Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Nutrition And Metabolism > Endocrinology > Flashcards

Endocrinology Flashcards

(165 cards)

Start Studying
1
Q

Composition of thyroid follicle

A

follicular cells

colloidal substance inside

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Composition of colloid substance in thyroid follicle

A

A glycoprotein called thyroglobulin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Function of thyroglobulin

A

Store thyroids hormones extracellular

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Thyroid hormones are the reserves of which amino acid

A

Tyrosine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Why are thyroid hormones bones to pretend carriers in circulation

A

Because they are hydrophobic molecules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Function of thyroid hormones

A

Maintain metabolic homeostasis (Intermediary metabolism, body weights, oxygen requirements, body temperature)

Control of growth , reproduction, differentiation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Names of thyroid hormones

A

Thyroxine T4

3,5,3’ triiodothyronine T3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Which thyroid hormones is secreted in larger amounts

A

T4 (80 µg)

T3 is only 5 µg

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Which territories has a greater biological activity than the other one

A

T3 about 10 times more activity 24

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Major sources of iodine for thyroid hormone

A

IodiZed salt
Iodated bread
dairy products

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Daily requirement of iodide in diet for thyroid hormone

A

75 µg a day (10g of iodated salt )

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Steps of iodide cycle

A 
Uptake 
 oxidation 
Organification 
coupling 
storage
 release
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Iodide uptake

A

Transported from interstitial fluid

Concentrated in epithelial cells through Na/I symporter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Iodide uptake regulation

A

Uptake influenced by TSH and inhibited by perchlorate and thiocyanate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Oxidation of iodide

A

Thyroid peroxidase oxidize iodide and form I2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Iodide organification

A

Thyroid peroxidase helps form Mono-iodotyrosine and then di-iodotyrosine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Coupling of iodide

A

Catalyzed by thyroid peroxidase
2 x diiodotyrosine form T4

1 diiodotyrosine and 1 mono iodiotyrosine (T3)

Requires thyroglobulin for ether o bridges

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Iodide storage

A

8000 ug of iodide stored in thyroid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Iodide release

A

Colloid droplets containing thyroglobulin with the hormones fuse with lysosomes

Hydrolysis of content with digestion of thyroglobulin and release of iodinated AA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Iodothyronine deiodinases function

A

Activation and inactivation of thyroid hormones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Types of Iodothyronine deiodinases

A

Type 1 deiodinase

Type 2 deiodinase

Type 3 deiodinase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Type 1 deiodinase

A

Converts t4 to T3 in liver kidney thyroid and brain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Type 2 deiodinase

A

Source of intracellular and circulatory T3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Type 3 deiodinase

A

Inactivation of T3 and t4

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Wolf chaikoffs effect
Adaption to increase in plasma iodine Inhibitor of NIS to reduce iodine extraction Inhibits organification process
26
Which thyroid hormone is more potent
T3 (10x more than t4)
27
Main source of circulating T3
Monodeiodination of t4 (80%)
28
Transport of thyroid hormones
Thyroid binding hormones (70%) Transthyretin (10% of T4) Albumin (25% of T3 , 15% T4)
29
Primary carrier of T4 in CSF
Transthyretin
30
Excretion of thyroid hormones
Glucuronidqtion | Excreted via bile into feces
31
2 mechanisms of control of thyroid hormones synthesis
Autorégulation with iodine levels Hypothalamus and anterior pituitary regulation
32
TSH action
Increases iodide transport into follicular cells Increases production and iodination of thyroglobulin Increases endocytosis of colloid form lumen into follicular cells
33
TSH MOA
Bind GPCR in thyroid follicle Activated Gs Increase of cAMP and PKA activation .
34
TSH release regulation
Inhibited by thyroid hormone with negative feedback at anterior pituitary ( reduce synthesis of TSH, decrease pituitary receptors for TRH, inhibit TRH synthesis) Thyrotropin releasing hormone (TRH) released from hypothalamus stimulate release of TSH ( GPCR with IP3 and DAG action ) Dopamine, somatostatin, glucocorticoids inhibits TSH release
35
Impact of diet on thyroid hormone.
High carbohydrates diet increases T3 and metabolic rate ( diet induced thermogenesis) Low carbohydrates diet decrease T3
36
Carbohydrate metabolism of T3 and T4
Low amount enhance glycogenesis with insulin Large amount promotes glycogenolysis
37
Lipid metabolism of T3 and T4
Increase fat mobilization and oxidation of fatty acids when high amount Low amount lead to increased serum cholesterol
38
Effects of TH on cardiovascular
Increase heart rate, contractility, cardiac output | Promote vasodilation , increase blood flow
39
Th effect on CNS
Alterations. In mental state When small -> sluggish state When high -> anxiety , nervousness
40
Th effect on reproductive system
Low levels can be linked to infertility
41
Thyroid hormone action
GH, prolactin production and secretion GH action Glucose intestinal réabsorption Increase in mitochondrial oxidative phosphorylation Enzyme synthesis
42
Hypothyroidism more common in men or women
Women
43
Hypothyroidism impact in infancy
Growth and mental retardation ( cretinism )
44
Hypothyroidism types
Primary Secondary Severe generalized hormone resistance
45
Causes of primary hypothyroidism
Endemic iodine deficiency Destruction of thyroid tissue by surgery or during treatment of hyperthyroidism
46
Characteristics of primary hypothyroidism
Low thyroid hormones with high TSH stimulation Enlarged goiter due to increased activity
47
Primary hypothyroidism symptoms
``` Cold intolerance Lethargy constipation slow mental function and motor activity weight gain decreased appetite abnormal menses .m dry thick skin hair loss horse voice stroke volume and heart rate decreased ```
48
Hyper thyroidism more common in men or women
Woman
49
Main causes of hyperthyroidism
Graves’ disease which is auto immune Toxic uni nodular of multi nodular goiter’s or inflammation of thyroid gland
50
Characteristics of Hyper thyroidism
Hi thyroid hormones level | low response of TSH to TRH
51
Hyperthyroidism symptoms
``` Heat intolerance nervousness irritability emotional instability pounding heart Fatigue weight loss increased food ingestion increased bowel movements abnormal menses . tachycardia atrial arrhythmias ```
52
What’s unique feature appear in the Hyperthyroidism
Infiltrative ophtalmopathy | Which is protuberance of eyes
53
Composition of endocrine system
Endocrine glands Hormones Target organ
54
Endocrine gland
Ductless glands which secrete chemical products in interstitial space to reach circulation
55
Hormones
Chemical products released in very small amounts from cell and exert biological action on target cell
56
Classic Endocrine organs
``` Hypothalamus thyroid gland adrenal glands ovaries Pituitary gland parathyroid glands testes pancreas ```
57
Hormones released by the hypothalamus
GHRH (gonadotropin releasing hormone) CRH( corticotropin releasing hormone) TRH (thyrotropin releasing hormone) GnRH (gonadotrophin releasing hormone ) Somatostatin Dopamin antidiuretic hormone oxytocin
58
Hot hormones released by the thyroid gland
T3 T4 Calcitonin
59
Hormone released by adrenal glands
``` Cortisol Aldosterone adrenal androgens Epinephrine norepinephrine ```
60
Hormones released by the ovaries
Estrogen | progesterone
61
Hormones released by the pituitary gland
Growth hormone Prolactin ACTH (adrenocorticotropic hormone) MSH (mélanocyte stimulating hormone) TSH (thyroid stimulating hormone ) FSH (follicle stimulating hormone) LH (luteinizing hormone)
62
Hormone released by the parathyroid glands
Parathyroid hormone
63
Hormones produced by the pancreas
Insulin glucagon somatostatin
64
Hormones released by the testes
Testosterone
65
Possible chemical structure of hormones
Proteins Glycoproteins steroids amines
66
Most Abundant form of hormone
Protein glycoproteins
67
Pathway of protein hormone synthesis and release
Sensitized as a pre-prohormone Converted to prohormone Packaged in the Golgi apparatus to a hormone Stored in secretory vesicles Secreted through exocytosis in the interstitium with a calcium intake gradients
68
What are steroid hormone Derived from
Cholesterol
69
What are Amine Hormone derived from
Tyrosine
70
Two means of transport of hormones
As free hormone | bound to carrier proteins
71
What type of hormone can be transported as free hormone
Peptides Protein and glycoprotein
72
What type of four months require carrier proteins
Steroid hormone | thyroid hormone
73
Main type of hormone carrier proteins
Globulins Synthetized by the liver
74
What factor determines half life of Hormones
Binding to carrier proteins which regulates excretion from circulation and dynamic equilibrium
75
What organs are responsible for the inactivation of hormones
The liver via bile And kidney
76
What is l Hormone receptor desensitization
Decreased response to prolong exposure to Hormone
77
What are or some cases of hormone receptor desensitization
Down regulation with sequestration and hormone receptor endocytosis Inactivation through phosphorylation Truncation of intracellular signaling
78
What are Some factors controlling hormones
Central nervous system through Autonomic centers Hormonal control with some hormones stimulating or inhibiting release of other hormones Nutrient or ion regulation like glucose with insulin and glucagon Negative and positive feedback
79
Name of rhythm of most hormones
Circadian rhythm
80
What rythm exist within the circadian rhythm and control cortisol levels
Ultradian rythm
81
Two types of neurons which mediates endocrine function
Magnocellular (posterior pituitary) | Parvocellular (anterior pituitary)
82
What’s structure connect the pituitary gland to the hypothalamus
Pituitary stalk
83
Three parts of pituitary glands
Anterior / adenohypophysis Posterior / neurohypophysis intermediates / pars intermedia
84
Why if there is disconnection of the pituitary stalk to the hypothalamus only prolactin levels increases
PIF ( prolactin releasing inhibiting factor) released normally by hypothalamus is not acting on prolactin anymore
85
All hormones of hypothalamic pituitary axis are pulsation except … ?
TRH
86
Sheehan syndrome
Occur in pregnancy | Enlargement of pituitary glands which becomes vulnerable to infarction
87
Hypothalamic control of GH
GHRH | GHIH/ somatostatin
88
What can increase secretion of growth hormones
``` Sleep starvation stress puberty related hormones exercise hypoglycemia ```
89
What can decrease secretion of growth hormone
``` Somatostatin Somatomedins obesity hyperglycemia pregnancy ```
90
Direct Actions of growthhormone
``` Decreases Cellular glucose uptake Increases lipolysis Increases Protein synthesis in muscle mass increases lean body mass Increase production of IGF ```
91
Causes of Laron dwarfism due to deficiency in GH
Lack of anterior pituitary GH hypothalamic dysfunction D’ailier to generate IGF GH receptor deficiency
92
Excess GH before puberty
Gigantism
93
Excès Gh After oubeeety
Acromegaly
94
Adrenal glands different parts
Adrenal cortex outer layer | adrenal medulla inner layer
95
Type of hormones secreted in adrenal cortex
Steroid hormones
96
Type of steroid hormones found in the adrenal cortex
glucocorticoids mineralocorticood androgens
97
What Hormone from the pituitary gland triggers secretion of the steroid hormones in the adrenal cortex
ACTH
98
Glucocorticoids function
Increase glucose level by gluconeogenesis in liver Increase protein and fats catabolism Inhibits ACTH secretion Sensitize arterioles to action of noradrenaline (blood pressure action ) Allow water excretion Anti-inflammation effects on the body
99
How do you use glucocorticoids in therapy
In auto immune disease like rheumatoid arthritis in transplantations of organs Control asthma
100
Example of glucocorticoids
cortisol
101
How is cortisol transported into the blood
Cortisol binding globulin transcortin
102
Rhythm of secretion of cortisol
Diurnal - | Highest in the morning lowest at night
103
What time should you take a sample of cortisol levels
Between 8 AM to 9 AM
104
Main mineralocorticoid
Aldosterone
105
Function of aldosterone
Conserve sodium in the kidney help in secretion of potassium and allow water retention to stabilize blood pressure Increase sensitivity of the taste buds to sources of sodium Act on sweat glands to reduce less of sodium in perspiration
106
Secretion of aldosterone stimulated by
Sodium level drop in blood Potassium levels rise in blood Angiotensin II AC TH in stress condition and in congenital adrenal hyperplasia
107
Type of androgens
Androstenedione (A) Dehydroepiandrosterone (DHEA) DHEA sulphate
108
At what stage of life do you have a rise in androgens
During puberty
109
Disorders of hyper function of adrenal cortex
``` Cushing’s syndrome ( excess cortisol) Conns syndrome ( excess aldosterone) ```
110
What type of people at risk of Cushing’s syndrome
Diabetics
111
Causes of Cushing’s syndrome
ACTH dépendant ACTH indépendant Iatrogenic
112
ACTH dependent Cushing’s syndrome
Pituitary hypersécrétion of ACTH Mostly due to adenoma (60%) Ectopic ACTH secretion (bronchial cancer) ACTH therapy
113
AC TH independent Cushing syndrome
Excessive production of adrenal hormones themselves | could be due to adenoma, adrenal carcinoma, or in glucocorticoid therapy
114
Iatrogenic causes
Google cortical therapy for some other disorder like rheumatoid arthritis or in organ transplants
115
What is the difference between Cushing syndrome and Cushing’s disease
Cashing disease means that the pituitary is involved | Cushing’s syndrome when other cause
116
Pseudo Cushing syndrome
Patient appear cushingoid | Occur in severe depression and alcoholism
117
Clinical feature of Cushing syndrome
``` Truncal obesity (moon face, protuberant abdomen ) Thinning of skin Purple stretch marks on the breasts arms abdomen thighs excessive bruising Hirsutism skin pigmentation (elevated ACTH) hypertension Glucose intolerance muscle weakness menstrual irregularities back pain Psychiatric disturbances Euphoria depression ```
118
Cushing syndrome biochemistry
Hypokalemia Kaliuresis Glucose intolerance Metabolic alkalosis
119
Investigation of Cushing syndrome
Initial screening test for Cushing’s syndrome 24h urinary cortisol excretion Low dose dexamethasone surpression test. Diurnal rythm of plasma Insulin hypoglycemia test
120
24 h urinary cortisol excretion test
Urine collected over 24h period Free cortisol measured. Cushing syndrome excluded if cortisol < 300nmol/24h Not specific to tell if pseudo Cushing’s syndrome
121
Disorders of hyper function of adrenal cortex
``` Cushing’s syndrome ( excess cortisol) Conns syndrome ( excess aldosterone) ```
122
What type of people at risk of Cushing’s syndrome
Diabetics
123
Causes of Cushing’s syndrome
ACTH dépendant ACTH indépendant Iatrogenic
124
ACTH dependent Cushing’s syndrome
Pituitary hypersécrétion of ACTH Mostly due to adenoma (60%) Ectopic ACTH secretion (bronchial cancer) ACTH therapy
125
AC TH independent Cushing syndrome
Excessive production of adrenal hormones themselves | could be due to adenoma, adrenal carcinoma, or in glucocorticoid therapy
126
Iatrogenic causes
Google cortical therapy for some other disorder like rheumatoid arthritis or in organ transplants
127
What is the difference between Cushing syndrome and Cushing’s disease
Cashing disease means that the pituitary is involved | Cushing’s syndrome when other cause
128
Pseudo Cushing syndrome
Patient appear cushingoid | Occur in severe depression and alcoholism
129
Clinical feature of Cushing syndrome
``` Truncal obesity (moon face, protuberant abdomen ) Thinning of skin Purple stretch marks on the breasts arms abdomen thighs excessive bruising Hirsutism skin pigmentation (elevated ACTH) hypertension Glucose intolerance muscle weakness menstrual irregularities back pain Psychiatric disturbances Euphoria depression ```
130
Cushing syndrome biochemistry
Hypokalemia Kaliuresis Glucose intolerance Metabolic alkalosis
131
Investigation of Cushing syndrome
Initial screening test for Cushing’s syndrome 24h urinary cortisol excretion Low dose dexamethasone surpression test. Diurnal rythm of plasma Insulin hypoglycemia test
132
24 h urinary cortisol excretion test
Urine collected over 24h period Free cortisol measured. Cushing syndrome excluded if cortisol < 300nmol/24h Not specific to tell if pseudo Cushing’s syndrome
133
Disorders of hyper function of adrenal cortex
``` Cushing’s syndrome ( excess cortisol) Conns syndrome ( excess aldosterone) ```
134
What type of people at risk of Cushing’s syndrome
Diabetics
135
Causes of Cushing’s syndrome
ACTH dépendant ACTH indépendant Iatrogenic
136
ACTH dependent Cushing’s syndrome
Pituitary hypersécrétion of ACTH Mostly due to adenoma (60%) Ectopic ACTH secretion (bronchial cancer) ACTH therapy
137
AC TH independent Cushing syndrome
Excessive production of adrenal hormones themselves | could be due to adenoma, adrenal carcinoma, or in glucocorticoid therapy
138
Iatrogenic causes
Google cortical therapy for some other disorder like rheumatoid arthritis or in organ transplants
139
What is the difference between Cushing syndrome and Cushing’s disease
Cashing disease means that the pituitary is involved | Cushing’s syndrome when other cause
140
Pseudo Cushing syndrome
Patient appear cushingoid | Occur in severe depression and alcoholism
141
Clinical feature of Cushing syndrome
``` Truncal obesity (moon face, protuberant abdomen ) Thinning of skin Purple stretch marks on the breasts arms abdomen thighs excessive bruising Hirsutism skin pigmentation (elevated ACTH) hypertension Glucose intolerance muscle weakness menstrual irregularities back pain Psychiatric disturbances Euphoria depression ```
142
Cushing syndrome biochemistry
Hypokalemia Kaliuresis Glucose intolerance Metabolic alkalosis
143
Investigation of Cushing syndrome
Initial screening test for Cushing’s syndrome 24h urinary cortisol excretion Low dose dexamethasone surpression test. Diurnal rythm of plasma Insulin hypoglycemia test
144
24 h urinary cortisol excretion test
Urine collected over 24h period Free cortisol measured. Cushing syndrome excluded if cortisol < 300nmol/24h Not specific to tell if pseudo Cushing’s syndrome
145
Low dose dexamethasone suppression test
1mg dexamethasone given At night Blood sample taken next morning Normal individual have serum cortisol suppressed to less than 50 nmol/l Failure to suppress suggestive of Cushing syndrome Not specific
146
Diurnal rythm of plasma
Normal patients would have high cortisol in the morning and low Cortisol in the knights Loss of diurnal variation in patient with Cushing syndrome So cortisol level at night could be raised Not specific
147
Insulin hypoglycemia test
Insulin given IV to lower blood glucose 2.2 mmol/liter Blood glucose and cortisol measured at 30 45 60 and 90 minutes Normal patients ( and pseudo Cushing’s) serum cortisol at max at 60 or 90 minutes patient with Cushing syndrome show little or no response
148
Test used to know the cause of Cushing syndrome
Measurement of plasma ACTH Would be increased or normal in Cushing’s disease Would be non-detectable in an adrenal tumor Would be increased or Much increased in Ectopic ACTH secreting tumor
149
What does is use to confirm diagnosis Of Cushing syndrome and it’s cause
High dose Dexamethasone suppression test Cortisol levels decreased to less than 50% in Cushing’s disease Cortisol level not depressed in adrenal tumor and ectopic ACTH secreting tumor
150
Name of test used to differentiate between Cushing’s disease and ectopic ACTH secretion
CRH stimulation test
151
Name of adrenocortical hypofunction disease
Addison’s disease
152
Primary Causes of Addison’s disease
Destruction of adrenal gland by infection or autoimmune adrenalitis
153
Addison’s disease secondary cause
Infiltrative lesion CAH / Hypoplasia Inherited mutation in ACTH receptor on adrenal cells
154
Biochemistry of Addison’s disease
``` Hypoglycemia Hypomatremia Hyperkalemia Raised ureA Acid base disturbance ```
155
Clinical features of Addison’s disease
``` Tiredness Weakness Lethargy Anorexia Nausea Vomiting Weight loss Dizziness Pigmentation Loss of body hair Hyperpigmentation when high ACTH (melanocytes stimulating activity) ```
156
Adrenal crisis
Chronic form of adrenal disturbance | Precipitated by stress
157
Clinical symptoms of adrenal crisis
``` High fever Dehydration Nausea Vomiting Hypotension Hypovolaemia Hypoglycemic shock Hyperkalemia Hyponatremia Hemoconcentration ```
158
Diagnosis of primary adrenal hypo function
Cortisol < 50nmol at 9am | ACTH high because lack of negative feedback
159
Diagnosis of secondary adrenal hypo function
Low cortisol and ACTH
160
Conns syndrome
Excessive production of aldosterone
161
Conns syndrome causes
Adrenal Aldosterone producing adenoma Diffuse hypertrophy of zona glomerulosa of adrenal cortex Glucocorticoid remediable aldosteronism
162
Conns syndrome clinical feature
``` Hypokalemia Hypertension Muscle weakness Polydipsia Polyuria ```
163
Biochemistry conns syndrome
``` Hypokalemia Kaliuresis Impaired glucose tolerance Metabolic alkalosis H ```
164
Diagnosis of conns disease
Measure aldosterone , plasma renin activity and do ratio Very possible if ratio over 2000
165
Confirmatory diagnosis of conns syndrome
Saline infusion test (if plasma aldosterone superior to 240 pmol/L) Posture test

Nutrition And Metabolism (17 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions