Female Reproductive Tract

Question 1

Where is LHRH (Luteinizing Hormone Releasing Hormone) produced?

Answer 1

hypothalamus

Question 2

LHRH is also known as?

Answer 2

GnRH (gonadotropin releasing hormone)

Question 3

What type of hormone is LHRH (GnRH)?

Answer 3

Peptide it is 10 amino acids long

Question 4

Where in the hypothalamus is GnRH (LHRH) made?

Answer 4

arcuate nucleus and the medial preoptic area

Question 5

Once it travels through the portal vessels to the anterior pituitary LHRH (GnRH) will bind to?

Answer 5

receptors on gonadotrophs

Question 6

Once GnRH is bound to the receptors on the gonadotrophs, how does it work?

Answer 6

GnRH is a peptide, so it does not enter the cell. It activates the second messenger system, including Ca++ to release LH and FSHto the systemic circulation.

Question 7

GnRH (LHRH) causes the anterior pituitary to release which hormones?

Answer 7

LH (luteinizing hormone) and FSH (follicle stimulating hormone)

Question 8

LH and FSH act on what?

Answer 8

the ovary which releases progesterone and estrogen

Question 9

What type of hormone is LH or FSH?

Answer 9

both are glycoprotein hormones (not simple polypeptides but have sugars attached to a backbone of amino acids)

Question 10

Do LH and FSH have the same structure?

Answer 10

Very similar. Their alpha subunits are identical. They differ in their beta subunits. (this allows for specificity of binding)

Question 11

Which 4 hormones have identical alpha subunits but differ in beta subunits?

Answer 11

TSH, hCG, FSH, LH all have identical alpha subunits

Question 12

After FSH and LH bind to receptors on the ovaries they________________________.

Answer 12

Work together to make estrogen and progesterone.

Question 13

What is the main estrogen produced in the ovary?

Answer 13

17 beta estradiol

Question 14

There are 3 different kinds of gonadotrophs, what does each do?

Answer 14

the kind that only make LH, only make FSH, and some that make both. All 3 respond to GnRH

Question 15

Do the hormones with the same alpha subunits intereact with each others receptors?

Answer 15

Not usually, but a pathologically high levels, there will be some overlap and they will interact.

Question 16

17 beta estradiol utilizes long loop negative feedback, how exactly does it act?

Answer 16

It provides negative feedback at the hypothalamus arcuate nucleus to suppress GnRH, It provides negative feedback to the anterior pituitary to downregulate receptors on gonadotrophs.

Question 17

17 beta estradiol is the only hormone that provides positive feedback. How does it work?

Answer 17

17 beta estradiol acts on the medial preoptic area of the hypothalamus.