed in HYPERCHOLESTEROLEMIA Occurs in Eyelids Microscopically = Cholesterol Ester Accumulation in Cytoplasm of Skin's MACROPHAGES --> FOAMY / PSEUDOXANTOMATOUS Cells