Intro to Endocrine (lect 1) Flashcards

1
Q

Define Hormone

A

chemical substance that sends a message to another cell in the body

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2
Q

How are cellular messages sent to other cells in the body?

A

Via blood stream - endocrine
GI tract - exocrine
Neurolog - neurocrine
Intersistial - paracrine

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3
Q

What are a few glands covered in the endocrine system

A

hypothalamus, pituitary, thyroid, adrenal, pancreas, ovaries/testes

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4
Q

Describe Amine hormone classification

A

tryptophan or tyrosine (amino acid) modified
Epinephrine (tyrosine) Melatonin (tryptophan)
Very Short Half life

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5
Q

Describe Peptide

A

unbroken chain of amino acids 50 or less
hydrophilic, dont cross membrane easily
must first bind to membrane bound receptors

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6
Q

Describe Proteins

A

chains of amino acids 50 or less
primary,secondary,tertiary structures

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7
Q

Describe glycoproteins

A

conjugate proteins bound to carbs (galac/mannose/fruct)
solubility/half life similar to protein hormones

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8
Q

Describe Steriod

A

derived from lipid/typically cholesterol
hydrophobic, must be transported in blood bound to carrier proteins
can cross membrane

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9
Q

Describe fatty acid

A

small derived from arachidonic acid
rapidly degraded and effective for only seconds

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10
Q

Describe metabolism

A

Sum fo chemical processes that occur within a living organism to maintain life, includes catabolism and anabolism

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11
Q

T/F Hormones and all other cellular signals are not metabolized

A

false they are

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12
Q

What determins the extent to which hormones are metabolized of which they are capable of binding to receptors and eliciting intended effects?

A

Speed of catabolism (break down) and anabolism (creation)

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13
Q

What are some conditions that modify met. of hormones

A

speed of breakdown/creation
concentration of protein bound hormones will be affected by availibility to binding
cirrhosis can enhance enzymatic breakdowns

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14
Q

Describe what happens with alcohol consumption

A

increase degradation of testosterone
extended consumption - cirrhosis - less alb and binding proteins

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15
Q

What is the main two mechanisms of elimination

A

Kidney and liver

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16
Q

T/F blood passes through the kidney and is taged with certain hormones for destruction or creation of different molecules

A

false it passes through the liver

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17
Q

Describe steriod hormones

A

eliminated by inactivating metabolic pathways and excreted in urine and bile

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18
Q

Describe Thyroid hormones

A

inactivated by intracellular deiodinases

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19
Q

Describe catecholamine hormones

A

rapidly degraded within blood circulation

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20
Q

Describe fatty acid derivitive hormones

A

rapidly inactivated by metabolism and typically active for short period (seconds)

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21
Q

Briefly describe hormone transport

A

after release from endocrine, circulate in bloodstream in one of two forms:
protein bound or unbound

Free floating subject to metabolism

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22
Q

Describe solubility

A

water soluble (hydrophilic) or fat soluble (lipophilic)

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23
Q

Describe carrier proteins

A

fat-soluble hormones are transport bound to a carrier protein

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24
Q

Describe Micelles

A

enclosed packages in lipid-rich sub. with hydrophilic outerlayer and hydrophobic inner

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25
Q

Describe negative feedback mechanisms

A

most common
stimulus with feedback upstream to decrease production of itself
ex: thyroid

26
Q

Describe postive feedback mechanisms

A

control mechanism that increases stimulus recieved until a endpoint is achieved
can easily go out of control
ex. coag cascade

27
Q

Describe 1/2/3 disorders

A

disorder of endocrine characterized by organ dysfunction, whether it has regulating gland (2/3) or endocrine gland (1)

Thyroid is 1
Pituitary 2
hypothalamus 3

28
Q

Describe other factors that affect hormone levels:

A

stress: well adaptive or mal adaptive
Time of Day: syst regulates func through external signals
mesnstration
menopause
food intake/diet
drugs

29
Q

Hypothalamic/pituitary function
three distinct parts are?

A

anterior
indermediate lobe
posterior

30
Q

what do post posterior arise from

A

diencephalon; storage and release of oxytocin and AVP

31
Q

Briefly describe Anterior pituitary

A

80-90% blood supply and hypothalamus factors via hypo-hypo portal system

32
Q

T/F Pituitary function can be detected between 7-9th week gestation

A

t

33
Q

Describe lactotrophs:
somatotrophs:
thyrotrophs:
corticotrophs:
gonadotropphs:

A

Lacto: prolactin secreting
Soma: GH secreting
Thyro: TSH
Cortico: ACTH
Gonad: LH/FSH

34
Q

T/F Afferent pathways to hypothalamus are integrated in various specific nucleli then resolved

Efferent pathways to higher brain centers, responses are similar to specific hormone charact. by negative feedback/pulsatity and diurnal variation

A

t

35
Q

Briefly describe the endocrine feedback loop

A

hypothalamus, pituitary, thyroid axis

36
Q

Hypophyseal unit: how do anterior hormones secrete?

A

pulse fashion, generally regulated by neural modulation and is specific to each unit

37
Q

What is the interpulse for males and duration?

A

interpulse is 55 min, for LH, duration is 40 min

38
Q

T/F pulse frequency of hypoth hormone GnRH does not have a major effect of LH secretion

A

false it does

39
Q

t/f hormone nature is cyclic

A

true

40
Q

T/F many hormones are secrected in different amounts depending on time

A

true, this is best shown with ACTH or TSH

ACTH peak 0600-0900
TSH nocturnal are 2x the day levels

41
Q

Briefly describe pituitary tumors
20% harbor
10-30% during
account for 91%
enlargment seen in?

A

20% harbor clinically silent adenomas
10-30% in MRIs

account for 91% of lesions in pts undergone transpen, surgery

Enlargment seen in puberty/preg

42
Q

What are the most clinically significant tumors of pituitary

A

prolactin, then null cells, then THS, GH, ACTH or gonado

43
Q

Describe anterior pitutiary hormones
larger….
either…or….

A

larger and more complex than those synth in hypothalamus,either tropic or direct effectors

44
Q

Give examples of tropic vs direct effectors for anterior pituitary hormones

A

LH
FSH
TSH
ACTH
(tropic)

IGF-1
Prolactin (direct

45
Q

Describe growth hormone
vital for
ceases?
what stimulates GHRH
Stimulators?

A

vital for normal growth (pituitary)
growth ceases if pituitary removed, not restored unless GH administered
Somatotropin stimulates GHRH

Stimulators: sleep, excerise…etc

46
Q

Actions of GH
what type of hormone
transition from…w/o?
direct antagonizer of?
STOMA….

A

amphibolic hormone (cata/anabolic)
transition from fed to fast state w/o shortage of substrate
direct antagoner of insulin/glucose metabolism

STOMATOMEDINS -IGF

47
Q

major growth factor induced by GH is what
from liver
what can cross rxn w….causes?
what kind of testing for …. deficiencies/pathologies?

A

ICF-1 from the liver

ICF-2 can cross react with insulin and cause hypoglycemia

Glucose testing for diagn of acromegaly/GH def

48
Q

Briefly describe GH pulsitity
based off
testing…

A

based on dyn phys of growth hormone axis

testing IGF-1 for assessing GH def and acromegaly/giagantism

49
Q

Describe GH excess

A

usually tumor, before closure of long bones, gigantism
after puberty classical but soft bony tissues overgrowth, enlarged hands/feet

tumor ablation

50
Q

Describe GH deficiency
children:
adults:

A

both adults and child
children: growth failure, short stature
adult: complete/partial failure of anterior pituitary
osteoporosis seen

51
Q

Describe Prolactin

A

struct similar to GH and HPL
stress hormone, vital funct in relation to reproduction
tonic inhibitor
DOPAMINE INHIBITS PROLACTIN

52
Q

Prolactinoma

A

pituitary tumor that secretes prolactin most common type of func pit. tumor

53
Q

T/F in hyperprolactinemia greater than >150 correlates with tumor size

A

true

54
Q

What must you obtain in order to eliminate primary hypothyrodismn disease causing elevations of prolactin in hyperprolactinemia?

A

obtain TSH/Free T4

55
Q

Describe Idiopathic galactorrhea

A

lactation occuring in women with normal prolactin
usually in women who have been pregnant several times, no pathological implications

56
Q

Briefly describe hypopituitarism
failure of….results in loss of…
complete…..
low/norm levels

A

failure of either pituitary or hypothalamus resulting in a loss of anterior pit. function
complete loss or loss of single monotropic
Low or norm levels of tropic hormone

57
Q

T/F Both tropic and target hormones should be monitored w hypopitutiarism

A

true

58
Q

Describe posterior pituitary hormones
extension of?
storage of?
tightly linked to?
synth outside of?

A

extension of forebrain
storage of AVP/Oxytocin
tightly linked to prod of neurophysin
SYNTH OUTSIDE OF HYPOTHALAMUS

59
Q

Describe Oxytocin

A

critical for lactation/labor
positive feedback loop
Pitocin - synthesized oxytocin
linked to maternal bond

60
Q

Describe AVP

A

regulates free water excretion in henles loop
potent pressor agent, blood clotting and factor VII release
diabetes insipidus