Ch. 27- The Reproductive System Flashcards
Primary sex organs produce what?
Gametes (testes or ovaries)
What type of ducts develop into the reproductive system in males?
Mesonephric ducts
What type of ducts develop into the reproductive system in females?
Paramesonephric ducts
What protein does the SRY gene code for?
TDF
The SRY causes the testis to secrete what two things?
Testosterone and mullerian-inhibiting factor (MIF)
What three structures do all 8 week old fetuses have?
Phallus, urogenital fold, labioscrotal fold
At what week is the fetus distinctively male or female?
Week 12
What is the function of the gubernaculum?
Shortens and guides the testes to the scrotum
Cryptorchidism refers to what?
Undescended testes
Sperm is stored in…
The epididymis
What structure engorges with blood during an erection?
Corpus cavernosa
Where does sperm production occur?
Seminiferous tubules
Once the sperm is produced in the seminiferous tubules, where does it go into?
Rete testis
What is the purpose of the sperm’s development of mitochondria?
Helps them survive the hypoxic environment of female reproductive tract
True or False.
Testicular veins drain to the inferior vena cava
True
Germ cells give rise to…
spermatozoa
What secrets inhibin?
Sustentacular cells
What type of cells have the receptor for FSH?
Sustentacular cells
FSH is produced where?
The brain
True or False
The blood-testis barrier is formed by gap junctions.
False, tight junctions
What makes up the blood-testis barrier?
Sustentacular cells
What is the purpose of the blood-testis barrier?
To prevent an immune attack/ destruction of sperm
Sustentacular cells secrete what?
Inhibin and ABP
What does ABP do?
Binds to testosterone in the tubules
What type of cells contain the receptor proteins for LH?
Interstitial/Leydig cells
These cells stimulate the secretion of testosterone
Leydig cells
Spermatogonia produce 2 kinds of daughter cells. Explain each type and what their role is?
Type A- remains outside blood-testis barrier and produces more daughter cells until death (replenishes the stock)
Type B- Undergos meiosis/spermiogenesis
The transformation into spermatozoon
Spermiogenesis
How many days does it take for spermatogonium to mature into spermatozoon?
74 days
What are the main changes that occur during spermiogenesis?
The sperm discard of excess cytoplasm and grow tails
What is optimal temperature for sperm production?
35 degrees C
Network of veins from testis that surround testicular artery in spermatic cord
Pampiniform plexus
What muscles of the male reproductive system contract in cold temperatures?
Cremaster and Dartos muscle
True or False
The pampiniform plexus is based on a countercurrent heat exchanger
True
A mature hypothalamus produces…
Gonadotropin releasing hormone (GnRH)
What is the function of GnRH?
Stimulates gonadotrope cells in anterior pituitary and causes secretion of FSH and LH
Does inhibin increase or decrease sperm production?
Decrease
What happens in menopause for men?
Rise in FSH and LH secretion
What is the breakdown of semen?
60% seminal vesicle fluid
30% prostatic
10% sperm
What is normal sperm count?
50-120 million
What is considered infertility?
< 25 million/mL
What provides the energy for sperm motility?
Fructose
A base stabilizing sperm pH at 7.2-7.6, neutralizing the vaginal tract
Spermine
What type of signals produce an erection?
Parasympathetic
Sympathetic nervous system propels sperm through ducts as glandular secretions are added
Emission
Semen in urethra activates muscular contractions that lead to expulsion
Expulsion
What happens with resolution after ejaculation?
Sympathetic signals constrict the internal pudendal artery and reduce blood flow to penis
In what part of the cell cycle does chromosome replication occur?
S phase
What are the products of mitosis?
2 identical daughter cells
Meiosis reduces chromosome numbers _______ for gamete cells
In half
True or False
Multiple oocytes go through one complete meiosis each month to produce one final viable egg
False
Where exactly is the egg fertilized?
Upper 1/3 of fallopian tube
What is the reproductive age in females?
12-50 years
What triggers puberty in girls?
GnRH
What does GnRH do in females?
Stimulates anterior pituitary to produce FSH and LH
What does FSH stimulate?
Stimulates the follicles to secrete estrogen and progesterone
What is thelarche?
Development of breasts
What is pubarche?
Growth of pubic and axillary hair, apocrine and sebaceous glands
What is menarche?
First menstrual period
What is a distinctive characteristic of female hormones?
They are secreted cyclically and in sequence
What does age related depletion of follicles mean?
Less secretion of estrogen and progesterone
What is HRT?
Low dose estrogen and progesterone therapy
Events occurring between fertilization and birth
Reproductive cycle
Events recurring every month in females when pregnancy does not occur is called the…
Sexual cycle
What is the hormone cycle that produces a hierarchy of control?
hypothalamus–> pituitary–> ovaries–> uterus
What happens in the follicular phase (2 weeks)?
Menstruation first and then the uterus replaces lost endometrium and follicles grow
What happens during the postovulatory phase (2 weeks)?
Corpus luteum stimulates endometrial thickening
What is secreted by the hypothalamus?
GnRH
GnRH stimulates the ____________ to produce _______ and ________
Anterior pituitary; FSH; LH
FSH and LH act on the ________ to stimulate follicle growth and produce ____________ and _____________
Ovary; estrogen; progesterone
High estrogen levels leads to…
Ovulation
The wound in the ovary after ovulation forms the __________
Corpus luteum
What layer does mitosis occur in?
Stratum basalis
What causes progesterone levels to fall?
Atrophy of corpus luteum
Average woman loses how much blood and serous fluid in an average menstrual cycle?
40 mL of blood and 35 mL of serous fluid
What does the serous fluid contain that prevents it from clotting?
Fibrinolysin
As LH increases, estrogen _________
Increases
What is an ectopic pregnancy?
When the implantation occurs outside of the uterus
True or false.
Zygote is diploid
True
Trophoblast secretes….
HCG
HCG stimulates the corpus luteum to secrete….
Progesterone and estrogen
Trophoblast develops into a membrane called the…
Chorion
Progesterone is required to keep the endometrium in tact, therefore it suppresses ____________
Menstruation
What are the three facts about progesterone secreted by the placenta and corpus luteum?
- Suppresses secretion of FSH and LH preventing follicular development
- Prevents menstruation and thickens endometrium
- Stimulates development of acini in breast tissue
What are the three facts about HCS (human chorionic somatomammotropin)?
- It is called the human placental lactogen
- It is secreted from placenta in direct proportion to it’s size
- Decreases mother’s glucose usage and increases release of fatty acids
Lack of spermatozoa in the ejaculate
Azoospermia
Lowered concentration and motility of spermatozoa
Oligoasthenozoospermia
Lowered proportion of spermatozoa of normal shape
Teratozoospermia
Lowered concentration and motility and lowered proportion of spermatozoa of normal shape
Oligoasthenoteratozoospermia
Spermatozoa are not motile (they appear as dead)
Necrospermia
Spermatozoa are so rare, that they could be found as far as after centrifugation of the sample
Cryptospermia
