Hormonal Communication Flashcards
Factors controlled by homeostasis
Body temp
Blood glucose
Blood ph
Negative feedback steps
Change in internal environ
Receptors are stimulated when level is too high
Receptors send signal to effectors through nervous system
Effectors counteract the change
Can only maintain within specific range
Normal blood glucose
90mg per 100cm3
What monitors blood glucose levels
Pancreatic cells
Controlling blood glucose in the liver
Gluconeogenisis
Glycogenisis
Glycogenolysis
What cells detect high glucose
Beta cells
Hormones responsible for restoring blood glucose if too low
Glucagon
Adrenaline
When is adrenaline released
In response to exercise
Primary messengers
Glucagon
adrenaline
Insulin
When blood glucose is too low
Adrenaline and glucagon bind to receptors on membrane of liver cells
Binding activates an enzyme - adenylate Cyclase converts atp to cAMP
CAMP activates protein kinase A
Glycogenolysis breaks down glycogen to glucose
Gluconeogenisis
Production of glucose from non carbohydrate sources eg liver makes glucose from glycerol and AA
Diabetes 2
Develops when muscle and liver cells stop responding to insulin
Diabetes 1
Autoimmune disease attacks beta cells prevent secretion of insulin
Glucose in urine technique
Colorimetry with Benedict’s solution
Glycogenisis
Production of glycogen when insulin bonds to cell membrane
Insulin bonds to liver cell
Increase uptake of glucose
Glycogenisis forming glycogen
Lipigenisis glucose forms fatty acids
Increased respiration
Islets of langerhans
Alpha cells glucagon
Beta cells insulin
Endocrine pancreatic cells
Islets of langerhans produce insulin and glucagon
Exocrine pancreatic cells
Acinar cells secrete enzymes into the pancreatic duct
Adrenal cortex
Secrete steroid hormones - cortisol aldosterone
Adrenal medulla
Secretes protein based hormones
Adrenaline increasing heart rate widen pupils etc
Fight or flight response
Hypothalamus sends impulse along sympathetic neurone to the adrenal medulla release adrenaline
Pituitary gland release acth neurotransmitter cortex secrete cortisol break down fats suppress immune system
Action of adrenaline
To trigger the liver cells to undergo Glycogenolysis so glucose released in blood stream - incr respiration for muscle contraction
Adrenaline process
Hormone binds to cell membrane receptor site
Fuses to receptor site and activates adenylyl cyclase inside membrane
Activated adenylyl cyclase converts ATP to cyclic AMP which acts as a secondary messenger activating protein kinases - enzymes for glycogen to glucose process
Protein kinases
Phosphorylate and activate enzymes
in the adrenaline process activate enzymes in Glycogenolysis process
Diabetes 1 treatment
Regular insulin injections - prick finger
(Too much hypoglycaemia)
Pancreatic transplant
B cell injection
Stem cell treatment
Diabetes 2 treatment
Regulate carbohydrate intake - diet and exercise
Insulin stimulation drugs
Drugs slow down glucose absorption
Insulin injections - rare
Insulin artificial production
Genetically modified bacteria produce insulin
Produce pure insulin
Can be produced in higher quant
Costs cheaper
Ethical animal use overcome
Stem cell diabetes treatment
Totipotent cells in embryo - has to be destroyed
Source would be from infertility treatments or abortions
Or can use umbilical stem cells
Advantages of stem cell treatments
Donor availability not issue - stem cells produce unlimited
Reduce likelihood of rejection issues - can be made by somatic cell nuclear transfer
No longer have to inject w insulin
Steroid hormones
Lipid soluble
Pass through phospholipid bilayer
Receptors in cytoplasm or nucleus
Hormone- receptor complex acts as transcription factor to synthesise protein
Non steroid hormones
Hydrophilic cannot enter the cell binds to cell surface membrane receptors trigger secondary messengers cause reactions
Adrenaline -> adenylyl cyclase
