Endocrinology Flashcards
(246 cards)
1
Q
When is the level of GH highest?
A
2-5 hours after falling asleep in young animals
2
Q
what’s the effect of GH on protein metabolism?
A
It increases the synthetic activity of all cells
3
Q
How does GH affect lipid metabolism?
A
It increases catabolic processes
4
Q
Which statement is false?
A
GH inhibits glucagon production of pancreas
5
Q
Which organ’s hormone production is stimulated by GH?
A
Liver
6
Q
Which is the glandotropic effect of GH?
A
Somatomedin Production
7
Q
Which tissue does not respond to somatomedin?
A
Adipose tissue
8
Q
What’s the effect of somatomedins?
A
Sulphate incorporation into chondrocytes
9
Q
Why is the rat called an ever young animal?
A
It’s epiphysis never stops growing
10
Q
For what do you use the tibia test?
A
Quantitative GH determination
11
Q
What can a decreasing GH level cause in the blood?
A
Low glucose concentration
12
Q
How does the low glucose conc of the blood affect GH production?
A
GHRH secretion increases in the hypothalamus
13
Q
How can we use GH in practice?
A
Fat/muscle ratio can be diminished by its use
14
Q
What’s the precursor of ACTH
A
POMC
15
Q
On which hormone does CRF have no effect?
A
GH
16
Q
What’s the function of ACTH?
A
Stimulates production of glucocorticoids
17
Q
What is Addisons disease?
A
Skin discolouring due to adrenal insufficiency
18
Q
How can steroids influence ACTH production?
A
via negative effect on CRF
19
Q
Which factors stimulate TSH secretion?
A
TRH
20
Q
Which part of TSH is responsible for biological action?
A
beta subunit
21
Q
What’s the effect of FSH?
A
Increase spermatogenesis in the testis
22
Q
Which is true for FSH?
A
It’s a glycoprotein with 10% carbohydrate
23
Q
What is the function of LH?
A
It’s the primary factor of ovulation
24
Q
Which is not the effect of PRL?
A
Follicle maturation of ovary
25
Which substance suppresses PRL production?
Dopamine
26
What does MSH do?
Even distribution of pigments in the pigment cells
27
What's true for the pineal gland?
It produces biogenic amines
28
What's true for pineal gland activation?
Decreasing light increases it's activity
29
What's meant by the pineal gland being an endocrine transducer?
It translates light effects into endocrine signals
30
What's true regarding hormone production by the pineal gland?
Darkness activates the hydroxy-o-methyltransferase enzyme in this tissue
31
What's not the role of pineal gland?
Increasing pigment production
32
How does a high melatonin level affect sexual maturation of women?
It inhibits it
33
Which species sexual cycle is least dependent on illumination?
Humans
34
In which pair of animals does the increasing amount of sunshine stimulate the estrus?
Cat and horse
35
In which pair of animals does the decreasing amount of sunshine stimulate the estrus?
Sheep and goat
36
Which cells do the hormones of the thyroid gland effect?
Every body cell
37
How does an active thyroid gland appear?
Follicles contain relatively little colloid; high cylindrical cells appear with resorption vacuoles
38
How does hyporthyroidism develop?
Lack of iodine
39
What's the symptom of thyroid deficiency in young animals?
Disproportionate dwarfism
40
What's a symptom of thyroid deficiency in mature animals?
Decreased metabolic rate
41
What is Basedow syndrome?
Hyperthyroidism
42
`What can be the symptoms of overproduction of thyroid hormones?
Increase O2 consumption
43
How is the plasma level of thyroid hormones regulated?
The free T4 level plays a greater role than T3 level
44
How many types of thyroid hormones does the thyroid gland produce
3
45
How is iodine taken up by thyroid gland?
Active process
46
From what elements is the tri-iodo-thyronine composed of?
one MIT and one DIT
47
What is TG?
a component of colloid contained in the follicle
48
What happens after endocytosis of TGB?
The protein breaks down and only T3, rT3 and T4 enter the bloodstream
49
Which carbon atoms bind iodine in the active T3?
3, 5, 3'
50
Which carbon atoms bind iodine in rT3?
3, 3', 5'
51
Which one is the active thyroid hormone?
T3
52
Which factor does not transport T4 in the plasma?
TG
53
What do we call transit time?
The time during which the tissue is in contact with the blood passing in the capillary
54
Which one of the carrier proteins has the strongest affinity for the thyroid hormones
TBG
55
What is the direct communication among cells
Substance or charge flow across the gap junction
56
What is the autocrine effect?
The hormone acts on the same cell that produced the signal
57
How do neurotransmitters reach the target cells?
via diffusion
58
What is the integrator of the neuro-immuno-endocrine regulation?
Hypothalamus
59
Whats an example of a short feedback loop?
The gland effects the hypophysis
60
What statement is true for the group of hydrophilic hormones
They act through membrane receptors
61
Which substance is not a second messenger
Sodium ion
62
Which statement is true for the steroid hormones?
They have a lipophillic character
63
What can be examined by the Scatchard analysis
The affinity of ligand-receptor binding and number of binding sites
64
Which statment is true for down-regulation
Long lasting hormonal effects decrease their own receptors expression
65
What is transduction?
Molecular events that lead to biological action
66
What is not the result of metabotrop signalling?
Opening of ion channels
67
Which is true for Ligand-Receptor interactions?
G protein system is not activated certainly after the formation ligand-membrane receptor complex
68
Which enzymes can be activated by the G protein system?
Proteinkinase-A, Phospholipase-C and adenylate cyclase
69
What is characteristic for the receptors that serve as ion channels?
Some of them can be stimulated by nicotine
70
Which statement is not true for nicotinic receptors?
In skeletal tissue the delta domain is the Acetylcholine binding part
71
Which substance has a stimulation effect on the glutamate receptors?
NMDA
72
Which statement is not true for anion channels?
Their activation causes depolarisation
73
How do the cytoplasmic receptors work?
After ligand binding the complex binds to DNA HRE, which initiates expression
74
Which statement is false for the cytoplasmic receptors?
The variable domain binds to the DNA promoter.
75
What binds the G-protein in resting state?
GDP
76
What part of the G protein is able to activate ion channels?
the alpha subunit-GTP complex
77
What is the Gi protein?
the alpha subunit-GTP complex which can inhibit ion channels
78
Which is the most common G-protein dependent ion channel?
Potassium channel
79
Which hormone cant be the ligand of the G-protein dependent ion channel?
Vasopressin
80
Which is the receptor that does not increase adenylate cyclase activity?
alpha-1 catecholamine receptor
81
Which receptor increases the adenylate cyclase activity?
Dopamine D1 receptor
82
Which is a substrate for phospholipase-C?
phosphatidyl-inositol-biphosphate
83
The IC conc of which ions increase as a response to IP3 stimulation?
calcium
84
Which enzyme is activated by DAG in the cell?
Protein kinase C
85
What is not a PLC activating ligand?
Insulin
86
Which material is formed by phospholipase A2 from the phospholipids of the membrane?
Arachidonic acid
87
How many carbon atoms in arachidonic acid?
20
88
Which is not a member of arachidonic acid activation?
Hydrogenase activity
89
Which materials are formed in the cyclooxygenase pathway?
prostacyclins, prostaglandins and thromboxanes
90
Which ligand's receptor doesn't work as an IC enzyme?
catecholamines
91
During autophosphorylation, which aa is phosphorylated?
Tyrosine
92
What is internalisation?
When hormone-receptor complex is taken into cell
93
Which is not member of parvocellular area of Hypothalamus?
Nucleus paraventricularis
94
What is product of nucleus supraopticus?
Oxytocin, ADH
95
How are products transported from magnocellular area to place of secretion?
Axoplasmatic transport
96
Where is action of hormones produced in parvocellular area exerted?
In the hypophysis- anterior lobe
97
What happens to hormone after axonal transport?
It enters the circulation
98
Which motor protein transports the products from neuronal body to synaptic knob?
Kinesin
99
Which motor protein transports the products from synaptic knob to neuronal body?
Dynein
100
Along what element are the hormones transported in the axon?
Microtubules
101
Which hormones are called hypophyseotropic hormones?
Hypothalamic hormones that reach adenohypophysis via portal circulation
102
How many aa in TRH
3
103
How many aa in PRF
structure not known yet
104
What is effect of GnRH
Increases production of FSH and LH in females and males
105
What's the other name of CRF
Corticoliberin
106
How many aa in dopamine
1
107
What is not a dopamine containing factor
GH-IH
108
Which is a general inhibitor in pituitary gland
NE
109
Which is a general stimulator in pituitary gland
Bombesin
110
What is substance-P
A tachykinin of paracrine effect
111
Which effect is not characteristic of V|P
TSH stimulation
112
How many aa in ADH
9
113
How does ADH exert its effect
It stimulates water reabsorption in the distal tubule and in the collecting duct
114
What is the main function of oxytoxin?
Preparing the womb for estrogen answer
115
What is the essence of the classical neuro-endocrine reflex?
The neural signal is translated to a hormonal stimulus by the CNS
116
In relation to which hormone can we talk about a classical neuroendocrine reflex?
Oxytocin
117
What kind of hormones are pituitary hormones?
Peptides
118
Which hormone is not a classical gonadotropin?
STH
119
Which statement is false about pituitary development?
Pars distalis originates from the ectoderm
120
Which statement is false about the location of the pituitary gland?
There's no sella turcica in the horse
121
Which hormones are produced by the acidophil cells of the hypophysis?
GH, PRL
122
Which hormones are produced by the basophilcells of the hypophysis?
TSH, ACTH
123
Which hormone-producing cells form large groups
GH
124
What is the consequence of hypopituitarism in young animals?
Reduced sexual activity
125
What is not characteristic of STH?
Its circadian rhythm is the same as that of ACTH
126
What is characteristic of the Growth Hormone receptor?
After binding the hormone it activates adenylate cyclase
127
How does GH affect growth?
Its increased release causes acromegaly in adults
128
Which of the transporter molecules has the highest capacity for thyroxine transport?
Albumin
129
Which transformations cant occur in the peripheral cells?
T3 to T4
130
Which deiodinase is found mainly in the liver?
DI
131
Which deiodinase is most abundant in the body?
D I
132
Which deiodinase is found mainly in the CNS?
D II
133
Which organs metabolic rate is affected by thyroxine?
Heart
134
What is not characteristic of thyroxine effect on muscles?
The activity of the sodium-potassium pump decreases
135
How does thyroxine affect carbohydrate metabolism?
Raises glycogenolysis
136
How does thyroxine affect lipid metabolism?
Reduces the phospholipid content of the blood plasma
137
How does thyroxine affect protein metabolism?
Increases protein synthesis
138
How does thyroxine affect the circulation?
Permissively
139
What is goitre
Enlargement of the thyroid mass
140
Why is a high quantity of iodine goitregenic?
A high quantity of iodine inhibits hormone release
141
Why is SCN goitregenic?
Because it inhibits the uptake of iodine
142
What may be the cause of an endemic goitre?
Iodine-poor alimentation
143
In which tissue does iodine not accumulate?
Adipose tissue
144
What is the Wolff-Chaikoff effect?
When excess iodine intake inhibits the production of thyroid hormones
145
Why is hypothyroidism common in cats?
its not ... hyperthyroidism is
146
Which statement is true for the adrenal gland?
95% of the organ is cortex of mesodermal origin, the medulla evolved from the ectoderm.
147
What is the sequence of different layers in the adrenal gland of birds (from outside to inside)?
The cells of medulla an cortical region are mixed
148
What is the sequence of different layers in the adrenal gland of dogs (from outside to inside)?
z glomerulosa - z fasciculata - z reticularis - marrow
149
What is the basic source of steroid hormone synthesis?
Cholesterol
150
What is the first key enzyme of steroid synthesis?
20,21-desmolase
151
The lack of which adrenal cortex enzyme results in death?
3-beta-hydroxysteroid-dehydrogenase 4-5-isomerase
152
The lack of which adrenal cortex enzyme may cause virilism?
C21 hydroxylase
153
Which synthetic step diverts male and female steroidogensis?
When androstenedione is transformed/changed
154
How many carbon atoms does testosterone contain?
19
155
How many carbon atoms does corticosterone contain?
21
156
In which part of the adrenal cortex is aldosterone produced?
In the stratum of z. glomerulosa
157
What is the function of aldosterone?
The reabsorption of sodium and excretion of potassium
158
What happens when mineralcorticoids are overdosed?
aciduria, paradox alkalosis develops
159
What happens in the organism in mineralcorticoid deficiency?
Extracellular hypovolemia develops
160
Which event has little effect on the production of aldosterone?
The reduction of sodium concentration in the blood
161
In which species is corticosterone the dominant steroid?
Birds and rabbits
162
In which species of animal is cortisol the dominant steroid?
Sheeps and hogs
163
How do glucocorticoids affect intermediary metabolism?
The increase gluconeogenesis, the N-balance of the organism will be negative
164
How do lack of mineralcorticoids affect the circulatory system and the nervous system?
Depression and oedema develops
165
What pharmacological effects do glucocorticoids have?
Their antiphologistic effect may decrease inflammation
166
When can stress develop?
When the stimulus that hits the organism is harmful, but there is no possibility of a specific answer
167
What are stressors?
All the above (viruses, common everyday stimuli, surgical interventions)
168
Which statement is not true regarding stress?
In every case the introductory phase consists of ACTH release and the Cannon-reaction
169
What is typical regarding Chromaffin-cells?
They stain a brownish colour with chromium salts
170
How does the removal of the adrenal medulla affect the organism?
The blood sugar level does not stabilise easily after insulin application
171
From which aa are catecholamines synthesized?
Phenylalanine
172
Which sequence of synthesis is correct?
Thyrosine-dopa-dopamine
173
Which conversion is due to PNMT effect?
Norepinephrin-epinephrine
174
How do the precursors of the catecholamine synthesis get into the granula?
By hydrogen antiport
175
How does NE get into the cytoplasm?
Passively
176
What does a chromagranin granule contain?
NE, E and modulator peptides
177
How does the re-uptake of norepinephrine proceed?
Presynaptically through alpha-2 receptors
178
How does enzymatic decomposition of catecholamines happen?
In mitochondria by MAO enzyme
179
Which receptor is stimulated mainly by epinephrine?
Beta2
180
Which receptors agonist is plenartarol?
Beta 1
181
Which receptor activates the IP3 pathway?
Alpha 1
182
What is the major role of alpha 2 receptor?
It has a function in reuptake
183
What is the effect of alpha 1 receptors on the heart and circulation?
It causes vasoconstriction
184
Which of the following do catecholamines depend on the least?
Time of day
185
In which arterioles do alpha receptors predominate?
Intestinal
186
What causes the small quantity of epinephrine?
Circulatory redistribution
187
How do catecholamines affect metabolism?
Metabolic rate increases
188
What effect does beta 2 receptor stimulation have on the eye?
m. ciliaris relaxes
189
What is the effect of the alpha 1 receptor?
Uterine contraction
190
What does the beta 1 receptor stimulate?
Bronchi dilation
191
What happens during the alarm reaction
The blood glucose level increases
192
What controls the activity of the adrenal medulla?
Sympathetic nervous system
193
Which cells are found in the Islets of Langerhans?
A,B,D,F
194
Which cells of the Islets of Langerhans produce insulin?
B
195
Which cells of the Islets of Langerhans secrete somatostatin?
D
196
Which cells of the Islets of Langerhans secrete glucagon?
A
197
Which cells of the Islets of Langerhans secrete pancreatic polypeptide?
F
198
Which hormone has the shortest polypeptide chain?
somatostatin
199
Which hormone has a larger polypeptide?
Insulin
200
Which hormone has the shortest half-life?
PP
201
Whats the main function of somatostatin?
Inhibits A and B cells
202
Whats the main function of PP?
Increases motion of ventricle
203
How does glucagon affect insulin production?
Stimulates its production
204
How does glucagon affect D cells?
Stimulates production of somatostatin
205
How does GIP regulate emptying of insulin?
Mode of feed forward
206
What type of transporter takes glucose to B cells?
GLUT2
207
What type of transporter takes glucose to liver cells?
GLUT3
208
What type of transporter takes glucose to muscle cells?
GLUT4
209
How does the glucose in B cells stimulate the release of insulin?
ATP increase closes the potassium channels then depol starts and at the end influx of calcium gives rise to release
210
What nervous effects do B cells receive?
They are under autonomic nervous control
211
How does sympathetic nervous system affect B cells?
Inhibits and also stimulates in a complex way
212
How many types of insulin receptors are known?
7
213
Which is the most important insulin receptor among its subtypes?
the 4th in skeletal muscle
214
What are characteristics of the 3rd type of insulin receptor?
High affinity, found in neurons
215
How many insulin molecules are bound to an insulin receptor?
2
216
Which tissue is dependent on insulin for glucose intake?
Muscle
217
How does insulin affect protein metabolism?
Gives rise to positive nitrogen balance
218
Which transformation is not stimulated by glucagon?
Glucose into glycogen
219
Which substance can not be precursor for glucose synthesis?
Fatty-acid
220
How does the lack of insulin affect metabolism?
Increased emptying of potassium - the organism loses water - becomes dehydrated
221
How does the lack of insulin affect fat metabolism?
Lipaemia develops
222
How does the lack of insulin affect carbohydrate metabolism?
Dehydration develops due to osmotic diuresis
223
Which type of diabetes is not sensitive to insulin?
Type 2
224
Whats characteristic of type 2 diabetes?
Cured by adjusting dietary intake
225
What's characteristic of type 1 diabetes?
Hereditary
226
Which type of cells can produce eicosanoids?
All somatic cells
227
Whats the starting material in producing eicosanoids?
Arachidonic acid
228
Which compounds originate from HPETE?
Lipoxins
229
Which compounds originate from HETE?
Leukotrienes
230
Which enzyme catalyses arachidonic acid - HPETE transformation?
Lipoxygenase
231
Which material originates from PGH2 by the action of prostacyclin-synthase?
PGI
232
What kind of receptors bind the eicosanoids?
Act through G-protein system
233
Which substances are phlogistic?
Prostaglandins and leukotrienes
234
Which material inhibits the elimination of insulin?
PGE2
235
Which material prompts the mobilisation of calcium from the bone?
PGE2
236
The inhibition of which factor prompts TXA2 synthesis in the platelets?
PGI
237
How does prostacyclin affect the kidney?
Increases RPF and antagonises ADH's action
238
Which enzymes activation is inhibited by corticoids?
Phospholipase A2
239
Which enzymes activation is inhibited by a salicylic derivative?
Cyclo-oxygenase
240
Which enzymes activation is inhibited by imidazole?
Thromboxane-synthetase
241
Which material is not produced in Merkel's cells of the skin?
Substance K
242
Which organ doesn't produce calcitonin?
Stomach
243
To which group does Kallidin belong?
Kinins
244
To which group do neuromedins belong?
Bombesin-like substances
245
Which group is characterised by these effects - hypothermia, hypoglycaemia, gastric juice output increase?
bombesins
246
Which group contains the most analgesic compounds?
Neurotensins
