Unit 8

Knowing what you now know about positive and negative feedback effects of sex steroids, how do you think hormonal contraceptives work to prevent ovulation? a) Maintain E & P at low levels b) Maintain E & P at moderate levels c) Maintain E & P at high levels

B because if E & P are too low, it will stimulate more to be released, and if E & P are too high, then high E will cause an egg to be released via ovulation

Which of the following statements about GnRH are true? A. Estrogen secreted by follicles always provides negative feedback regulation of GnRH secretion. B GnRH is a steroid hormone secreted by cells in the hypothalamus. C. Testosterone secreted by interstitial cells in the testes provides negative feedback regulation of GnRH secretion. D. GnRH stimulates the release of LH and FSH from cells in the posterior pituitary E. During the luteal phase of the ovarian cycle, estrogen secreted by the corpus luteum provides negative feedback regulation of GnRH secretion F. Estrogen can increase or decrease the amount of GnRH secretion by the hypothalamus, depending on the amount of estrogen.

C, E, F

Which of the following can be found in the seminiferous tubules of testes? a) Sertoli Cells b) Primary spermatogonia c) Mature, motile sperm d) a) and b) are correct; c) is incorrect e) a), b), and c) are all correct

D c is incorrect because sperm do not become mature until they are in female reproductive system

Very high levels of estrogen will increase GnRH, whereas very high levels of testosterone will decrease GnRH. a. True b. False

True

What is the name of the uterine tissue layer that changes in thickness during the menstrual cycle, and into which a fertilized embryo implants at the start of pregnancy?

endometrium

after leaving the seminiferous tubule, spermatozoa enter the

epididymis

Match the descriptions with the correct phases of the ovarian cycle menses occurs during the first part of this phase

follicular phase

Match the descriptions with the correct phases of the ovarian cycle the antrum of the follicle grows larger during the end of this phase

follicular phase

Cortisol and ________________ are both hormones that bind to receptors found on/in liver cells, and both promote gluconeogenesis and increases in blood glucose concentration.

glucagon

which hormone keeps the corpus luteum from disintegrating at the beginning of a pregnancy

human chorionic gonadotropin (hCG)

Match the descriptions with the correct phases of the ovarian cycle GnRH secretion is inhibited by estrogen secreted from the corpus luteum during this phase

luteal phase

Match the descriptions with the correct phases of the ovarian cycle progesterone levels are highest during this phase

luteal phase

Match the descriptions with the correct phases of the ovarian cycle this phase corresponds to the secretory phase of the uterine cycle

luteal phase

phases of ovarian cycle

luteal phase ovulation follicular phase

• Is the posterior pituitary gland protected by the blood brain barrier? a) Yes b) No

no

Match sex organs with structures they are derived from. ovary testis uterus fallopian tubes vas deferens seminal vesicles labia majora scrotum all answer choices: A. Mullerian duct B. bipotential gonad C. bipotential external genitalia D. wolffian duct

ovary & testes - B uterus & fallopian tubes - A vas deferens & seminal vesicles - D labia major and scrotum - C

Match the descriptions with the correct phases of the ovarian cycle LH levels peak during, or just before, this phase

ovulation

Match the descriptions with the correct phases of the ovarian cycle a follicle ruptures during this phase

ovulation

what defines a hormone (4 main characteristics)

1. secreted by cells 2. secreted into blood 3. transported to a distant target 4. exert their effect at very low concentrations

How will increased parasympathetic output affect insulin secretion? (a)Increase (b)Decrease (c)No change

A

Dexamethasone is a corticosteroid that is very similar to cortisol (they are both glucocorticoid receptor agonists). Dexamethasone has been in the news lately because it was used to treat President Trump for COVID-19. Which of the following statements about dexamethosine is/are correct? a) Dexamethasone suppresses immune system function b) Dexamethasone increases ACTH levels c) Dexamethasone helps people with diabetes control their blood glucose levels d) a) and b) are both correct; c) is incorrect e) a), b), and c) are all correct

A a is correct because cortisol suppresses immune system function b is incorrect because increasing "cortisol" would cause negative feedback pathway to be activated and ACTH would decrease so that cortisol would decrease d is incorrect because cortisol is released to increase glucose in blood via glucogenesis, which would be bad for someone who already has high plasma glucose levels

match following hormones with appropriate chemical class a. modified cholesterol molecules b. cortisol c. modified tyrosine molecules d. epinephrine e. short chains of amino acids f. insulin type of hormone: amine steroid peptide

A - steroid B - steroid C - amine D - amine E - peptide F - peptide

peptide or steroid? match the following characteristics with the appropriate type of hormone A. lipophobic B. lipophilic C. slow response time D. rapid response time E. G-protein coupled receptors F. intracellular receptors

A. peptide B. steroid C. steroid D. peptide E. peptide F. steroid

Which of the following is/are true about the male reproductive system? a. Sertoli cells secrete DHT, which stimulates spermatogenesis b. Leydig cells express cell surface receptors that bind LH c. Sperm are fully motile and mature when they leave the seminiferous tubules d. (a) and (b) are correct; (c) is incorrect e. (a), (b), and (c) are all correct

B a is incorrect because DHT is derived from testosterone which is secreted by Leydig cells c is incorrect because sperm do not become fully motile and mature until they enter the female reproductive system

which of the follow statements is/are correct about the cortisol pathway? a. Cortisol is secreted by cells in the adrenal medulla b. Cells of the anterior pituitary gland express cortisol receptors (i.e., glucocorticoid receptors) c. A decrease in cortisol causes a decrease in ACTH. d. (a) and (b) are correct; (c) is incorrect e. (a), (b), and (c) are all correct

B a is incorrect because cortisol is released by the adrenal cortex b is correct because when cortisol levels increase in the blood they will create negative feedback system by binding to receptors in the anterior pituitary gland to stop/start releasing ACTH depending on cortisol levels in blood c is incorrect because a decrease in cortisol would signal for an increase in ACTH

Which of the following will stimulate the release of the hormone insulin? a) Low plasma glucose b) ACh binding to muscarinic ACh receptors on β-cells of the pancreas c) Cortisol secretion from the adrenal cortex d) a) and b) are correct; c) is incorrect e) a), b), and c) are correct

B a is incorrect because insulin release is stimulated by high levels of plasma glucose, since insulin causes glucose to be taken up and stored b is correct because these cells would be activated to release insulin then c is incorrect because glucagon is what stimulates the release of insulin

In response to the presence of food in the stomach, G cells secrete gastrin, a peptide hormone, into the lumen of the stomach. a) True b) False c) Not enough information to answer the question.

B - False This is false because gastrin is secreted into the plasma of blood, not the lumen

Which of the following statements is correct about an embryo with an XX genotype that is exposed to DHT early in development? a. The bipotential gonads will develop into testes b. The Wolffian duct will develop in this embryo c. This embryo may have masculinized external genitalia d. (a) and (b) are correct; (c) is incorrect e. (a), (b), and (c) are all correct

C a is incorrect because the SRY gene would be absent so the bipotential gonads would develop into ovaries b is incorrect because testosterone won't be produced because there are no testis so the wolffian duct will regress c if DHT is present, then the bipotential genitalia may develop masculinized external genitalia

What kind of receptors on the β cells of the pancreas respond to parasympathetic output? ( a) α-receptors (b) β-receptors (c) nACh receptors ( d) mACh receptors

D

How will an increase in ACTH production affect CRH levels in the blood? Increase CRH Decrease CRH Cause no change in CRH

Decrease CRH - this is because CRH is what stimulates ACTH to be released, so as ACTH increases this would provide negative feedback to decrease CRH production

Which of the following statements about the female reproductive cycle is/are correct? a) The corpus luteum secretes progesterone, which is why this hormone is high during the luteal phase. b) The LH surge ends when ovulation happens and the follicular cells remaining in the ovaries become the corpus luteum. c) Menstruation is triggered by the drop in progesterone that occurs with the corpus luteum degrades. d) a) and b) are correct; c) is incorrect e) a), b), and c) are all correct

E

• An embryo with the genotype XX develops a uterus and fallopian tubes (and does not develop a prostate, vas deferens, or epididymis) due to which of the following influences? a) Regression of the Wolffian Duct b) Development of the Mullerian Duct c) Low DHT levels. d) a) and b) are correct; c) is incorrect e) a), b), and c) are all correct

E

Which of the following is/are true about the hormonal control of female reproduction a. High testosterone in a female may prevent ovulation b. The corpus luteum forms from follicular cells after ovulation c. Ovulation occurs when estrogen and LH are high d. (a) and (b) are correct; (c) is incorrect e. (a), (b), and (c) are all correct

E a is correct because this could create negative feedback to stop producing LH and FSH b is correct C is correct

list the steps that lead to an increase in cortisol levels. Be sure to include the anatomical location where each of these steps take place.

Exocytosis of vesicles that contain CRH (hypothalamus) → CRH goes into plasma → portal vessels → CRH exits capillaries and binds to anterior pituitary cells → ACTH is released from ant pit cells → ACTH goes into plasma → ACTH exits capillaries and binds to adrenal cortex cells → Adrenal cortex secretes cortisol → cortisol goes into plasma = increase in plasma cortisol.

As a component of the overall response to stress, epinephrine is released from cells of the adrenal cortex into the interstitial compartment where it acts on neighboring cells. True or false

False - epinephrine is secreted by the adrenal medulla, and cortisol is secreted by the adrenal cortex

Oxytocin and vasopressin are two peptide hormones that are synthesized and released by the posterior pituitary. True or false

False - vasopressin and oxytocin are synthesized in the hypothalamus then released by the posterior pituitary

If an XX fetus is exposed to DHT early in development, at birth the child will have a uterus, and the external genitalia may be masculinized. True or false?

True

Which of the following is/are true about steroid hormones? a) Since they diffuse through cell membranes, steroid hormones will affect any cells they encounter. b) Steroid hormones quickly bind to a carrier protein after they are released from a gland. c) Steroid hormones cannot cross the blood brain barrier. d) a) and b) are correct; c) is incorrect e) a), b), and c) are all correct

a is incorrect because the response depends on the presence of corresponding intracellular receptors b is correct because they are hydrophobic so cannot dissolve in the plasma d is incorrect because they are lipophilic and can easily cross the BBB because they can easily cross the plasma membrane

which of the following conditions permits the bipotential gonads to develop into ovaries in a female fetus

absence of SRY gene

which hormone is produced by the testes and is responsible for preventing the development of a uterus and fallopian tubes in male fetuses?

anti-Mullerian hormone

a 42 year old has a total hysterectomy and bilateral oophorectomy (removal of both ovaries). What effect would this have on her hormone levels?

increased FSH and LH, decreased estrogen and progesterone E + P are released by the ovaries, so they would decrease when ovaries are removed. FSH and LH are released by the anterior pituitary and if there is no estrogen and progesterone to exhibit negative feedback then they would just be released because they think they need to create more estrogen and progesterone

In Type 1 diabetes mellitus, the beta cells of the pancreas are unable to produce insulin. Would a person with untreated Type 1 diabetes mellitus have (a) more, (b) less, or (c) equal levels of glycogen in his/her liver compared to a healthy person?

less because less insulin means that there will be less glycogenesis in the liver (less storage of glycogen)