click
on this image for an audio message I. Male reproductive anatomy
The primary function of sex organs are to form gametes (haploid sex cells like
sperm and oocytes). A typical body cell has 23 pairs of chromosomes containing
all of the genes that code for all proteins. A haploid cell has 1/2 of the number
of chromosomes (or 23) which, during fertilization, fuses with 23 from other
gender's haploid sex cell to form a new individual.
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I. Male reproductive anatomy
2. Ductus ( or vas) deferens -pathway for sperm to continue (cut during vasectomy)
3. Ejactulatory duct
receives secretions of seminal vesicle and prostate glands
stores sperm to be ejaculated into urethra
4. Urethra -pathway for sperm and semen out of the body.
5. Penis -male copulatory organ contains erectile columns for erection
click
on this image for an audio message2. seminal vesicle -most volume, alkaline (to neutralize acidic secretions of female) and high fructose (to provide nutrition for sperm)
3. prostate -promotes sperm activity (for instance, promotes movement)
b. Meiosis
cell division process that involves NOT exact duplication of nuclear and cytoplasmic
materials into four cells, each with one half (N or haploid ) or normal amount
of genetic information. Two divisions result in halving the amount of genetic
information to make the haploid cell (primary spermatocyte to secondary spermatocyte,
secondary spermatocyte to spermatid )
c. Differentiation
biochemical change in a cell to make it a different cell results in formation
of spermatozoa (or sperm) into spermatid
a. Spermatogonia are replaced via mitosis-maintains reserve of these stem cells.
b. Spermatogonia differentiate into primary spermatocytes
c. Each primary spermatocyte begins first division of meiosis- to make two secondary spermatocytes
d. Each secondary spermatocytes undergo second meiotic division to make four spermatids
e. Spermatids differentiate into sperm
Therefore, production of four sperm from one primary spermatocyte
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Describe the processes, including important cell functions, that must occur for sperm to be produced. .
2. Increased GnRH causes anterior pituitary gland to release gonadotropins
b. Leutinizing hormone, or Interstitial Cell Stimulating Hormone (LH or ICSH),
gonadotropin
targets interstitial cells which then produce more testosterone
4. less GnRH inhibits LH production and therefore testosterone production
(classic example of negative feedback mechanism via hypothalamic releasing hormones)
Describe negative feedback loop that regulates testosterone production. Describe functions of Testosterone. .
A. Ovaries
2. Follicular cells-surround a single oocyte cell to form a "follicle'
produce estrogen and progesterone
2. Myometrium -smooth muscle tissue for birth contractions.
Readied by increasing estrogen during pregnancy but controlled by Oxytocin
3. Endometrium -epithelial secretory tissue for nutritional support of embryo
via its blood supply
controlled by estrogen and progesterone
D. Vagina
female copulatory organ and birth canal
highly acidic to decrease microbial (and sperm) survival
E. External genitalia
2. Clitoris
3. Mons pubis/pubic symphysis
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List sequence that a sperm must travel from its site of production to site of fertilization of secondary oocyte. Describe functions of each organ the sperm must pass through.
F. Breasts -modified sweat glands embedded in adipose tissue.click
on this image for an audio messageb. Every monthly reproductive cycle from puberty to menopause
2. secondary oocyte is ovulated (in response to LH surge) and captured by fimbriae
(mature follicle bursts).
3 . Fate of oocyte
3. Estrogen
a) Increasing estrogen levels promote production of LH (stored in anterior pituitary
until mid-cycle); initiates growth of endometrium, maintain female secondary
sex characteristics
b) very high levels trigger release of LH (mid cycle).
4. LH
Increased LH causes rupture of mature follicle (ovulation) and formation of
corpus luteum which produces increased amounts of progesterone and, to lesser
degree, estrogen.
Increasing estrogen and progesterone inhibit LH and FSH production (late cycle)
to prevent second ovulation.
5 . Progesterone
a ) increased levels primarily maintain endometrium for implantation (promote
gestation by maintaining endometrial nutrient supply)
If oocyte is fertilized then embryonic development begins (embryo will produce
hormone to maintain corpus luteum)
If oocyte NOT fertilized then corpus luteum dies and progesterone levels drop.
Decreased levels, along with lower levels of Estrogen, trigger destruction of
endometrium (menses).
Describe feedback loops that control estrogen and progesterone levels. Describe the function of GnRH, LH, FSH, Estrogen and Progesterone..
b. Increased FSH, at beginning of cycle, stimulates initiation of follicular growth
c. Increased estrogen from follicular cell proliferation causes positive feedback triggering LH peak (mid cycle).
d. LH peak triggers ovulation and leutinizing of burst mature follicle (corpus luteum)
e. Corpus luteum grows for next week producing increasing progesterone which acts to maintain endometrium so an implanting embryo can survive
f. Increased progesterone and estrogen causes inhibition of FH and FSH (therefore no more ovulation for the cycle)
g. Fate of oocyte
2) If fertilized then growing embryo produces Human Chorionic Gonadotropin (an embryonic LH) which causes the corpus luteum to keep making progesterone so endometrium stays during gestation (pregnancy).
On
a single sheet of graph paper, diagram the changes of gonadotropin hormones,
ovarian hormones, oocytes, follicular development, and phase of endometrium.
Do this for a 28 day cycle.
Human Anatomy and Physiology Courses
at St. Petersburg College
St. Petersburg/Gibbs Campus
5/2008