Exam3Lec1Hormones Flashcards
1
Q
What is a hormone?
A
a substance in the body that transmits a signal to produce an effect or alteration at the cellular level
2
Q
What are the major glands of the endocrine system?
A
hypothalamus, pituitary, thyroid, parathyroid, adrenals, pineal body
3
Q
What are the major organs of the endocrine system?
A
reproductive organs (ovaries, testes), pancreas, kidneys
4
Q
_____ and____ produce hormones
A
glands, organs
5
Q
What is the “endocrine” affect?
A
1 cell releases their hormones, goes to blood, and go the target cell where it releases its effect
6
Q
What is the “paracrine” effect?
A
Cell that releases their hormone and the target cell is in close vicinity so it does not have to go through the blood
7
Q
What is the “autocrine” effect?
A
Cell effects itself (hormone released onto itself)
8
Q
Hormones are working in a cascade and with every release the magnification is _______ fold.
A
1,000
9
Q
Explain the hormonal cascade
A
- We get a clue from the environment or an internal signal
- Signal goes into CNS, limbic system, and is sent to the hypothalamus. Hypo gets signals and secretes hormones called releasing hormones (ng)
- This affects anterior pitiutary and it secretes tropic hormones. (micrograms)
- This reaches the target cell and then is releases the ultimate hormone (mg). The release of this causes systemic effect.
10
Q
Which two hormones are released by the posterior pituitary?
A
oxytocin and vasopressin
11
Q
There are two negative feedback loops in the hormonal cascade. What inhibits what?
A
Too much of ultimate hormone inhibits the release of hormones from the hypo or ant. pit.
12
Q
Which hormones are produced in the hypothalamus?
A
CRH, GHRH, GnRH, TRH, Dopamine
13
Q
Which hormones are produced in the ant. pit?
A
ACTH, FSH, LH, GH, Prolactin, TSH
14
Q
Which hormones are produced in the post pit?
A
ADH(vasopressin), Oxytocin
15
Q
Which hormones are produced in the thyroid gland?
A
Calcitonin, Thyroid hormones
16
Q
Which hormones are produced in the parathyroid gland?
A
PTH
17
Q
Which hormones are produced in the endocrine pancreas?
A
glucagon, insulin
18
Q
Which hormones are produced in the adrenal medulla?
A
circulating catecholamines (epi and norepi)
19
Q
Which hormones are produced in the kidney?
A
Vitamin D, Renin
20
Q
Which hormones are produced in the renal cortex?
A
aldosterone, adrenal androgens, cortisol
21
Q
Which hormones are produced in the testes?
A
Testosterone
22
Q
Which hormones are produced in the ovaries?
A
Estrogen, progesterone
23
Q
Which hormones are produced in the corpus luteum?
A
estrogen, progesterone
24
Q
Which hormones are produced in the placenta?
A
HCG, estrogen, progesterone
25
What are the three types of hormones?
Polypeptide and protein hormones, amino acid derived hormones, steroid hormones
26
Peptide and protein hormones are products of
translation
27
Peptide hormones are relatively smaller or bigger than protein hormones?
smaller
28
What are two ways that peptide and protein hormones can be released?
The cell stores peptide or protein hormones in secretory granules and releases them in "bursts" when stimulated This allows cells to secrete a large amount of hormone over a short period of time (stored for later release)
Cell synthesizes the hormone and releases it immediately in secretory vesicles (synthesized and secreted immediately)
29
POMC gene can encode for several hormones? How?
POMC gene can produce many hormones from the same gene and it gets translated into huge proteins and gets cleaves and released to small peptides and different hormones and gets released. (1 protein sequence can give you multiple hormones)
30
What is neurophysin I and II?
It is a carrier protein for vasopressin (II) and oxytocin (I)
31
Why do we need a carrier protein for vaso and oxy?
The hormone is so small and is vulnerable to getting cleaved w/ proteases.
32
How is vasopressin and oxytocin cleaved for release?
prepro-oxytocin/vasopressin, cleaved to pro-oxytocin/vasopressin, cleaved to oxytocin/vasopressin to be released
33
What is the function of insulin?
Facilitates uptake of glucose by cells, stimulates lipids and glycogen formation to decrease blood glucose levels
34
How is insulin cleaved to get released?
1. The 1st cleavage is the signal sequence in ER, then we get disulfide binds bridge between A and B.
2. In golgi the cleavage of C peptide and mature insulin is formed.
3. C peptide is connecting A and B chain and it gets released
35
What is an example of a disease associated with peptide hormones?
Diabetes (type 1 and 2)
36
What is diabetes mellitus?
No glucose uptake, patient manifests high circulating glucose levels (hyperglycemic)
37
What are type 1 diabetes?
Juvenile onset: pancreatic cells destroyed production of insulin (no insulin production)
38
What are type 2 diabetes?
adult onset: body does not produce enough insulin and/or does not utilize insulin efficiently; insulin resitance
39
Generally, what is the treatment for type 1 and type 2 diabetes?
Type 1: insulin injections
Type 2: diet and exercise, drugs targeting organs involved in glucose metabolism, chronic cases-insulin injections
40
What are 4 ways that these diabetes drugs work (Niketa said we don't need to know names, just how they work)
Drugs that incr insulin
1. Drugs that enhance insulin action in peripheral tissues
2. Drugs that enhance endogenous insulin secretion
3. Drugs that suppress endogenous glucose production
4. Drugs that delay the absorption of carbohydrate from the GI tract
41
What are amino acid derived hormones? It is hydrophobic or hydrophilic, what is its release method, and does it require a carrier?
hormones derived from amino acids
they are both hydrophobic and hydrophilic
the release method is dependent on the hormone
it does require a carrier
42
Catecholmaines are what type of hormone?
amino acid derived hormone
it is hydrophilic hormones/neurotransmitters that responds to stress
ex: norepi and epi
43
Norepi and epi are synthesized from what amino acid in what organ? Why is it released?
They are synthesized from phenylalanine and tyrosine in the adrenal medualla. It is released in response to stress.
44
What physiological effects do we see with the release of nep and ep?
accelerates heartbeat, increase blood pressure and bloodflow to heart and lungs
45
What is the ultimate hormone after the hypo receives the signal and goes though the cascade for catecholamines?
cortisol
46
What does cortisol initiate?
The synthesis of PNMT (phenylethanolamine N-methyltransferase). PNMT then catalyzes nep to ep.
47
What is the ep mode of action? slide 17 of lecture
1. Epi comes in
2. GPCR
3. Second messengers (ex like cAMP)
4. Transcription
5. Biological action
48
What is the thyroid hormone?
Amino acid derived hormone
hydrophobic hormone released by thyroid to utilize energy and regulate growth and development
49
Where does the thyroid hormone synthesis occur?
follicular space of thyroid gland
50
What are the steps of thyroid hormone synthesis and secretion into the bloodstream? (slide 18-21)
1. Uptake of Iodide (I-)
2. Iodide turns into iodine (I) and thyroglobulin by the peroxidase enzyme
3. Iodine and thyroglobulin turns into T1 and T2 by peroxidase enzyme
5. T1 and T2 turns into T4 and small amounts of T3 by peroxidase
6. Hypothalamus secretes TRH to stimulate ant pit. Pit releases TSH and stimulates thyroid to secrete T4 + small amount of T3 into the blood
7. T4 is converted to T3 in peripheral tissues and causes systemic effect
51
Thyroid hormone synthesis is responsible for the rate of what?
metabolism
52
T3 is the _____ hormone
active
53
What is rT3?
reverse T3, this inhibits T3
54
T4 is the _____ form
storage
55
T4 is converted to
T3
56
What is rT3 and what does it do?
reverse T3 and it inhibits T3, it can dock with thyroid receptor and compete with T3.
57
What is the fxn of Thyroid hormone
Increases energy utilization, oxygen consumption, growth and development
58
What are the examples of thyroid hormone disorders?
1. Graves disease: Hyperthyroidism (autoimmune disease)
2. Hashimoto's Disease: chronic lymphocytic thyroiditis. HYPOthyroidism (autoimmune disease)
59
What is graves disease?
autoantibody (immunoglobulin) stimulates TSH receptor--> stimulates thyroid--> incr T3--> negative feedback to TSH
metabolic characteristics: Low TSH, High T3 and T4
60
What is a key indicator of grave's disease?
Increased production of T3
61
What are the sx and tx of graves disease?
SX: nodules on thyroid-goiter, restlessness, anxiety, sweating, bulging eyes
TX: anti thyroid drug Tapazole, surgical removal of thyroids
62
What is Hashimotos's disease? slide 25
autoantibody binds to thyroglobulin or peroxidase--> inhibited thyroid hormone synthesis
63
What is the diagnosis, sx, and tx of Hashimotos's disease?
diagnosis: high liters of antibodies to thyroglobulin, thyroid peroxidase and TSH receptor
sx: weight gain, dry skin, low heart rate, depression, most cases are women between age 30-50
tx: thyroid hormone pills
64
What are the 5 classes of steroid hormones?
mineralcorticoids, glucocorticoids, androgens, estrogens, progestogens
65
What is the definition of steroid hormone, is it hydrophobic or hydrophilic, what is its release method, does it require carrier proteins?
Def: cholesterol-derived hormones with many functions dependent upon the derivation
hydrophobic
release method is immediately secreted NOT STORED
It does require a carrier protein
66
True or False, for steroid hormones, structure defines receptor specificity
True
67
All steroid hormones are formed from what?
cholesterol
68
What are examples of each class of steroid hormones?
-mineralocorticoids: aldosterone is the most prominent
-glucocorticoids: cortisol is the major representative in most mammals
-androgens: testosterone
-estrogens: estrodiol and estrone
-progestogens: (also known as progestins) progesterone
69
What is the function of aldosterone(mineralocorticoids)?
Acts mainly in the functional unit of the kidneys to aid in the conservation of sodium, secretion of potassium, water retention and to stabilize blood pressure
70
What is the function of cortisol (glucocorticoids)?
-Metabolic:increases insulin resistance, increases gluconeogenesis, lipolysis
-Immunosuppresive: inhibits leukotrienes and prostaglandins, blocks histamine release from mast cells, blocks IL-2 production
-Maintains blood pressure
71
What does mineralcorticoids and glucocorticoids have in common?
they are both cholesterol precursor and they both affect blood pressure
72
Glucocorticoids suppress immune and inflammatory responses mediated by cytokines. How? slide 29,30
1. Glutocorticoid attaches to the receptor in the cytoplasm and enters the nucleus
2. Gene transcription of IKBA occurs and stays bound to NF-KB.
3. NF-KB attached to IKBA means that its inactive so NF-KB CANNOT do its job, and ultimately cytokines cannot be released to mediate immune response
73
Glucocorticoids suppress immune and inflammatory responses mediated by cytokines. What are some examples of diseases that can occur?
allergic rhinitis, rheumatoid arthritis, asthma, multiple sclerosis, carpal tunnel, dermatitis, copd, osteoarthritis, gout, psoriasis, inflammatory bowel disease, sinusitis, lupus
74
What is the core of androgen, estrogen, and progesterone (sex hormones)?
cholesterol ring
75
Why are steroid hormones hydrophobic?
because of the bulky cholesterol ring
76
How are steroid hormones typically eliminated?
by inactivating metabolic transformation and excretion in urine or bile
77
Biologically, how are active steroids transported in the blood?
By albumin, sex hormone-binding globulin (SHBG), and corticosteroid-binding globulin (CBG)
78
What are the diseases associated with steroid hormones?
Congenital Adrenal Hyperplasia (CAH) and Cushing's disease
79
What is CAH? What are the sx?
group of autosomal recessive diseases resulting from mutations of genes for enzymes in synthesis of steroid hormones in adrenal glands. Adrenal hyperplasia as ACTH continues to stimulate steroid production due to lack of feedback inhibition from cortisol
SX: excessive loss of salt, ambiguous genitalia in infants
80
What is cushing's disease? what are the sx and fxn of medications?
High cortisol levels
-SX: growth in retardation, hump in shoulder and weight gain
-Medications: to control excessive production of cortisol at the adrenal gland:
81
Explain cyclic hormonal signaling with serotonin and melatonin?
Your cyclic hormonal signaling is constantly being modulated day and night, the levels are constantly going up and down
82
Is serotonin or melatonin high during the day?
serotonin (tryptophan releases this)
83
Is serotonin or melatonin high during the night?
melatonin (serotonin is converted to melatonin at night bc n-acetyl transferase binds to serotonin)
84
Explain cyclic hormonal signaling with the ovarian cycle
LH FSH levels are controlling levels of estrogen and progesterone and vice versa
85
Once a hormone is secreted by an endocrine tissue, what generally occurs?
It generally binds to a specific plasma protein carrier, with the complex being disseminated to distant tissues
86
What do carriers for steroid and thyroid hormones allow for?
Allows for these very hydrophobic substances to be present in the plasma at concentrations several hundered-fold greater than their solubility in water would permit
87
Carriers for small, hydrophilic amino-acid derived hormones prevent their filtration through the _______, greatly prolonging their circulating half-life.
renal glomerulus
88
Do most peptide hormones circulate freely without carrier proteins or does it need carrier proteins?
Most peptide hormones circulate freely without carrier proteins. Carrier proteins for peptide hormones such as IGF prevent hormone destruction by plasma proteases
89
True or false Plasma carrier hormones exist for all classes of endocrine hormones?
True
90
Hormones can be ______ in the liver through hydroxylation or oxidation and/or glucouronidation, sulfation, or reduction with glutathione reactions and excreted via kidney
inactivated
91
Hormones can be ______ at their target cell through internalization of the hormone-receptor complex followed by lysosomal degradation of the hormone
degraded
92
A small fraction of total hormone production is _____ intact in the urine and feces
excreted
93
The _______ of hormone is measured as the volume of plasma cleared of the hormone per unit of time
metabolic rate of clearance
94
What do hormones regulate?
cellular function, gene expression, growth, development, reproduction, senescence, maintain homeostasis
95
Hormones can be classified into what classes of hormones?
peptide/protein hormones, amino-acids derived hormones, steroid hormones
96
The _________ amplifies the signal (1000+ fold) to produce the biological effect in the target organ
hormonal cascade system
97
The _________ are synthesized as preprohormones and proteolytically cleaved. They act by binding to its cell surface receptor and activating a cascade of intracellular events
peptide and protein hormones
98
The ________ T4( thyroxine-the storage form) is converted to T3 which binds to its nuclear receptor to activate transcription of genes
amino-acid derived thyroid hormone
99
_______ hormones are produced from cholesterol. These include_____,_____, and______
steroid, mineralocorticoids, glucocorticoids, sex hormones
100
Peptide hormones ____, ____, as well as____, ____are regulated in a cyclic manner.
melatonin, serotonin, estrogen, progesterone
