Reproductive System 2.3

Question 1

23rd Chromosome

Answer 1

Determines male and female.

Question 2

Hemizygous

Answer 2

Males are considered hemizygous with respect to many of the genes on the x chromosome because they only have one copy (xy).

A male with a disease causing allele on the unpaired part of X-chromosome will necessarily express that allele.

Question 3

Sex linked disorders

(DJ, verify the answer to this question.)

Answer 3

Mutations on the X chromosome. Also known as X – linked disorders.

(Mutations on either X or Y chromosomes?)

Question 4

What is the sex determining region? (SRY)

Answer 4

(sex determining region Y)

Codes for a TRANSCRIPTION FACTORS that initiates testis differentiation, and thus the formation of male gonads. Therefore, in the absence of the Y chromosome, all zygotes will be female. In the presence of the chromosome, a zygote will be male.

Question 5

Male reproductive anatomy

Answer 5

Question 6

Pathway of sperm through the male reproductive system (seven up)

Answer 6

Seminiferous tubules
Epididymis
Vas deferens
Ejaculatory duct
Nothing
Urethra
Penis

Question 7

Androgens

Answer 7

Male sex hormones

Question 8

Two functional components of the testes

Answer 8

Seminiferous tubules, and interstitial cells of Leydig.

Question 9

Seminiferous tubules

Answer 9

Tubes located in the testes where sperm is produced and nourished by Sertoli cells.

Question 10

Interstitial cells of Leydig

Answer 10

Where testosterone is secreted in the testes. Testosterone production is triggered by LH (released by the anterior pituitary) which is released in response to GnRH from the hypothalamus.

Question 11

Ductus deferens

Answer 11

Layer of muscle located around the vas deference that raise and lower the testes to maintain the proper temperature for sperm development (2°C to 4°C lower than body temperature of 37°C).

Question 12

Epididymis

Answer 12

Area just outside of test testis where sperm flagella gain motility and are stored until ejaculation.

Question 13

Ejaculation

Answer 13

During ejaculation, sperm travel through the vas deferens and enter the ejaculatory duct at the posterior edge of the prostate gland. A two ejaculatory duct infused to form the urethra.

Question 14

Seminal fluid

Answer 14

Produced by seminal vesicles, prostate gland, and bulbourethral gland.

Seminal vesicles contribute fructose to nourish the sperm.

Prostate gland give the fluid mildly alkaline properties so the sperm can survive in the relative acidity of the female reproductive tract.

Bulbourethral glands Produce a clear viscous fluid that cleans out any remnants of hearing and lubricates the urethra during sexual arousal.

Question 15

Semen

Answer 15

The combination of sperm and seminal fluid

Question 16

Spermatogenesis

Answer 16

Formation of haploid sperm through meiosis, occurs in the seminiferous tubules.

Question 17

Primary and Secondary spermatocytes, Spermatids, spermatozoa.

Answer 17

Primary: created in S stage of meiosis (2n)
Secondary: created in the first meiotic division (n).
Spermatids: produced under meiosis two (n)
Spermatozoa: mature spermatids

Question 18

Ovaries

Answer 18

Female reproductive organ, specifically the gonads, produces estrogen and progesterone. Located in the pelvic cavity. Consist of thousands of follicles, which are multi layered sacs that contain nourish and protect immature ova (eggs).

Question 19

Follicle

Answer 19

Sac or cavity, such as in the ovaries or skin pores.

Question 20

Peritoneal sac

Answer 20

Sac lining the abdominal cavity where eggs are ovulated once per month between puberty and menopause.

Question 21

Fallopian tube

Answer 21

Connects the ovary and the uterus, also called the oviduct, that is aligned with cilia to propel the egg forward.

Question 22

Uterus

Answer 22

Muscular area that is the site of fetal development.

Question 23

Cervix

Answer 23

Lower end of the uterus that connects to the vaginal canal.

Question 24

Vulva

Answer 24

Collective term for the external parts of the female genital organs.

Question 25

Pathway of egg through the female reproductive system.

Answer 25

Ovaries
Peritoneal sac
Fallopian tube
Uterus
Cervix
Vagina
Vulva

Question 26

Endometrium

Answer 26

Lining of the uterus

Question 27

Oogenesis

Answer 27

Production of female gametes

Question 28

Primary oocytes

Answer 28

Diploid cells created after S stage of the cell cycle during s phase of interphase (2n). All of the primary oocytes are created by the time the female is born. Progression of meiosis is arrested in prophase I.

Likened to Primary spermatocytes.

Question 29

Secondary oocytes

Answer 29

After menarche (the first menstrual cycle) one primary oocyte per month will complete meiosis I, creating a secondary oocyte. Secondary oocytes are haploid cells. Remains arrested in metaphase II does not complete meiosis II unless fertilization occurs. Ovulated from the follicle on approximately day 14 of the menstrual cycle. Can be fertilized up to 24 hours after ovulation.

Question 30

Two layers surrounding oocytes.

Answer 30

Zona pellucida and Corona radiata.

Question 31

Zona pellucida

Answer 31

Surrounds the oocyte itself and is an acellular mixture of glycol proteins that protects the oocyte and contains compounds necessary for sperm cell binding.

Question 32

Corona radiata

Answer 32

Lies outside of the Zona pellucida and is a layer of cells that adheres to the oocyte during ovulation.

Question 33

Zygote

Answer 33

Diploid cell post fertilization and completion of meiosis II.

Question 34

Ovum

Answer 34

Egg cell. Very large cell consisting of large quantities of cytoplasm and organelles, contributes nearly everything to the zygote (half of the DNA and all of the cytoplasm, organelles, and RNA for early cellular processes), and sperm contribute half of the DNA.

Question 35

Sexual Development

Answer 35

Question 36

Gonadotropin-releasing hormone (GnRH)

Answer 36

Once reaching puberty, the hypothalamus stops restricting GnHR. Gonadotropin-releasing hormone triggers sexual development, releasing follicle-stimulating hormone (FSH) and lutenizing hormone (LH)

FSH in males triggers production of sperm. FSH in females triggers production of estrogen.

LH in males triggers production of testosterone.
LH in females triggers the production of progesterone.

Question 37

Fetal Period

Answer 37

From nine weeks after fertilization until birth

Question 38

Follicle Stimulating Hormone (FSH)

Answer 38

FSH is synthesized and secreted by the gonadotropic cells of the anterior pituitary gland and regulates the development, growth, pubertal maturation, and reproductive processes of the body.

Regulates the amount of sperm made in the testicles and stimulates Sertoli Cells located in the seminiferous tubules in males.

Triggers the growth of eggs in the ovaries and gets the eggs ready for ovulation.

Question 39

Luteinizing Hormone (LH)

Answer 39

Produced by ganadoptrooic cells in anterior pituitary gland, production of LH is regulated by gonadotropin releasing hormone.

Cause the interstitial cells of Leydig to produce testosterone in males.

LH surge causes ovulation and development of corpus luteum in females.

Question 40

Secondary Sexual Characteristics

Answer 40

Males: Facial hair, axillary hair, deepening of the voice, increased muscle and bone mass. Results from the presence of testosterone.

Females: breasts, widening of the hips, changes in fat distribution.

Question 41

Estrogens

Answer 41

Female sex hormones. Secreted in response to FSH. Stimulate the development of the reproductive tract. Leads to thickening of the endometrium each month in preparation for the implantation of a zygote.

Question 42

Progesterone

Answer 42

Secreted by the corpus luteum, the remains of the ovarian follicle following ovulation, in response to LH (luteinizing hormone).

Allows uterus to grow
Improves blood flow
Supports growth of uterine lining
Makes uterus more suitable for implantation of a fertilized egg

Question 43

Corpus Luteum

Answer 43

The corpus luteum forms in the ovary after ovulation from the remnants of the ovarian follicle.

TEMPORARY ORGAN in the ovary that produces hormones to support pregnancy and childbirth during a woman’s menstrual cycle. The corpus luteum’s main function is to prepare the uterus for pregnancy by releasing progesterone.

Question 44

Estrogen and Progesterone Mnemonic

Answer 44

ESTrogen ESTablishes, PROgesterone PROtects the endometrium.

Question 45

Menstrual cycle

Answer 45

Happens during the reproductive years (from menarche to menopause). Estrogen and progesterone levels rise and fall in a cyclic pattern during the menstrual cycle.

The follicular phase
Ovulation
Luteal Phase
Menstruation

Question 46

Follicular Phase of the menstrual cycle

Answer 46

Begins with menstrual flow, which sheds the uterine lining of the previous cycle. GnRH secretion from the hypothalamus increases in response to decreased concentration of estrogen and progesterone, which fall off toward the end of each cycle leading to increases in FSH and LH which work to develop several ovarian follicles. The follicles then produce estrogen which has negative feedback effects and causes GnRH, LH, and FSH concentrations to stabilize. Estrogen stimulates regrowth of the endometrial lining, stimulating vascularization and glandularization of the decidua.

Question 47

Decidua

Answer 47

the thick layer of modified mucous membrane which lines the uterus during pregnancy and is shed with the afterbirth.

Question 48

Ovulation phase of menstrual cycle

Answer 48

Occurs after follicular phase of menstruation. Estrogen play pivotal role in ovulation. Estrogen plays a negative feedback role and a positive feedback role in the ovulation phase of menstruation. Developing follicles secrete more and more estrogen until a high threshold is reached where it provides positive feedback causing GnRH, FSH, and LH levels to spike. This surge in LH causes OVULATION.

Question 49

Ovulation

Answer 49

Release of the ovum from the ovary into the peritoneal cavity (abdominal cavity).

Question 50

Luteal phase of menstruation

Answer 50

Occurs after ovulation stage of menstruation. LH causes the ruptured follicle to form the corpus luteum which secretes progesterone. Progesterone levels begin to rise while estrogen levels remain high. The high levels of progesterone cause negative feedback on GnRH, FSH, and LH, preventing the ovulation of multiple eggs.

Question 51

Menstruation

Answer 51

Assuming that fertilization does not occur, the corpus luteum loses its stimulation from LH, progesterone levels decline, and the uterine lining is sloughed off. Loss of high levels of estrogen and progesterone removes the block on GnRH so that the next cycle can begin.

Question 52

Pregnancy

Answer 52

If fertilization has occurred the resulting zygote will develops into a blastocyst that will implant in the uterine lining and secret human chorionic gonadotropin (hCG), an analogue of LH that can stimulate LH receptors. This maintains the corpus luteum.

Question 53

human Chorionic Gonadotropin (hCG)

Answer 53

Secreted post fertilization by implanted blastocyst. Looks similar chemically to LH and can stimulate LH receptors, maintaining the corpus luteum. Critical in first trimester because it keeps the uterine lining in place by maintaining the corpus luteum which in turn produces estrogen and progesterone. Levels of hCG decline by second trimester because the placenta has grown to sufficient size to produce enough progesterone and estrogen by itself. These high levels of progesterone and estrogen continue to serve as negative feedback on GnRH secretion.

Question 54

Menopause

Answer 54

With age, ovaries become less sensitive to FSH and LH, resulting in ovarian atrophy. Estrogen and progesterone levels drop resulting in atrophy of the endometrium and menstruation stops. Blood levels of FSH and LH rise because of the negative feedback loop being removed due to drops in levels of estrogen and progesterone.

Question 55

Key Concepts of menstrual cycle

Answer 55

-follicles mature during the follicular phase (FSH and LH).

-LH surge at mid cycle triggers ovulation.

-ruptured follicle becomes corpus luteum, which secretes estrogen and progesterone to build up uterine lining in preparation for implantation, FSH and LH are inhibited.

-if fertilization does not occur, corpus luteum atrophies, progesterone and estrogen levels decrease, menses occurs, and LH and FSH levels begin to rise again.

Question 56

Cheat sheet for menstrual cycle

Answer 56