Flashcards in Reproductive System Deck (170):
contains paired testes and hangs outside abdominopelvic cavity
What winkles the scrotal skin?
What elevates the testes?
What is the name of the serous membrane covering the testes?
What is the fibrous capsule of testis?
What produces testosterone?
interstitial endocrine cells
What produces sperm?
What are the testes divided into?
What encloses nerve fibers, blood vessels, lymphatics and ductus deferens?
What are the major part of the penis?
root, shaft, glans penis and prepuse
What does the internal penis contain?
spongy urethra and 3 cylindrical of erectile tissue
What are the erectile tissue in the penis?
corpus spongiosum and corpus cavernosa(paired)
What is the order of the male duct system?
epididymsis-> ducyus deferens -> ejaculatory duct -> urethra
Site where sperm gain ability to swim
stores sperm prior to ejaculation
immature sperm conveyed from seminiferous tubules
Where does the epididymis empty into?
Ductus deferens joins duct of what to form the ejaculatory duct?
Cutting and ligating ductus deferens
What are the 3 regions of the urethra?
1. prostatic urethra
2. membranous urethra
3. spongy urethra
Which of the accessory glands are paired?
seminal vesicles, bulbo-urethral glands and prostate
What contains 70% of semen volume?
What are the 2 components of semen?
fructose and prostaglandins
Contains up to 1/3 of semen volume
Pea-sized glands inferior to prostate
lubricates glans penis and neutralizes traces of urine
What are the functions of semen
1. provides transport medium for sperm
2. provides fuel for ATP synthesis
3. contains chemicals that enhance sperm motility
pH of sperm
Why is the pH of the sperm so basic?
this is because the vagina is acidic
How many total chromosomes in a diploid cell?
How many chromosomes in a haploid cell?
Nuclear division process that occurs only in gonads?
crossing over for genetic variation
tetrads line up at metaphase plate
homologous chromosomes separate
Product of meiosis I
2 diploid daughter cells
Product of meiosis II
4 genetically distinct haploid daughter cells
What is the function of meiosis?
introduce genetic variability
Sperm formation in seminiferous tubules
What are the major steps in the spermatogenesis?
1. Mitosis of spermatogonia
Stem cells at outermost tubule
Starting at puberty, each mitotic division become what?
type A and type B daughter cells
Which cell type remains at basal lamina?
Which cell type moves toward lumen and becomes primary spermatocyte?
What occurs during meiosis I to the primary spermatocyte?
it becomes 2 secondary spermatocytes
Are the cells haploid or diploid at primary spermatocyte?
Are the cells haploid or diploid at secondary spermatocytes?
During meiosis II what happens to the secondary spermatocyte?
Are the cells haploid or diploid at the 2 spermatids?
Spermatid elongates loses excess cytoplasm and forms a tail
what is another name for sperm?
What are 3 major regions of a sperm?
Part of the sperm that has hydrolytic enzymes?
What does the midpiece of the sperm contain?
Surround spermatogenic cells
divide seminiferous tubule into basal compartment and adluminal compartment
tight junctions between sustentocytes
2 functions of the blood-testis barrier
1. prevents antigens of developing sperm from activating immune system
2. sperm absent during immune system development and so not recognizedas "self"
What lies outside blood-testis barrier in basal compartment?
What is the purpose of tight junctions opening following mitosis?
type B daughter cells pass into adluminal compartment
What are other functions of sustentocytes?
1. provide nutrients to dividing cells
2. secrete testicular fluid for sperm transport
3. move cells toward lumen
4. produce chmical signals that help regulate spermatogenesis
hormonal interactions between hypothalamus, anterior pituitary and gonads
What does the hypothalamus releases?
GnRH (gonadotropin-releasing hormone)
FSH and LH
What is stimulated by sustentocytes to release androgen-binding protein?
What is the function of FSH stimulation in males?
keeps concentration of testosterone high near spermatogenic cells
What stimulates interstitial endocrine cells to release testosterone?
What is the final trigger for spermatogenesis?
What do rising levels of testosterone feed back and inhibit release of?
GnRH, FSH, snd LH
When sperm count is high, sustentocytes do what?
release inhibin to inhibit release of GnRH and FSH
What directly stimulates the testes?
What stimulates the release of gonadotropins?
What exerts negative feedback controls on hypothalamus and anterior pituitary?
What are the function of testosterone?
1. stimulate spermatogenesis
2. stimulates maturation of accessory reproductive organs
3. promotes development of secondary sex characteristics
4. responsible for male libido
Featured induced in nonreproductive organs by male sex hormones at puberty
male secondary sex characteristics
List male secondary sex characteristics
1. increased oilness of skin
2. increased size and mass of bones and skeletal muscles
3. deepening of voice
4. appearance of pubic, axillary and facial hair
What organs are in the internal genitalia in a female?
ovaries, uterine tubes, uterus and vagina
What organs are in the external genitalia in a female?
mons pubis, labia majora and minora, and clitoris
What surrounds the ovaries?
What are the 2 regions in the ovaries?
outer cortex and inner medulla
Where are ovaries located?
embedded in cortex are ovarian follicles
1 cell layer thick
more than 1 layer present
Ejection of oocyte from mature follicle
What are the components of the female duct system?
uterine tubes -> uterus -> vagina
Does the female duct system make contact with ovaries?
What are the 2 functions of the uterine tubes?
1. receives ovulated oocyte
2. usual site of fertilization
What occurs during at ovulation?
beating cilia create currents that move oocyte into uterine tube then the oocyte carried toward uterus by peristalsis and ciliary action
What is the function of the uterus?
receives, retains, and nourishes fertilized ovum
What are the 3 layers of the uterine wall?
perimetrium, myometrium and endometrium
What are the 2 layers of the endometrium?
stratum functionalis and stratum basails
What sheds during menstruation?
What forms new stratum functionalis?
Thin-walled tube 8-10cm in length; extends from cervix to exterior
What are the functions of the vagina?
1. birth canal
2. female organ of copulation
Membrane that partially covers external vaginal opening
Fatty area overlying pubic symphysis
hair-covered, fatty skin folds and counterpart of male scrotum
What is the hair-free folds enclose vestibule?
flank vaginal opening
greater vestibule glands
What in a female is homologous to male bulbo-urethral bland?
Greater vestibular glands
In a female what secretes mucus for lubrication?
greater vestibular glands
In a female what is the male counterpart of the penis?
What is the skin fold of the clitoris?
What is the exposed portion of the clitoris?
What is the pigmented skin surrounding the nipple?
What attaches the breast to underlying muscles?
Lobules within lobes contain alveoli produce what?
What is the milk pathway in the mammary gland?
lactiferous ducts -> lactiferous sinuses
What is the production of the female gametes called?
When does oogeneis begin?
begins in the fetal period
What are 2n stem cells called in oogenesis? How do they multiply?
oogonia and multiply by mitosis
What develops in primordial follicles?
Where do primary begin and stall?
begins in meiosis and stalls in prophase I
At birth, what is the female lifetime supply of primary oocytes?
At puberty, how many oocytes remain?
Each month after puberty what are activated?
few primary oocytes are activated
What are the results of the oogenesis?
2 haploid cells of different sizes
What are 2 cell types after the primary oocyte?
secondary oocyte and first polar body
What happens to the secondary oocyte in metaphase II and ovulation?
What happens to secondary oocyte if not penetrated by sperm?q
What happens to the secondary oocyte if penetrated by sperm?
completes meiosis II
What is the result of meiosis II when the secondary oocyte penetrates sperm?
ovum and secondary polar body
How many viable sperm does spermatogenesis yield? Error rate?
4 viable sperm and 3-4% error rate
How many viable ovum and polar bodies does oogenesis yield? Error rate?
1 viable gamete and 3 polar bodies
30% error rate
Monthly series of events associated with maturation of egg
What are the phases in the ovarian cycle?
follicular and luteal phase
period of follicle growth; days 1-14
period of corpus luteum activity (days 14-28)
When does ovulation occur?
ovulation occurs midcycle of ovarian cycle
What are the steps in the follicular phase?
1. Primordial follicle is surrounded by a single layer of flattened follicle cells
2. Primordial follicle becomes primary follicle and the oocyte enlarges
3a. Primary follicle becomes secondary follicle; granulosa cells form around oocyte
3b. secondary follicle become late secondary follicle ; theca folliculi condenses around follicle and fluid accumulates between granulosa cells
4. Late secondary follicle becomes vesicular follicle; antrum begins to form
5. Primary oocyte completes meiosis I
What occurs during ovulation?
ovary wall ruptures, expels secondary oocyte with its corona radiata into peritoneal cavity
During conception if there is 1 egg and 1 sperm with same placenta and separate amniotic sacs, what type twins are the result?
During conception if there are 2 eggs and 2 sperms, separate placenta and separate amniotic scas, what type twins are the result?
What occurs in the luteal phase
1. ruptured follicle collapses forming corpus luteum; secretes progesterone and some estrogen
In the luteal phase, if no pregnancy what happens to corpus luteum?
it degenerates into corpus albicans (scar) in 10 days
In the luteal phase if pregnancy occurs what happens to the corpus luteum?
produces hormones until placenta takes over around 3 months
What happens in the ovarian cycle during childhood?
ovaries secrete small amounts of estrogens that inhibit hypothalmic release of GnRH
What happens to in the ovarian cycle as puberty nears?
Hypothalamus becomes less sensitive to estrogen; release GnRH
Approximately how long after puberty near does menarche occur?
after 4 years
In the ovarian cycle what does LH stimulate? Result of stimulation?
LH stimulates cells of theca folliculi which release androgens
In the ovarian cycle what does FSH stimulate? Result of stimulation?
FSH stimulates granulosa cells which convert androgens to estrogens
What inhibits gonadotropn release in females?
In females what inhibits FSH and LH during gonadatropin inhibition?
1. rising estrogen levels
2. rising inhibin levels (released by granulosa cells)
What stimulates gonadotropin release?
What is the cause of estrogen output?
What happens once estrogen levels reach critical level?
brief positive feedback on hypothalamus and anterior pituitary
Sudden burstlike release of LH at midcycle
What are the 3 effects of LH surge?
1. stimulates primary oocyte to complete meiosis I
2. triggers ovulation
3. transforms ruptured follicle into corpus luteum
What occurs when negative feedback inhibits LH and FSH release?
1. inhibits follicle maturation
2. prevents additional LH surges
What are the 4 events that occur if no fertilization?
1. LH levels fall
2. corpus luteum degenerates
3. estrogen and progesterone levels drop sharply
4. blockade of FSH and LH secretion ends
Cyclic changes in endometrium in response to fluctuating ovarian hormone levels
What are the 3 phases in the uterine cycle?
1. Menstrual phase (days 1-5)
2. Proliferative phase (days 6-14)
3. Secretory phase (days 15-28)
What occurs during the menstrual phase?
1. stratum functionalis sheds (menstruation)
2. ovarian hormones at lowest levels
3. gonadotropins beginning to rise
What occurs during the proliferative phase?
1. stratum functionalis rebuilt (due to rising levels of estrogen)
2. ovulation occurs at end of proliferative phase
What 2 events occur during secretory phase?
endometrium prepares for embryo and rising progesterone levels
In what phase do progesterone levels rise? What 2 things does it prompt?
1. enrichment of blood supply
2. glandular secretion of nutrients
In the uterine cycle what occurs if there is no fertilization?
1. corpus luteum degenerates,
2. progerstone levels fall
3. spiral arteries kink, spasm, and relax
4. weakened capillary beds fragment (functional layer sloughs-off)
Which 2 phases in the in the uterine cycle overlap with which phase in the ovarian cycle?
the menstrual and proliferative phase overlaps with the follicular phase
What phase responds to a phase in the ovarian cycle?
the secretory phase corresponds to the luteal phase
List the 4 effects of estrogen
1. promotes oogenesis and follicle growth in ovary
2. exert anabolic effects n female reproductive tract
3. stimulate rapid but short-lived growth spurt at puberty
4. induce secondary sex characteristics
List the female secondary se characteristics
1. growth of breasts
2. deposition of subcutaneous fat
3. widening and lengthening of pelvis
What is the number of chromosomes in a human gamete?
What is the function of ABG?
keeps the concentration of testosterone in the vicinity of the spermatogenic cells high to stimulate spermatogenesi
Which layer of the uterus is the site for implantation of a fertilized egg
stratum functionalis layer of the endometrium
What part of the breast produces milk
Which layer of the uterine wall is made of smooth muscle?
What is the role of the corpus luteum?
to produce hormones that maintain the uterine lining during the first months of pregnancy
What type of cell is released during ovulation?