Lecture 40 Flashcards
What is metabolism in the brain and skeletal muscle like?
Metabolism in the brain is aerobic and done via oxidation of ketone bodies (starvation), key pathways are glycolysis, pyruvate to acetyl coa, citric acid cycle, electron transport chain and oxidative phosphorylation. It requires oxygen. In skeletal muscle aerobic oxidation occurs for glucose , fatty acids, ketone bodies and triacylglycerols, it could also be anaerobic (glycogen) (releasing the lactate into the blood (fatigue is not due to pH) and amino acids (starvation only for AAs)).
What is metabolism in the heart and adipose tissue like?
Metabolism in heart muscle is completely aerobic and oxidises all fuels (glucose, fatty acids, ketone bodies and lactate), this means its key pathways are beta oxidation, citric acid cycle, electron transport chain and oxidative phosphorylation. Metabolism in adipose tissue iis acting as a major triacylglycerol store, for the uptake and storage of TAG. The mobilisation of which releases free fatty acids and glycerol and synthesis and secretion of leptin when the fat stores are full. (also other signalling molecules called adipokines).
What is metabolism in the liver like?
The liver is the major metabolic processing organ, it is the first to receive glucose and amino acids after digestion of food and does the synthesis and storage of glycogen, fat synthesis and exports VLDL (for TAG). It also does synthesis of plasma proteins, provision of glucose, synthesis of ketone bodies and conversion of toxic excess ammonia to urea, also plays a large role in detoxification.
How do the endocrine and nervous system work? How do their products work?
The endocrine system involves chemical signalling, these are synthesised in endocrine gland and released into the blood to act on long distance organs. The nervous system uses neurotransmitter signals and either can be steroid, amino acid or (SEE SLIDE). Regulated functions include cell growth and differentiation, digestion of oods, fluid and electrolyte balance, wound healing, response to infection and metabolism. They typically work by stimulating or inhibiting activity of enzymes (quick acting), these regulate metabolic and secretory processes or work by altering transcription of specific genes (regulate the amount of enzymes and proteins and the growth and differentiation.
