Unit 4. Ch 23 Flashcards
What is the difference between anabolism/ catabolism?
- Anabolism: ATP requirement. manufacturing materials
- Catabolism: breakdown of materials. ATP creation
What is key about fuel metabolism and glucose?
- glucose must be continually supplied to brain
- excess glucose stored in liver and muscle as glycogen.
- Additional glucose transformed to triglycerides
- Excess amino acids are converted to glucose and fat
What is the importance of glucose for the brain?
- blood glucose must stay constant for brain
- liver glycogen is FIRST reservoir.
- Fatty acids used as fuel and amino acids are converted to glucose (gluconeogenesis)
What are the two metabolic states?
- absorptive (fed) state- yum just ate. lots of glucose. Extra is stored
- postabsorptive (fasting) state- storage is used.
What is the rule of liver/adipose/muscle in metabolic states?
- liver: stores glycogen, releases glucose when needed. gluconeogenesis site
- Adipose: primary energy storage. FAT
- muscle: amino acid storage. major energy USER
What is the role of glycerol, lactic acid, and ketone bodies as lesser energy sources
- glycerol: triglyceride hydrolysis converts to glucose
- lactic acid: converted to glucose by liver
- ketone bodies: from Acetyl CoA by liver, alternate energy
What is the pancreatic endocrine function?
- ENDOCRINE: ISLETS
- 3 cell types produce: somatostatin (D Cells, inhibit digestion), insulin(Betal cells, decrease glucose levels, promotes storage), glucagon (released by alpha cells, oppose insulin)
What is insulin activity on carbs/fats/and AAs
- **BASICALLY stores energy obtained
- Carbs: stimulates glycogenesis, inhibits gluconeogenesis
- Fats: enhance fatty acids from blood to adipose, glucose to adipose, triglyc synthesis
- AAs: promotes AA to muscles, stimulates protein synthesis, inhibits protein degradation
What happens when blood glucose concentration is elevated? What is the result of para/sympathetic stimulation?
- islet Beta cells detect change
- secrete insulin which decreases blood glucose, fatty acids, and AAs. Increases storage and protein synthesis.
- PARA stimulation: increased insulin secretion
- SYMP stimulation (and epinephrine: decreased insulin secretion
What are the adrenal glands? What is secreted from the areas?
- located above kidneys
- Cortex (secretes everything else)
- Medulla (secretes catecholamines)
What is the role of cortisol?
- stimulates gluconeogenesis
- inhibits glucose uptake in non brain tissue
- increases fatty acid and AA concentraton by stimulating protein degradation and lipolysis
- CRH-> ACTH-> Cortisol (which inhibits both)
- suppresses immune system
- adaptation to stress (metabolism increase?)
What is the the role of the adrenal glands and DHEA?
- adrenal glands produce androgens and estrogens. Not powerful enough to masculinize and feminize.
- dihydroepiandrosterone (DHEA): overpowered in males by testosterone. Female sex drive and androgen processes. Activated by ACTH but feeds back to GnRH (instead of CRH)
What is the role of the thyroid gland?
- two lobes overlying trachea below larynx
- hollowed sphere surrounded by follicular cells that secrete colloid into the follicular lumen
What is key to TH synthesis
- Tyrosine and iodine
- Two thyroid hormones are T3 and T4.
- T3 is active, T4 converted to it.
What is T4 vs T3?
- T4 is converted into T3
- T3 is 4x more potent
- Conversion in kindey and liver
