2. Reproductive System

Question 1

Homozygous vs heterozygous vs hemizygous

Answer 1

XX, xx vs Xx vs XY

Question 2

Which chrm determines sex?

Answer 2

23rd

Question 3

What is SRY?

Answer 3

Transcription factor on Y chrm that initiates testis and male gonads formation –> it’s a dude

Question 4

What are the 2 functional components of testes?

Answer 4

seminiferous tubules containing Sertoli cells that produce sperm, inhibin, and androgen-binding protein (that maintains testosterone lvls), and interstitial cells of Leydig that secrete testosterone and androgen
Seminiferous tubules also contain immobile sperm incapable of fertilization

Question 5

Pathway of sperm thru male reproductive system

Answer 5

Seminiferous tubules, epididymis, vas deferens, ejaculatory duct, urethra, penis

Question 6

What is semen composed of?

Answer 6

Sperm and seminal fluid

Question 7

What do bulbourethral/Cowper glands do?

Answer 7

produce clear viscous fluid to clear remnants of urine and lubricate urethra

Question 8

What do seminal vesicles and prostate glands do?

Answer 8

Seminal vesicles supply fructose for sperm. Both seminal vesicles and prostate give sperm alkaline properties to survive female acidity

Question 9

What is spermatogenesis? Describe process

Answer 9

Formation of haploid sperm via meiosis that occurs in seminiferous tubules. After replicating genetic material (S stage), they become primary spermatocytes –> undergo meiosis I => haploid secondary spermatocytes –> meiosis II => haploid spermatids –> maturation => spermatozoa. Results in 4 functional sperm per spermatogonium

Question 10

What are spermatogonia and oogonia?

Answer 10

Diploid stem cells

Question 11

Structure of sperm

Answer 11

Head contains genetic material and is covered by acrosome to penetrate ovum. Midpiece contains lots of mito that generate ATP from fructose for swimming. Flagella for motility

Question 12

What is oogenesis? Describe process

Answer 12

Production of female gametes. At birth, females have diploid stem cells aka oogonia and undergo mitosis —> diploid oogonium + diploid primary oocytes which is arrested in prophase I => dictyate state; when reaching menarche, 1 primary oocyte per month undergoes meiosis I => secondary oocyte and polar body –> secondary oocyte is arrested in metaphase II and doesn’t continue meiosis II until fertilization

Question 13

What two layers surrounded oocytes?

Answer 13

zona pellucida is a mixture of glycoproteins necessary for sperm binding and protects oocyte; corona radiata is a layer of cells that surrounds zona pellucida and adhere to oocyte during ovulation. Sperm has to pass these two layers for fertilization

Question 14

Which hormones are produced before and after puberty?

Answer 14

Before: hypothalamus prevents gonadotropin-releasing hormone (GnRH)
After: hypothalamus releases gonadotropin-releasing hormone (GnRH) –> anterior pituitary gland releases follicle-stimulating hormone (FSH) and luteinizing hormone (LH)

Question 15

What does release of FSH and LH lead to?

Answer 15

FSH stimulates the Sertoli cells and triggers sperm maturation, whereas LH causes the interstitial cells to produce testosterone.
FSH secrete estrogen –> endometrium thickens for soon-to-be zygote. LH causes corpus luteum to secrete progesterone to maintain endometrium

Question 16

What are the 4 phases of menstrual cycle?

Answer 16

follicular phase, ovulation, luteal phase, menstruation

Question 17

What happens in follicular phase?

Answer 17

GnRH increases –> FSH and LH increases –> follicles produce estrogen –> GnRH, FSH and LH decreases and thickens endometrium. Estrogen can also inc GnRH, FSH and LH that helps with ovulation

Question 18

What happens in ovulation?

Answer 18

When LH increases –> release of ovum from ovary to to abd/peritoneal cavity

Question 19

What happens in luteal phase?

Answer 19

LH causes the ruptured follicle to form corpus luteum, which secretes progesterone; both estrogen and progesterone are high –> GnRH, FSH and LH decreases

Question 20

What happens in menstruation?

Answer 20

LH decreases –> corpus luteum dec –> progesterone dec –> endometrium is sloughed off. Estrogen dec –> GnRH starts to increase for next cycle

Question 21

What are ova?

Answer 21

Eggs that is produced in follicles in ovaries. Each month, one egg is ovulated into the peritoneal sac and is drawn into the fallopian tube or oviduct.

Question 22

What do epididymis vs vas deferens do?

Answer 22

Store sperm for maturation and mobility till ejaculation, gain fertilization capabilities vs surrounded by muscle that raises and lowers testes to main constant temp for sperm production

Question 23

At which stage of embryogenesis does uterine implantation occur?

Answer 23

Blastula. After zygote forms, it undergoes cleavage into morula while simultaneously traveling to uterus. By the time it reaches lining, it becomes a blastula

Question 24

What inhibits milk secretion before birth?

Answer 24

High estrogen and progesterone

Question 25

Which gamete = responsible for providing all organelles after a zygote is formed?

Answer 25

ovum, so any d/o of organelle = from mother