Lab 4: Reproductive

Question 1

Where in the male pelvis do the urinary and reproductive pathways first converge?

Answer 1

prostatic urethra

Question 2

which of the following pairings is CORRECT?

-Oral combined contraceptive pill- prevents the fertilization of a mature oocyte

-Condom- prevents the implantation of a fertilized egg

-IUD- interferes with gamete motility and viability

-Diaphragm- prevents sperm from entering the vagina

-Vasectomy- interferes with oocyte transport

Answer 2

IUD- interferes with gamete motility and viability

Question 3

what is the function of Sertoli cells?

Answer 3

form the blood-testis barrier
- support and protect developing spermatogenic cells in several ways. They nourish spermatocytes, spermatids, and sperm; phagocytize excess spermatid cytoplasm as development proceeds, and control movements of spermatogenic cells

Question 4

how long does spermatogenesis takes in humans?

Answer 4

65-75 days

Question 5

what is the chromosome number in primary spermatocytes?

Answer 5

2n= 46

Question 6

what is the chromosome number in the secondary spermatocyte?

Answer 6

n= 23

Question 7

what happens during spermiogenesis?

Answer 7

the development of haploid spermatids
into sperm. No cell division occurs in spermiogenesis; each
spermatid becomes a single sperm cell. During this process,
spherical spermatids transform into elongated, slender sperm.
An acrosome (described shortly) forms atop the nucleus, which
condenses and elongates, a flagellum develops, and mitochondria
multiply.

Question 8

where are primary spermatocytes located?

Answer 8

The rest
of the spermatogonia lose contact with the basement membrane, squeeze through the tight junctions of the blood-testis
barrier, undergo developmental changes, and differentiate into
primary spermatocytes

Question 9

features of the primary follicle

Answer 9

-zona pellucida between primary oocyte and granulosa cells
-several layers of cuboidal and low-columnar cells called granulosa cells.
- stromal cells surrounding the basement
membrane begin to form an organized layer called the theca
folliculi

Question 10

features of secondary follicle

Answer 10

In a secondary follicle, the
theca differentiates into two layers: (1) the theca interna, a
highly vascularized internal layer of cuboidal secretory cells that
secrete estrogens, and (2) the theca externa, an outer layer of
stromal cells and collagen fibers. In addition, the granulosa cells
begin to secrete follicular fluid, which builds up in a cavity called
the antrum in the center of the secondary follicle. The innermost
layer of granulosa cells becomes firmly attached to the zona pellucida and is now called the corona radiata

Question 11

what is the 1st polar body?

Answer 11

While in this follicle,
and just before ovulation, the diploid primary oocyte completes
meiosis I, producing two haploid (n) cells of unequal size—each
with 23 chromosomes (Figure 28.15). The smaller cell produced
by meiosis I, called the first polar body, is essentially a packet of
discarded nuclear material. The larger cell, known as the secondary oocyte, receives most of the cytoplasm. Once a secondary
oocyte is formed, it begins meiosis II but then stops in metaphase.
The mature (graafian) follicle soon ruptures and releases its secondary oocyte, a process known as ovulation

Question 12

what is released on ovulation?

Answer 12

At ovulation, the secondary oocyte is expelled into the pelvic
cavity together with the first polar body and corona radiata.

Question 13

what is the 2nd polar body?

Answer 13

After ovulation. If fertilization does not occur, the cells degenerate. If sperm are present in
the uterine tube and one penetrates the secondary oocyte, however, meiosis II resumes. The secondary oocyte splits into two
haploid cells, again of unequal size. The larger cell is the ovum.
or mature egg; the smaller one is the second polar body

Question 14

difference between male and female gamete production.

Answer 14

In female primary oocyte ultimately
gives rise to three haploid polar bodies, which all degenerate,
and a single haploid ovum. Thus, one primary oocyte gives rise
to a single gamete (an ovum). By contrast, recall that in males
one primary spermatocyte produces four gametes (sperm).

Question 15

what is the ovarian cycle?

Answer 15

The ovarian cycle is a series of events in the ovaries that
occur during and after the maturation of an oocyte.

Question 16

what is the uterine cycle?

Answer 16

The uterine
(menstrual) cycle is a concurrent series of changes in the endometrium of the uterus to prepare it for the arrival of a fertilized ovum
that will develop there until birth. If fertilization does not occur,
ovarian hormones wane, which causes the stratum functionalis of
the endometrium to slough off

Question 17

what is the female reproductive cycle?

Answer 17

The general term female reproductive cycle encompasses the ovarian and uterine cycles, the
hormonal changes that regulate them, and the related cyclical
changes in the breasts and cervix

Question 18

what hormones and organs control the female ovarian and uterine cycles?

Answer 18

Gonadotropin-releasing hormone (GnRH) secreted by the hypothalamus controls the ovarian and uterine cycles.
GnRH stimulates the release of follicle-stimulating hormone
(FSH) and luteinizing hormone (LH) from the anterior pituitary.
FSH initiates follicular growth, while LH stimulates further development of the ovarian follicles. In addition, both FSH and LH
stimulate the ovarian follicles to secrete estrogens. LH stimulates
the theca cells of a developing follicle to produce androgens.
Under the influence of FSH, the androgens are taken up by the
granulosa cells of the follicle and then converted into estrogens. At
midcycle, LH triggers ovulation and then promotes formation of
the corpus luteum, the reason for the name luteinizing hormone.
Stimulated by LH, the corpus luteum produces and secretes estrogens, progesterone, relaxin, and inhibin

Question 19

what are the 4 phases of the female reproductive cycle?

Answer 19

the menstrual phase, the preovulatory
phase, ovulation, and the postovulatory phase

Question 20

what is the primary action of hormonal birth control?

Answer 20

The primary action of COCs is to
inhibit ovulation by suppressing the gonadotropins FSH and LH.
The low levels of FSH and LH usually prevent the development
of a dominant follicle in the ovary. As a result, levels of estrogen
do not rise, the midcycle LH surge does not occur, and ovulation
does not take place. Even if ovulation does occur, as it does in
some cases, COCs may also block implantation in the uterus and
inhibit the transport of ova and sperm in the uterine tubes

Question 21

what are the surgical contraception methods for males and females?

Answer 21

Males:

Vasectomy- portion of each Vas Deferens is removed. Although sperm production
continues in the testes, sperm can no longer reach the exterior.
The sperm degenerate and are destroyed by phagocytosis

Females:

tubal ligation. both uterine
tubes are tied closed and then cut.
the result is that the secondary oocyte
cannot pass through the uterine tubes, and sperm cannot reach the
oocyte.

Question 22

what is IUD and how does it work?

Answer 22

An intrauterine device (IUD) is a small object made of plastic,
copper, or stainless steel that is inserted by a health-care professional into the cavity of the uterus. IUDs prevent fertilization from
taking place by blocking sperm from entering the uterine tubes.

Question 23

what is the female athlete triad?

Answer 23

The observation that three
conditions—disordered eating, amenorrhea, and osteoporosis—often occur together in female athletes led researchers to coin the term
female athlete triad.

Question 24

what causes amenorrhea?

Answer 24

In
female athletes, amenorrhea results from reduced secretion of
gonadotropin-releasing hormone, which decreases the release of LH
and FSH. As a result, ovarian follicles fail to develop, ovulation does
not occur, synthesis of estrogens and progesterone wanes, and
monthly menstrual bleeding ceases.

Question 25

why do female athletes get osteoporosis?

Answer 25

Because estrogens help bones retain calcium and other minerals,
chronically low levels of estrogens are associated with loss of bone
mineral density. The female athlete triad causes “old bones in young
women.”

Question 26

how does the diaphragm work?

Answer 26

A diaphragm is a rubber, dome-shaped structure that fits
over the cervix and is used in conjunction with a spermicide. It can
be inserted by the female up to 6 hours before intercourse. The
diaphragm stops most sperm from passing into the cervix and the
spermicide kills most sperm that do get by