Quiz 3

Question 1

What is the site of sperm/testosterone production

Answer 1

Testes/seminiferous Tubules

Question 2

What do interstitial cells and nurse cells do in the seminiferous tubules?

Answer 2

Interstitial cells: secrete testosterone
Nurse Cells: aid in spermatogenesis, required to make sperm but they are not part of sperm, where mitosis occurs

Question 3

How are nurse cells linked outside the seminiferous Tubules ?

Answer 3

through tight junction: form the Blood-testes barrier which filter nutrients for the developing sperm.

Question 4

What do nurse cells secrete in response to testosterone?

Answer 4

they secrete inhibin, which decreases FSH secretion

Question 5

What is the pathway for FSH/LH with the testes and their inhibition ?

Answer 5

GnRH from the hypothalamus allows Anterior pituitary to release LH and FSH
The FSH allows Nurse cells to facilitate spermatogenesis and release inhibin
The LH allows Interstitial cells to release testosterone and excite the nurse cells to make more sperm
Both testosterone and inhibin will inhibit the anterior pituitary (inhibin is stronger). Testosterone will also inhibit the hypothalamus

Question 6

Explain division from spermatogonia to spermatids

Answer 6

-spermatogonia (2n) go through mitosis to produce 2 daughter cells
-one of these remains a spermatogonium, the other becomes a primary spermatocyte (2n)
-primary spermatocytes undergo meiosis producing 4 daughter cells called spermatids (1n)

Question 7

What is the anatomy of a sperm?

Answer 7

Head wrapped in acrosome, nucleus, midpiece with mitochondria, tail(flagellum) of microtubules

Question 8

Where do sperm move for maturation?

Answer 8

at the end of spermiogenesis, sperm move to the epididymis for maturation, here they acquire the ability to whip their flagellum

Question 9

When do sperm start swimming?

Answer 9

sperm are capable of using their flagellum but do not fully swim or demonstrate chemotaxis until exposure to progesterone, which activates Ca2+ signaling

Question 10

What are oocytes encased in? What occurs to this after ovulation?

Answer 10

They are encased in follicles. After ovulation, the follicle remains in the ovary and is called the corpus luteum. The average lifespan of a corpus luteum is 8~16 days unless fertilization occurs

Question 11

What are the 3 types of cells in a follicle?

Answer 11

Thecal cells, Ovum (secondary oocyte), granulosa cells

Question 12

What do Granulosa and Thecal cells do?

Answer 12

Granulosa: present since ovum was created, proliferate because of FSH

Thecal: originally part of ovary connective tissue but become part of follicle under the guidance of FSH.

Both secrete estrogen into the blood and antrum

Question 13

What are the two phases of the ovarian cycle?

Answer 13

follicular and luteal phases

Follicular phase: spans the first day of menstruation and end at ovulation. This time will be between 10-18 days

Luteal phase: begins at ovulation and ends at the beginning of the menstrual cycle, when the corpus luteum is no longer producing sufficient progesterone

Question 14

What is the hormonal pathway in the follicular phase?

Answer 14

LH and FSH allow Developing Follicle to grow.
This developing follicle releases inhibin and estrogen. Estrogen and Inhibin inhibit FSH, preventing more follicles from developing. Estrogen and progesterone can inhibit LH together

Question 15

What occurs at the end of the follicular phase?

Answer 15

Estrogen levels are very high. These levels will trigger a dramatic increase in LH secretion. This LH surge causes ovulation

Question 16

What is secreted and inhibited in the luteal phase?

Answer 16

high levels of both estrogen and progesterone are secreted . FSH is inhibited by estrogen, and LH is inhibited by the high levels of progesterone.

Question 17

What is the “getting ahead of the storm” theory regarding menstruation?

Answer 17

The developing placenta presents a unique danger to tissues. By making a big endometrium, we reduce risk of major damage. Unprepared tissues, such as the uterine tube, can suffer major damage, or even rip open causing internal bleeding, when the placental cells invade.

Question 18

What are the three layers of the uterus?

Answer 18

perimetrium: outer membrane
myometrium: thick smooth muscle layer
endometrium: lining of the uterus composed of thick connective tissue, sloughed off and re-grown every cycle.

Question 19

What do the secretions of the endometrial glands contain? What are their function?

Answer 19

amino acids, ions, glucose, fats, signaling molecules. First four are nutrients for Fetus. The functions: provide endometrial cells with signals that cause them to prepare for implantation.

Question 20

Hormones: bottom line on function

Answer 20

FSH: stimulates the development of follicles
LH: triggers ovulation
Estrogen: prepares uterine lining, breasts for lactation. Surge in estrogen triggers LH secretion. No variations in estrogen=no LH
Progesterone: maintains uterine lining by preventing uterine contraction

Question 21

In the 4 days before menstruation the following moods are often reported:

Answer 21

irritability, hostility, feelings of helplessness or frustration, known as premenstrual syndrome

Question 22

What is Premenstrual Dysphoric Disorder(PMDD)

Answer 22

5% of cycling women report severe symptoms including lack of concentration, depression, severe anxiety. These, collectively, are symptoms of PMDD

Question 23

What is Amenorrhea? Primary and Secondary?

Answer 23

-lack of period in a person that expects to menstruate
-Primary amenorrhea=lack of a first period in an individual aged 16 or older; usually low body fat
-Secondary amenorrhea= loss of a period for 6 months or more in an individual who was previously menstruating (pregnancy, lactation, low/high body fat)

Question 24

How would both obesity and low body fat inhibit the menstrual cycle?

Answer 24

-obesity increases the risk factors for a number of conditions that complicate the menstrual cycle (PCOS, endometriosis)
-it makes evolutionary sense to inhibit reproductive function in times of caloric scarcity; athletes resume menstruation almost immediately after stopping exercise, did not require gain in body fat

Question 25

During a given cycle, there are two-three other groups of follicles, which are?

Answer 25

Group 1: antral follicles that more advanced, one is the dominant follicle and is getting larger and larger, the others are going through atresia

Group 2: antral follicles that are less advanced, they will become group 1 in the next cycle

if there is a group 3, its like group 2 but may be further behind

Question 26

What does it mean for a cycle to be anovulatory ?

Answer 26

no eggs ever escape their follicles

Question 27

What can occur if cilia didn’t line the fallopian tube?

Answer 27

Without cilia, oocyte could end up in the wrong body cavity. Cilia sweep the oocyte toward the uterus

Question 28

What does the enzyme vesiculase do ?

Answer 28

it is produced by seminal glands and catalyzes a polymerization forming a semen plug at the cervix to prevent the backflow of sperm. It thickens semen to make this plug to stop outflow of semen from vagina. the plug will fall out after several hours.

Question 29

What do prostaglandins in the semen stimulate?

Answer 29

the prostaglandins in the semen stimulate these contractions, as does the woman’s orgasms

Question 30

What are the six steps of fertilization beginning with the acrosomal reaction?

Answer 30

1) sperms pass through the corona radiata
2) penetration of the zona pellucida
3) block to polyspermy: once one sperm has made it through the zona, enzymes from inside the egg harden the zona to stop any more sperm
4) Fusion of plasma membranes
5) completion of oocyte meiosis and formation of its nucleus
6) fusion of egg and sperm nuclei

Question 31

What is the acrosomal reaction?

Answer 31

The intact acrosome binds to proteins within the zona pellucida of the egg. This binding initiates small holes in the acrosomal membrane. Enzymes from the acrosome leak out and begin to digest the zona pellucida

Question 32

What is the blastocyst composed of and what are their purposes?

Answer 32

Inner cell mass-destined to become fetus
Trophoblast-accomplishes implantation and develops into fetal portions of placenta

Question 33

When does the zona pellucida dissolve?

Answer 33

from morula to blastocyst to allow for implantation

Question 34

What are the 3 cell types of the embryo and what will they become?

Answer 34

cells of inner cell mass-will become the embryo
cells of the cytotrophoblast- will become placenta
cells of the syncytiotrophoblast-will fuse becoming a “shell” separating maternal blood from placental cells

Question 35

Explain the mechanics of uterine invasion

Answer 35

cytotrophoblasts invade throughout the uterine lining, but seek O2 and gather at uterine arteries. Here, they replace the endothelial cells, and rip apart the vascular smooth muscle. Goal is to remodel the arteries to create blood jets. The pregnant person needs to increase their blood volume by 50% to meet the expansion of the system

Question 36

What will the cytotrophoblasts nearest to the fetus grow into?

Answer 36

they will grow into tree-like structures called placental villi. Inside the villus are capillary beds filled with fetal blood

Question 37

What occurs if the placenta does not grow fast enough?

Answer 37

If the placenta does not gain enough size swiftly enough, it cannot provide enough surface area for transmission of nutrients to the fetus

Question 38

What is important of L monocytogenes (B)?

Answer 38

They can cross the placenta. They are found in soft cheeses and can be fought off easily in adult bodies but fetuses do not have the immune system for it.

Question 39

Why is it important for peptides to cross the placenta?

Answer 39

Peptides allow the fetus to make an immune system. If the fetus is not exposed to certain food peptides, they will develop food allergies.

Question 40

What is Rh factor and how is it inherited? explain the relationship between mother and fetus regarding Rh factor

Answer 40

Rh factor is the gene for either positive or negative blood type. Positive is dominant and those that are negative for Rh factor will make Rh antibodies after exposure to external blood that contain Rh. Rh antibodies can cross the placenta. This causes an issue when the fetus is Rh positive and the mother is Rh negative. This usually causes an issue during a second pregnancy as in the first birth, this could have been when the mother was exposed to the fetus’ Rh+ blood. If Rhogam is not administered, the mother will release Rh antibodies that will cross the placenta and attack the blood cells of the fetus, killing it.

Question 41

Define microchimerism

Answer 41

microchimerism occurs when the cells from the fetus cross to the mother (nearly all pregnancies) or the cells from the mother pass into the fetus (1/4 of pregnancies). This may trigger unwanted immune responses. This transfer occurs during uterine invasion.

Question 42

How do the trophoblast and endometrium stick to eachother?

Answer 42

The endometrium contains L-selectin ligands while the trophoblast contains L-selectin

Question 43

What is sperm capacitation

Answer 43

Sperm capacitation is a process that occurs in the female reproductive tract where sperm undergo physiological changes that enable them to fertilize an egg. During capacitation, sperm gain the ability to penetrate and bind to the zona pellucida, which is the outer layer of the egg. This process involves alterations in the sperm’s membrane properties, changes in motility patterns, and modifications in intracellular signaling pathways. Capacitation prepares the sperm for the acrosome reaction, which is necessary for sperm to penetrate the zona pellucida and fuse with the egg cell during fertilization.

Question 44

If our goal is to promote multiple follicles to ready towards an ovulatory state, but we do not want ovulation to occur, what hormone would be delivered exogenously, in supraphysiological doses (above the typical range)?

GnRH,LH,FSH,Estrogen, or Progesterone-explain

Answer 44

FSH would be delivered. Since we do not want ovulation to occur, we can immediately eliminate LH and estrogen since the surges in these two lead to ovulation and the luteal phase. Progesterone only affects the lack of shedding. GnRH would cause an increase in LH which we dont want.