Chapter 9: Endocrine Physiology Flashcards
1
Q
classes of hormones
A
amine, peptide, steroid
2
Q
amine hormones
A
- catecholamines (epinephrine, norepinephrine, dopamine)
- thyroid hormones (thyroxine, T4)
- melatonin
3
Q
amine hormones are amino acid (2) derivatives
A
- tyrosine (catecholamines, thyroid)
- tryptophan (melatonin)
4
Q
steroid hormones are () derivatives
A
lipid
5
Q
2 main classes of steroid hormones
A
- eicosanoids
- steroid hormones
6
Q
eicosanoids are lipid derivatives of ()
A
arachidonic acid
7
Q
steroid hormones are structurally similar to ()
A
cholesterol
8
Q
anterior and posterior pituitary glands are separated by ()
A
pars intermedia
9
Q
the hypothalamic-hypophyseal portal system has capillary networks in the ()
A
median eminence
10
Q
summary of hypothalamic-hypophyseal portal system
A
hypophyseal artery -> capillary networks (median eminence) -> hypophyseal portal vein -> capillary networks (aka sinuses; anterior pituitary endocrine cells) -> hypophyseal vein
11
Q
pair releasing hormones with secreting hormones:
- thyrotropin-releasing hormone (TRH): (1)
- corticotropin-releasing hormone (CRH): (2)
- gonadotropin-releasing hormone (GnRH): (3)
A
- thyroid-stimulating hormone (TSH)
- adrenocorticotropic hormone (ACTH)
- luteinizing hormone (LH), follicle-stimulating hormone (FSH)
12
Q
growth hormone secretion from anterior pituitary is bidirectionally regulated by (1) and (2); both go to the liver and work by the action of (3)
A
- growth hormone-releasing hormone (GHRH) ++
- somatostatin (SRIF) –
- somatomedins (insulin-like growth factors, IGFs)
13
Q
actions of growth hormone
A
- diabetogenic or anti-insuling effects
- increased protein synthesis/organ growth
- increased linear growth
14
Q
2 outcomes of too much growth hormone secretion
A
- gigantism (tall stature)
- acromegaly (normal stature, enlarged extremities and facial features)
15
Q
hormones mediating prolactin secretion from anterior pituitary
A
- dopamine (–)
- thyrotropin-releasing hormone (TRH) (++)
16
Q
actions of prolactin
A
- breast development
- milk prduction
- inhibition of ovulation
17
Q
(1) is the muscular part of the uterus, which is lined with (2)
A
- myometrium
- endometrium
18
Q
size of endometrium increases and decreases depending on ()
A
menstrual cycle
19
Q
ovarian follicle maturation requires (1) -> follicle becomes (2)
A
- FSH and LH
- corpus luteum
20
Q
FSH and LH rapidly increase when?
A
just before ovulation
21
Q
through the action of FSH, ovarian follicle produces ()
A
estradiol
22
Q
once a follicle becomes the corpus luteum, it then produces ()
A
progesterone
23
Q
(1) from anterior pituitary stimulates (2) cells to release testosterone
A
- LH
- Leydig
24
Q
(1) from anterior pituitary stimulates (2) cells to perform spermatogenesis
A
- FSH
- Sertoli
24
major functions of testosterone
1. expression of male secondary sex characteristics
2. stimulates Sertoli cells
25
Sertoli cells also produce () that serves as negative feedback towards anterior pituitary
inhibin
26
zones of the adrenal gland and their secretions
1. zona glomerulosa: mineralocorticoids
2. zona fasciculata: glucocorticoids
3. zona reticularis: androgens
4. medulla: catecholamines
27
actions of glucocorticoids may result in (disease)-like state
diabetes (increase blood glucose and keep it that way, metabolize proteins and lipids); also decrease insulin sensitivity
28
effect of glucocorticoids on immune response
suppress immune response and inhibit inflammatory response
29
how do glucocorticoids inhibit inflammation
stabilizing lysosomes
30
most potent anti-inflammatory agents available in clinic
glucocorticoids
31
examples of non-steroidal anti-inflammatory drugs
aspirin, tylenol
32
drawback in using corticosteroids as anti-inflammatory agents
enhance vascular responsiveness to catecholamines -> likely to cause hypertension
33
other actions of glucocorticoids
increase GFR, decrease REM sleep
34
action of mineralocorticoids
increase Na+ reabsorption
increase K+ and H+ secretion
35
actions of adrenal androgens in females
stimulate pubic and axillary hair growth, as well as libido
36
actions of adrenal androgens in males
same as testosterone
37
Cushing's syndrome can occur from multiple causes
1. adenomas of anterior pituitary
2. abnormal function of the hypothalamus -> high levels of CRH
3. ectopic secretion by a tumor somewhere else in the body
4. adenomas of the adrenal cortex
38
differentiate Cushing's syndrome vs Cushing's disease
Cushing's disease is a specific type of Cushing's syndrome
39
Cushing's disease is mainly caused by ()
too much cortisol secretion
40
common factor of all possible Cushing's syndrome causes
excessive ACTH secretion
41
nowadays most common cause of Cushing's syndrome is ()
iatrogenic (caused by medicine/doctors)
42
disease caused by primary adrenocortical insufficiency
Addison Disease
43
main divisions of the thyroid gland
left and right lobe; isthmus
44
specific place of thyroid hormone production
thyroid follicle
45
C cells in the thyroid produce ()
calcitonin
46
most important building blocks of thyroid hormones
tyrosine and iodide (I-)
47
glycoprotein produced in rough ER and Golgi of thyroid follicle cells -> needed to produce thyroid hormone
thyroglobulin
48
monoiodotyrosine (MIT) + diiodotyrosine (DIT) = ()
T3
49
diiodotyrosine (DIT) + diiodotyrosine (DIT) = ()
T4
50
(T3/T4) is produced much faster than the other -> has higher concentrations
T4
51
main inhibitor of thyroid hormone secretion
propylthiouracil (PTU)
52
(1) is the major secretory product of the thyroid gland, but (2) is the more active form
1. thyroxine (T4)
2. triiodothyronine (T3)
53
in target tissues, () converts T4 to T3
5' iodinase
54
Grave's disease is a form of ()
hyperthyroidism
55
other terms for anti-diuretic hormone
vasopressin, arginine vasopresssin
56
ADH is synthesized in () of hypothalamus
supraoptic nucleus (SON)
57
oxytocin is synthesized in () of hypothalamus
paraventricular nucleus (PVN)
58
ADH and oxytocin are examples of () hormones
peptide
59
SON and PVN have axon projections towards (), which is where ADH and oxytocin are released
posterior pituitary
60
ADH function in kidney is to stimulate (1) in the collecting duct -> control (2)
1. water reabsorption
2. plasma osmolarity
61
() is sensed by osmoreceptors in hypothalamus; most important physiologic stimulus for ADH secretion
increased plasma osmolarity
62
() is sensed by baroreceptors in left atrium, aortic arch, and carotid sinus -> stimulates ADH release in response to decreased blood pressure in blood vessels
hypovolemia
63
actions of ADH
1. increase in water permeability (major action)
2. contraction of vascular smooth muscle
64
increase in water permeability by ADH is mediated by (1) receptors -> mainly due to insertion of (2) in luminal membranes
1. V2
2. aquaporin 2 (AQP)
65
major stimulus for oxytocin secretion is ()
suckling of the breast
66
(1) pancreas: 99% of pancreatic volume, secrets digestive enzymes
(2) pancreas: pancreatic islet
1. Exocrine
2. Endocrine
67
hormones in the endocrine pancreas:
- alpha cells produce (1)
- beta cells produce (2)
- delta cells produce (3)
1. glucagon
2. insulin
3. somatostatin
68
in the synthesis of insulin, (1) is cleaved in the Golgi apparatus of pancreatic beta cells to form (2)
1. proinsulin
2. C peptide (connecting peptide) and insulin (A and B chains)
69
A and B chains in insulin are connected by ()
disulfide bonds
70
why is measuring C peptide levels more accurate and preferred when measuring the level of naturally-produced insulin production in type 1 diabetic patients?
treatment for diabetes includes injection of insulin into bloodstream -> insulin levels include exogenous insulin while C peptide is endogenous
71
actions of () drugs work to increase insulin secretion by blocking ATP-gated K+ channels
sulfonylurea (e.g. glyburide, tolbutamide)
72
major effect of insulin is to ()
increase glucose uptake into cells (specifically skeletal muscle, brain, liver)
73
the () is the major site of ketone body production
liver
74
ketone body production is especially important during (1), when ketone bodies are the (2)
1. starvation
2. predominant fuel
75
ketone bodies are transported from liver () into blood by transport proteins and are delivered to other tissues (e.g. heart, kidney, brain)
mitochondria
76
in the absence of insulin, excess ketone bodies are formed and released into the blood
diabetic ketoacidosis
77
glucose appears in urine and blood glucose levels is increased
diabetes mellitus
78
type 1 diabetes mellitus is caused by ()
insufficient insulin secretion (insulin-dependent DM)
79
type 2 diabetes mellitus is caused by ()
insulin resistance (non-insulin-dependent DM)
80
examples of life-threatening complications due to diabetes
diabetic retinopathy, nephropathy, neuropathy
81
complications due to diabetes are mostly caused by ()
blood clots in small vessels because blood is too viscous
82
actions of glucagon
increases glycogenolysis, gluconeogenesis, lipolysis, ketoacid formation
83
glucagon is released in responseto (increased/decreased) blood glucose
decreased
84
() is the only form of biologically active Ca2+
free, ionized Ca2+
85
hormone synthesized in the kidney in response to PTH; promotes Ca2+ and phosphate absorption from Gut
calcitriol (1,25-dihydroxycholecalciferol)
86
2 hormones that work antagonistically for the reabsorption of Ca2+ from kidney filtrate, as well as bone resorption
PTH (+reabsorp), calcitonin (-reabsorp)
87
major effect of calcitonin is to ()
reduce bone resorption by inhibiting osteoclasts
88
() is converted via an intermediate form to calcitriol, which is the active form
cholecalciferol (vit. D3)
89
() is a hormone secreted by the kidney that stimulates the production of red blood cells by the bone marrow -> treatment for patients with chronic kidney failure need this in supplements
erythropoietin (EPO)
90
() is a hormone released by the kidney that starts an enzymatic cascade that contributes to elevating blood pressure
renin
91
renin starts an enzymatic cascade known as ()
renin-angiotensin system (RAS)
92
angiotensin I is converted to angiotensin II by
angiotensin-converting enzyme (ACE)
93
() is a hormone synthesized and released from adipose tissue; binds to () receptors expressed by hypothalamic (and many other) neurons and works to decrease appetite and increase energy expenditure
leptin
94
in the hypothalamus, leptin stimulates () neurons -> feel satiated and appetite is suppressed
POMC (pro-opiomelanocortin) neuron
95
in the hypothalamus, leptin inhibits () neurons, which increase hunger and appetite
Agouti-related peptide (AgRP) neuron
96
major downstream targets of POMC and AgRP neuron are () -> mediate appetite suppressing/increasing effect of these peptides
melanocortin 4 receptors (MC4R)
97
all ACTH, MSHs and beta-lipoprotein are from the pre-protein called (1), which is cleaved by (1)
1. pro-opiomelanocortin (POMC)
2. prohormone covertases 1 and 2 (PC1/2)
98
AgRP and () neurons are identical in the arcuate nucleus of the hypothalamus
neuropeptide Y (NPY)
99
the () consists of the POMC, alpha-MSH and MC4Rs
central melanocortin pathway/satiety circuit
100
satiety circuit starts with POMC releasing () for MC4Rs
alpha-melanocyte stimulating hormone (alpha-MSH)
101
activation of satiety circuit suppresses insulin secretion by () in parasympathetic NS
opening K-ATP channels
101
() channels work to burn fat by the stimulation of MC4Rs
TRPV1
