Endocrinology and Reproduction

Question 0

Increase insulin production

Answer 0

Rise in: glucose, aa, FA
Parasympathetic N S - Aco
Sulfonylurea
Obesity, insulin resistance
Beta- adrenergic, GI hormones, GH, cortisol, glucagon

Question 1

Mechanism of glucose stimulation of insulin production

Answer 1

Glucose>100mg/dl - transported by GLUT2 - phosphorilated - oxidated to form ATP - close ATP sensitive K channels - depolarization of membrane - open Ca channels - move lysosomes w insuline and peptide C to membrane - exocytosis.

Question 2

Inhibit insulin production

Answer 2

Sympathetic NS
Reduction in glucose
Somatostatin
Alfa-adrenergic activity
Leptin

Question 3

Withdraw of which hormone causes mentruation?

Answer 3

Progesterone

Question 4

Immunization to produce antibodies that would bind to FSH and negate its activity is being investigated as a potential male contraceptive. Men immunized in this manner would exhibit ____.

Answer 4

decreased serum inhibin levels

Question 5

The two essential hormones for the production of sperm (spermatogenesis) are _____.

Answer 5

FSH and testosterone

Question 6

In males and females, secretion of luteinizing hormone (LH) by the pituitary is regulated by ____.

Answer 6

Gonadotrophin Releasing Hormone (GnRH)

Question 7

In a female patient with an inactivating mutation of the estrogen receptor genes (both alpha and beta), one would expect _____.

Answer 7

1-low progesterone receptor number in breast tissue
B. high plasma estrogen concentration.
C. no mid-cycle LH and FSH surge.

Question 8

Steroid hormones such as estrogen and progesterone _____.

Answer 8

A. freely diffuse through cell membranes.

Question 9

In the first 8 days of the menstrual cycle, how does estrogen affect the release of FSH and LH from the pituitary?

Answer 9

B. Decrease

Question 10

In the male and female gonad, ____ is converted to estrogen by aromatase activity.

Answer 10

A. androgen Correct 1.00

Question 11

What hormone(s) are negatively regulated by inhibin B in the male and in the female?

Answer 11

A. FSH

Question 12

In males and females what hormone(s) does kisspeptin regulate?

Answer 12

B. GnRH

Question 13

What is the phenotype of a XY individual in which all forms of the enzyme, 5’alpha reductase, are inactive?

Answer 13

A. female

Question 14

Insulin dependent glucose uptake occurs in which of the following sites?

Answer 14

A. kidney
B. skeletal muscle Correct
C. brain
D. cardiac muscle

Question 15

Jane, a 23 year old female, presents with complaints of a 15 lb weight loss and periodic episodes of weakness 2 hours after eating. On examination you find her blood pressure is 120/80. Her laboratory data shows fasting hyperglycemia (glucose, 200 mg/dl). You suspect an endocrine pathology and request an RIA for the hormone _____.

Answer 15

E. insulin

Question 16

Jane’s, 23 years old, complaining of weight loss and episodes of weakness 2 hours after meals. Laboratory results shows fasting hyperglycemia (glucose 200mg/dl) and confirm insulin is absent. You administer an oral glucose tolerance test. Her glucose tolerance test fails (400 mg/dL at 4 hours post ingestion) . You would classify this endocrine pathology as ______.

Answer 16

B. primary, pancreatic islet insufficiency.

Question 17

Which of the following hormones is catabolic in its action?

Answer 17

E. cortisol and glucagon

Question 18

During the fed state, nervous tissue derives most of its metabolic energy from:

Answer 18

A. glucose

Question 19

During the fasting state, most of the circulating glucose is due to the _____which breaks down glycogen to glucose.

Answer 19

A. liver

Question 20

Which of the following hormones stimulates lipolysis (break down of fat)?

Answer 20

A. insulin
B. aldosterone
C. insulin like growth factor 1
D. epinephrine - correct

Question 21

Epinephrine acts in a synergistic manner to regulate blood levels of glucose by inhibiting:

Answer 21

A. insulin secretion

Question 22

A patient with diabetic ketoacidosis hyperventilates because____.

Answer 22

C. elevated plasma H+ concentration stimulates respiratory centers.

Question 23

At the end of a strenuous workout lasting 3 hours, John’s blood glucose levels were 70 mg/dL. Which of the following hormones would be increased in his blood at this time?

Answer 23

E. cortisol, growth hormone, and epinephrine

Question 24

Effects of insulin in carbohydrates metabolism

Answer 24

Promote absorption of glucose in all cells of body except brain, cardiac muscle and kidneys.
Promote muscle glucose uptake: use as energy during moderate or heavy exercise, during the few hours after a meal
Storage of glycogen in muscles (anaerobic energy - glycogen=>lactic acid) and liver
Conversion of excess glucose in FA =>triglycerides=>blood=>stored in adipose tissue
Inhibits gluconeogenesis

Question 26

Effects of insulin on the liver

Answer 26

Inactivates phosphorylase ( enzyme that splits glycogen into glu)
Enhances uptake of glucose by increase activity of glucokinase (phosphorylation of glucose)
Increase activity of enzymes that promote glycogen synthesis
Depresses the rate of gluconeogenesis (conserves aa in ptn stores)
Promotes conversion of excess of glucose in FA

Question 27

Effect of insulin on fat metabolism

Answer 27

Increases utilization of glucose by most tissues, which decreases utilization of fat
Promotes FA synthesis:
a) glu=>liver =>Pyruvate=> Acetyl-CoA=>FA=>triglycerides=>blood=>insulin activates lipoprotein lipase in capillary wall of adipose tissue=> triglycerides to FA=>absorbed into adipose cells.
Inhibits action of hormone-sensitive lipase (causes hydrolyses of stored triglycerides )
Promotes transport of glu into fat cells=>glycerol and minute amounts of FA

Question 28

Consequences of lack of insulin

Answer 28

Increase blood glucose
Increases use of FA for energy in mitochondria=> Acetyl-CoA=>acetoacetic acid (some are converted in beta-hydroxybutyric acid and acetone)
Depresses utilization of acetoacetic acid in peripheral tissues
increase plasma concentration of free FA =>liver converts FA into phospholipids and cholesterol that together with the excess of triglycerides causes atherosclerosis

Question 29

Effect of insulin on protein metabolism

Answer 29

Stimulates transport of aa into the cells
Increases translation of RNAm
Increases rate of transcription of DNA
Inhibits catabolism of ptn
Depresses rate of gluconeogenesis in the liver (most used substract are plasma aa