Endocrine Physiology Flashcards
1
Q
What causes dwarfism in most of the cases?
A
Panhypopituitarism where there is undersecretion of all ant pituitary hormones
2
Q
In what percentage of dwarfs is there undersecretion of growth hormone alone?
A
33.3% (1/3)
The dwarf still matured sexually and is able to reproduce
3
Q
What’s the cause of dwarfism in the LeviLorain dwarf?
A
The LeviLorain dwarf is able to produce growth hormone but there is an hereditary inability to form somatomedin C(a hormone produced by the liver that promotes the action of growth hormone)
4
Q
What disease is associated with over secretion of growth hormone in childhood?
A
Hyperglycemia due to oversecretion of GH, which antagonises the action of insulin leading to degeneration of beta cells
In 10% of giants, it leads to full blown diabetes
5
Q
Inability to produce growth hormone in adult hood can lead to ……
A
Increased rate of aging due to decreased protein deposition in most tissues of the body and replacement with fat
6
Q
What percentage of secretory cells do the gonadotrophs make up?
A
20%
7
Q
What is the name of the secretory cells of the testes?
A
Leydig cells that secrete testosterone
8
Q
What cells help to support sperm cell maturation?
A
Sertoli cells
9
Q
How many amino acid residues does thyroglobulin have and what is its molecular weight?
A
140
660000
10
Q
What’s the minimum daily intake of iodine I order to avoid diseased state of thyroid gland?
A
100-150mg
11
Q
What percentage of iodide is used by the body?
A
1/3 is used by thyroid gland
2/3 is excreted
12
Q
What stimulates the endocytosis of organified thyroglobulin back into the cell?
A
TSH
13
Q
Propylthiouracil helps to prevent …….. by inhibiting ………..
A
Hyper thyroidism
Thyroperoxidase
14
Q
Concerning transportation of thyroid hormones, state the percentage of how they are transported?
A
67% by tyrosine binding globulin
20% by tyrosine binding prealbumin
13% by albumin
15
Q
In what form is thyroid hormone physiologically active?
A
In free form(same as Ca)
16
Q
What are the daily amounts of thyroid hormone secreted?
A
80mg T4
4 mg T3
2mg rT3
17
Q
What is the effect of Stress on TSH?
A
Decreases TSH levels
Glucocorticoids inhibit the secretion of TRH
18
Q
What’s the effect of low thyroid hormones in men and women?
A
Low libido in men
Frequent menstrual bleeding in women and irregular periods
19
Q
What’s the effect of high levels of thyroid hormones in men and women?
A
Impotence in men
Reduced menstrual bleeding and amenorrhea
20
Q
What are the main functions of aldosterone?
A
Na reabsorption
K and H secretion
21
Q
What steroidal hormone antagonizes vitd3
A
Cortisol
22
Q
NE causes vasoconstriction via ….. while epinephrine causes vasodilation via ….
A
Alpha receptors
Beta 2 receptors
23
Q
What’s the action of catecholamines on K conc?
A
Initial rise in K, prolonged fall in K because it’s entry into the cell is increased
24
Q
Deficiency of 21 beta hydroxylase leads to what?
A
Undersecretion of cortisol and aldosterone with oversecretion of androgens leading to adrenogenital syndrome or congenital adrenal hyperplasia
25
Deficiency of 17 alpha hydroxylase leads to what symptoms?
Inability to produce androgens and cortisol but excessive amounts of aldosterone is produced
26
What are the physiologic effects of dopamine?
Increased renal blood flow
+ve ionotropic effect on the heart
Increased systolic bp, but doesn’t affect diastolic BP?
27
What are the stimulus for the release of adrenal medulla hormones?
Sym Ns
Hypoglycemia
28
What’s the length of the pineal gland?
10mm
29
What are the examples of sulfonylurea drug?
Tolbutamide, glyburide
30
What’s the function of metformin?
It’s a biguanide drug which up regulate insulin receptors on target tissues. It helps to treat lifestyle diabetes
31
What hormone is regarded as the hormone of Abundance?
Insulin
32
What hormone is regarded as the hormone of starvation?
Glucagon
33
Beta adrenergic …… levels while alpha adrenergic agents ………
Increases cAMP
| Decreases cAMP
34
What are the stimulators factors for the release of somatostatin?
Nutrients
Glucagon
Beta adrenergic agonists
35
Somatostatin is inhibited by what hormone and inhibits what hormones?
Insulin
Insulin and Glucagon
36
What quantity of Calcium is ingested per day?
1000mg
Only about 1/3 is absorbed from GIT into ECF
About 190mg is lost back to the gut
37
What is chvostek sign indicate?
The Chvostek sign is a clinical finding associated with hypocalcemia, or low levels of calcium in the blood. This clinical sign refers to a twitch of the facial muscles that occurs when gently tapping an individual's cheek, in front of the ear.
38
Constipation, polyuria and dipsia , lethargy and hyporeflexia are usually symptoms seen in
Hypercalcemia
39
Hypocalcemia is characterized by what symptoms?
Hyperreflexia
Muscle cramps
Spontaneous twitching
Tingling and numbness
40
Trousseau sign indicates ………
Hypocalcemia
It is indicated by carpopedal spasms
41
How many amino acids does PTH have?
84 aa, secreted by chief cells
Biological activity is on N terminal 34 amino acid
42
In what part of the kidney is calcium reabsorbed under the influence of PTH?
Distal tubule
43
PTH action on the kidney, what happens?
Promotes PO4 secretion at PCT and Ca reabsorption at DCT
44
Secondary hyperparathyroidism is usually caused by
Vit D deficiency or chronic renal failure
There are high levels of PTH in the blood, but blood levels of Ca are low or normal, but never high
45
What’s the treatment for hypoparathyroidism?
Ca supplements
| And supplements of active vit d3
46
Albright’s hereditary osteodystrophy is characterized by
Pseudohypoparathyroidism (PHP) is a genetic disorder in which the body fails to respond to parathyroid hormone.
47
Furosemide is used to treat ……..
Hypercalcemia by inhibiting Ca reabsorption
48
Etidronate is used to treat ……
Hypercalcemia by inhibiting bone resorption
49
How many amino acids does Calcitonin have?
32
50
What is the effect of cortisol on ca metab?
Decreases serum ca
Antagonises Vit d3 so it prevents absorption of ca and PO4 from the gut
51
…. Increases renal Ca excretion and increases absorption of Ca from the gut. Net effect is +ve
Growth hormone
52
How many amino acids does Renin have?
340aa
53
What are sufonylurea drugs?
Sulphonylureas are a class of oral (tablet) medications that control blood sugar levels in patients with type 2 diabetes by stimulating the production of insulin in the pancreas and increasing the effectiveness of insulin in the body.
54
Angiotensin II has how many aa?
8 aa
| It is an octapeptide
55
AG II decreases GFR by……
Constriction of efferent arterioles and constriction of mesangial cells to reduce the surface area of the glomerular capillaries
56
AG directly increases plasma osmolality by……
Directly increasing the reabsorption of Na at the PCT
57
How does AG II indirectly increase BP?
It stimulates sympathetic fibres to release NE which causes vasoconstriction via alpha receptors
58
What’s the half life of angiotensin II?
1-2 mins
59
What’s the dimension of the testes?
2.5*4cm
60
What are the substances produced by sertolli cells?
Inhibin
Activin
Androgen binding proteins
Mullerian inhibiting hormone
61
How are sex hormones transported in the blood?
1. Sex hormone binding globulin or gonadal steroid binding globulin 65%
2. Albumin 33%
3. Cortisol binding globulin to a little extent
62
What’s the action of cAMP on cholesterol?
Increases its conversion to pregnenolone by activating pkA
63
What are the characteristics of hypogonadism in childhood in males
Tallness due to late epiphyseal plate closure
Small genitalia
High pitched voice
Narrow shoulders and small muscles
Sparse body hair
Sterility due to the absence of spermatogenesis
Pubic hair with female pattern
64
Sterility in males may be due to ……
Little or no testosterone to stimulate spermatogenesis
65
What structure secretes relaxin?
Corpus luteum
66
What hormone increases basal body temp in females?
Progesterone
67
What maintains the corpus luteum and where is it produced from?
HCG
Syncytiotrophoblast and placenta later on
68
When does the mammary gland along with its lobules and ducts develop?
Halfway through pregnancy
69
The largest duct of the mammary gland is the …..
Lactiferous duct which drain into sinuses before coming out into the areola
70
Around what month is oogenesis completed in fetal life?
7 month
71
What secretes inhibin in females?
Granulosa cells
72
What hormone increases uterine sensitivity to oxytocin and increases uterine excitability?
Estrogen
| It also increases uterine blood flow
73
What hormone acts as an antagonist to estrogen by decreasing the number of estrogen receptors and decreasing uterine excitability and sensitivity?
Progesterone
74
….. stimulates the enlargement of the lobules and alveoli of the breast?
Progesterone
75
At what day does the dominant follicle emerge?
Day 6
76
What is responsible for ovulation?
LH surge
77
Apart from the LH surge, how is the follicle ruptured?
Through the action of proteolytic enzymes
Progesterone
Prostaglandins
78
At what day does the corpus luteum degenerate of pregnancy doesn’t occur?
Around day 24
79
In the follicular phase, estrogen inhibits ……. And enhances …….
FSH
LH
80
What hormone inhibits LH?
Progesterone
81
In the proliferative phase, occurs from days ………. And what hormone influences this?
5-14
Estrogen that causes endometrial thickening
82
In the secretory phase, occurs from days ………. And what hormones influences this?
14-28
Progesterone causes the endometrium to be secretory
Estrogen causes endometrial vascularisation
83
Polymenorrhea is characterized by?
A menstrual cycle that’s shorter than 21 days caused by stress and endometriosis
84
Dysmenorrhea is characterized by ……..
Painful menstruation and menstrual cramps
85
What is menometrorrhagia?
Menometrorrhagia, defined as excessive and prolonged uterine bleeding occurring at irregular and/or frequent intervals, occurs in up to 24% of women aged 40-50 years.
86
The syncytiotrophoblast is formed ———— after fertilization?
3-6 days
87
The placenta is formed when?
7-8 weeks after pregnancy
88
At what week is hCG maximum during pregnancy?
10-12 weeks
89
…… is also known as human chorionic somatomammotropin?
Human placental lactogen
90
What hormone produced by the placenta promotes genital tract differentiation and fetal testicular secretion?
hCG
91
What hormone during pregnancy acts as an insulin antagonist, decreases glucose utilization by the mother and causes Na, K and Ca retention?
Human chorionic somatomammotropin
92
The breast ductal system dev is stimulated by …….
Estrogen
93
What hormone increases maternal ventilation during pregnancy?
Progesterone
94
In how many weeks can hCG be detected in the urine
About 2 weeks
| 14 days
95
By how many percent does CO increase in a 20 week pregnant woman?
30-40%
96
In pregnancy, blood volume and respiratory volume are increased by …….. but BMR is increased by ……
20%
| 15%
97
Polymenorrhea is characterized by
A cycle shorter than 21 days due to stress and endometriosis
98
At what week does labor start?
At week 40
99
Braxton Hick’s contractions are …….
Rhythmic contractions of the myometrium
100
How long do the stages of labor last?
1st stage- 8-24 hours
2nd stage 20-90 mins
3rd stage 15-30 mins
101
The shedding of the endometrium after birthing is a discharge called
Lochia
102
At what stage of pregnancy is the baby given birth to
2nd stage
103
What two hormones contribute to the functional dev of the breast by stimulating the production of the enzymes?
Prolactin and hCG
104
Rhythmic method of contraception involves ————-
Avoid fertile period + or - 3 days around ovulation
105
In how many weeks is the pre pregnant body regained after birthing?
4-6 weeks
106
Cholostrum contains …… and …… that helps to provide immunity to the child
Lactoferrin which has anti bacterial action and IgA
107
High levels of prolactin can inhibit …… and ………
Estrogen and progesterone and this can disrupt the menstrual cycle and lead to infertily. That’s why lactation during breastfeeding when there is high levels of prolactin, can be used as a form of natural contraceptive
108
What’s the half life of insulin?
5-6 mins
109
What stimulates the secretion of insulin?
Blood sugar levels 90mg/dL
110
Congenital absence of 1 alpha hydroxylase leads to
Vit D resistance
111
In what type of diabetes mellitus is there weight loss?
Type 1
112
What hormones are used as steroidal contraceptives?
Estrogen and Progesterone
Or progesterone alone
113
What are the symptoms of deficiency of 17 alpha hydroxylase?
Lack of pubic and axillary hair in females
Deficiency of glucocorticoids
High levels of mineralocorticoids
114
In Depot intramuscular injection contraception, how long does it last?
2-3 months
115
How long can a subdermal contraceptive last?
< 2 years
116
Exogenous testosterone supports …….. but does not support …..
Androgen effects of sexual function and other targets of testosterone but does not support spermatogenesis
117
In menopause, the existing follicles are unresponsive to …….
FSH and LH
118
What are the characteristics of hotflushes?
```
Vasomotor instability
Wide fluctuation in BP
Fatigue
Nervousness
Emotional outburst
Insomnia
Palpitations
Vertigo
Headache and numbness
Osteoporosis
```
119
What can be used to treat hot flushes?
Estrogen replacement therapy
Estrogen progesterone replacement therapy
Calcium supplements
120
Addison’s disease is characterized by…..
Weight loss
Chronic hypotension(addisonian crisis)
Elevated levels of ACTH leading to hyperpigmentation
Hyperkalaemia
121
What is the action of thyroid hormones on serum cholesterol?
It upregulates LDL receptors of the liver to transport cholesterol into the liver
Increases the uptake of cholesterol via steroid producing cells
Excretes sterol via the gut
122
How does stress affect thyroid hormone synthesis?
Stress decreases tsh levels cause glucocorticoids inhibit TRH
123
Whats the action of melatonin in humans?
it delays the onset of puberty by inhibiting the gonads
124
AG1 has .............. amino acids while AG2 has ............... aa
10
| 8
125
```
in the dev of the gonads,
5th-6th week is for
7th-8th week is for
8th -12th week is for
10th-12th week is for
```
1. dev of bipotential gonad
2. sex determination and gonadal differentiation
3. endocrine hormone secretion
4. development of internal genitalia(testosterone and MIF dependent) and external genitalia(testosterone dependent only)
126
how long does spermatogenesis take?
72-74 days
127
GnRH is a peptide with how many aa?
10
128
what is the normal sperm count?
100-200million per ml
| amount of sperm in a single ejaculate is 3-4ml
129
turner's syndrome is ... while kinefelter syndrome is .........
45X0
| 47XXY
130
characteristics of turner syndrome includes ..........
shorter than average
slightly larger necks
infertility
131
characteristics of turner syndrome includes ..........
shorter than average
slightly larger necks
infertility
132
characteristics of Klinefelter syndrome includes ..........
low testosterone production
reduced fertility or infertility
taller than average
moree breast tissue
133
granulosa cells secrete ... while theca cells produce .........
inhibin and they also produce estradiol(under the action of FSH)
granulosa cells receive androstenedione made by the theca cells as their precursor for its synthesis
theca cells produce androstenedione from cholesterol under the action of LH
134
…… is the life saving hormone
Aldosterone
135
Estrogen has actions similar to what hormone? Cause it causes …….
Aldosterone
| Salt and water retention
