Condition Details Flashcards
Outline the mechanism underlying alcoholic liver disease
How can ALD lead to lactic or ketoacidosis
Alcohol –> acetaldehyde –> acetate /acetic acid
NAD+ is used for:
- Fatty acid oxidation
- Conversion of Lactate –> Pyruvate
- Metabolism of Glycerol
The conversion of alcohol to acetaldehyde by alcohol dehydrogenase also produces NADH. The decreased NAD+/NADH ratio favours the formation of triacylglycerols which accumulate in the liver cells, leading to ‘fatty liver’
Accumulation of Lactate in the blood due to low NAD+ may cause lactic acidosis.
It will also reduce the kidney’s ability to excrete URIC ACID and urate may accumulate in tissues producing the painful condition GOUT.
Gluconeogenesis cannot be activated (¯NAD+/¯lactate use/¯glycerol use) and fasting hypoglycaemia becomes a serious problem.
Increase in NADH –> increase in fatty acids and ketone bodies - in extreme cases ketoacidosis
How could you differentiate destruction from underproduction anaemia?
reticulocytes >3% suggests destruction
What is the molecular composition of hemoglobin? Does the functionality of hemoglobin as a protein depend on its tertiary or quaternary structure?
Hemoglobin is a molecule made of four polypeptide chains, each bound to an iron-containing molecular group called a heme group. Therefore, the molecule contains four polypeptide chains and four heme groups.
As a protein composed of polypeptide chains, the functionality of hemoglobin depends upon the integrity of its quaternary structure.
How can the blood coagulation (clotting) process be described?
Blood clotting encompasses a sequence of chemical reactions whose products are enzymes that catalyze the subsequent reactions (that is why clotting reactions are called cascade reactions). In the plasma, thromboplastinogen transforms into thromboplastin, a reaction triggered by tissue and platelet factors released after injury to a blood vessel. Along with calcium ions, thromboplastin then catalyzes the transformation of prothrombin into thrombin. Thrombin then catalyzes a reaction that produces fibrin from fibrinogen. Fibrin, as an insoluble substance, forms a network that traps red blood cells and platelets, thus forming the blood clot and containing the hemorrhage.
Differentiate two types of asthma
Atopic - extrinsic asthma, systemic IgE production
Non-atopic - intrinsic asthma, local IgE production
Describe the Pathogenesis of asthma inc the role of the immune system
Allergen –> dendritic cell –> CD4 (Th2)cells –>
Sequential activation of immune cells (in response to an allergen) leads to the stimulation of 1) eosinophils and 2) plasma B cells (IgE) that cause mast cells to degranulate –> histamine etc
Bronchospasm
Oedema & mucus production
Inflammation & muscle hypertrophy
Describe the Pathogenesis of COPD inc the role of the immune system
Cigarette smoke triggers alveolar macrophages –> IL8 which recruits:
1) CD8 T cells –> TNF alpha & cytokines
2) Neutrophils –> proteases
Chronic inflammation & oxidative stress –> mucous gland hyperplasia, smooth muscle hypertrophy, destruction of lunch parenchyma and fibrosis, pathological bacterial colonisation, and hypoxic vasoconstriction leads to pulmonary hypertension.
Describe the mechanisms behind hypoxia and hypercapnia
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