Endocrinology Exam 1 - Miscellaneous

Front 1

negative feedback

Back 1

drives system toward setpoint; maintains homeostasis

Front 2

positive feedback

Back 2

drives system away from setpoint; disrupts homeostasis

Front 3

feedfoward

Back 3

anticipates change in parameter to maintain homeostasis

Front 4

Receptors act by:

Back 4

1. causing enzyme activation
2. opening ion channels
3. activating transcription factors
(4. 2nd messenger systems)

Front 5

diurnal

Back 5

daily cycles (=24 hr, regulated by light cues); also day active

Front 6

nocturnal

Back 6

night active

Front 7

circadian cycle

Back 7

appear to be approximately 24 hr (independent of light cues); under control of endogenous clock (must reset daily to stay on track with day/night cycle)

Front 8

ultradial cycle

Back 8

less than 24 hr

Front 9

lunar cycle

Back 9

28 day cycle

Front 10

circannual cycle

Back 10

annual/seasonal

Front 11

protein/peptide synthesis

Back 11

amino acids joined by peptide bonds

Front 12

secretion

Back 12

synthesis AND release

Front 13

physiological doses

Back 13

ng/ml, pg/ml

Front 14

biological half-life (blood level) determined by:

Back 14

1. metabolism rate (inactivation)
2. excretion rate

Front 15

proteins - precursor? stored?

Back 15

precursor: amino acids; stored: yes

Front 16

indoleamines - precursor? stored?

Back 16

precursor: tryptophan (AA); stored: yes

Front 17

catecholamines - precursor? stored?

Back 17

precursor: tyrosine (AA); stored: yes

Front 18

amino acid --> (biogenic) amine

Back 18

decarboxylase

Front 19

thyroid hormones - precursor? stored?

Back 19

precursor: tyrosine (AA); stored: yes

Front 20

steroid hormones - precursor? stored?

Back 20

precursor: cholesterol; stored: no

Front 21

eicosanoids - precursor? stored?

Back 21

precursor: arachidonic acid; stored: no

Front 22

binding proteins

Back 22

plasma proteins that bind to hormones (esp. steroids, eicosanoids, increase solubility); less tight assoc. than receptors and greater density

Front 23

inactivation of bioregulators

Back 23

1. enzymatic degradation (proteins, peptides --> AA)
2. enzymatic inactivation (small changes to chemical structure); biogenic amines, etc.
3. conjugation: add a large charged group (sugar); change conformation, make more water soluble so they can be targeted for excretion (steroids, thyroid hormones)