exam 1 lecture notes Flashcards
(169 cards)
1
Q
what is endocrinology
A
the study of endocrine glands and their secretions (hormones)
2
Q
what is the difference between endocrine glands and exocrine glands
A
endocrine: secrete inside body
exocrine: secrete outside body
3
Q
what is extirpation
A
removal of an endocrine gland
4
Q
what is hormone replacement
A
treating an individual who lacks a particular hormone with that hormone or a drug substitute for that hormone
5
Q
what are the three classes of evidence for determining hormone-behavior interactions
A
- hormonally dependent behavior should be altered/disappear when the source of the hormone is removed or blocked
- restoration of the hormone should reinstate or normalize the behavior
- hormone concentrations and the behavior should be covariant
6
Q
does pharmacological treatment with a hormone mimic the normal secretion pattern of the endogenous hormone? why?
A
usually no because of different doses and different temporal considerations
7
Q
what are organizational effects of hormones
A
relatively permanent effects of hormones on structure and function of the body
8
Q
when do organizational effects usually take place
A
during a critical period of development
9
Q
what are activational effects of hormones
A
relatively immediate (temporary) effects of hormones that come and go with the presence or absence of the hormone
10
Q
when transplanted testis were autopsied, what was discovered to be reestablished and what was not reestablished
A
they had reestablished a blood supply but not a neural supply
11
Q
what was determined about the size of the transplanted testis
A
2x larger than normal
-compensatory hypertrophy of the single testis
12
Q
what is a bioassay
A
using a physiological or behavioral measure to indirectly assess hormone activity/levels
13
Q
what are direct hormone assays
A
hormones are measured directly in the blood or saliva samples
14
Q
what is a hormone
A
intercellular signal that is delivered via blood vessel
15
Q
what is the main difference between a hormone and a neurotransmitter
A
NT diffuse through a synapse to a nearby cell
hormones travel via blood vessels
16
Q
if a hormone travels a short distance through the pituitary stalk is it a systemic hormone
A
no
17
Q
if the hormone travels a long distance throughout the body is it a systemic hormone
A
yes
18
Q
what determines which cells are a target for a systemic hormone
A
whether or not a particular cell expresses receptors for the specific hormone
19
Q
what are receptors
A
specialized protein molecules produced by a cell and located either inside or on that cells surface
20
Q
does hormonal signaling or NT signaling have better temporal and spatial resolution
A
NT signaling
21
Q
what are the four chemical structures of hormones
A
steroid
lipid
monoamine
peptide/protein
22
Q
how do endocrine glands usually produce effects on targets
A
by clumping together into a gland
23
Q
can glands secrete more than one type of hormone
A
yes
24
Q
what is a neurohormone
A
a hormone that is produced by a neuron
25
what is a neurosecretory neuron
a neuron that produces a neurohormone
26
what are the two main functional classes of hormones
release control hormone (releasing factor)
effector hormone
27
what is a releasing factor (release control hormone)
hormone that acts on endocrine cells to regulate the release of other hormones
(can be stimulatory or inhibitory)
28
what is an effector hormone
non-releasing factors
hormones that produce a regulatory effect on physiological/psychological function
29
what is the master gland
pituitary
30
what is the master of the master gland
hypothalamus
31
what do hypothalamic neurons innervate
the posterior pituitary
32
how does the hypothalamus communicate with the anterior pituitary
through hormones
33
do any neurons innervate the anterior pituitary
no
34
what is a first order hormone
the neurohormone itself is an effector hormone
35
where is a first order hormone released
in the posterior pituitary through axon terminals
36
what order hormone is oxytocin
first
37
what are the two main physiological effects of oxytocin
milk ejection and contraction in the uterus
38
what is a second order hormone
neurohormone is a releasing factor for an anterior pituitary hormone that is an effector hormone
39
in a second order hormone where are the two hormones released
the releasing factor is released by hypothalamic neurons
the effector hormone is released in the anterior pituitary
40
what is a third order hormone
neurohormone is a releasing factor for an anterior pituitary hormone which is a releasing factor for an effector hormone
41
what order hormone is growth hormone
second
GHRH released by hypothalamus
growth hormone released by anterior pituitary
42
what does growth hormone do
stimulates growth of various target tissues
43
what order hormone hormone is testosterone
third order
44
where and by what are neurohormones produced
produced by neurosecretory neurons in the hypothalamus
45
what is the "home" of a neuron designated as
the location of that neuron's cell body
46
where is the hypothalamus located
below thalamus
base of forebrain
surrounding the third ventricle
47
what is the median eminence
part of the hypothalamus immediately above the pituitary stalk
48
what are two examples of effector hormones
oxytocin
vasopressin
49
what is the size of the cell body that produces effector hormones
magnocellular neurons
large
50
where is the location of the cell body that produces effector hormones
lateral paraventricular neuron (PVN)
supraoptic nucleus (SON)
51
where is the location of the axon terminal of the cell that releases effector hormones
posterior pituitary
52
what is the size of the cell body that produces releasing hormones
parvocellular neurons
small
53
where is the location of the cell body that produces releasing hormones
various hypothalamic nuclei
54
where is the location of the axon terminal of the cell that releases releasing hormones
median eminence (part of hypothalamus)
55
why is there a difference in neuronal cell body size
differ in the quantity of hormone
56
the axon terminals of hypothalamic neurosecretory neurons that secrete effector hormones are located in the
posterior pituitary
57
the axon terminals of hypothalamic neurosecretory neurons that secrete releasing hormones are located in the
median eminence
(hormones are released from anterior pituitary but the neurons do not extend to there)
58
why is it important that there are more effector hormones produced (larger cell body) than releasing hormone
releasing hormones only need to travel a small distance to the pituitary but effector hormones are released into systemic circulation
59
why are hormones secreted in the median eminence not systemic hormone
they are not secreted in a large enough quantity to circulate throughout the entire body
60
where is the pituitary located
in the sella tursica indentation in the sphenoid bone
61
what are the three subdivisions (lobes) of the pituitary
anterior
posterior
intermediate
62
where does the anterior pituitary originate from
the roof of the mouth
63
where does the posterior pituitary originate from
the brain
64
what is the intermediate pituitary
the distinct junction between anterior and posterior pituitary in non-human mammals
65
how is the pituitary attached to the hypothalamus
by the infundibulum or pituitary stalk
66
what is the portal blood system
blood vessel system that carries neurohormones from the median eminence to the anterior pituitary
67
what are the three components of the portal blood system
primary plexus
secondary plexus
portal vein
68
where is the primary plexus located
in the median eminence
69
where is the secondary plexus located
in the anterior pituitary
70
what is the portal vein
connects the primary and secondary plexus
located in pituitary stalk
one way blood flow from hypothalamus
71
oxytocin and vasopressin are neurohormones secreted by neurosecretory neuron axon terminals in the
posterior pituitary
72
how can the milk letdown reflex be classically conditioned
suckling can be associated with cues that become conditioned stimuli for milk letdown
73
what are the two main functions of vasopressin (ADH)
mediates vasoconstriction
mediates water retention at kidney
74
what is the affect of alcohol on vasopressin secretion
alcohol inhibits vasopressin
75
how many AA do the peptides of oxytocin and vasopressin contain
nine
9
76
what is the difference between a peptide and a protein
peptide: short chain of amino acids
protein: long chain of amino acids
77
what are the two variants of vasopressin
arginine vasopressin: found in most mammals
lysine vasopressin: found in other animals
78
what is a prohormone
precursor molecule that may have some other hormonal function of its own but can be converted into another hormone
79
when the cell cleaves the large proteins, what are the proteins that are left over besides oxytocin and vasopressin
oxytocin - neurophysin I
vasopressin - neurophysin II
80
what do neurophysin I and II function as
secreted into circulation with oxytocin and vasopressin to act as carrier proteins
81
what is a carrier protein
protein that binds to hormone molecule and escorts it around in the blood stream
- often protects the hormone from degradation
82
what is the half-life
time for 50% degradation/clearance
83
does the half life increase or decrease with a carrier protein
increases
84
what kind of signals are oxytocin and vasopressin
neuropeptide/neurotransmitter intercellular signals
85
what is the difference between hormone vasopressin and oxytocin and NT vasopressin and oxytocin
the hormones are peptide hormones that cannot cross the BBB so it is unclear if they are involved in brain processes
86
releasing factor neurohormones are secreted by neurosecretory neuron axon terminals located in the
median eminence
87
what inhibits prolactin secretion
dopamine
88
what do tropic and trophic mean
tropic: causing a change
trophic: nourishing, promoting growth
89
what are trophic/tropic factors
all hormones produced by the anterior pituitary
90
what are the three general classes of endocrine cells
basophils
acidophils
chromatophobes
91
what kind of dye stains the three kinds of endocrine cells
basophils: stain with basic dyes
acidophils: stains with acidic dye
chromatophobes: stains weakly (color phobic)
92
can anterior pituitary hormones be effector hormones
yes
93
what is the structural relationship between ACTH, beta endorphin, and MSH
they are all peptide fragments of the POMC prohormone
94
what does a second order neuroendocrine arrangement mean
the neurohormone is a releasing factor for an anterior pituitary hormone that is an effector hormone
95
what does a third order neuroendocrine arrangement mean
neurohormone is a releasing factor for an anterior pituitary hormone, which is a releasing factor for an effector hormone
96
what is the effect of LH
tropic effect on leydig cells in testes which stimulates the production and secretion of testosterone
also has trophic effect on leydig cells, promoting growth
97
what is the effect of FSH
tropic effect on sertoli cells in testes, stimulating spermatogenesis
trophic effect on sertoli cells, promoting growth
98
what is receptor downregulation
phenomenon when cells decrease the number of receptors for a given hormone that they produce
- often caused by exposure of cells to greater than normal levels of the receptor ligand
99
what is a gene
sequence of DNA that contains the code for a particular protein
100
where does transcription occur for proteins/peptide hormones
nucleus
101
where does translation occur for proteins/peptide hormones
cytoplasm
102
are proteins/peptide hormones water solubles
yes
and bulky
103
do proteins/peptide hormones require a carrier protein
no can circulate through blood without carrier
104
can proteins/peptide hormones pass through the phospholipid bilayer
no
-receptors on cell membranes
105
what is the BBB
tight junction between endothelial cells forming the walls of the blood vessels in the brain that prevents most molecules from being able to leak out of the blood vessels into brain tissue
106
can proteins/peptide hormones cross the BBB
no
107
how are proteins/peptide hormones stored
in vesicles
108
is there a gene that encodes for steroid hormones
no, they are synthesized by a series of enzyme mediated chemical reactions
109
what is a common precursor for steroids
cholesterol
110
what is a common precursor for thyroid hormones
tyrosine
111
what are steroid hormones soluble in
soluble in lipids/fats but not soluble in water
112
do steroid hormones need a carrier protein
yes, need to be escorted by carrier protein to circulate through bloodstream
113
are steroid hormones able to pass through cell membranes
yes
114
are steroid hormones able to penetrate the BBB
yes because they are lipid soluble
115
where are receptors for steroid hormones located
inside the cell since steroids can pass through the membrane
116
are steroid and thyroid hormones packaged into vesicles
no
117
what is the carrier protein for oxytocin
neurophysin I
118
what is the carrier protein for vasopressin
neurophysin II
119
what is the carrier protein for glucocorticoids (cortisol)
corticosteroid binding globulin (CBG)
120
what is the carrier protein for androgens
sex hormone binding globulin (SHBG)
121
what is the carrier protein for estrogens
sex hormone binding globulin (SHBG)
alpha fetal protein
122
what is the carrier protein for progesterone
CBG
123
what is the carrier protein for thyroid hormones
thyroid binding globulin (TBG)
124
where are metabotropic receptors located
in the outer cell membrane
125
how do metabotropic receptors mediate change
by triggering a series of intracellular chemical reactions (metabolism)
- activation of G protein and increase second messenger concentration
126
what are intracellular steroid and thyroid hormone receptors also called
hormone dependent transcription factors
127
what happens after steroid/thyroid hormone receptors are bound (activated)
the activated receptor binds to DNA to modulate the transcription of genes and therefore modulate protein synthesis
128
what happens to the glucocorticoid receptor protein when cortisol binds
the activated receptor:
-translocates to the nucleus
-dimerizes
-binds to specific sequence of DNA
129
what is gene expression largely determined by
transcription factors
130
what are transcription factors
proteins that bind to specific sequences of DNA and increase or decrease transcription of specific genes
131
why is protein synthesis a continuous process
most proteins live a short life and are continuously breaking down and being replaced by new proteins
132
why is there a time lag in the release of the hormone into the blood stream
it takes time to:
- release RF into median eminence
- RF traveling to anterior pituitary
- tropic factor release in anterior pituitary
- travel of tropic factors to steroid producing cells
- synthesis of new steroid
- diffusion of new steroid into blood stream
133
what happens in between the hormone being released into the blood stream and the hormone modulating gene transcription
the hormone reaches the target cell
the receptor is activated
gene transcription is modulated
134
why is there a time lag in the onset of a change in gene transcription and a change in cell function
there is delay before an increase/decrease in newly synthesized proteins will significantly alter the concentration of that protein
there is a delay before the change in protein concentration actually produces a change in cellular function
135
how long will a steroid hormone induced change in cellular function last
hours-days
as long as the levels of the regulated proteins remain altered
136
is the effect of steroid hormones fast or slow to develop
slow to develop
137
are the effects of steroid hormones long or short lasting
long lasting
138
what are the female accessory sex organs
fallopian tubes
uterus
cervix
139
what are the male accessory sex organs
epididymis
vas deferens
seminal vesicle
140
what is the female external genitalia
vagina
clitoris
labia major
labia minor
141
what is the male external genitalia
penis
scrotum
142
what is the sex determining region on the Y chromosome
SRY gene
143
what is the TDF protein
a protein product of the SRY gene
- testis determination factor
144
what is differentiation
anatomical development
- process by which cells develop (differentiate) into specific cell types
145
what is an anlagen
the first accumulation of cells in an embryo which constitutes the beginning of a future tissue or organ
146
what does the germinal ridge develop into
can develop into either an ovary or testis
147
what does DHT act as
a super testosterone that is a more potent agonist for androgen receptors than testosterone
148
what is testicular feminization mutation
individual has testosterone but no functioning testosterone receptors
149
in a genetically male individual (XY), what gonads develop when there is a lack of TDF
ovary
150
in a genetically male individual (XY), what gonads develop when there is testicular feminization mutation (absence of androgen receptors)
testis
151
in a genetically male individual (XY), what gonads develop when there is lack of MIH or defective MIH receptors
testis
152
in a genetically male individual (XY), what gonads develop when there is a 5-alpha reductase deficiency
testis
153
in a genetically male individual (XY), what accessory sexual organs develop when there is a lack of TDF
female
154
in a genetically male individual (XY), what accessory sexual organs develop when there is testicular feminization mutation (absence of androgen receptors)
neither male or female
155
in a genetically male individual (XY), what accessory sexual organs develop when there is a lack of MIH or defective MIH receptors
both female and male
156
in a genetically male individual (XY), what accessory sexual organs develop when there is a 5-alpha reductase deficiency
male
157
in a genetically male individual (XY), what external genitalia develops with a lack of TDF
female
158
in a genetically male individual (XY), what external genitalia develops with testicular feminization mutation (absence of androgen receptors)
female
159
in a genetically male individual (XY), what external genitalia develops when there is a lack of MIH or defective MIH receptors
male
160
in a genetically male individual (XY), what external genitalia develops when there is a 5-alpha reductase deficiency
female
161
in a genetically male individual (XY), what secondary sex characteristics develop with a lack of TDF
female
162
in a genetically male individual (XY), what secondary sex characteristics develop with testicular feminization mutation (absence of androgen receptors)
female; no pubic hair and full breast development
163
in a genetically male individual (XY), what secondary sex characteristics develop with lack of MIH or defective MIH receptors
male; may experience abdominal cramps
164
in a genetically male individual (XY), what secondary sex characteristics develop with a 5-alpha reductase deficiency
male; hole at the base of the penis
165
is TDF a hormone
no it is a protein - transcription factor and only has an effect in the cell that it is produced in
166
which chromosome is the androgen receptor on
X
167
what are LH, FSH, and testosterone levels in someone with testicular feminization mutation
LH and FSH are high because there is no negative feedback because testosterone has no receptors to bind to
testosterone levels are high because of high LH levels
168
what is hypospadias
birth defect of the urethra that results in an abnormally placed urinary hole
169
what is the gender assignment at birth and usual gender identity of someone born with 5-alpha reductase deficiency
gender assignment at birth: female
gender identity: in most cases male after puberty
