hormones

Question 1

functions of cortisol

Answer 1

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

Question 2

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

Answer 2

polydipsia - given to excessive thirst

Question 3

method of a water deprivation test

Answer 3

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

Question 4

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?

Answer 4

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

Question 5

prolactin function

Answer 5

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

secretion is under constant inhibition by dopamine

Question 6

too much aldosterone effect

Answer 6

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

Question 7

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.

features

Answer 7

hypertension

hypokalaemia
hypernataumia

muscle weakness in exam questions due to potassium
alkalosis

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

Question 8

in stress or surgery what hormones are reduced

Answer 8

insulin , testosterone and oestrogen and thyroxine sometimes

Question 9

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

Answer 9

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.

Question 10

leptin stimulates the release of what other hormones

and low levels of leptin stimulate the release of what

Answer 10

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)

Question 11

as we know leptin induces satiety but what hormone stimulated hunger

Answer 11

ghrelin

Question 12

ghrelin is produced by which cells

Answer 12

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

Question 13

when do gherlin levels decrease and increase

Answer 13

Ghrelin levels increase before meals and decrease after meals

Question 14

GH released by what and released in what kind of manner

Answer 14

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

Question 15

what enzyme does PTH act on

Answer 15

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.

Question 16

PTH secreted by what cells

Answer 16

chief cells

Question 17

3 effects of pth on bone , kidneys and intestine

Answer 17

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

Kidney
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.

Question 18

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?

Answer 18

GH

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.

Question 19

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

Answer 19

aquaporin-2 channels

Question 20

dibetes insidious characterised by defiecney of ADH or insensitivity to it

Answer 20

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

Question 21

what hormones decrease and increase appetite respectively

Answer 21

gherlin increases and leptin decreases

thyroxin also increases

Question 22

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

Answer 22

somatostatin
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

Question 23

what does somatostatin regulate

Answer 23

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

Decreases secretion
insulin

Question 24

what can use to manage acromegaly and why

Answer 24

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

Question 25

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

Answer 25

FSH and LH

Question 26

Prolactin release is persistently inhibited by

Answer 26

dopamine and dopaminergic agonists

Question 27

Prolactin release is upregulated by what two hormones

what drug increases its secretion

Answer 27

thyrotropin-releasing hormone and oestrogen

pregnancy
breastfeeding
sleep
stress

drugs e.g. metoclopramide, antipsychotics

Question 28

Prolactin has an inhibitory effect on

Answer 28

gonadotropin-releasing hormone and luteinising hormone.

Question 29

what is the function of prolactin

Answer 29

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.

Question 30

what do antipsychotics block

Answer 30

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

Question 31

what condition is indicative of a lack of ADH

Answer 31

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

Question 32

Where does parathyroid hormone act in the kidney to increase calcium reabsorption?

Answer 32

DCT

Question 33

functions of glucagon

Answer 33

Glycogenolysis
Gluconeogenesis
Lipolysis

Question 34

what does insulin do to potassium

Answer 34

Insulin decreases serum potassium through stimulation of the Na+/K+ ATPase pump
Important for meLess important

Question 35

when is growth hormone stopped in the body

Answer 35

it isn’t In fully grown adults, adequate growth hormone levels are still required for maintenance of tissues

Question 36

what hormone increases the volume of pancreatic secretions

Answer 36

Cholecystokinin will often increase the volume of pancreatic secretions.

Question 37

A 38-year old male presents to the GP with nipple discharge. On investigation his serum prolactin is markedly elevated. Apart from prolactin releasing hormone which other hypothalamic hormone can increase the secretion of prolactin?

Answer 37

TRH