2/12: General Endocrinology Flashcards
(79 cards)
1
Q
What are responses from the endocrine system like?
A
Slower but longer lasting responses compared to the NS
1
Q
What does the endocrine system provide a “broadcast” for?
A
Many tissues; specificity due to receptors
2
Q
What are some endocrine and metabolic disorders?
A
including diabetes
mellitus, osteopenia, dyslipidemia,
metabolic syndrome, and thyroiditis
3
Q
What three things do all hormones regulate?
A
- Maintenance of homeostasis
- Growth and differentiation
- Reproduction
4
Q
What hormones maintain homeostasis?
A
Thyroid Hormone, Insulin, PTH, Vasopressin, Aldosterone
5
Q
What hormones work with growth and differentiation?
A
Growth Hormone, Thyroid Hormone
6
Q
What hormones work with reproduction?
A
LH, FSH, Estrogen, Progesterone, Testosterone, etc.
7
Q
What are specialized endocrine glands?
A
– Pituitary Gland
– Thyroid Gland
– Parathyroid Gland
– Adrenal Gland
– Pineal Gland
8
Q
Some organs contain _______ cells that secrete _______ even though their primary function is not endocrine regulation
A
endocrine; hormones
9
Q
What does the hypothalamus secrete?
A
TRH, CRH
10
Q
What does the skin secrete?
A
Vitamin D
11
Q
What does adipose tissue secrete?
A
Leptin
12
Q
What does the thymus secrete?
A
Thymosin
13
Q
What does the heart secrete?
A
Atrial natriuretic peptide
14
Q
What does the liver secrete?
A
Insulin-like GF1
15
Q
What does the stomach secrete?
A
Gastrin
16
Q
What does the pancreas secrete?
A
Insulin, glucagon
17
Q
What does the small intestine secrete?
A
Secretin, CCK
18
Q
What does The kidney secrete?
A
Renin, EPO, vitamin D
19
Q
What do the gonads secrete?
A
Testes, ovaries
20
Q
What are the three classes of hormones?
A
- Proteins and Polypeptides
- Steroids
- Derivatives of Tyrosine
21
Q
What are protein and polypeptide hormones?
A
Hormones from the Hypothalamus, Anterior Pituitary, Posterior
Pituitary, pancreas
22
Q
How are protein and polypeptide hormones synthesized first as?
A
Preprohormone
23
Q
What is preprohormone converted to?
A
Prohormone
24
What is the prohormone cleaved into?
Active hormone and inactive fragments that are then secreted by the endocrine cell
25
Where are steroid hormones from?
Adrenal cortex, ovaries and testes
26
What are steroid hormones synthesized from?
Cholesterol
27
Steroid Hormones are synthesized upon _______ rather than being stored
Demand
28
What are amine hormones derived from?
Amino acid tyrosine
29
What are exampels of amine hormones?
Thyroid hormone and adrenal medullary neurohormones (epinephrine and norepinephrine)
30
When are amines produced and stored?
Produced and then stored until secreted
31
What do thyroid hormones bind to?
Protein thyroglobulin
32
Where are epinephrine and norepinephrine stored?
In vesicles and released by exocytosis
33
Describe how proteins are released
Into the circulation and then circulate freely or bound to carrier proteins, also known as binding proteins
34
What do binding proteins serve as?
A reservoir for the hormone and prolong the hormone's half-life
35
What is the active form of the hormone?
The free unbound hormone
36
How do a majority of amines, peptides, and protein hormones circulate?
In their free form
37
How do steroid and thyroid hormones circulate?
Bound to specific transport proteins
Some binding proteins are specific for a given hormone but some plasma
proteins, such as globulin and albumin can bind to hormones
38
How do thyroid hormones travel?
In the plasma bound to: Thyroxine-binding Globulin (TBG), Transthyretin (TTR)
and Albumin
39
Because most binding proteins are synthesized in the liver, what do changes in the liver function alter?
Binding - protein levels and could indirectly affect plasma hormone levels
40
What affects cortisol hormone levels?
Circadian rhythym
41
What affects growth hormone levels?
Pulsatile secretion
42
What does the location of the hormone receptor depend on?
Chemical properties of the hormone (lipophobic/lipophilic)
43
What do ligand/receptor binding demonstrate?
Specificity, affinity, and saturation
44
What are plasma membrane receptors?
Polypeptide, protein and amine hormones
45
What are nuclear receptors?
Thyroid and steroid hormones
46
What are plasma membrane hormone receptors?
1. G-protein coupled
2. Tyrosine kinase: insulin
3. Serine kinase
4. Cytokine: leptin
47
What are Gs coupled receptors?
Beta drenergic
Calcitonin
ACTH
glucagon
TSH
Vasopressin
48
What do Gs coupled receptors produce?
Second messenger cAMP
49
What are examples of Gq coupled receptors?
Alpha adrenergic
Angiotensin II
TRH
50
What do Gq coupled receptors activate?
Second messengers IP3
DAG
Ca2+
51
What hormones are more widely distributed?
Insulina nd thyroid hormone receptors
52
What are nuclear hormone receptors?
A large family of receptors that are located either in the cytoplasm or
nucleus
53
What do nuclear hormone receptors act to do?
Increase or decrease gene expression
54
What does the hormone receptor complex bind to?
a hormone responsive
element in the
promoter region of a
gene
55
When the hormone receptor complex binds, what does this lead to? What does this form?
activation or
repression of
transcription; Forms
new proteins
56
What are the effects of combined hormone actions?
– Antagonism
– Synergistic
– Permissiveness
57
Which hormone interaction is described?
Parathyroid increases plasma calcium levels; Calcitonin decreases plasma calcium levels
Antagonist
58
Which hormone interaction is described?
Glucagon, cortisol and epinephrine all increase blood glucose more than the sum of their individual effects
Synergistic
59
Which hormone interaction is described?
Thyroid hormone causes expression of B adrenergic
receptors in bronchiolar smooth muscle
Permissiveness
60
What are tropic hormones?
Hormones that have other endocrine glands as their targets
61
What are the steps of regulation of thyroid hormone secretion?
1. Stimulus causes the hypothalamus to secrete TRH, which acts on anterior pituitary
2. Thyrotropic cells in the anterior pituitary released TSH
3. TSH stimulates follicular cells of the thyroid gland to release thyroid hormone
4. TH stimulates target cells to increase metabolic activities, resulting in an increase in basal body temp
5. Increased body temp is detected by the hypothalamus and then inhibited
62
What detects increased body temp?
Hypothalamus
63
What does TH block?
TRH receptors on the thyrotropic cells, inhibiting synthesis and release of TSH
64
How are hormone levels kept in balance?
Negative feedback mechanisms, if this doesn't occur, endocrine disorders occur
65
What are primary disorders?
Abnormality in the last
endocrine organ secreting the hormone leading to either hypo- or hyper-secretion
66
What are causes of primary hyposecretion?
(1) Partial destruction of the gland
(2) Dietary Deficiency
(3) Enzyme deficiency required for hormone synthesis
67
What does a tumor in an endocrine gland cause?
Primary hypersecretion
68
What are secondary disorders?
Abnormality in tropic hormone leading to either hypo- or hyper-secretion
69
What does a lack of sufficient tropic hormone lead to?
Secondary hyposecretion
70
A tumor (either in an endocrine gland
that secretes tropic hormones or in
non-endocrine tissue (lung)) can secrete hormones and cause
Secondary hypersecretion (paraneoplastic endocrine syndrome)
71
What is a PRIMARY endocrine pathology?
Where the abnormality is in the endocrine organ secreting hormone (ex. thyroid gland is either secreting too much or insufficient amount of TH)
72
What is a SECONDARY endocrine pathology?
where the abnormality is in one of the endocrine glands that secrete trophic hormones (Hypothalamus or Anterior Pituitary)
73
The graph below shows plasma TSH levels
in normal people (euthyroid) and in several pathologies. Which TSH data would be
found in the following situations?
Primary Hyperthyroidism? _________
Secondary Hyperthyroidism? _________
Primary Hypothyroidism? _________
Secondary Hypothyroidism? _________
1. B
2. A
3. A
4. B
74
What are diagnostic tests of endocrine function?
1. Plasma hormone levels
2. Autoantibodies
3. Urine hormone or hormone metabolite levels
4. Stimulation tests by administration of a tropic or stimulating hormone
5. Suppression tests when hyperfunction of an endocrine organ is suspected
6. Measurement of hormone receptor presence, number and affinity
7. Imaging: Radioactive scanning of the thyroid and
parathyroids; MRI of pituitary and hypothalamic imagine, CT scanning of adrenal and abdominal endocrine lesions
75
Hormones using negative feedback traveling to the anterior pituitary and hypothalamus use what kind of loop?
Long loops
76
Hormones using negative feedback traveling from the anterior pituitary to the hypothalamus use what kind of loop?
Short loop
77
What is a long loop?
End hormone goes back and inhibits secretion of a previous hormone
78
What is a short loop?
Tropic hormone goes back up and inhibits at the level of the beginning organ
