R E P R O D U C T I V E

Question 1

list the structure through which sperm pass during development and ejaculation

Answer 1

1. epididymis
2. ductus (vas) deferens
3. ejaculatory duct
4. urethra

Question 2

which organs are responsible for gamete production in males and females?

Answer 2

females: ovaries make ova
males: testes make sperm

Question 3

spermatocyte development

Answer 3

1. spermatogonia (type A&B)
2. primary spermatocyte
3. secondary spermatocyte
4. early spermatids
5. late spermatids
6. spermatozoa

Question 4

oocyte development

Answer 4

1. oogonium
2. primary oocyte
3. secondary oocyte + first polar body
4. second polar body + ovum

Question 5

Compare and contrast the timing of events during the development of spermatocytes and oocytes

Answer 5

at puberty in males, spermatocytes go through meiosis I and II

before birth, oocytes go through mitosis and at birth primary oocyte enters meiosis I arrested in prophase I, secondary oocyte arrested in metaphase II

Question 6

mitosis

Answer 6

2 diploid cells formed from diploid cell (one division)

for development of multicellular adult from zygote

produces cells for growth and tissue repair as multicellular adult develops
- ensures genetic make-up of all body cells is constant

Question 7

meiosis

Answer 7

four haploid cells formed from diploid cell (2 divisions)

produces cells for reproduction (gametes)

introduces genetic variability in the gametes and reduces chromosomal number by half (haploid - 23), so that when fertilization occurs, the normal diploid chromosome number is restored (46)

Question 8

when does meiosis occur in humans?

Answer 8

when the human body is producing gametes

Question 9

what are the 2 gonadotropins?

Answer 9

1. FSH

2. LH

Question 10

FSH

Answer 10

stimulate follicles in ovaries to grow, mature, and secrete sex hormones

Question 11

LH

Answer 11

stimulate thecal cells to secrete androgens, surge cause ruptured follicle involved in ovulation

Question 12

prostate gland

Answer 12

the prostate gland’s milky, slightly acidic fluid, which contains citrate, enzymes, and prostatic-specific antigen (PSA), accounts for 1/3 of semen volume; activates sperm

Question 13

bulbo-urethral gland

Answer 13

produce thick, clear mucus that neutralizes acidic urine and lubricates urethra prior to ejaculation

Question 14

seminal gland

Answer 14

secretes 60% of volume of semen

Question 15

stratum functionalis

Answer 15

endometrium; undergoes cyclic changes in response to ovarian hormones and is shed during menstruation

Question 16

stratum basalis

Answer 16

endometrium; forms a new functionalis after menstruation ends and does not respond to ovarian hormones

Question 17

Describe the phases of the menstrual (uterine cycle)

Answer 17

1. Menstrual phase
Days 1-5
Uterus sheds functional layer of endometrium
2. Proliferative (preovulatory) phase
Days 6-14
Endometrium rebuilds
3. Secretory (postovulatory) phase
Days 15-28
Endometrium prepares for implantation of embryo

Question 18

Describe the phases of the ovarian cycle

Answer 18

follicular phase
period of follicular growth (days 1-14); form antrum

luteal phase
period of corpus luteum activity (days 14-28); secrete progesterone/estrogen

ovulation
occurs midcycle; boundary btw the two, ovary wall ruptures and 2nd oocyte is expelled surrounded by corona radiata

Question 19

Describe the hormonal and vascular event that causes menses

Answer 19

If fertilization does not occur, progesterone levels fall, depriving the endometrium of hormonal support

spiral arteries begin to kink and go into spasms and endometrial cells begin to die
The functional layer begins to digest itself
Spiral arteries constrict one final time then suddenly relax and open wide
The rush of blood weakens and fragments capillary beds and the functional layer breaks down

Question 20

List in order all of the structures that the oocyte encounters from ovulation to implantation

Answer 20

1. ovary
2. pelvic cavity
3. fimbriae
4. infundibulum
5. ampulla
6. isthmus
7. lumen of uterus
8. endometrium of uterus

Question 21

Which characteristics signify the imminent rupture of a Graafian follicle?

Answer 21

large fluid filled Antrum (follicular phase)

Question 22

Describe the events involved in fertilization.

Answer 22

• capacitation has to happen so that freshly ejaculated sperm can penetrate an oocyte
• capacitation enhances motility of the sperm and the membranes of the sperm head becomes fragile to allow release of hydrolytic enzymes from acrosome
• hyaluronidase on the surface of the sperm digests intercellular attachments between cells of the corona radiata and cause them to fall away
• after penetrating the corona radiata, sperm heads bind to receptors on zona pellucida
• acrosomal reaction: acrosomal enzymes (hyaluronidase, acrosin, proteases, etc.) are released and digest away the zona pellucida
• once a path through the zona pellucida is cleared, the back portion of the sperm head binds to plasma membrane of the oocyte
• the oocyte membrane forms microvilli that encases the sperm head
• cytoplasmic contents of the sperm enters to oocyte, and its plas

Question 23

Following fertilization, how long is it before the zygote divides into two cells?

Answer 23

12-24 hrs

Question 24

What is the term for the cell divisions taking place following fertilization? What is each new cell called?

Answer 24

cleavage; blastomere; morula; blastocyst (“hatches” from zona pellucida”; trophoblast cell (flattened outer layer) with inner cell mass

Question 25

gastrulation

Answer 25

Process by which two-layered embryonic disc becomes three-layered
Involves cellular rearrangement and migration
Begins with primitive streak formation
Groove with raised edges appears on dorsal side of embryonic disc
Extends from caudal toward cranial end
Establishes longitudinal axis of embryo
Epiblast cells migrate medially to enter primitive streak
First cells to enter primitive groove displace hypoblast cells and become the definitive endoderm
Cells that follow become the middle germ layer - the mesoderm
Cells that remain in epiblast are now termed the ectoderm
All body organs derive from these three germ layers.

Question 26

Name the four extraembryonic membranes and their functions or what they develop into

Answer 26

here are four extraembryonic membranes that form during the first 2-3 weeks of development:

1. chorion helps to form the placenta, and encloses embryonic body and all other membranes
2. amnion contains amniotic fluid
3. yolk sac forms part of the gut
4. allantois is the structural base for the umbilical cord

Question 27

During labor and birth what are the sources and signals for more oxytocin?

Answer 27

Produced initially by fetal cells and stimulates uterine muscle contraction
- Distention of cervix triggers hypothalamus to signal oxytocin release from posterior pituitary; estrogens from placenta induce oxytocin receptors in uterus

Question 28

What are the major stages of labor during pregnancy and what is the term for false labor?

Answer 28

1. Dilation
2. Expulsion
3. Placental Stage

False contractions are known as: Braxton Hicks contractions are weak, irregular contractions that occur due to estrogen’s irritating effect on uterine muscle