ablation, replacement, isolate and purify hormone, and assay changes
New cards
19
What is ablation?
removal of hormones and studying change in activity
New cards
20
What is replacement of a hormone?
adding the substance back after ablation
New cards
21
What does it mean to isolate and purify the hormone?
study chemical properties
New cards
22
What are the three ways to measure hormones?
Bioassay, radio immunoassay, and enzyme linked immunosorbant assay.
New cards
23
What is a bioassay?
Uses living cell and tissues of the individual to test a response
New cards
24
What is a radioimmunoassay (RIA)?
looking for amount of hormone in the body by using radiolabeled isotope
New cards
25
What is enzyme linked immunosorbent assay (ELISA)?
Uses chemical reactions to determine charge in hormonal concentration
New cards
26
What are the classes of hormones?
non-steroid and steroid
New cards
27
What is the backbone of all steroid hormones?
cholesterol
New cards
28
What are examples of steroid hormones?
adrenocorticoid and sex hormones
New cards
29
What are examples of sex hormones?
testosterone, progesterone, estrogen
New cards
30
What are some chemical properties of steroid hormones?
small, hydrophobic, lipophilic, travels via blood with a carrier, lipid soluble, diffuses through cell membranes, cytoplasmic or nuclear receptor
New cards
31
What is the pathway from cholesterol to progesterone?
27 carbon cholesterol to pregnenolone to progesterone
New cards
32
What steroid takes cholesterol to pregnenolone?
Cytochrome P450 side-chain cleavage or P450scc
New cards
33
What steroid takes pregnenolone to progesterone?
3-beta-hydroxysteroid dehydrogenase or 3beta HSD
New cards
34
What steroid takes testosterone to estrogen?
aromatase
New cards
35
Which process is very slow and has a long duration?
steroid hormones
New cards
36
What is the fate of steroids?
steroids are secreted by gonads - they enter the blood and go to their target tissue - they cause a change in target tissue - steroid in the blood passes to the liver where it is rendered as water-soluble (makes it hydrophilic and lipophobic) - reenters blood and enters kidney or bile - excreted into urine and/or feces as glucronides or sulfates
New cards
37
What are examples of non-steroid hormones?
proteins/peptide hormones, eicosanoids, and biogenic amines and catecholamines
New cards
38
What is an example of a protein/peptide hormone?
oxytocin, FSH, LH
New cards
39
What is an example of a eicosanoid?
prostaglandins
New cards
40
What is an example of a biogenic amine or catecholamine?
melatonin
New cards
41
What are the chemical properties of a non-steroid hormone?
large, hydrophilic, lipophobic, can’t fit through cell membrane, not lipid soluble, received by receptors external to the cell membrane, requires secondary messenger mechanism of action
New cards
42
What occurs in steroid hormone action?
Steroid hormone binds to sex steroid-binding globin and unbinds when they come in contact with their target tissue - passes through the cell membrane because it’s lipophilic - steroid binds to the receptors in the cytoplasm or nucleus of the cell - binds to steroid response element of the DNA - changes the conformation of the DNA which forms mRNA - mRNA is released into the cytoplasm and is taken by ribosomes to make more proteins
New cards
43
What occurs in non-steroid action?
Non-steroid hormone passes through the blood and binds to hormone receptors on the cells membrane - second messenger system (G-protein) is attached to receptor - the binding of hormone to the receptor activates adenylate cyclase on the cell membrane which converts ATP to cAMP - cAMP activates protein kinase in the cytoplasm which activates new protein synthesis
New cards
44
What is the lock and key approah?
describes the interaction between the hormone and its specific receptor
New cards
45
Where are receptors for steroid hormones located?
in the cells cytoplasm or its nucleus
New cards
46
Where are receptors for non-steroid hormones located?
on the cells membrane
New cards
47
What does effectiveness of the hormone depend on?
number of receptors and the affinity of that hormone to its receptor
New cards
48
What is an agonist?
something that looks like a hormone and can bind to its receptor to cause a positive response
New cards
49
What is an antagonist?
something that looks like a hormone and can bind to its receptor to cause a negative response
New cards
50
What does an antagonist do?
shuts down hormone signaling
New cards
51
Which feedback loop is self-regulating?
negative feedback
New cards
52
Which feedback loop is most common?
negative feedback
New cards
53
What is positive feedback?
when a stimulus leads to an increase in the reaction
New cards
54
What is an example of positive feedback?
action of oxytocin on uterine muscle during birth
New cards
55
What is negative feedback?
the primary mechanism through which your endocrine system maintains homeostasis
New cards
56
What causes a stop in positive feedback?
What the stimulus is gone
New cards
57
What causes a stop in negative feedback?
levels of hormones returning back to homeostasis
New cards
58
What is an example of negative feedback?
plasma glucose and insulin response
New cards
59
Where is oxytocin produced?
hypothalamus
New cards
60
Where is oxytocin stored?
posterior pituitary
New cards
61
What type of hormone is oxytocin?
neuropeptide
New cards
62
What signals for the release of oxytocin?
nerves
New cards
63
What are the main functions of oxytocin?
promoting smooth muscle contractions in the uterine wall, the epididymis, and the mammary glands
milk letdown
New cards
64
What is the love/trust hormone?
oxytocin
New cards
65
What type of hormone is GnRH?
neuropeptide
New cards
66
Where is GnRH produced and stored?
hypothalamus
New cards
67
What happens to GnRH in the anterior pituitary?
It stimulates gonadotropes
New cards
68
What does the tonic release of GnRH do?
maintains normal homeostasis
New cards
69
What does the surge release of GnRH do?
causes ovulation in females
New cards
70
The hypothalamus is the ___ hormone while the anterior pituitary is the ___ hormone
stimulate follicle growth and development and estrogen production
New cards
75
What does FSH do to the testes?
supports Sertoli cell function and estrogen production
New cards
76
What does LH do to the ovaries?
stimulate ovulation and lutenization of the follicles/ progesterone secretion
New cards
77
What does LH do to the testes?
targets leydig cells to stimulate testosterone production
New cards
78
What is the major difference between males and females when it comes to LH?
Produced progesterone in females and testosterone in males
New cards
79
What are the two subunits of FSH and LH?
alpha and beta
New cards
80
Which subunit for FSH and LH provides specificity?
beta
New cards
81
What is the 2 cell, 2 gonadotropin model?
LH binds to LH receptor on the theca cell - ATP is converted to cAMP which creates a pathway to take cholesterol through the mitochondrial membrane to produce progesterone - progesterone goes through a few synthesis steps to make testosterone
FSH binds to FSH receptor on the granulosa cell - ATP is converted to cAMP which releases protein kinase - an increase of aromatase occurs which aromatizes testosterone to estrogen
New cards
82
What are some examples of anterior pituitary hormones?
Somatotropin or Growth Hormone, prolactin, thyroid stimulating hormone, adrenocorticotrophic hormone
New cards
83
What does somatotropin or growth hormone do?
stimulates cell growth, reproduction, and regulation
New cards
84
What is the function of prolactin?
promotes lactation, nest building, and monthly instinct
New cards
85
What is the function of thyroid stimulating hormone?
stimulates T3 and T4 from thyroid
New cards
86
What is the function of adrenocorticotrophic hormone?
stimulates the release of cortisol from the adrenal gland
New cards
87
What type of hormone is testosterone?
steroid hormone
New cards
88
What is testosterone produced by in the testes?
Leydig cells
New cards
89
What is testosterone produced by in the ovary?
theca cells
New cards
90
What does testosterone respond to?
LH surges
New cards
91
Is testosterone negative or positive feedback?
negative
New cards
92
What are the actions of testosterone?
behavioral changes for sexual receptivity and stimulation of anabolic growth
New cards
93
What is the function of testosterone in males?
promotes spermatogenesis, promotes secretion of accessory sex glands
New cards
94
What is the function of testosterone in females?
substrates for estrogen production, masculization
New cards
95
What type of hormone is estrogen?
steroid hormone
New cards
96
What is estrogen secreted by?
sertoli cells in testes, granulosa cells in follicles, and placenta
New cards
97
What does estrogen respond to?
FSH
New cards
98
Does estrogen have negative or positive feedback in females?
both
New cards
99
Does estrogen have negative or positive feedback in males?
negative feedback
New cards
100
What determines positive or negative feedback with estrogen?
If estrogen binds to the tonic center, negative feedback occurs
If estrogen binds to the surge center, positive feedback occurs
Studied by 2 people
Note 
Flashcard (32)