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137 Cards in this Set

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The ovarian cycle is regulated by what?
The ovarian cycle is regulated by complex hormonal interactions
Ovarian cycle hormonal regualtion involves ? related ? units.
Ovarian cycle hormonal regulation involves 2 related endocrine units.
List the two related endocrine units involved in the hormonal regulation of the ovarian cycle?
l. Estrogen secreting FOLLICLE in first half of cycle

2. Progesterone and estrogen secreting CORPUS LUTEUM in last half of cycle
The two related endocrine units involved in the hormonal regulation of the ovarian cycle (the follicle and corpus luteum) are triggered by what?
The units are triggered by cyclical hormonal changes among the...

1. hypothalamus

2. anterior pituitary

3. the ovarian endocrine units themselves (follicle & corpus luteum)
Gonadal ('ovarian') function is directly controlled by what?
Gonadal function is directly controlled by the following anterior pituitary gonadotropic hormones:

1. follicle stimulating hormone (FSH)

2. luteinizing hormone (LH)
Gonadal function is directly controlled by anterior pituitary gonadotropic hormones: follicle stimulating hormone (FSH) and luteinizing hormone (LH).

So what controls FSH and LH?
These are controlled by hypothalamic gonadotropin-releasing hormone (GnRH) and feedback from gonadal hormones
What are the major events of the follicular phase of the ovarian cycle?
1. A rise in FSH (from the anterior pituitary) signals the ovarian follicle to secrete more estrogen.

This rise in estrogen feedsback to inhibit FSH secretion, which declines as the follicular phase proceeds.

2. LH rises and peaks in mid-cycle, triggering ovulation.

Estrogen output decreases and the mature follicle is converted to a corpus luteum.
The FSH ? the follicle which leads to an ? in estrogen which inhibits ?.
The FSH STIMULATES the follicle which lead to an INCREASE in estrogen which inhibits FSH.
What are the major events of the luteal phase of the ovarian cycle?
1. Corpus luteum secretes progesterone (predominantly) and estrogen (to a lesser extent than the follicular phase).

2. Progesterone output inhibits the release of FSH and LH.

3. Low LH results in corpus luteum degeneration.

4. Corpus luteum degeneration causes progesterone levels to decline.

5. FSH can start to rise again, initiating a new cycle.
The corpus luteum secretes ? and ?.
The corpus luteum secretes progesterone predominantly and estrogen to a lesser extent.
Progesterone ? the release of FSH and ? the release of LH.
Progesterone INHIBITS the release of both FSH and LH.
? LH results in ? ? degeneration.
LOW LH results in corpus luteum degeneration.
Corpus luteum degeneration causes progesterone levels to ?.
Corpus luteum degeneration causes progesterone levels to DECLINE.
What is the main output of the follicular phase?
Estrogen (stimulated by FSH).
What are the main outputs of the luteal phase?
Progesterone and estrogen
The antrum is formed because of ?.
The antrum is formed because of FSH.
FSH and LH stimulate the proliferation of what that is partially responsible for estrogen production?
FSH and LH stimulate the proliferation of GRANULOSA CELLS which are partially responsible for estrogen production.
Although FSH and LH are both required for ? ? they both act on ? ?.
Although FSH and LH are both required for ESTROGEN SYNTHESIS they both act on DIFFERENT CELLS.
Once produced where does the estrogen go?
Into the antrum and blood.
What does estrogen that is released into the blood do?
Estrogen in the blood inhibits the hypothalamus (GnRH) and the anterior pituitary. Causes a decline in FSH.
The LH surge seen during ovulation is important for what?
Stimulates the differentiation of follicle cells to luteal cells.
The LH maintains ?.
LH maintains corpus luteum.
Once progesterone and estrogen are produced what do they prevent? Why?
They prevent another LH surge. This prepares the body for fertilization.
What are the two gonadotropic hormones?
1. LH

2. FSH
What are the two gonadal hormones?
1. Progesterone

2. Estrogen
What are the phases of the uterine changes during the ovarian cycle?
The phases of the the changes in the uterus (endometrial thickness) are:

1. Menstrual phase

2. Proliferative phase (endometrial thickness increases)

3. Secretory (Progestational) phase (Continues to thicken...provides environment for fertilized ovum)

4. New menstrual phase
LH and FSH come from where?
The anterior pituitary.
LH stimulates ? cells.
LH stimulates Thecal cells.
FSH stimulates ? cells.
FSH stimulates Granulosa cells.
Once stimulated by LH what do thecal cells stimulate?
Thecal cells stimulate the conversion of cholesterole to androgens.
Androgens are ? soluble.
Androgens are Lipid soluble.
Once synthesized from cholesterol what do androgens do?
They diffuse from thecal cells into the granulosa cells.
What do granulosa cells stim?
The conversion of androgens to estrogen.
How does estrogen feedback?
Estrogen feedsback positively to granulosa cells.
Once synthesized where might estrogen go?
1. May be secreted into the blood to exert effects throughout the body

2. May remain in the follicle and contribute to antrum formation.
What does the hypothalamus release that stimulates the anterior pituitary's FSH-secreting cells and LH-secreting cells?
Gondaotropin-releasing hormone (GnRH).
Once secreted by the anterior pituitary FSH and LH act on the ? to increase ? development.
Once secreted by the anterior pituitary FSH and LH act on the ovary to increase follicular development.
Follicular development causes the presence of what?
1. Low levels of estrogen
in the blood stream

2. Inhibin
What do low levels of estrogen in the blood stream feedback to?
1. Positive feedback to the ovaries and follicular development.

2. Negative feedback to the anterior pituitary.

3. Negative feedback to the hypothalamus.

(negative feedback is preferential to FSH)
What does inhibin feedback to?
Negative feedback to the anterior pituitary. (also preferential to FSH)
Reductions in FSH stops the advancement of what?
Reductions in FSH stops the advancement of all but the most mature follicles.
What day in the 28 day cycle can you expect to see a surge in LH?
About day 14.
High levels of estrogen in the follicular phase feedback to what?
1. Positive feedback to hypothalamus

2. Positive feedback to LH
In the luteal phase moderate levels of estrogen feedback to what?
1. Positive feedback to hypothalamus

2. Positive feedback to Anterior pituitary
In the luteal phase high levels of progesterone feedback to what? Why?
1. Negative feedback to hypothalamus

2. Negative feedback to anterior pituitary.

This is the dominant hormone (over estrogen) and prevents another LH surge.
Fluctuating estrogen and progesterone levels produce what?
Fluctuating estrogen and progesterone levels produce cyclical changes in the cervical mucus.
How does estrogen effect the cervical mucous?
Estrogen causes it be be clear and thin. This is in mid-cycle. This helps sperm reach their target.
How does progesterone effect the cervical mucous?
Progesterone causes the mucous to become thick and sticky. This plugs the cervix. This is important for the fertilized ovum.
List 3 pubertal changes that are similar in females and males?
l. GnRH secretion increases at the onset of puberty

2. GnRH stimulates hormonal release from the anterior pituitary

3.vEstrogen release promotes changes in female reproductive system and other body characteristics
? is unique to females.
Menopause is unique to females.
What may cause the onset of menopause?
Mid-life hypothalamic change may cause the onset of menopause.
What is menopause characterized by?
Characterized by increasingly irregular cycles and dwindling estrogen levels.
What makes up 80% of the testis mass?
The seminiferous tubules.
The seminiferous tubules are the site of what?
The site of spermatogenesis.
What is at the center of a seminiferous tubule?
The center is the lumen. Sperm starts developing from the outside of the tubule and makes way toward the lumen for release.
When and how do the testes descend?
Testes descend from abdominal cavity through inguinal canal into scrotum during last months of fetal life.
What is the importance of the scrotum?
Scrotum provides cool environment -- optimal for spermatogenesis.
How can the position of the testis be varied?
This position can be varied by spinal reflex mechanism.
What structure carries out spermatogenesis?
Seminiferous tubules carry out spermatogenesis.
What cells secrete testosterone? Where is the testosterone secreted to?
Leydig cells in the testis secrete testosterone. Secreted into blood where it is carried by plasma proteins.
Leydig cells are ? cells that are located where?
Leydig cells are INTERSTITIAL cells that lie between the seminiferous tubules.
List 6 testosterone effects?
1. Secretion by fetal testis masculinizes reproductive tract and external genitalia

2. Secretion at onset of puberty signals growth and maturation of reproductive system

3. Essential for spermatogenesis and maintaining male reproductive tract

4. Development and maintenance of libido in adult male

5. Signals development of secondary sexual characteristics:
(voice change, hair, muscle growth)

6. Nonreproductive functions: signals protein anabolism, bone growth at puberty followed by closure of epiphyseal plates
Testosterone is a ? hormone. This means it is derived from what.
Testosterone is a STEROID hormone. This means it is derived from CHOLESTEROL (like estrogen and progesterone).
Secretion of testosterone by the fetal testis causes what?
Secretion by fetal testis masculinizes reproductive tract and external genitalia.
Secretion of testosterone at the onset of puberty signals what?
Secretion at onset of puberty signals growth and maturation of reproductive system.
Testosterone is absolutely essential for what two functions?
Essential for spermatogenesis and maintaining male reproductive tract.
Testosterone is important for the development and maintenance of what?
Development and maintenance of libido in adult male.
Testosterone signals the development of what sexual characteristics?
Signals the development of secondary sexual characteristics:

(Voice change, hair, muscle growth)
Besides reproductive functions what else is testosterone responsible for?
Nonreproductive functions: signals protein anabolism, bone growth at puberty followed by closure of epiphyseal plates (this is the end of skeletal growth).
What does spermatogenesis produce?
Produces highly-specialized, mobile sperm.
Where would a spermatogonium be found?
In the outer portion of the seminiferous tubules.
Where would a spermatozoan be found?
In the lumen of the seminiferous tubule.
What does the spermatogonium do while it is developing?
It moves toward the lumen.
List the stages of spermatogenesis.
1. Mitotic proliferation

2. Meiosis

3. Packaging
Give a general summary of the process of spermatogenesis.
1. Unlike women there is always mitotic proliferation in men. This occurs in the outer edge of the seminiferous tubule.

2. Begin with a spermatogonium cell (46 diploid; single strands)

2. Then have two spermatatogonia each (46 diploid; single strand)

3. One daughter cell remains at the outer edge of the seminiferous tubule to maintain the germ cell line.

4. One daughter cell moves toward lumen to produce spermatazoa.

5. Then you get 4 primary spermatocytes (46 diploid numbers; DOUBLE strands)


6. Then you have the 1st meiotic division where you get 8 secondary spermatocytes(23 haploid; DS)

7. Then you have a 2nd meiotic division.

8. You then have 16 undifferentiated spermatids (23 haploid, SS)

9. You end up with 16 specialized spermatozoa (23 haploid, SS)
1 primary spermatocytes leads to how many spermatozoa?
16 ideally but in actuality this process is not 100% effective.
What is Spermiogenesis?
Spermiogenesis is the packaging (remodeling) of cellular elements of spermatids. It includes differentiation into four parts: head, acrosome, tail, and midpiece.
A fully developed sperm cell is basically a ? ? cellular element.
Basically a stripped down cellular element. (nothing extraneous)
What is an acrosome?
An enzyme filled sac that aids in penetration during fertilization. It is located on the head of a fully developed sperm cell.
Where is the nuclear/DNA material located on a fully developed sperm cell?
In the head.
What is the function of the mitochondria on a fully developed sperm cell?
Supplies energy for movement.
What is the purpose of the microtubules on a fully developed sperm cell?
Movement.
What is the purpose of the tail on a fully developed sperm cell?
Motility. Grows out of centrioles/spindles.
What is the sperms goal?
To get nuclear material to the ovum.
Throughout maturation, sperm cells are intimately associated with what?
Throughout maturation, sperm cells intimately associated with Sertoli cells
Sertoli cells are found where?
Sertoli cells found in wall of the seminiferous tubules
List 6 functions of sertoli cells?
Functions include:

1. Selective transport of materials into the lumen of the tubules
(Tight junctions between the Sertoli cells form a blood-testes barrier, BTB)

2.Provide nourishment for sperm cells (barred by BTB)

3. Phagocytosis of cytoplasm extruded during remodeling
(Destroy defective germ cells by phagocytosis)

4. Secrete seminiferous tubule fluid into the lumens of the tubules; flushes released sperm into epididymis

5. Secrete androgen-binding protein, maintaining high level of testosterone in lumen
(Essential for sperm production)

6. Site of action for spermatogenesis by testosterone and FSH
There are tight junctions between the Sertoli cells that form a blood-testes barrier (BTB). What does this allow?
Selectively allows for transportation of material necessary for sperm.
Sertoli cells provide nourishment for sperm cells (barred by the BTB). What does this cause?
It causes the composition of the seminiferous tubules to be different than that of the blood. It also prevents Abs from reaching the sperm.
Inhibin is also secreted by what?
Sertoli cells.
Testosterone is important for ? and ? or germ cells.
It is important for mitosis and meiosis.
There is a higher concentration of testosterone in the ? than in the ?. What is this due to? What does this sustain?
Higher concentration in testes than blood due to androgen-binding protein.
High concentration sustains sperm production.
FSH is important for the remodeling of what?
FSH is important for spermatid remodeling.
In men what is estrogen important for? Where is it secreted from?
Estrogen is important for spermatogenesis and normal sexuality. Small amount produced by adrenal cortex. Portion of testosterone secreted by testes converted to estrogen by aromatase (widely distributed in male reproductive tract).
Gonadotropin-releasing hormone activity increases when?
Gonadotropin-releasing hormone activity increases at puberty.
Generally speaking what transports sperm from the testis to the outside of the body.
A winding series of tubules transport sperm from the testis to outside the body.
What is the purpose of the accessory glands in the male reproductive system?
Accessory glands secrete fluid into the tract for sperm viability and motility.
What is the purpose of the penis?
Penetration and deposition of sperm in female.
Where is the epididymis located?
Epididymis is attached to the rear of the testis.
What is the purpose of the epididymis?
l. Exit route from the testis to the ductus deferens

2. Sperm cells gain abiltity to move and fertilize in epididymis

3. Epididymis concentrates sperm (100x) as they mature
Where is the Ductus deferens located?
Ductus deferens passes from the scrotal sac up through the inguinal canal into the abdomen.
The ductus deferens is the ? ? for ? sperm.
The ductus deferens is the storage site for concentrated sperm.
Where do the ductus deferens unite?
Two ductus deferens unite behind the bladder, forming a V.
After the bladder what do the ductus deferens form?
They form an ejaculatory duct. (1 duct)
What does the ejaculatory duct eventually join up with?
The ejaculatory duct joins the urethra in the prostate gland under the bladder.
The male accessory sex glands add to what?
They add to what is ejaculated.
Male accessory sex glands contribute to what?
They contribute secretions that constitute the bulk of semen.
What is semen composed of?
Sex gland secretions, sperm, and mucus.
The secretions that constitute the bulk of the semen provide what?
Provides support for the viability of sperm (in males and females). So they facilitate fertilization.
Where are the seminal vesicles located? Generally speaking what do they supply?
There are 2 of them that join the last part of each ductus deferens. They supply food.
What do seminal vesicles supply to nourish ejaculated sperm?
Fructose for energy.
What do seminal vesicles secrete?
Prostaglandins which stimulate smooth muscle contraction, helping sperm move.
What do seminal vesicles supply precursors for?
They supply precursors (fibrinogen) for clotting of semen.
The three general things provided by the seminal vesicles?
1. Energy

2. Clotting precursors

3. Prostaglandins
Describe the general structure of the prostate gland?
Single, completely surrounds urethra at neck of bladder.
The two functions of the prostate gland?
1. Secretes alkaline fluid that neutralizes acidic vaginal secretions.

2. Provides clotting enzymes and fibrinolysin
What is the function of the clotting enzyme provided by the prostate gland?
Clotting enzymes act on fibrinogen to form fibrin, thus clotting the semen. This keeps sperm in the vagina during penis withdrawal.
What is the purpose of the fibrinolysin provided by the prostate gland?
Fibrinolysin degrades seminal clot, releasing motile sperm within the female tract.
Describe the structure of the bulbourethral gland. What is it's function?
Two, both empty into urethra just before it enters the penis. Secretes mucous for lubrication for intercourse.
List 3 male accessory glands.
1. Seminal vesicles (2)

2. Prostate gland (1)

3. Bulbourethral glands (2)
What are prostaglandins and where were they first discovered?
They are locally-acting chemical messengers. First discovered in the semen.
Prostaglandins are derivatives of what? Where are they produced?
They are fatty acid derivatives produced in most tissues. (Arachidonic acid derivatives)
List 6 effects of prostaglandins.
1. Promote sperm transport (because of smooth muscle contraction)

2. Promotes bronchodilation

3. Increases renal blood flow

4. Inhibits hydrochloric acid secretion in the stomach

5. Enhancing cortisol secretion

6. Also in females they cause follicle digestion, bursting, an release of egg (ie, ovulation).
Define fertilization.
Union of male and female gametes (sperm and ovum)
Where does fertilization occur?
Typically in the oviduct. Normally in the upper third, called the ampulla.
Describe the structure of the oviduct?
Dilated end of the oviduct contains fimbriae (finger-like projections) which attracts the ovum into the oviduct.
What is the window for fertilization in the ovum?
Within 24 hours after ovulation.
How long can sperm cells survive in the female reproductive tract? Theoretically what does this mean?
Sperm cells can survive up to five days in the female reproductive tract; so longer window for sperm than ovum.

Theoretically, sperm deposited in female 5 days before ovulation up to 24 hours after ovulation may be able to fertilize ovum.
What do fimbria do?
Move the egg into the ampulla of the oviduct.
How does the sperm travel to the site for fertilization? (path)
Sperm travels through the cervical canal to the uterus and to the ampulla for fertilization.
Sperm migration is helped by what?
The female tract helps sperm migration. It does this by contractions of the myometrium (smooth muscle layer) of the uterus and antiperistaltic ("upward") contractions of the oviduct. It also displays a cervical mucus change.
What breaks down barriers surrounding the ovum?
Acrosomal enzymes.
What does the ovum release to attract sperm?
Alluren (~sp). This causes sperm to be more attracted to one oviduct. However, sperm can still go the wrong way.
How many sperm are there per mL of semen?
20 million per mL (this increases the chance of fertilization)
How many sperm penetrate the ovum? Why?
Only one sperm penetrates the ovum, this is due to chemical changes in the ovum plasma membrane.
What is an ectopic pregnancy?
Pregnancy in the abdomen. This is very dangerous. This can occur when the ovum is released into the abdomen.
What can the sperm penetrate only after it has binded to a specific receptor on the ovum?
Zona pellucida. The sperm receptor is fertillin. Integrin is on the ovum and binds to the fertillin of the sperm. Only sperm of the same species can bind. Fertilization is species specific.