Lecture 14: Female and male repro

Question 1

What do the reproductive systems consist of?

Answer 1

1) Gonads (testes and ovaries)
2) Reproductive tracts
3) External genitalia
4) Accessory sex glands

Question 2

What do the gonads (testes and ovaries) produce and secrete?

Answer 2

1) Gametes (sperm and ova)
2) Sex hormones (testosterone and estrogen/progesterone)

Question 3

Reproduction depends on the union of what?

Answer 3

1) male and female gametes

Question 4

1) Each gamete has a __________ set of chromosomes.
2) Estrogen is a group of compounds containing what 3 things?
3) What is the principle ovarian estrogen?

Answer 4

1) half
2) Estradiol, estrone, and estriol
3) Estradiol

Question 5

1) Testes are suspended in a skin covered sac called the __________
2) Sperm exit via what? Is this bilateral or unilateral?

Answer 5

1) scrotum
2) Male reproductive tract; bilateral

Question 6

1) What 3 things does the male repro tract consist of?
2) What does it empty into?

Answer 6

1) Epididymis, vas deferens, ejaculatory duct
2) Urethra, which runs along the penis and empties into the exterior

Question 7

List the 6 primary jobs of the female repro organs

Answer 7

1) Oogenesis
2) Reception of sperm
3) Transporting gametes for conception
4) Developing the fetus
5) Birth
6) Lactation

Question 8

1) What do gametes fuse into?
2) What does this divide into?
3) What does this then develop? What is it called?
4) When is it called a fetus?

Answer 8

1) A zygote (single cell)
2) Ball of cells called a blastocyst
3) An amniotic sac; an embryo
4) 9 weeks after conception (or 11 weeks after LMP)

Question 9

1) Define ovulation
2) What role does the fallopian tube play?

Answer 9

1) Ovaries release ovum
2) Ovum travels down it

Question 10

1) What organ maintains the fetus during development?
2) What is the lowest portion of this organ?
3) What opening does this contain? What does it do during birth?

Answer 10

1) Uterus
2) Cervix (projects into the vagina)
3) Cervical canal; dilates during birth

Question 11

1) Define gametogenesis
2) Define meiosis and how this applies to reproduction

Answer 11

1) Process of cells dividing by meiosis to form gametes
2) Half of the genetic information is distributed to four daughter cells
-Sperm and ova each have haploid number of chromosomes (23) which fuse into a full set (46)

Question 12

Nuclear division in somatic cells is accomplished by what? Define this proces.

Answer 12

Mitosis: Chromosomes replicate, then separate into two daughter cells

Question 13

Differences between males and females exist at what three levels?

Answer 13

1) Genetic (XX vs XY)
2) Gonadal
3) Phenotypic

Question 14

___[type of]_______ sex is dependent on ___[type]_______ sex which is dependent on ____[type]____ sex

Answer 14

Phenotypic; gonadal; genetic

Question 15

1) What does genetic sex depend on?
2) What does it determine?

Answer 15

1) Combination of sex chromosomes at time of conception
2) Gonadal sex

Question 16

1) Presence of testes or ovaries (gonadal sex) is determined by _____________ sex
2) Gonadal specificity manifests during week _____ when the undifferentiated gonadal tissue (in both m&f) differentiates under the influence of the sex-determining region of the Y chromosome

Answer 16

1) genetic
2) 7

Question 17

1) The Y chromosome masculinizes the gonads by coding for the production of what?
2) When do the female gonads develop?

Answer 17

1) testis-determining factor (SRY protein)
2) Week 9: undifferentiated gonadal tissue starts developing into ovaries

Question 18

1) Define phenotypic sex
2) What determines it? What mediates it?
3) When is it developed?

Answer 18

1) Anatomicsex of an individual
2) Determined by gonads and mediated by hormones
3) Embryonic development of external genitalia

Question 19

Undifferentiated genital tissue consists ofwhat 3 things? Define each.

Answer 19

1) Genital tubercle: Clitoris and penis
2) Urethral folds: Labia minora and erectile tissue around urethra
3) Genital swellings: Labia majora and scrotum/prepuce(foreskin)

Question 20

True or false: External genitalia develop from same undifferentiated embryonic tissue, but reproductive tracts develop from two different systems present in all embryos

Answer 20

True

Question 21

Reproductive tracts develop from two different systems present in all embryos; what are they? What happens when each duct is used and what happens when they’re not?

Answer 21

1) Wolffian ducts: develop into male reproductive tracts
2) Müllerian ducts: develop into female reproductive tracts
-The other duct degenerates

Question 22

1) Define secondary sex characteristics
2) What two hormones are they influenced by?

Answer 22

1) The external characteristics that distinguish males from females, but are not directly involved in reproduction
2) Testosterone and estrogen

Question 23

1) Testosterone in the fetus induces what?
2) Why?

Answer 23

1) Descent of the testes into the scrotum
2) Spermatogenesis cannot occur at normal body temperature; temperature of scrotum needs to b regulated by its position

Question 24

Position of scrotum can be varied by a spinal reflex mechanism; describe what happens when it’s cold or hot

Answer 24

1) Cold: reflex contraction of scrotal muscles raises the scrotal sac to warm the testes
2) Hot: relaxation of scrotal muscles moves the testes away from the body’s heat

Question 25

1) List 3 hormones that are all derived from a cholesterol precursor molecule
2) Out of the 3, some of which is secreted into the blood?
3) Where does much of it go? Why?

Answer 25

1) Testosterone, estrogen, and progesterone
2) Testosterone
3) Much of it goes into the lumen of the seminiferous tubules of the testes to participate in sperm production

Question 26

Describe how testosterone affects the reproductive system development before birth (2 ways)

Answer 26

1) Masculinizes the reproductive tract and external genitalia
2) Promotes descent of testes into the scrotum

Question 27

1) What produces testosterone?
2) What happens to testosterone after birth?

Answer 27

1) Leydig cells
2) Secretion ceases until puberty

Question 28

1) Effects on sex-specific tissues after birth begins between what ages? (in males and females)
2) Are adult men fertile forever, or do they have a process comparable to menopause?
3) Are there any degenerative changes with age? If so, where? If not, why?

Answer 28

1) 10–14 years of age in males; 9 – 13 in females
2) Spermatogenesis becomes less efficient around 45yo, but men in their70s can potentially father children. Not like menopause
3) Testes do not degenerate, the degenerative changes occur in the testicular blood vessels

Question 29

List 2 other reproduction-related effects of testosterone not yet mentioned (incl. at least one type of feedback control).

Answer 29

1) Sexual drive
2) Negative-feedback control of gonadotropin secretion by anterior pituitary

Question 30

List 4 effects of testosterone on secondary sex characteristics

Answer 30

1) Male hair growth
2) Deep voice due to enlargement of larynx and thickening of vocal folds
3) Thickening of the skin
4) Broadening of the shoulders and development of musculature

Question 31

List 3 nonreproduction actions of testosterone. Include which is disputed.

Answer 31

1) Increases protein synthesis
2) Stimulates bone growth
-Also eventually prevents further growth [by ossifying the epiphyseal plates]
3) Aggressive behavior (disputed in humans)

Question 32

1) Define spermatogenesis
2) Spermatogenesis takes ______ days per sperm.
3) Up to __________________________ sperm reach maturity daily.

Answer 32

1) The complex process by which undifferentiated germ cells proliferate and are converted into sperm.
2) 64 days
3) several hundred million

Question 33

List the 2 steps of mitosis in the context of spermatogenesis

Answer 33

1) Spermatogonia divide into new cells which contain 46 chromosomes
2) One cell moves closer to the lumen and divides twice more to produce 4 primary spermatocytes

Question 34

List the 2 steps of meiosis in the context of spermatogenesis

Answer 34

1) Each primary spermatocyte forms: 2 secondary spermatocytes (w. 23 doubled chromosomes)
2) Divide to yield 4 spermatids (w. 23 single chromosomes)

Question 35

1) Spermatids are remodeled intospermatozoa (sperm) in a process called ___________.
2) What occurs during this process?

Answer 35

1) packaging
2) Stripped of most of the cytosol and organelles not needed for transferring genetic information to the ovum

Question 36

A spermatozoon has 3 parts; what are they? Describe each.

Include which contains the nucleus and which contains mitochondria.

Answer 36

1) Head: consists primarily of the nucleus, capped by the acrosome
-Acrosome: enzyme-filled cap that is an “enzymatic drill” to penetrate ovum
2) Midpiece: contains mitochondria which power the tail
3) Tail: provides mobility

Question 37

1) An “enzyme-filled cap that is an ‘enzymatic drill’ to penetrate ovum” describes what structure?
2) How does testosterone eventually prevent further growth?

Answer 37

1) Acrosome
2) By ossifying the epiphyseal plates

Question 38

1) The male reproductive tract consists of what 3 things?
2) Define male repro tract

Answer 38

1) Tubes that transport sperm, accessory sex glands, penis
2) Tubes that transport the sperm from the testes to the outside of the body

Question 39

1) What part of the male reproductive tract stores sperm? Where is it?
2) What do the ducts of this part converge to form?
3) Where does this structure go?

Answer 39

1) Epididymis, attached to posterior of the testes
2) Vas deferens
3) Into abdominal cavity, empties into urethra at neck of bladder

Question 40

1) What do male accessory sex glands contribute to?
2) What is the collection of their secretions called?
3) What does the penis do? (reproductively)

Answer 40

1) Secretions vital to the viability of sperm
2) Semen
3) Deposits sperm carried by semen

Question 41

What are the 3 male accessory sex glands that contribute secretions vital to the viability of sperm?
State what each surrounds or secretes into.

Answer 41

1) Seminal vesicles: empty into vas deferens bilaterally
2) Prostate: surrounds ejaculatory ducts and urethra
3) Bulbourethral glands: secrete into the urethra just before the penis

Question 42

1) What accessory sex glands provide 60% of the semen volume?
2) What is the primary energy for ejaculated sperm? What supplies it?
3) What secrete prostaglandins (which stimulate contractions in male and female tracts to help transport sperm)?
4) What part of the male repro system secretes fibrinogen?

Answer 42

1) Seminal vesicles
2) Fructose; seminal vesicles
3) Seminal vesicles
4) Seminal vesicles

Question 43

1) What secretes alkaline fluid (which neutralizes acidic vaginal secretions)?
2) What does the prostate gland provide regarding clotting?
3) What does the prostate release that’s prostate-specific?

Answer 43

1) Prostate gland
2) Clotting enzymes
3) Prostate-specific antigen

Question 44

1) What helps keep semen in the female reproductive tract? (hint: one word)
2) _______ is fibrinolytic, and eventually releases the sperm from the female tract
3) What glands provide some lubrication? Is this comparable to female lubrication?

Answer 44

1) Coagulation
2) PSA
3) Bulbourethral glands; minimal compared to female

Question 45

1) Testes are controlled by 2 AP gonadotropic hormones; what are they?
2) Do they act on the same components of the testes?

Answer 45

1) FSH and LH
2) Act on separate components

Question 46

1) LH acts on __________ cells to regulate testosterone secretion
2) This hormone is is needed for ___________________.
3) What hormone acts on Sertoli cells to enhance spermatogenesis? What is this hormone needed for?

Answer 46

1) Leydig; testosterone
2) germ cell division
3) FSH; spermatid remodeling

Question 47

1) Secretion of LH and FSH is stimulated by what hypothalamic hormone?
2) How often is it released?

Answer 47

1) Gonadotropin-releasing hormone (GnRH)
2) In bursts every 2-3 hours

Question 48

1) LH and FSH secretion is influenced by what 2 hormones?
2) Which one decreases LH by negative feedback? What structures does it act on to do this?

Answer 48

1) Testosterone and inhibin
2) Testosterone; hypothalamus and AP

Question 49

Testosterone decreases LH (negative-feedback) by acting on what two structures?

Describe the effects of each (this pt not super important).

Answer 49

1) Hypothalamus: slightly decreases FSH too
2) Anterior pituitary: only decreases LH

Question 50

1) What is inhibin? What is it secreted by?
2) What does it inhibit?

Answer 50

1) Peptide hormone; by Sertoli cells
2) FSH secretion by AP

Question 51

1) GnRH activity increases when?
2) What is occurring before then?

Answer 51

1) At puberty
2) It’s inhibited, thus LH/FSH are not secreted at adequate levels for any significant testicular activity

Question 52

Factors responsible for initiating puberty are unclear, but ____[hormone]______ might play a role

Answer 52

melatonin

Question 53

1) What processes can hypogonadism cause defects in? (Males)
2) What are the two types?

Answer 53

1) Spermatogenesis, steroidogenesis or both
2) Primary (testis) or secondary (hypothalamic-pituitary)

Question 54

Gonadal failure before puberty (hypogonadism) results in what? What is this called?

Answer 54

Absence of secondary sex characteristics; eunuchoidism

Question 55

What are the two major components of the female reproductive system?

List the primary and secondary functions of each.

Answer 55

1) Ovaries: produce the ovum; secrete progesterone, estradiol and androgens
2) Ductal System: union for sperm and egg; maintains the developing fetus

Question 56

What 3 hormones do the ovaries secrete?

Answer 56

Progesterone, estradiol and androgens

Question 57

1) What two parts do the ovaries (8-12g) consist of?
2) What do they contain?

Answer 57

1) Outer cortex and inner medulla
2) Follicles, corpora lutea, corpora albicantia, and stromal cells

Question 58

What are the 3 parts of the oviduct (fallopian tube)?
What is the primary function of each?

Answer 58

1) Infundibulum: Contains fimbria to gram the ovum
2) Ampulla: Fertilization should occur here
3) Isthmus: [none listed]

Question 59

1) Puberty in females occurs when what hormone increases for the first time?
2) This hormone stimulates what two hormones? What does this then do?

Answer 59

1) GnRH
2) LH and FSH; stimulate ovarian estrogen

Question 60

1) When GnRH stimulates LH and FSH which stimulate ovarian estrogen, what 2 things does this induce?
2) List 3 physical traits this includes
3) Which 3 induced physical traits are attributed to androgens (DHEA) rather than estrogen?

Answer 60

1) Maturation of the female reproductive tract and development of secondary female sex characteristics
2) Fat deposition, enlargement of breasts, closing of the epiphyseal plates
3) Axillary & pubic hair, growth spurt, and sex drive

Question 61

List the 4 stages of female puberty

Answer 61

1) Thelarche
2) Pubarche
3) Adrenarche
4) Menarche

Question 62

1) In what stage does the first physical sign of puberty occur? What is this sign?
2) In what stage does pubic hair appear? Where is this in relation to the first sign of puberty?

Answer 62

1) Thelarche; breast budding
2) Pubarche; usually 6 months later

Question 63

1) What characterizes adrenarche stage of puberty? What physical characteristic accompanies this?
2) Is adrenarche the same as gonadarche? If not, specify the order in which each occurs
3) What defines menarche?

Answer 63

1) Adrenal production of DHEA; axillary hair
2) No, they’re separate; precedes gonadarche by 2 years (usually 6-8 years old)
3) Beginning of menstrual cycles

Question 64

1) Define precocious puberty.
2) What hormone does it involve the premature reactivation of?
3) What are 3 potential causes? Which is the most common? Describe each.

Answer 64

1) Early signs of secondary sexual maturation; ages 6-7
2) Premature reactivation of GnRH
3) Congenital Adrenal Hyperplasia
-Follicular Cysts (most common; secrete estrogen)
-McCune-Albright Syndrome (mutations that lead to increased ovarian estrogen synthesis (or test. in boys))

Question 65

1) Secretion of female sex hormones displays cyclic swings and release of _______ is intermittent.
2) During each cycle,the repro. tract is prepared for fertilization. What happens if fertilization does occur? What about if it does not occur?
3) What structure is responsible for oogenesis [producing ova]? What two hormones does this structure secrete?

Answer 65

1) ova
2) Cycles are interrupted; cycles repeat
3) Ovaries; estrogen and progesterone

Question 66

____________ in the females governs functions similar to those of testosterone in the male

Answer 66

Estrogen

Question 67

List 4 responsibilities of estrogen in females

Answer 67

1) Maturation and maintenance of female reproductive system
2) Establishment of secondary sex characteristics
3) Ova maturation and release
4) Breast development in anticipation of lactation

Question 68

1) What hormone is important in preparing suitable envt. for developing embryo and contributes to breasts’ ability to produce milk?
2) What reproductive process occurs via steps of chromosome replication?

Answer 68

1) Progesterone
2) Oogenesis

Question 69

In oogenesis:
1) Undifferentiated germ cells develop into __________.
2) Then these divide mitotically to produce ______________ of them by the 5th month of gestation.
3) What happens after this?

Answer 69

1) oogonia
2) 7 million
3) Mitotic proliferation ceases

Question 70

1) During the last part of fetal development,oogonia do what?
2) Primary oocytes contain ____[diploid/ haploid]___ number of ___#__ replicated chromones.
3) True or false: after the last part of fetal development, the primary oocytes then remain in a state of meiotic arrest for years until prepared for ovulation

Answer 70

1) Begin (but do not complete) the first meiotic division
2) diploid; 46
3) True

Question 71

1) Each primary oocyte is surrounded by a layer of ____________ cells
2) What two things are collectively known as follicular cells?
3) What happens to follicular cells that aren’t incorp. into mature follicles?

Answer 71

1) granulosa
2) Thecal and granulosa cells
3) Undergo apoptosis

Question 72

1) At birth, how many primordial follicles remain?
2) What does each primordial follicle contain? What is this capable of producing?
3) True or false: new oocytes or follicles can appear after birth.

Answer 72

1) 2 million
2) A single oocyte; a single ovum
3) False; no new oocytes or follicles will appear

Question 73

1) Define atresia
2) What two things can happen to a follicle?
3) What do paracrine factors cause?
4) __________ follicles remain at puberty, about ______ will mature

Answer 73

1) The process of a follicle degenerating to form scar tissue.
2) Either reach maturity and ovulate, or undergo atresia.
3) Trickling of follicles (poorly understood).
4) 300,000; 400

Question 74

1) Just before ovulation, the primary oocyte, whose nucleus has been in meiotic arrest for years, does what?
2) What does this yield?

Answer 74

1) Completes the first meiotic division
2) Two daughter cells (each receiving a haploid set of 23 double-strandedchromosomes)

Question 75

1) Almost all of the cytoplasm remains with one of the daughter cells, called the ____________ oocyte, and will become the ______________.
2) What is the other daughter cell called? What happens to it?

Answer 75

1) secondary oocyte; ovum
2) First polar body; divides once

Question 76

1) When does the secondary oocyte undergo second meiotic division?
2) Technically, the __________________ is ovulated and fertilized, and then becomes the “ovum”

Answer 76

1) Upon sperm entry
2) secondary oocyte

Question 77

1) What is the result of the second meiotic division of the secondary oocyte upon sperm entry?
2) What do these unite with? What does this do?
3) What then happens to the polar bodies?

Answer 77

1) Half set of chromosomes is extruded as the second polar body, other half set of 23 unpaired chromosomes remains as the mature ovum
2) 23 paternal chromosomes of the sperm; complete fertilization
3) Polar bodies degenerate

Question 78

After the onset of puberty, the ovary constantly alternates between what two phases?
List what characterizes each, and what each accomplishes.

Answer 78

1) Follicular phase: Dominated by presence of maturing follicles
-Produces a mature egg
2) Luteal phase: Presence of corpus luteum
-Prepares the tract for pregnancy

Question 79

1) When is the ovarian cycle interrupted?
2) When is it terminated?
3) How long is the avg. cycle?

Answer 79

1) If pregnancy occurs
2) Menopause
3) 28 days (but can vary)

Question 80

Follicular phase:
1) What is the primary oocyte doing?
2) What 3 things are delivered to the oocyte?
3) What then forms? What does this collect?

Answer 80

1) Synthesizing and storing materials in preparation for fertilization
2) Glucose, amino acids, and other molecules
3) Antrum forms; estrogen (secreted by follicular cells)

Question 81

Follicular phase:
1) Follicle with the most ______ receptors grows more rapidly than others, developing into a __________ follicle; aka “_____________ follicle”
2) What signifies ovulation?

Answer 81

1) FSH; mature; “dominant follicle”
2) Follicle pushes against ovarian surface, until it cannot be contained
3) Follicle ruptures, ovum is swept into fallopian tube

Question 82

Luteal phase:
1) Define luteinization
2) What is the involvement of the corpus luteum?
3) What is the goal of this phase?

Answer 82

1) Ruptured follicle left behind undergoes a transformation into the corpus luteum
2) Secretes abundant progesterone and small amt. of estrogen
3) Prepares uterus for implantation

Question 83

Luteal phase:
1) What does the corpus luteum do if the ovum is not fertilized?
2) What does the corpus luteum do if the ovum is fertilized and implantation occurs?
3) How long does this last?

Answer 83

1) Degenerates within 14 days
2) Grows and produces increasing amounts of progesterone and estrogen
3) Until pregnancy ends

Question 84

The ovary has two endocrine units; what are they, and what does each secrete?

Answer 84

1) Follicle: estrogen during the first half of the cycle
2) Corpus luteum: estrogen and progesterone during the second half

Question 85

The ovary is governed by cyclic hormonal relationships among the ______________ and _____________

Answer 85

hypothalamus and AP

Question 86

1) What 3 hormones control the ovary (like in the male)?
2) What about this differs from the male?

Answer 86

1) GnRH, FSH, and LH
2) Effects of FSH ad LH depends on the stage of the ovarian cycle (unlike the male)

Question 87

1) __________________ is part of negative feedback in one part of the cycle ,and positive feedback in another
2) True or false: FSH is not solely for gametogenesis, and LH is not solely for gonadal hormone secretion

Answer 87

1) Estrogen
2) True

Question 88

Follicular phase:
1) What 3 hormones are needed for antrum development?
2) What two hormones are req. for synth. and secretion of estrogen by the follicle?
3) Secreted estrogen inhibits ___[hormone]__and __[hormone]__ (negative feedback).
4) What does estrogen indirectly inhibit? How?

Answer 88

1) Estrogen, FSH, and LH
2) Both LH and FSH
3) hypothalamus and AP (negative feedback)
4) GnRH; acts on upstream regulators

Question 89

Follicular phase:
1) Inhibin acts on the AP to inhibit ___[hormone]__ just as it does in the male
2) Does GnRH inhibition stop the rise of LH?
3) Re #2; why?

Answer 89

1) FSH
2) No; LH continues to rise, despite inhibition of GnRH
3) B/c estrogen alone cannot completely inhibit LH, progesterone is also required

Question 90

LH surge brings about 4 changes in the follicle; what are they? Describe each

Answer 90

1) Halts estrogen synthesis
2) Reinitiates meiosis: by blocking release of oocyte maturation inhibitor.
3) Triggers local prostaglandins: which promote follicular swelling.
4) Causes differentiation of the follicular cells into luteal cells

Question 91

An LH surge is triggered by a ____[pos/neg]____ feedback effect

Answer 91

positive

Question 92

Follicular phase/ ovulation:
1) Moderate levels of estrogen in the early follicular phase inhibit ______; high estrogen peak during late follicular phase activates ____________________ (unique in females).
2) Where are these located?
3) What do these do? Describe the 2 step chain rxn effect it has.
4) How long does this last? When?

Answer 92

1) LH; upstream regulators
2) Antroventral periventricular (AVPV) nucleus of hypothalamus
3) Stimulate GnRH release, which increases LH and FSH, which enhances estrogen further
4) ~ A day at midcycle

Question 93

Luteal phase:
1) What happens to the estrogen secreting follicle? What does this result in?
2) What two hormones does the resulting structure secrete? What effects do these have?
3) What do these two hormones effects inhibit and prevent?

Answer 93

1) Transformed into corpus luteum (luteal cells);doesn’t reach the same peaks
1) Progesterone: powerfully inhibits LH
Inhibin: inhibits FSH
2) Inhibit LH and FSH; prevents follicular maturation during the luteal phase

Question 94

1) Corpus luteum degenerates by what?
2) What two hormone levels then fall? What effects are withdrawn?
3) The secretion of what two hormones begins to increase again? What does all of this then cause?

Answer 94

1) Mechanisms not fully understood
2) Estrogen and progesterone; inhibitory effects
3) FSH and LH; another batch of follicles is recruited for development