lecture 25 Flashcards
define negative feedback
an effector activated by the control centre opposes or negates the original stimulus.
define positive feedback
an initial simtulus produces a response that exaggerates or enhances the change in orginal conditions rather than oppose it.
the individual normal range is more what when compared to the population reference range
individual normal range is more narrow.
endocrine system on a surface level depends on
the endocrine cells making and secreting the hormone, the hormones which are carried by the bloodstream, to the target cells which they act upon.
true hormones are
chemical messengers that are produced in one location and transported via the bloodtream to a different target cell.
difference between lipid soluble and water soluble hormones in regards to chemical classification
water soluble are most peptide hormones and some catecholamines, which includes adrenaline and noradrenaline.
lipid soluble are steroids and thyroid hormones
difference between lipid soluble and water soluble hormones in regards to storage
water soluble can be made and stored for later use when needed, released by exocytosis.
lipid soluble cant be stored so are made and secreted on demand. except thyroid hormone
difference between lipid soluble and water soluble hormones in regards to transport
water soluble: travel dissolved in blood
lipid soluble travel in blood bound to a carrier protein
difference between lipid soluble and water soluble hormones in regards to receptor location
water soluble is on the plasma membrane. lipid soluble is within the cytoplasm or nucleus, they are intracellular receptors
difference between lipid soluble and water soluble hormones in regards to mechanism of action
water-soluble: through a second messenger
lipid-soluble: by altering gene transcription
difference between lipid soluble and water soluble hormones in regards to speed of response
water-soluble: miliseconds to minutes
lipid soluble: hours to days
where is the pancreas found
underneath the liver
how much pancreas weight is made by the islets
1% of weight is made by the beta and alpha cells and fluid in the islet
during the day we move between what two states
fed and fasting state
fed state is what and when
cellular uptake of nutrients & anabolic metabolism
(synthesis of glycogen, protein and fat). right after we’ve eaten
fasting state is what and when
mobilisation of nutrients & catabolic metabolism
(breakdown of glycogen, protein and fat). sometime after eating
what is gluconeogenesis
production of new glucose from fatty acids and amino acids
what is glycogenolysis
Glycogenolysis
(Use stored glucose)
Quick release of glucose
in hubs 191 what homeostatic variables are we concerned with
blood glucose concentration, blood calcium concentrations, growth and repair and basal metabolic rate
examples of catecholamines
adrenaline and noradrenaline
