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Flashcards in hormones Deck (37)
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functions of cortisol

Cortisol has numerous actions and is essential for life

Increases blood pressure: permits normal response to angiotensin II and catecholamines byup-regulating alpha-1 receptors on arterioles

Inhibits bone formation: decreases osteoblasts, decreases type 1 collagen, decreases absorption of calcium from the gut, increases osteoclastic activity

Increases insulin resistance

Metabolism: increases gluconeogenesis, lipolysis and proteolysis

Inhibits inflammatory and immune responses

Maintains function of skeletal and cardiac muscle


The water deprivation test is designed to help evaluate patients who have

polydipsia - given to excessive thirst


method of a water deprivation test

prevent patient drinking water
ask the patient to empty their bladder
hourly urine and plasma osmolalities


A 3-month-old boy is suspected of having hypospadias. At which of the following locations is the urethral opening most frequently located in boys suffering from the condition?

The defect is located ventrally and most often distally. Proximally located urethral openings are well recognised. Circumcision may compromise reconstruction.


prolactin function

simulates breast development
stimulates milk production
blocks action of LH on testes or ovaries

secretion is under constant inhibition by dopamine


too much aldosterone effect

Usually, aldosterone balances sodium and potassium in your blood. But too much of this hormone can cause you to lose potassium and retain sodium.


Primary hyperaldosteronism was previously thought to be most commonly caused by an adrenal adenoma, termed Conn's syndrome. However, recent studies have shown that bilateral idiopathic adrenal hyperplasia is the cause in up to 70% of cases. Differentiating between the two is important as this determines treatment. Adrenal carcinoma is an extremely rare cause of primary hyperaldosteronism.




muscle weakness in exam questions due to potassium

drenal adenoma: surgery
bilateral adrenocortical hyperplasia: aldosterone antagonist e.g. spironolactone


in stress or surgery what hormones are reduced

insulin , testosterone and oestrogen and thyroxine sometimes


what hormone plays a key role in the regulation of body weight and is produced by adipose tissue acting on the satiety centres.

Leptin is thought to play a key role in the regulation of body weight. It is produced by adipose tissue and acts on satiety centres in the hypothalamus and decreases appetite. More adipose tissue (e.g. in obesity) results in high leptin levels.


leptin stimulates the release of what other hormones

and low levels of leptin stimulate the release of what

Leptin stimulates the release of melanocyte-stimulating hormone (MSH) and corticotrophin-releasing hormone (CRH). Low levels of leptin stimulates the release of neuropeptide Y (NPY)


as we know leptin induces satiety but what hormone stimulated hunger



ghrelin is produced by which cells

It is produced mainly by the P/D1 cells lining the fundus of the stomach and epsilon cells of the pancreas


when do gherlin levels decrease and increase

Ghrelin levels increase before meals and decrease after meals


GH released by what and released in what kind of manner

Growth hormone (GH) is an anabolic hormone secreted by the somatotroph cells of the anterior lobe of the pituitary gland. It has actions on multiple organ systems and is important in postnatal growth and development. Growth hormone is also responsible for changes in protein, lipid, and carbohydrate metabolism


what enzyme does PTH act on

PTH increases the activity of 1-α-hydroxylase enzyme, which converts 25-hydroxycholecalciferol to 1,25-dihydroxycholecalciferol, the active form of vitamin D.
Osteoclasts do not have a PTH receptor and effects are mediated via osteoblasts.


PTH secreted by what cells

chief cells


3 effects of pth on bone , kidneys and intestine

Effects of PTH
Binds to osteoblasts which signal to osteoclasts to cause resorption of bone and release calcium.

Active reabsorption of calcium and magnesium from the distal convoluted tubule. Decreases reabsorption of phosphate.

Intestine via kidney
Increases intestinal calcium absorption by increasing activated vitamin D. Activated vitamin D increases calcium absorption.


A 50-year-old man comes into your clinic with numbness and paraesthesia felt in his right thumb and index finger. His hands appear to be quite large and you notice wide spaces in between his teeth. Which hormone is most likely to be raised?


Jaw prominence (prognathism), spade like hands and tall stature are all signs that would be seen in growth hormone excess. Patients may complain that their hats or shoes no longer fit, as well as joint pain, headaches and visual problems. Note that excess growth hormone secretion before growth plate fusion results in gigantism, whilst excess secretion after growth plate fusion results in acromegaly.


Antidiuretic hormone (ADH) is secreted from the posterior pituitary gland. It promotes water reabsorption in the collecting ducts of the kidneys by the insertion of

aquaporin-2 channels


dibetes insidious characterised by defiecney of ADH or insensitivity to it

Diabetes insipidus (DI) is a condition characterised by either a deficiency of antidiuretic hormone, ADH, (cranial DI) or an insensitivity to antidiuretic hormone (nephrogenic DI)
Cranial DI can be treated by desmopressin, an analog of ADH


what hormones decrease and increase appetite respectively

gherlin increases and leptin decreases

thyroxin also increases


what hormone known as the growth inhabiting hormone is produced in the pancreas by delta cells ( pylorus and duodenum ) and inhibits the secretion of insulin and glucagon

Glucagon increases the secretion of somatostatin via the feedback mechanism, while insulin decreases its secretion. Somatostatin also controls the emptying of the stomach and bowel.

Decreases acid and pepsin secretion, decreases gastrin secretion, decreases pancreatic enzyme secretion

Inhibits trophic effects of gastrin

Stimulates gastric mucous production


what does somatostatin regulate

Increases secretion
fat, bile salts and glucose in the intestinal lumen

Decreases secretion


what can use to manage acromegaly and why

Somatostatin analogs are used in the management of acromegaly, as they inhibit growth hormone secretion


GH is somatotropin which make up 50% of the anterior pituitary what are some example of gonadotrophs

FSH and LH


Prolactin release is persistently inhibited by

dopamine and dopaminergic agonists


Prolactin release is upregulated by what two hormones

what drug increases its secretion

thyrotropin-releasing hormone and oestrogen


drugs e.g. metoclopramide, antipsychotics


Prolactin has an inhibitory effect on

gonadotropin-releasing hormone and luteinising hormone.


what is the function of prolactin

Stimulates breast development (both initially and further hyperplasia during pregnancy)

Stimulates milk production

It decreases GnRH pulsatility at the hypothalamic level and to a lesser extent, blocks the action of LH on the ovary or testis.


what do antipsychotics block

Risperidone is an atypical antipsychotic. Antipsychotics all block dopamine activity to various degrees.