Endocrinology

Question 1

What are the hormones secreted by anterior pituitary

Answer 1

FSH,LH, ACTH,TSH, PRL( prolactin), GH, Beta-endorphins and MSH

Question 2

Out of all hormones produced by adenohypophysis which are basophils and which are acidophils

Answer 2

Basophils are : FSH,LH,ACTH, TSH

Acidophils are: PRL, GH

Question 3

What are derivative of proopiomelanocortin

Answer 3

beta-endorphin, GH and MSH

Go Pro with BAM

Question 4

What is the other name of anterior pituitary and what is it derived from

Answer 4

Adenohypophysis

Derived from oral ectoderm (Rathke pouch)

Question 5

What is another name for posterior pituitary and what is it derived from

Answer 5

Neurohypophysis it is derived from neuroectoderm

Question 6

Ft. Of posterior pituitary

Answer 6

Storage of vasopressin ( ADH) and oxytocin

Question 7

Where are the hormones oxytocin and ADH produced

Answer 7

Hypothalamus (supraoptic and paraventricular nuclei)

Question 8

How are the hormones produced in the hypothalamus moved to the posterior pituitary

Answer 8

By carrier proteins ( neurophysin)

Question 9

Prolactin

Answer 9

Inhibited by: dopamine
Stimulated by : TRH

Inhibits: GnRH

Question 10

Prolactin ft.

Answer 10

Causes lactation in breasts

Question 11

GH

Answer 11

Released by anterior pituitary

Question 12

How is it induced

Answer 12

By GHRH from hypothalamus

Question 13

How is GHRH stimulated

Answer 13

By deep sleep, hypoglycemia and stress

Question 14

Explain the pathway

Answer 14

GHRH stimulates GH from pituitary that activates IGF-1 in liver that stimulates bone and muscle growth and decrease glucose uptake and increase lipolysis

Question 15

How is it inhibited

Answer 15

Negative feedback loop
GH inhibits GHRH

IGF-1 inhibits both GH and GHRH

Obesity, aging and glucose inhibits GHRH

Also by somatostatin and somatomedin

Question 16

What happens in case of excess GH

Answer 16

Adults: Acromegaly

Children: gigantism

Question 17

ACTH

Answer 17

Produced by hypothalamus

Stored in posterior pituitary

Question 18

Ft. Of ACTH

Answer 18

Increase water permeability in DCT and covulated tubules by increasing expression of aquaporins

Question 19

What induces the release of ACTH

Answer 19

Increases serum osmolality and low blood volume

Question 20

What does ACTH do ?

Answer 20

Decreases osmolality and increase blood volume

Question 21

What happens in case of decreased ACTH

Answer 21

Diabetes insipidus ( central)

Question 22

What happens if tubules are resistant to ACTH

Answer 22

Diabetes insipidus ( nephrogenic)

Question 23

What is hypopituitarism ?

Answer 23

It is the absence of hormones released from pituitary gland

Question 24

Causes of hypopituitarism ?

Answer 24

Sheehan syndrome ( postpartum ischemia of the pituitary due to excessive bleeding )

Empty stella syndrome : absence of pituitary due to its atrophy or compression asc. with idiopathic intracranial hypertension

Pituitary apoplexy: hemorrhages of pituitary gland usually in presence of existing pituitary adenoma ( shows visual impairment) refer to first AID book for more info

Question 25

Symptoms of hypopituitarism

Answer 25

Depends on the hormones lost
dec. GH: impaired growth decreased muscle mass in adults and inc. LDL inc. risk of CVD

Dec. TSH: hypothyroidism

Dec. ADH : diabetes insipidus

Dec. LH And FSH and prolactin : amenorrhea, infertility, non-lactation, loss of secondary sexual characteristic

Dec. ACTH: adrenal insufficiency

Dec. MSH: decreased pigmentations in skin and hair

Question 26

How to diagnose hypopituitarism

Answer 26

MRI ( shows any lesions but might miss microadenomas)

And decrease in levels of hormones or their trophic hormones

Question 27

How to treat ( hypopituitarism)

Answer 27

Replacement therapy of hormones lost

Question 28

What is acromegaly

Answer 28

Acromegaly is a condition that occurs in adults due to increased GH release after the epiphyseal bone closure

Question 29

Findings of acromegaly?

Answer 29

Large tongue with deep furrows
Aging features 
Coarsening features 
Increased size of hands and feet
Cardiomyopathy 
Organomegally 
Frontal bossing 
Deep voice

Question 30

Metabolic features of Acromegaly ?

Answer 30

Insulin resistance ( DM) ( glucose intolerance)

Severe sweating ( hyperhidrosis)

Increased risk of colorectal polyp and cancer

Question 31

How to diagnose acromegaly ?

Answer 31

IGF-1 must be increased

Oral glucose tolerance test ( failure to suppress GH)

MRI ( showing any pituitary adenoma)

Question 32

Parasellar features ? Of acromegaly

Answer 32

Visual problems ( bitemporal hemisnopsia)

Headaches

HTN

Sleep apnea

Question 33

What is laron syndrome

Answer 33

Autosomal recessive syndrome ( defective GH receptors) characterized by: High GH low IGF-1

Features: short stature(dwarfism), small head circumference, prominent forehead and saddle nose, delayed skeletal maturation, small genitalia

Question 34

Syndrome of inappropriate ADH secretion:

Answer 34

Characterized by: volume expansion and hyponatremia

Continued excretion of sodium due to ANP AND BNP that will lead to normalization of ECF fluid and euvolemic Hyponatremia ( without edema)

Correct hyponatremia slowly not more than (0.5mEq/kg in 1 hr) to prevent osmotic demyelinization syndrome ( central pontine myelinolysis)

Question 35

Causes of SIADH ?

Answer 35

Neuronendocrine tumors : small cell lung carcinoma

CNS injury/ trauma

Pulmonary disease
Drugs: vincristine and cyclophosphamide