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Flashcards in 5.1 Intro To Endocrine Deck (91):
0

Study of processes involved in the regulation and integration of cells and organ systems by hormones

Endocrinology

1

Functions of endocrine system

1. Regulates multiple organs
2. Maintains growth and reproductive needs
3. Respond to fluctuations within the internal environment

2

Endocrine glands of the brain

Hypothalamus gland and pineal gland

3

Transitory endocrine gland

Placenta

4

Type of communication where the cell recognizes itself as the target cell

Autocrine

5

Signaling molecule is received by a neighboring cell (type of communication)

Paracrine

6

Characteristics of neuron doctrine communication

1. Secreted by neuron
2. Travels via blood
3. Acts on distant target cells

7

Mode of travel for endocrine communication

Via blood

8

Precursor of secretory peptides

Prehormone/preprohormone

9

What happens to secretory hormones after its synthesis

Stored in secretory vesicles

10

At what terminal of nascent peptides can signal peptides be found

N-terminal

11

Where are the receptors of hydrophilic peptides found

Membrane-bound/surface of cell membrane

12

Signals from hydrophilic peptides are amplified by

Second messengers

13

Water-soluble hydrophilic peptides can enter the circulatory system (T/F)

True

14

Peptide hormones are biologically active and are free to interact with receptor of target cell when in what form

Free form

15

What condition of free hormones will result to the release of hormones from transport protein?

Decreased levels of free hormones

16

Extends the half-life of hormones

Bound hormones

17

The only 2 peptide hormones that work in bound form

Growth hormone and IGF-1

18

Onset and duration of peptide hormone

Fast onset and short-time duration

19

Number of amino acids for it to be considered a protein

Greater than 100 amino acids
(Peptide if less than 100 amino acids)

20

Peptide hormone: Rough ER
Steroid hormone: __________

Smooth ER

21

Steroid hormones are stored in secretory vesicles (T/F)

False - peptide hormone not steroid

22

Peptide hormone: water soluble
Steroid hormone:

Lipid soluble/hydrophobic

23

Peptide hormones are degraded by

Peptidases

24

Site of steroid hormone receptors

Intracellular (cytoplasm or nucleus)

25

Steroid hormones with cytoplasmic receptors

Adenocorticosteroids, glucocorticoids, mineralocorticoids

26

Location of Vitamin D and sex steroid hormone receptors

Inside nucleus

27

Effect of steroid hormones

Increase or decrease transcription of regulatory proteins by modulating gene expression

28

Precursor of steroid hormone

Cholesterol

29

Steroid hormones have no storage, thus, must be synthesized after stimulus is received. How does the body compensate for this

Large stores of cholesterol esters in cytoplasm vacuoles are available for steroid synthesis

30

Amino acid derivatives

Tyrosine or tryptophan

31

Amino acids can function either as a peptide or a steroid (T/F)

True

32

Ioidothyronine, a steroid-like amine, is synthesized in

Thyroid gland

33

Ioidothyronine derivative

Tyrosine

34

Half-life of T3 and T4

T3- 18 days
T4- 7 days

35

Thyroid hormone is a steroid-like amine. How is it similar to steroid hormones

1. Intracellular receptor (nucleus)
2. Acts as a transcription factor
3. Protein bound
4. Slow onset and long duration

36

Primary hormones produced by endocrine system

Catecholamines

37

Catecholamines are synthesized by

Adrenal medulla and neurons

38

Catecholamines are copackaged with

ATP, Calcium, Chromogranins (proteins)

39

After Catecholamines are synthesized, the final product is stored in

Chromaffin granules

40

Catecholamines are secreted in response to

Sympathetic stimulation

41

Catecholamines only circulate when bound to albumin (T/F)

False - circulate either unbound or loosely bound to albumin

43

Half-life of Catecholamines

1-2 minutes

44

Catecholamines are peptide-like amines. How are they similar to peptide hormones

1. Do not cross cell membrane
2. Membrane-bound receptors
3. Make use of second messengers
4. Stored in vesicles
5. Plasma form is unbound
6. Fast onset and fast/short duration

45

Cells and receptors exhibit specificity (T/F)

False- only receptors exhibit specificity. Cells may have receptor for different hormones

46

What are the cell membrane receptors

GPCR, Catalytic, Cytokine

47

How many domains does GPCR have? Describe each

3 - extracellular (ligands bind), transmembrane (7 subunits), intracellular (G-protein bind)

48

When inactivated, alpha subunit remains dissociated from beta-gamma subunit (T/F)

False- alpha reforms with beta-gamma when inactivated

49

Peptide hormones that bind Receptor Tyrosine Kinase

Insulin
IGF-1
NGF

50

Peptide hormones that bind to Cytokine receptors

Prolactin
GH
Erythropoietin
Leptin

51

In the mechanism of GPCR, GTP binds to which heterotrimer subunit?

Alpha

52

Peptide hormones that bind to receptor tyrosine kinase (RTK)

Insulin
IGF-1
NGF

53

Peptide hormones that bind to Cytokine Receptor

Prolactin
GH
Erythropoietin
Leptin

54

Effectors of adenylyl cyclase, Phospholipids C, Phospholipase A2

adenylyl cyclase - cAMP
Phospholipids C - DAG (activate protein kinase C) and and IP3 (open calcium channels)
Phospholipase A2 - eicosanoids (releases arachidonic acid)

55

Catalytic receptors posses enzymatic activity on the cytoplasmic side (T/F)

True

56

Ligand of guanylyl cyclase receptor

ANP

57

Receptor of "Transforming Growth Factor beta (ligand)"

Serine/threonine kinase

58

In Serine/Threonine Kinase Receptor, ligand binding to type II receptor leads to

Dimerization of type I and type II receptors (type II phosphorylates type I)

59

Type I phosphorylates SMAD, which complexes with co-SMAD. What does this complex do

Act as a transcription factor

60

In Tyrosine kinase receptor mechanism, ligand binding results to

Dimerization and autophosphorylation

61

Effectors of tyrosine kinase

GRB2 and IRS1

62

Receptor with a single membrane spanning domain

Cytokine Receptors/ Tyrosine Kinase Associated Receptors

63

Cytokine receptors do not posses any catalytic activity instead they are associated with tyrosine kinases like JAK protein (T/F)

True

64

Mechanism of Cytokine receptors

Ligand binding -> Dimerization then activation of JAK -> JAK phosphorylates STAT -> dimerize STAT dimer

65

STAT dimer goes to the nucleus to act as

Transcription factor

66

Intracellular receptors are peptide receptors (T/F)

False- steroid receptors not peptide

67

Intracellular receptors function to modify protein synthesis through

Gene expression

68

2 types of intracellular receptors and describe in terms of their bound state

1. Cytoplasmic receptor (bound receptor)
2. Nuclear receptor (unbound receptor)

69

Intracellular receptors of glucocorticoids and mineralocorticoids

Cytoplasmic receptor

70

Intracellular receptor of progestins, androgens, estrogens, and vitamin D

Nuclear receptor

71

(T/F) Mechanism of cytoplasmic receptor:
Ligand binds in the cytoplasm -> dissociation of HSP -> ligand-receptor complex translocate to the nucleus -> complexes with HRE -> gene transcription is activated

True

72

In nuclear receptors, how do steroids pass through the cytoplasmic membrane

Diffusion

73

Steroid enters the nucleus through

Nuclear pore

74

Response counteracts the stimulus, shutting off the response loop

Negative feedback

75

Low levels of hormones: ______ production
High levels of hormones: ______ production

Increase
Decrease

76

Negative feedback ensures stability by

Keeping a physiologic parameter within normal range

77

Types of negative feedback loops

Response-driven feedback loop and endocrine axis-driven feedback loop

78

Negative feedback has little to do with the physiologic response to the hormone (T/F)

True

79

In positive feedback, the stimulus causes a _______ in response

Continuous increase

80

Required to shut off positive feedback cycle

Outside force

81

Causes the sequential series of release of hormones

HPT Axis

82

In HPT Axis, what are the hormones involved

Anterior Pituitary Hormones only

83

Which glands are involved in the HPT Axis and identify their hierarchy

Hypothalamus (1st tier)
Pituitary gland (2nd tier)
Peripheral endocrine gland (3rd tier)

84

Type of hormone released by the following glands in HPT Axis:
Hypothalamus
Pituitary gland
Peripheral endocrine gland

Hypothalamus: releasing hormone
Pituitary gland: stimulating hormone
Peripheral endocrine gland: final hormone

85

Negative feedback targets which glands in HPT Axis

Hypothalamus or pituitary gland

86

Organs not directly controlled by anterior pituitary gland

Free-standing endocrine organs (ex. Parathyroid gland and endocrine pancreas)

87

When does the parathyroid gland secrete hormones

When there is a decrease in ionized calcium

88

Decrease in ionized calcium -> Parathyroid gland is stimulated -> secrete hormone-> PTH Hormone increase ______

Serum calcium back to normal

89

Type of feedback loop wherein a change in substrate level causes negative feedback

Response-driven feedback

90

Hypothalamic releasing hormones : ________
___________ : posterior pituitary

Anterior pituitary
Nerve signals from hypothalamus

91

Steroid-like amino acid derivatives (T3 and T4) are produced in

Cytoplasm