lecture 25

Question 1

define negative feedback

Answer 1

an effector activated by the control centre opposes or negates the original stimulus.

Question 2

define positive feedback

Answer 2

an initial simtulus produces a response that exaggerates or enhances the change in orginal conditions rather than oppose it.

Question 3

the individual normal range is more what when compared to the population reference range

Answer 3

individual normal range is more narrow.

Question 4

endocrine system on a surface level depends on

Answer 4

the endocrine cells making and secreting the hormone, the hormones which are carried by the bloodstream, to the target cells which they act upon.

Question 5

true hormones are

Answer 5

chemical messengers that are produced in one location and transported via the bloodtream to a different target cell.

Question 6

difference between lipid soluble and water soluble hormones in regards to chemical classification

Answer 6

water soluble are most peptide hormones and some catecholamines, which includes adrenaline and noradrenaline.
lipid soluble are steroids and thyroid hormones

Question 7

difference between lipid soluble and water soluble hormones in regards to storage

Answer 7

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

Question 8

difference between lipid soluble and water soluble hormones in regards to transport

Answer 8

water soluble: travel dissolved in blood
lipid soluble travel in blood bound to a carrier protein

Question 9

difference between lipid soluble and water soluble hormones in regards to receptor location

Answer 9

water soluble is on the plasma membrane. lipid soluble is within the cytoplasm or nucleus, they are intracellular receptors

Question 10

difference between lipid soluble and water soluble hormones in regards to mechanism of action

Answer 10

water-soluble: through a second messenger
lipid-soluble: by altering gene transcription

Question 11

difference between lipid soluble and water soluble hormones in regards to speed of response

Answer 11

water-soluble: miliseconds to minutes
lipid soluble: hours to days

Question 12

where is the pancreas found

Answer 12

underneath the liver

Question 13

how much pancreas weight is made by the islets

Answer 13

1% of weight is made by the beta and alpha cells and fluid in the islet

Question 14

during the day we move between what two states

Answer 14

fed and fasting state

Question 15

fed state is what and when

Answer 15

cellular uptake of nutrients & anabolic metabolism
(synthesis of glycogen, protein and fat). right after we’ve eaten

Question 16

fasting state is what and when

Answer 16

mobilisation of nutrients & catabolic metabolism
(breakdown of glycogen, protein and fat). sometime after eating

Question 17

what is gluconeogenesis

Answer 17

production of new glucose from fatty acids and amino acids

Question 18

what is glycogenolysis

Answer 18

Glycogenolysis
(Use stored glucose)
Quick release of glucose

Question 19

in hubs 191 what homeostatic variables are we concerned with

Answer 19

blood glucose concentration, blood calcium concentrations, growth and repair and basal metabolic rate

Question 20

examples of catecholamines

Answer 20

adrenaline and noradrenaline