Reproductive Systems Flashcards
Mutations on which sex chromosome are most likely to cause problems for males and why?
Mutations on the X chromosome because of the hemizygous nature of males
What does hemizygous mean?
Having only one copy of each chromosomes, so XY for males, so mixed
What are the differences between X and Y chromosomes?
The X chromosome carries the bulk of the genetic information while the Y has very little.
What is SRY?
Sex-Determining Region Y found on the Y chromosome. This region codes for a transcription factor that initiates testis differentiation and formation of male gonads.
What is the pathway of sperm through the male reproductive system?
SEVE(N) UP S - Seminiferous tubules E - Epididymis V - Vas deferens (also the ductus deferens) E - Ejaculatory duct N - (Nothing) U - Urethra P - Penis
Describe the structure of the testis?
The testis consists of two main components
Seminiferous tubules - highly coiled where sperm are produced
-Serotoli cells - cells within the tubule which help nourish sperm and promote development
Interstitial cells of Leydig - cells that are outside of the tubules but still within the testis and they secrete testosterone and other androgens upon puberty
The testis are enveloped in the scrotum
Describe the epidiymis
The sperm are STORED here until ejaculation after they have been formed on their way from the testis. Their flagella gain motility here too
Describe the vas deferens
The vas deferens just acts to carry the sperm from the epidiymis to the ejaculatory duct during ejaculation
Describe the ejaculatory duct
Sits on the posterior edge of the prostate gland and then two of them fuse into the urethra.
Describe the urethra
Last portion of the pathway for sperm before exiting the penis, also part of the urinary system
What is seminal fluid?
Sperm mixed with other stuff to form semen
What is the process of forming sperm called?
spermatogenesis
What are male diploid stem cells called?
spermatogonia
What is the structure of sperm?
Head - contains the genetic material
-Acrosome - covers head
Midpiece - generates ATP from fructose, filled with mitochondria
Flagellum - for motility
What are the female gonads called and what hormones do they produce?
ovaries; estrogen and progesterone
What are follicles?
multilayered sacs that contain, nourish, and protect immature ova (eggs)
What is the peritoneal sac?
It lines the abdominal cavity of females
Describe the pathway of an ova
An ova is released from the ovaries, goes through the peritoneal sac, into the fallopian tube/oviduct lined with cilia, and into the muscular uterus, through the cervix and into the vaginal canal
What is the production of female gametes called?
oogenesis
What is GnRH and what does it do?
gonadotropin-releasing hormone - released by the hypothalamus upon reaching puberty which triggers the anterior pituitary gland to synthesize and release FSH and LH
What hormones affect male sexual development and how?
Testosterone - development of secondary sexual characteristics and helps sperm production begin
FSH - stimulates the Sertoli cells and triggers sperm maturation
LH - causes interstitial cells to produce testosterone
What hormones affect female sexual development and how?
Estrogens - secreted in response to FSH and result in development and maintenance of female reproductive system (lining of uterus) and secondary sex characteristics
Progesterone - involved in the development of endometrium but not creation
What are the phases of the menstrual cycle?
Ovulation —> Luteal Phase —> Menstruation —> Ovulation
What is hCG?
human chorionic gonadotropin - analog of LH which maintains the corpus luteum during pregnancy. This is important because the corpus luteum secretes estrogen and progesterone to keep the lining in place. After the second trimester though the placenta can secrete enough of those hormones itself
What causes menopause?
ovarian atrophy is when the ovaries become less sensitive to FSH and LH which causes the estrogen and progesterone levels to drop and therefore menstrual cycle stops. Menopause can cause hot flashes, headaches, bloating, etc.
What do the seminal vesicle produce?
produce fructose to nourish sperm and produce fluid with mildly alkaline properties
What do the prostate gland produce?
also produces fluid with mildly alkaline properties
What do the bulbourethral gland produce?
produce clear viscous fluid that cleans out urine and lubricates the urethra
What happens in the follicular phase with hormones?
Follicular Phase - begins with the menstrual flow of shedding the uterine lining. GnRH secretion increases due to decreases in estrogen and progesterone. High GnRH causes increases in FSH and LH. This creates follicles which produce estrogen. Estrogen causes the other hormones to level off and rebuilds the endometrial lining
What happens during ovulation with hormones?
Ovulation - follicles result in increasing levels of estrogen which after a certain threshold result in spikes of GnRH, FSH and LH. The spike in LH results in ovulation and ruptured the follicle
What happens during luteal phase with hormones?
Luteal Phase - LH causes the follicle to become a corpus luteum that secrete progesterone. These high levels of progesterone (and estrogen) help maintain the uterine lining and keep GnRH, FSH and LH down to prevent multiple ovulation
What happens during menstruation with hormones?
Menstruation - corpus luteum stops secreting LH, progesterone declines and uterine lining sheds and the block on GnRH so the next cycle begins
