Reproductive System

Question 1

What is the function of the reproductive system

Answer 1

Perpetuate the species and pass genetic material from generation to generation.

Question 2

What are the components of the reproductive system

Answer 2

Testes: produce sperm and males sex hormone

Ducts and glands: aid in delivery of sperm to the female reproductive tract

Ovaries: produce eggs and female sex hormones

Remaining structures: sites for fertilization and development of fetus.

Mammary glands: produce milk to nourish the newborn

Question 3

What are the gonads

Answer 3

Primary structure in the reproductive systems of both males and females.

Produce gametes and sex hormones:

Testes: produce sperm & testo

Ovaries: produce eggs, estro, and progresterone

Question 4

Name the 8 components of the male reproductive system

Answer 4

• Pair of testes
• Excretory ducts (3): Epididymis, ductus deferens, and ejaculatory ducts
• seminal vesicles
• prostate
• bulbourethral glands
• penis

Question 5

Why are the testes located outside of the body?

Answer 5

Because it provides a temperature of 3°C below the normal body T° which is necessary for the production of viable sperm.

Question 6

Describe the structure of the testes (include tunica albuginea, lobules,seminiferous tubes, straight tube)

Answer 6

Tunica a. : White fibrous connective tissue capsure

Lobules: 250 in each testis, contains 1 to 4 highly coiled seminiferous tubules.

Seminiferous tubules: Converge to form a single straight tubule

Straight tubules (ductules) exit the testes.

Question 7

Describe the epididymis

Answer 7

Each epididymis is a long tube (6m) tightly coiled to form comma-shaped organ along superior and posterior margins of testes.

Question 8

Where are mature sperm stored?

Answer 8

In the lower portion (tail) of the epididymis.

Question 9

Describe the path of sperm from the ductus deferens to the outside (include ejaculatory duct, prostrate, prostatic urethra, membranous urethra, penile urethra)

Answer 9

Sperm is stored in the proximal portion of the ductus deferens.

Each ductus deferens, joins duct from adjacent seminal vesicle to form a short ejaculatory duct.

Each ejac. duct passes through prostate and empties into urethra.

Question 10

Describe the three glands and their contribution to semen (seminal vesicles, prostrate and bulbourethral).

Answer 10

Seminal vesicles: Fairly large, shape/length of a little finger. Secretion accounts for 60% of the volume of the sperm.

Prostate gland: doughnut shaped gland about the size of a chestnut. Prostatic gland secretion accounts for 1/3 of semen volume.

Bulbourethral glands (Cowper’s glands): Pea-sized glands, produce thick clear mucous prior to ejaculation that drains into spongy urethra and neutralizes traces of acidic urine in urethra.

Question 11

Describe the three columns of erectile tissue

Answer 11

3 columns are wrapped in connective tissue and covered with skin, the two dorsal columns are the corpora cavernosa.

Single, midline ventral column surrounds urethra –> Corpus spongiuosum

Network of connective tissue and smooth muscle filled with vascular sinuses.
Vascular spaces fill with blood, causing pp to enlarge and become rigid.

Question 12

What are the functions of the organs of the female reproductive system?

Answer 12

produce and sustain the female sex cells (egg cells or ova)

transport these cells to a site where they may be fertilized by sperm

provide a favorable environment for the developing fetus

move the fetus to the outside at the end of the development period

produce the female sex hormones.

Question 13

Describe the external genitalia of the female reproductive system

Answer 13

Labia majora: Outer skin folds

Labia minora: Outer skin folds

Clitoris: Rich in sensory nerves for sexual arousal

Question 14

Describe the internal organs of the female reproductive tract (know the three layers of the uterus and describe the cervix)

Answer 14

Vagina is highly folded fibromuscular tube lined by non-keratinized stratified squamous epithelium.

• Vagina mucosa: Lubricated by mucus produced by the cervical glands. Undergoes changes during menstrual cycle which mimics those of the endometrium.
• Uterus (3 layers):
  1. Endometrium (columnar epit.) –> stratum basale and stratum functionalis
  2. Myometrium (thick smooth-muscular layer)
  3. Perimetrium
• Cervix: Barrel-shaped portion separated from body by isthmus. Lumen has constricted opening (os) at each end.
  Os is site of transition from vaginal strat squam to cervical simple columnar epit.

Question 15

What is a Papanicolaou (pap) smear?

Answer 15

A cervical test where epithelial cells from the epithelium covering the cervical tip are scraped away and examined for abnormalities. It is the most effective way to detect cervical cancer and all women should have it once a year.

Question 16

Describe the fallopian tubes (include infundibulum, fimbriae, ampulla, isthmus and intramural portions)

Answer 16

10-12 cm tubes providing proper environment for fertilization of ovum and transport into uterus;

1. infundibulum: funnel shaped, closest to ovarym opens into peritoneal cavity
2. ampula: 2/3 oviduct’s length; the site of fertilization
3. Isthmus: narrow middle segment adjacent to uterus
4. Intramural portion: lies within uterine wall and opens into uterine cavity

Question 17

What is the function of the fimbriae? What is the disadvantage to the fact the ovaries are not continuous with the oviducts?

Answer 17

the fimbriae become more closely apposed to the ovary, and the oviduct exhibits active ciliary movements and peristalsis. This sweeps the oocyte into the infundibulum and helps bring sperm to the vicinity of the oocyte.

Not continuous = women at risk of ectopic pregnancy –> abortion with bleeding (ovum fertilized outside of womb –> oviduct (most), peritoneoum, ovary)

Question 18

Describe LHS and FSH

Answer 18

LSH:

• In the testes, LH binds to receptors on Leydig cells, stimulating synthesis and secretion of testosterone.
• Theca cells in the ovary respond to LH stimulation by secretion of testosterone, which is converted into estrogen by adjacent granulosa cells.

-In females, ovulation of mature follicles on the ovary is induced by a large burst of LH secretion known as the preovulatory LH surge.

Residual cells within ovulated follicles proliferate to form the corpus luteum, which secrete the steroid hormones progesterone and estradiol.

Progesterone is necessary for maintenance of pregnancy, and, LH is required for continued development and function of corpora lutea.

FSH: Administration of FSH to humans and animals induces “superovulation”, or development of more than the usual number of mature follicles and hence, an increased number of mature gametes.

FSH is also critical for sperm production. It supports the function of Sertoli cells, which in turn support many aspects of sperm cell maturation.

Question 19

Describe primary follicle, secondary follicle, mature (Graffian) follicle and corpus luteum

Answer 19

Surrounding each early primary oocyte is a primordial follicle.
These follicles develop along with the oocytes, first becoming primary follicles and continuing as growing or secondary follicles, and ultimately becoming a mature (a.k.a. Graafian or vesicular) follicle which contains the secondary oocyte which is ovulated.

Once the oocyte is released from the follicle (ovulation induced by a large burst of LH secretion) the cells within ovulated follicles proliferate to form corpus luteum

the corpus luteum secretes the steroid hormones progesterone and estradiol.

The corpus luteum will degenerate after about 2 weeks due to dropping levels of LH. Without estrogen and progesterone the lining of the uterus is shed and the cycle begins anew.

Question 20

Describe the hormonal regulation of maturation of an oocyte to ovulation to development of the corpus luteum.

Question 21

What happens when fertilization does not occur?

Answer 21

LH blood levels fall and the corpus luteum degenerates. As corpus luteum degenerates blood estrogen and progesterone drop sharply. The decline in ovarian hormones at the end of the cycle (26-28 days) ends their inhibition of FSH and LH secretion and the cycle starts again.

Question 22

What happens if fertilization does occur?

Answer 22

If an egg is fertilized resulting tissues (the conceptus) will produce HCG, Human Chorionic Gonadotropin, which replaces LH to keep the corpus luteum intact and hormone levels high, continuing the maintenance of the endometrium

Question 23

Describe embryonic cleavage

Answer 23

Cleavage is a period of fairly rapid mitotic divisions of the zygote following fertilization. As there is little time for growth between divisions, the daughter cells become smaller and smaller.

Question 24

What is a morula?

Answer 24

solid mass of cells after cell division by day 5-6 it differentiates into a blastocyst.

Question 25

What is a blastocyst

Answer 25

1-the inner cell mass, which will become the baby

2- the trophoblast, which will develop into the extraembryonic membranes (the amnion, placenta, and umbilical cord) and begin to secrete human chorionic gonadotropin (HCG).

HCG is NOT inhibited by a rising level of progesterone. Thus HCG prevents the deterioration of the corpus luteum at the end of the 4th week and enables pregnancy to continue beyond the end of the normal menstrual cycle.

Question 26

Describe implantation

Answer 26

Implantation is the first stage in development of the placenta. Implantation is preceded by a close interaction of embryonic trophoblast and endometrial epithelial cells that is known as adhesion or attachment. Among other things, attachment involves a tight intertwining of microvilli on the maternal and embryonic cells.