Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Block 3; Week 5 Michelle > Intro to Endocrinology > Flashcards

Intro to Endocrinology Flashcards

1
Q

T/F Hormones can exert their effects on neighboring or distant targets.

A

True.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Where do endocrine glands secrete their products?

A

into the interstitium–>into circulation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Do endocrine glands use ducts?

A

No. they are ductless.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

In a basic sense: what is the regulatory goal of the endocrine system?

A

homeostasis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are some key roles of the endocrine system?

A
  • Regulation of salt/water balance
  • Regulation of blood volume/blood pressure
  • Regulation of calcium & phosphate
  • Regulation of energy balance
  • Regulation of stress response
  • Regulation of reproduction & development
  • Regulation of growth
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are the 2 main categories of hormones that the hypothalamus secretes?

A

releasing hormones

inhibitory hormones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the 4 main releasing hormones that the hypothalamus secretes?

A

GHRH: growth hormone releasing hormone
CRH: corticotropin releasing hormone
TRH: thyrotropin releasing hormone
GnRH: gonadotropin releasing hormone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the 4 main inhibitory hormones that the hypothalamus secretes?

A

somatostatin
dopamine
vasopressin
oxytocin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the 7 main hormones that the pituitary gland releases?

A 
Growth Hormone
Prolactin
ACTH: adrenocorticotropic hormone
MSH: melanocyte stimulating hormone
TSH: thyroid stimulating hormone
FSH: follicle stimulating hormone
LH: luteinizing hormone
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are the 3 main hormones released from the thyroid gland?

A

T3
T4
calcitonin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the main hormone released from the parathyroid glands?

A

parathyroid hormone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the 5 main hormones released from the adrenal glands?

A 
Cortisol
Aldosterone
Adrenal androgens
Epinephrine
Norepinephrine
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are the 3 main hormones released from the pancreas?

A

insulin
glucagon
somatostatin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are the 2 main hormones released from the ovaries?

A

estrogen

progesterone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the main hormone released from the testes?

A

testosterone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are the 8 main places that hormones are secreted in the endocrine system?

A 
Hypothalamus
Pituitary Gland
Thyroid Gland
Parathyroid gland
Adrenal Glands
Pancreas
Ovaries
Testes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are the 3 types of hormones?

A

steroids, amines, & peptides

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What types of secretions in the body include ducts?

A

exocrine secretions, like packages of enzymes secreted thru ducts. this is NOT a part of the endocrine system.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are the 3 types of hormone actions?

A

autocrine
paracrine
endocrine: acts at distant organs or tissues

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is an example of autocrine action of a hormone?

A

insulin inhibiting its own release

*this is where a hormone acts on the same cell that it was secreted from

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is an example of paracrine action of a hormone?

A

estrogen acting in the ovaries

*action in a neighboring cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is the usual pattern of hormone release in the endocrine system?

A

Hypothalamus: releases releasing hormone
Pituitary Gland: releases tropic hormone
Target Organ: releases effector hormone
**effector hormone goes to site of action

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

In the usual pattern of hormone release–>what acts to inhibit hormone release?

A

The effector hormone released from the target hormone will go back & inhibit the release of releasing hormone from the hypothalamus & tropic hormone from the pituitary gland.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What does thyroxine build up?

A

T3 & T4

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

ACTH released from the anterior pituitary acts on what? What does it release?

A

Acts on the adrenal gland.

Cortisol.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

GH released from the anterior pituitary acts on what? What does it release?

A

Acts on the liver.

Causes the release of insulin-like growth factors.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

TSH released from the anterior pituitary acts on what? What does it release?

A

Acts on the thyroid gland.

Releases thyroxine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

FSH & LH released from the anterior pituitary act on what? What does this release?

A

Acts on the sex organs.
Releases estrogen, progesterone, testosterone
causes ovulation & spermatogenesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Prolactin released from the anterior pituitary acts on what? What does this release?

A

Breasts

causes lactation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

How do peptide hormones travel in the blood? What is the significance of this?

A

They travel free in the blood.

this means that they are more easily degraded.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

How do steroid hormones travel in the blood? What is the significance of this?

A

They have to travel in the blood bound to something. A plasma transport protein, called globulins.
This means that they are protected from rapid degradation & clearance.
They are not active until they are free.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What are 4 examples of hormone-binding proteins? What do they bind to?

A

CBG: corticosteroid binding globulin
TBG: thyrotropin binding globulin
SHBG: sex hormone binding globulin
Albumin: non-specific binding

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

How does T4 travel in the blood? What is its half life? If someone is experiencing hypothyroidism…what are the implications of this for treatment?

A

T4 travels in the blood via TBG.
Its half life is therefore longer, 7 days.
**this means that a missed dose can be taken within the week.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

How does PTH (parathyroid hormone) travel in the blood? What does this mean for its half life? What are the clinical implications of this?

A

It travels free in the blood. Its half life is 2-4 minutes, much shorter b/c it isn’t bound to a globulin.
Clinical Significance: you can measure your progress during surgery when removing a hyper functioning parathyroid tumor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Where are the receptor sites for hormones?

A

Either on the surface of the cell or inside the cell.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What are 3 common types of cell surface receptors?

A

G coupled transmembrane receptors (7 domains)
Tyrosine kinase receptor (single domain)
Ligand gated ion channels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What are some amino acid derived hormones that use the G protein mechanism?

A

epinephrine

norepinephrine

38
Q

What are some peptide hormones that use the G protein mechanism?

A 
Glucagon
Angiotensin
GnRH
SS
GHRH
FSH
LH
TSH
ACTH
39
Q

Most _____ hormones use the G protein mechanism.

A

tropic

40
Q

alpha i in the G protein mechanism causes what cascade to occur?

A

targets adenylate cyclase

causes cAMP to go down

41
Q

alpha q in the G protein mechanism causes what cascade to occur?

A

targets phospholipase C

with the help of DAG & Ca++ it activates PKC

42
Q

alpha s in the G protein mechanism causes what cascade to occur?

A

target adenylate cyclase

causes cAMP to go up

43
Q

alpha12 in the G protein mechanism causes what cascade to occur?

A

targets RHOGEFs
causes an increase in RHO
whatever that means…

44
Q

What type of a receptor does insulin use?

A

tyrosine kinase receptor

binding leads to phosphorylation & lots of activity!

45
Q

What is the main effect of insulin binding tyrosine kinase receptor on a cell?

A

Glut 4 transporters are moved to the cell membrane so that glucose can move into the cell. This then leads to the metabolism & storage of glucose, the main effect of insulin.

46
Q

What are some of the other effects that insulin has on a cell, aside from glucose transport?

A

cell growth
protein synthesis
glycogen synthesis

47
Q

What is pseudohypoparathyroidism?

A

this is a defect in the G protein mechanism of the receptor for parathyroid hormone.
even with elevated levels of PTH, which patients have, there are symptoms of hypoparathyroidism.

48
Q

How do you confirm a diagnosis of pseudohypoparathyroidism?

A

administer exogeneous PTH
measure the urine level of cAMP
**if they have the condition the cAMP should be low

49
Q

How are intracellular nuclear receptors used?

A

they are sometimes used by second messengers of normal hormones that go to cell surface receptors…usu they are used by steroid hormones that diffuse thru the plasma membrane.

50
Q

How does an intracellular receptor work?

A

it is in the nucleus.
the hormone or second messenger binds a receptor inside the cell
the receptor-hormone complex binds a HRE (hormone response element) on the DNA
alters gene expression

51
Q

Overview:

what types of hormones bind cell surface receptors? What types of hormones bind intracellular nuclear receptors?

A

Cell Surface: peptide & amine hormones

Nuclear: steroid & thyroid

52
Q

What type of hormone is Vitamin D considered?

A

a steroid hormone

53
Q

Are thyroid hormones steroid hormones?

A

NO.
but thyroid hormones can diffuse thru the plasma membrane & they act like steroid hormones. They both use nuclear receptors.

54
Q

Explain how peptide hormones are made & released?

A

Transcribed as pre-hormones. Undergo post-translational modification.
Stored in secretory granules.
Released by exocytosis

55
Q

How do peptide hormones act once they are released?

A

They travel free in the blood w/o a carrier protein b/c they are hydrophilic. Thus, they have short half-lives. They bind to cell surface receptors & have their effect in the cell via second messengers.

56
Q

What are some examples of peptide hormones?

A 
Insulin 
Glucagon
ACTH
PTH
FSH
LH
TSH
HCG
57
Q

What are some examples of glycoproteins that are peptide hormones?

A

FSH
LH
TSH
HCG

58
Q

What are the 2 main classes of amino acid derived hormones? WHat are they derived from?

A

Catecholamines
Thyroid Hormones
**derived from tyrosine

59
Q

Where are steroid hormones synthesized? What are they synthesized from?

A

Locations: adrenal cortex, gonads, placenta

synthesized from cholesterol

60
Q

Once they are released, what do steroid hormones do?

A

They travel in the blood bound to a carrier protein b/c they are hydrophobic. Thus, they have longer half-lives.
They diffuse thru plasma membrane of target cell & they bind to the nuclear receptor.

61
Q

What are the 3 patterns of hormone secretion?

A

Pulsatile
Episodic
Diurnal

62
Q

What does it mean for a hormone to be released in a pulsatile fashion?

A

it is released in regular pulses varying in amplitude & frequency

63
Q

What are some examples of hormones that are released in a pulsatile fashion?

A

GH: growth hormone
GnRH: gonadotropin releasing hormone

64
Q

If you were treating someone who was infertile with a deficiency of Gonadotropin releasing hormone, how would you want to administer the exogenous GnRH? Why?

A

While it might be tempting to administer the GnRH continuously at high doses, this wouldn’t be wise b/c of how it is normally released.
Continuous release can cause desensitization for receptors that are used to hormones that are released in a pulsatile fashion. It would suppress FSH & LH.

65
Q

Why is it important to sleep while you are growing up, especially?

A

b/c the most GH is released while you are sleeping!

66
Q

Explain how diurnal secretions work.

A

These hormone secretions are based off of the sleep-wake cycle (circadian rhythm). There are low hormone levels at night that peak during the daytime.
**why jet lag & night shifts are difficult

67
Q

What determines the circadian rhythm?

A

the hypothalamus

specifically: the SCN: suprachiasmatic nucleus

68
Q

What is an example of a hormone that is released diurnally?

A

Cortisol

69
Q

When is the best time to measure cortisol levels? Why?

A

If you suspect low cortisol levels, you must check them around 10AM b/c that is when they are naturally highest. If you check at nighttime–>of course they will be low!!

70
Q

How does the dawn phenomenon relate to why patients with Diabetes can get a surge in fasting blood glucose in the morning?

A

We wake up w/ increasing hormone levels. This results in an increase in blood glucose. The body produces a bunch of insulin. Diabetics can’t do that so they get an elevated fasting blood glucose in the morning.

71
Q

After hormones hit their target…what is next for them?

A

they go to the liver for metabolic transformation

they are excreted in the urine

72
Q

What are the 3 forms of regulation of hormonal release?

A

hormonal
nutrient/ion regulation
neural

73
Q

what does hormonal regulation of hormone release entail?

A

this includes tropic hormones & feedback loops

74
Q

What does negative feedback require?

A

a closed loop system: product, effect, sensor

75
Q

What is the common example of positive feedback?

A

oxytocin: important in delivery & lactation
* with the presence of the head in the birth canal–>more oxytocin is released
* with suckling of the baby–>more oxytocin is released

76
Q

What are some examples of open loop hormones? Do they exhibit negative feedback?

A

Don’t exhibit negative feedback b/c it is an open loop!
Usu they involve the CNS, like Epi & Norepi.
Also includes peptide hormones that have a super short half life.
Once the storage of the hormone is depleted, it doesn’t get secreted anymore.

77
Q

In primary hypothyroidism…what is lacking? How do you treat it?

A

the thyroid gland doesn’t make thyroxine

Well, the TSH levels are normal–>so you look @ those to decide how much fake thyroxine (levothyroxine) to give.

78
Q

When you treat primary hypothyroidism…is it a closed loop or open loop system?

A

Open Loop. No more feedback. Now, the endocrinologist is trying to maintain homeostasis.

79
Q

What’s the basic idea behind hormone measurement?

A

often it is measured in the blood or the product of the hormone is measured in the blood
**super important for diagnosis

80
Q

What is the ACTH stimulation test? What is it used to diagnose?

A

Used to diagnose adrenal insufficiency
Give a bunch of exogenous ACTH.
Watch whether the adrenal gland produces a bunch of cortisol.
If not, something is wrong.

81
Q

What is the dexamethasone suppression test? What is it used to diagnose?

A

Give dexamethasone to a patient that you suspect has Cushing’s disease (excess cortisol).
This should inhibit the hypothalamus & pituitary gland. You measure cortisol levels. If they are high, that means that the adrenal gland is still releasing a ton of cortisol. Maybe Cushing’s.

82
Q

Radioimmunoassay (RIA) is a way of measuring hormone levels. Explain it in basic terms.

A

mix radio-labeled hormone w/ antigen so that they bind. Put in patient’s hormones to compete with the glowing hormone. Measure the radioactivity & using a Scatchard plot you kind of get an idea of hormone levels.

83
Q

What’s the difference b/w ELISA & RIA in measuring hormone levels?

A

ELISA doesn’t use radiation to measure bound hormone, but enzyme catalyzing color change.

84
Q

What is something that can lead to errors in measuring hormone levels w/ RIA & ELISA?

A

cross-reactivity of hormones
other hormones can bind to the same receptor–>you think oh, i have this amount of hormone X. But actually you have that amount of hormone X & hormone Y or something.

85
Q

What is a clinical example of the importance of cross-reactivity of hormones?

A

When women are first pregnant they can sometimes exhibit hypothyroidism. This is b/c their higher levels of hcG compete for the thyroid receptors…Gone after 1st trimester.

86
Q

What is the hook effect? How does it relate to hormone measurement w/ assays?

A

there is so much hormone, that the receptors are saturated. Looks like there are relatively normal levels of the hormone, but there is a LOT more. You need to dilute the sample to fix this measurement problem.

87
Q

So, if you get a patent’s hormone levels. How do you know if they are normal/healthY?

A

You compare it to reference ranges. This is the range that includes 95% of normal people & what their levels are. But…if someone is outside of the reference range, might not be a problem–>theoretically they could be a part of the normal 5%.

88
Q

So…if a woman comes in after removing an adenoma from her pituitary gland…and she exhibits symptoms of hypothyroidism…what should you check?

A

Check TSH. If that is normal…don’t stop b/c you are only focused on the pituitary gland!
Check the thyroid!

89
Q

What are the 3 basic categories of endocrine disorders?

A

Hormone Deficiency
Hormone Resistance
Hormone Excess

90
Q

What are some examples of endocrine disorders that have to do with hormone deficiency?

A

Type I Diabetes: autoimmune destruction of beta cells
Deficiency of a precursor, like lack of iodine–>can cause goiter (enlarged thyroid b/c it is constantly being hit w/ TSH to get high enough levels of thyroid hormones) & causes hypothyroidism.

91
Q

What are some examples of endocrine disorders that have to do with hormone resistance?

A

Type II Diabetes: insulin resistance

Pseudohypoparathyroidism: receptor mutation

92
Q

What are some examples of endocrine disorders that have to do with hormone excess?

A

Acromegaly: tumors/mutations

Grave’s disease: autoimmune activation

Block 3; Week 5 Michelle (5 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions