Endocrine Flashcards
1
Q
Hypothalamus coordinates component of ________ and _________
A
endocrine and behavior
2
Q
3 things the hypothalamus is critical for
A
- metabolism
- reproduction
- growth
3
Q
Endocrine (3)
A
- secreting internally (most commonly into systemic circulation)
- internal or hormonal secretion of a ductless gland
- denoting a gland
4
Q
What is a hormone?
A
chemical substance produced by specialized glands or tissue
5
Q
What is the root of hormone?
A
- Greek
- to excite/ arouse
- to set in motion
6
Q
How is a hormone transported?
A
by the blood
7
Q
T/F: Hormones bathe all cells
A
true
8
Q
What “acts on distant target organs at low concentrations”?
A
hormone
9
Q
How do targets receive the hormone?
A
targets have receptors that mediate the response
10
Q
Intracrine hormone
A
WITHIN one cell
11
Q
Autocrine hormone
A
released by cell and used on receptor of that cel
12
Q
Paracrine hormone
A
local hormone
13
Q
Endocrine hormone
A
genuine hormone
14
Q
Neuroendocrine hormone
A
neurohormone
15
Q
4 broad groupings of hormones
A
- repro/sexual differentiation
- development and growth
- homeostasis
- regulations of metabolism and nutrient supply
16
Q
T/F: A single hormone may have one or more functions
A
True
17
Q
T/F: A single function may be controlled by more than one hormone
A
True
18
Q
The autonomic reflex loops intergrate what 2 things?
A
ANS and endocrine system
19
Q
Examples of stress-related regulatory behaviors
A
- pacing
- licking
- excess groomin
- masturbation in primates
20
Q
4 Major Types of Hormones
A
- proteins
- peptides
- amines
- steroids
21
Q
_________ are synthesized as preprohormones and modified to prohormones
A
Protein hormones
22
Q
Approx. _____ % of the hormones are protein.
A
85%
23
Q
Are the actions of protein hormones fast or slow?
A
relatively fast
24
Q
Why can proteins NOT be administered orally?
A
easily digested and inactivated by GI enzymes
25
What portion of the cell cytoplasm does protein synthesis?
ribosome
26
Approx. ____% of the hormones are steroids
15%
27
What are steroid hormones derived from? Where are they made?
cholesterol; liver
28
Steroid hormones can alter _________ synthesis
protein
29
Steroids have relatively ________ actions than peptides, but are __________ acting
slower; longer
30
What type of hormones are hydrophilic and dissolve in plasma?
proteins/peptides
31
These types of hormones are lipophilic and thus need carrier proteins to be transported in the blood.
steroid and thyroid hormones
32
Can more of the steroid and thyroid hormones be found free or bound to protein in the blood?
bound to protein
33
Secondary messenger systems are related to what kind of hormones?
protein
34
What type of hormone can affect mRNA synthesis?
steroid
35
What is the purpose of the steroid hormone conjugation with sulfates and glucoronoids?
increases water solubility
36
Exogenous hormones may be influenced by... (6)
- tissue type
- time of observation
- species, sex, age
- type of hormone, formulation how and where delivered
- pattern of release or time of day (circadian rhythm)
- dose-effect relationship/ limit of endocrine regulation
37
Why are disturbances in feedback loops clinically important?
Significance in diagnosis is pivotal
38
Factors for hormone release
- sleep
- circadian rhythms (24 hr cycles)
- Diurnal rhythms (during day vs night)
- Daylength = esp. for seasonal breeders
- nutritional state
- ultradian rhytms (cycles more freq. than 24 hrs)
- exercise = strenous exercise can stimulate GH
39
Where is the timing mechanism?
in the superchasmatic nucleus
40
What does it mean if a disorder is iatrogenic?
brought on by physician's treatment
41
How is the hypothalamus KEY for regulating homeostasis?
coordination of behavior (Somatic Nervous System), ANS, and endocrine system
42
This system's response is quicker and in a more localized fashion.
What is the nervous system?
43
This system's response bathes all cells w/ hormone and may take minutes, days, or months to see actions of hormones.
What is the endocrine system?
44
These two neurohormones are produced in the posterior pituitary
oxytocin and vasopressin
45
Another name for the post. pit.?
neurohypophysis
46
6 hormones produced by the hypothalamus that control the ant. pit.
- corticotropin releasing hormone
- GHRH
- TRH
- GHIH
- PRL releasing factor
- prolactin inhibiting factor
47
3 major parts of the pituitary gland
- ant. pit.
- post. pit.
- pars intermediate
48
Other names for the ant. pit.? (3)
- pars distalis
- anterior lobe
- adenohypophysis
49
Other names for the post. pit.? (3)
- pars nervosa
- posterior lobe
- neurohypophysis
50
Other name for the pars intermediate? (1)
intermediate lobe
51
______ can damage/stretch the pit. stalk
head trauma
52
What is Rathke's pouch? What does it form?
oral ectoderm that forms pars distalis and part of pars intermediate
53
What forms the infundibulum and pars nervosa?
neuroectoderm at the base of the brain
54
Terminals of neurons in the neurohypophysis
pituicytes (glial cells)
55
Where do the axon terminals secrete in the neurohypophysis?
into the blood
56
what role do the paraventricular nuclei and the supraoptic nuclei play?
synthesize sites for vasopressin and oxytocin
57
What happens when vasopressin acts on arginine vasopressin receptor 2?
enhances water retention of kidney (antidiuretic effect)
58
What happens when vasopressin acts on AVR1?
direct pressor effect via contraction of smooth muscle of the vascular system
59
Where is vasopressin made? Stored?
Made: hypothalamus
| Stored; post. pit.
60
How is vasopressin released?
stimuli acting on hypothalamus
61
What are the two aa differences between vasopressin and oxytocin?
aa 3 and 8
62
What causes an increase in vasopressin release? (3)
- incr. plasma osmolality
- decr. blood vol
- decr. blood pressure
63
What has a permissive action and is require for max. antidiuresis?
aldosterone
64
______ stimulates contraction of myoepithelial cells surrounding the alveoli of mammary gland
oxytocin
65
T/F: Oxytocin follows a negative feedback loop
FALSE!!!!!!!!
66
How does the hypophyseal portal system work? (3)
1. stimulated hypothalamic neurons secrete releasing/ inhibiting hormones into primary capillary plexus and the median eminence
2. hypothalamic hormones travel through portal veins to ant. pit.- stimulate/inhibit release of ant. pit. hormones
3. Ant. pit. hormones are secreted into secondary capillary plexus
67
Adenohypophysis Cells (5)
- thyrotrope
- coritcotrope
- gonadotrope
- mammotrope
- somatotrope
68
Hormone produced by thyrotrope?
TSH
69
Hormone produced by corticotrope?
ACTH and beta-LPH
70
Hormone produced by gonadotrope?
FSH and LH
71
Hormone produced by mammotrope?
prolactin
72
Hormone produced by somatotrope?
GH
73
What hypothalamic hormone controls FSH and LH? Positive or Negative?
GnRH; (+)
74
What hypothalamic hormone controls GH? P or N?
GHRH; (+)
75
What hypothalamic hormone controls GH and TSH? P or N?
SS;(-)
76
What does SS stand for?
somatotropin
77
What else is somatotropin called?
GHIH
78
What hypothalamic hormone controls TSH and Prolactin? P or N?
TRH; (+)
79
What hypothalamic hormone controls prolactin by inhibiting it?
DA (dopamine)
80
What hypothalamic hormone controls ACTH? P or N?
CRH; (+)
81
Growth Hormone (GH) (4)
- polypeptide
- made in somatotropes
- synergizes w/ insulin-like growth factors (IGFs) or acts alone
- release is stimulated by GHRH, inhibited by SS
82
Corticotropin/ Adrenocorticotropic hormone (ACTH) (3)
- released by CRH
- made in corticotropes
- classic negative feedback control
83
Thyroid-stimulating hormone (TSH) (5)
- glycoprotein
- made in thyrotropes
- released by TRH
- classic negative feedback control
- has effects on cortisol release too
84
Adrenals
- next to kidney
- left is larger than the right
- buried in peritoneal fat
- crossed by Phrenicoabdominal trunk
- color coded
85
T/F: the right adrenal may appose the vena cava
True
86
What does it mean that the adrenals are color coded?
Cortex - pale to yellowish
medulla - dark red to brown
87
Can the adrenal medulla regenerate after injury?
No; has a neural origin
88
Can the adrenal cortex regenerate after injury?
Yes
89
Is the zona arcuata (AKA glomerulosa) superficial or deep in the adrenal cortex?
superficial
90
What is synthesized in the zona arcuata?
mineralocorticoids
| "salt"
91
Is the glomerulosa responsive to ACTH?
NO!
92
The _______ and ___________ make up the deeper portion of the adrenal cortex
zona fasciculata and reticularis
93
What is synthesized in the zona fasciculata and reticularis?
- glucocoricoids
- (some sex hormone synthesis)
("sugar")
94
Is the deeper portion of the adrenal cortex responsive to ACTH?
Yes
95
Site of sex hormone production in puberty?
Zona reticularis
96
Mineralocorticoids and glucocorticoids are structurally similar, except for one more hydroxyl group located here on the glucocorticoids
Carbon 17
97
where are binding proteins synthesized?
in the liver
98
how are coritsol and aldosterone metabolisized?
- hormones rendered water soluble
| - excreted in urine
99
T/F: Mineralocorticoids are critical for life
True
Removal of adrenals without hormone replacement leads to death in a few days
100
Most important mineralocorticoid?
aldosterone
101
How is overstiumulation of aldosterone receptors prevented?
11-beta hydroxysteroid dehydrogenase converts coritsol to inactive cortisone
102
Which one, cortisol or cortisone, CANNOT bind to mineralocorticoid receptors?
cortisone
103
Physiological actions of aldosterone (4)
- increases Na+ reasbsorption from urine, saliva, and gastric juices
- increases Angiotensin II production
- decreases K+ by increasing renal secretion
- conservation of water follows conservation of sodium
104
How does aldosterone decrease K+ by increasing renal secretion?
- stimulates expression of sodium/potassium ATPase
| - increases the number of these pumps
105
Aldosterone and Angiotensin II together do what?
drive salt seeking behavior
106
Aldosterone and Angiotensin II act upon the distal tubule and collecting duct for what purpose?
- resorption of renal sodium and water
| - excretion of potassium
107
Water movement is _________
passive
108
Main function of cortisol?
stimulate gluconeogenesis
109
Other than stimulating gluconeogenesis, name 4 other actions of cortisol?
- production of blood glucose via action on liver gluconeogenic enzymes
- release of stores from liver and muscle
- insulin antagonism in the periphery (anti-insulin effect)
- similar effect to insulin on liver
110
How does cortisol have an anti-insulin effect?
stimulation of insulin growth factor binding protein-1
111
Excesses of glucocorticoids .... (3)
- affects many other tissues
- affect other hormonal systems
- can be useful clinically (eg- inflammation)
112
Clinical uses of glucocorticoid (4)
- inhibition of inflammatory response
- immune suppressant
- palliative therapy for arthritis, arthrosis
- replacement therapy for hypoadrenocorticism
113
How can glucocorticoids inhibit inflammatory responses?
- prevents capillary dilation
- extravasation of fluid into tissue spaces
- leukocyte migration
- fibrin deposition
- CT synthesis
- inhibit allergic responses
- mediated by inhibition of inflammatory mediators
114
Two cells types in the adrenal medulla
- ganglion cells
| - chromaffin cells
115
Chromaffin cells in the adrenal medulla consist of two types. What are they?
- norepineprine secreting (15%)
| - epinephrine secreting (85%)
116
________ is the rate limiting step for catecholamines synthesis
Tyrosine hydroxylase
117
What does 50% of epinephrine bind to in the blood for transport?
albumin
118
In the synthesis of catecholamines, tyrosine can be inhibited by what two substances?
- NE
| - EPI
119
Catecholamines mediated by alpha-adrenergic receptors (2)
- vasoconstriction by norepinephrine
| - liver glycogenolysis
120
Catecholamines mediated by beta-adrenergic receptors (4)
- increased heart rate/contractility
- bronchodilator
- adipose tissue lipolysis
- vasodilation by EPI
121
How is the release of NE or EPI from the adrenal medulla regulated? (3)
- sympathetic preganglionic neurons
- cortisol
- stress/hypoglycemia
122
In the PVN and SON, what cells produce vasopressin and oxytocin?
magnocellular neurosecretory cells
