Reproduction Lec. 4, 5, 6

Question 1

What are the two compartments of the Testes and their function:

Answer 1

The semeniferous tubules and the interstial cells. The interstitial cells are predominatley leydig cells and produce hormone. But our semineferous tubulues are involved in sperm production.

Question 2

What is the effect of FSH on females? On Males?

Answer 2

Stimulates follicular development.

Stimulates spermatogenesis.

Question 3

What is the target of FSH in the male (which cell type has receptors)?

Answer 3

Sertoli cells (nurse cells)

Question 4

What is the target of LH in the male (which cell type has receptors)?

Answer 4

Leydig cells

Question 5

What does LH do in males?

Answer 5

It increases testosterone production.

Question 6

What does Testesterone inhibit? What produces it?

Answer 6

Leydig cells, and it inhibits production of the Gonadotropin releasing hormone and the production of LH by the anterior pituitary gland

Question 7

What does inhibin inhibit? What produces inhibin?

Answer 7

Inhibin is produced by the sertoli cells, and it inhibits FSH production in the anterior pituitary gland

Question 8

Slow decline in testerone with ______.

Answer 8

Age

Question 9

Spermatogonia:

Answer 9

Sperm stem cells

Question 10

What are some differences propagated by the increased presence of testosterone?

Answer 10

Higher hemoglobin levels.
More height (testesterone also causes calcification of the growth plates)
Longer vocal cords (deeper voices in males)
More muscle development
Sex drive

Question 11

What cells in the testicles produce estradiol?

What is estradiol?

Answer 11

Leydig cells, sertoli cells, and developing sperm cells.

The precursor to estrogen.

Question 12

Primary Spermatocyte:

Secondary Spermatocyte:

Answer 12

One meiosis

second meiosis

Question 13

Early Spermatid:

Late Spermatid:

Answer 13

spherical

beginning to be shaped like a sperm proper

Question 14

Spermatozoa:

Answer 14

Mobile form of sperm. The active sperm themselves

Question 15

What three ways are utilized to make the seminiferous tubules an immunologically privileged site?

Answer 15

Sertoli cells have tight gap junctions which form a blood-testis barrier.
Sertoli cells produce FAS ligand which binds to and causes suicide of T-cells.
Germinal cells also lack the MHC molecules, which helps protect them.

Question 16

How does the development of spermatogonia -> spermatocytes -> spermatids -> spermatazoa occur in terms of physical space?

Answer 16

Spermatagonia are on the basement membrane and travel to the lumen of the semineferous tubules whilst encapsulated between the tight junctions of the sertoli cells.

Question 17

What is autoimmune sympathetic orchitis?

Answer 17

if one of the testicles are damaged, the proteins within can be exposed to the outside, which can result in an immune response against both the healthy and unhealthy testicle.

Question 18

What causes the shape change which occurs as spermatids become spermatozoa?
In what other ways is spermatid development helped?

Answer 18

Sertoli cells engulf the cytoplasm of spermatids, actively shaping them into spermatazoa (this may provide needed regulatory molecules to inform sertoli cells about the progress of spermatogenesis).
Sertoli cell provides nutrients and gene products to the developing spermatids.

Question 19

Where is ABP produced and what does it stand for?
What is its function?
What stimulates its production?

Answer 19

In the sertoli cells, it is called androgen binding protein.
Binding protein and localizing it within the lumen of the seminiferous tubules
Production is stimulated by FSH

Question 20

What is the structure of the spermatazoon?

Answer 20

Head: acrosome (contains enzymes to allow entry into the cell) and the nucleus of the cell
Midpiece: has mitochondria, and has axoneme (9 + 2 flagella)
Principle piece: axoneme (9 + 2 flagella)
End piece: has nada

Question 21

When does the process of spermatogenisis begin?

Answer 21

During embryonic development, the spermatocyte will reach the primary stage but pause at prophase 1.
It will then pause until testosterone levels rise, which will cause spermatogenesis.

Question 22

In what manner does FSH effect spermatogenesis?

Answer 22

It increases the rate of spermatogenesis.

Question 23

What percentage of the total future number of sertoli cells exist in a newborn boy?
What causes the proliferation of these cells?
What is the impact of this?

Answer 23

FSH and Testosterone

If you go through puberty without FSH you may have decreased numbers of sertoli cells or take longer to develop them.

Question 24

Where do the sperm travel? Starting from the Lumen of the seminiferous tubules:

Answer 24

-> Rete testes -> efferent ductules -> epididymis -> Ductus deferens (vas deferens) -> ejaculatory duct -> prostate -> urethra -> cervix -> uterus

Question 25

How can you remember efferent ductules?

Answer 25

These ductules are where the sperm exit the testicles (efferent = exit)

Question 26

What is the function of the epididymis?

Answer 26

Sperm storage (sperm are also stored in the ductus deferens) and sperm maturation (they gain some resistance to changes in temperature and pH and some motility begins)

Question 27

When do sperm become fully mobile?

Answer 27

In the female reproductive tract.

Question 28

What are the glands of the male reproductive tract in the order they are encountered?

Answer 28

Seminal Vesicles: Prostate gland: Bulbourethral glands (copper's gland):

Question 29

Seminal vesicles: - Reason for name: - Contents of secretion:

Answer 29

- Reason for name: Seminal = semen (this is where most the volume of the semen comes from 60%) - Contents of secretion: Fructose solution (for energy) and prostoglandins (to stimulate uterine contractions)

Question 30

Prostate gland: | - Contents of secretion:

Answer 30

Produces an alkaline agent (citric acid and calcium) which neutralizes the acidity of the male and female reproductive tracts (40% of semen volume) Prostate also produces a coagulation factor

Question 31

Bulbourethral glands (copper's gland): - Contents of these glands - Timing of release:

Answer 31

- Contents of these glands: Produces lubrication, makes semen gelatinous. - Timing of release: released early in sexual stimulation

Question 32

What are the two androgen dependent glands?

Answer 32

Seminal vesicles: | Prostate:

Question 33

``` Erectile Tissue (spongy erectile tissue): - Name the two types: ```

Answer 33

Corpus spongiosum: surrounds the urethra, mushrooms into the head Corpora Cavernosa: two corpus cavernosa which house the deep penile artery. This is the predominant source of erection

Question 34

Point and shoot: | - What does this mean?

Answer 34

Parasympathetic system is involved in erection | Sympathetic nervous system is involved in ejaculation

Question 35

Erection: | - Innervation:

Answer 35

Innervation: - Parasympathetic nerves of the corpora cavernosa release NO. - Penile artery and other vasculature also produces NO. - NO binds to a heme subunit which activates guanalyl cyclase (cGMP) which closes Ca2+ channels - Causes drop in intracellular Ca2+ and relaxation of smooth muscles - This causes the blood to flow into the penis. Outflow of blood is occluded to help sustain erection

Question 36

Erection: | - Innervation:

Answer 36

Innervation: - Parasympathetic nerves of the corpora cavernosa release NO. - Penile artery and other vasculature also produces NO. - NO binds to a heme subunit which activates guanalyl cyclase (cGMP) which closes Ca2+ channels - Causes drop in intracellular Ca2+ and relaxation of smooth muscles - This causes the blood to flow into the penis. Outflow of blood is occluded to help sustain erection

Question 37

Phosphodiesterase and viagra:

Answer 37

Viagra inhibits phosphodiesterase 5 which is the enzyme which breaks down cGMP and causes sustained cGMP levels, lower intracellular Ca, increased relaxation of smooth muscles, and sustained erection

Question 38

Ejaculation: | - Two stages

Answer 38

Emission: sympathetic nervous system stimulates peristalsis of the tubular system, contraction of the seminal vesicles and prostate, Expulsion: semen in urethra activate somatic and sympathetic reflexes stimulate muscle contractions and lead to expulsion

Question 39

Sacral portion of the spinal cord: | - Modes of activation:

Answer 39

Modes of Activation: - touch receptors in the penis can cause direct stimulation of the sacral portion of the spinal cord - Hypothalamus of the brain can lead to integration of thought and erection. Erection can be stimulated or inhibited by thoughts.

Question 40

Nocturnal emission: - define: - Periodicity: - Spermarche:

Answer 40

- define: Emission of semen during sleep if it is not emitted through sexual activity - Periodicity: Monthly - Spermarche: The first nocturnal emission, arbitrarily signals the start of male puberty, but doesn't really because increased testosterone from the actual onset of puberty was needed to finish the develop of the sperm which where ejaculated in the first nocturnal emission

Question 41

Sperm counts: - Volume fluid: - Normal sperm per ml: - Oligospermia: - Infertility: - Factors which reduce sperm counts:

Answer 41

- Volume fluid: 1.5 - 5 mls - Normal sperm per ml: 60 - 150 million sperm per ml - Oligospermia: 20 million sperm per ml - Infertility: total ejaculation of less then 40 million sperms (in total volume of semen) - Factors which reduce sperm counts: Heat (sauna, hot tub), various pharmaceutical drugs, lead or arsenic poisoning, some illicit drugs (marijuana, cocaine) and anabolic steroids (can be permanent or temporary decrease

Question 42

Antibodies against sperm: - present in (males and/or females): - Most common cause: - Cause:

Answer 42

``` - present in (males and/or females): males and females - Most common cause: vasectomy - Cause: - Reduced fertility ```

Question 43

Condom: - Method of reduction: - Effects on sexual disease:

Answer 43

- Method of reduction: Barrier to seminal entry - Effects on sexual disease: Reduce transmission of sexual diseases

Question 44

Condom materials: - Natural membrane: - Latex condoms:

Answer 44

``` - Natural membrane: Reduce sperm entry - Latex condoms: Reduce sperm entry Prevent viral entry ```

Question 45

How large a reduction is there in yearly pregnancy rate from condom usage?

Answer 45

89% (so if you use condoms, and have sex when you'd like that year, there is a 89% chance she will not be pregnant by the end of the year)

Question 46

Male birth control?

Answer 46

Side effects have been serious. Large number of sperm made daily cause large hinderance. Blood testis barrier also interferes drug development

Question 47

Vasectomy: - Define: - Reversibility:

Answer 47

- Define: Vas deferens are cut and tied. - Reversibility: Not incredibly reversible. This is partially because the male will produce antibodies against the semen in 70% of vasectomies.