Zusammenfassung der Ressource
Reproduction
- Male Reproductive System
- Spermatogenesis occurs in the testes
- The stages of
spermatogenesis occur in the
seminiferous tubule
- The lumen of the
seminiferous tubule
contains the mature
spermatozoa
- Oogenesis in Females
- Unequal cytokinesis occurs in oogenesis
- Typically completed in ovary
- Steps leading to implantation of an embryo in the nucleus
- 1. Follicle Stimulating
Hormone (FSH) and
Luteinizing Hormone (LH)
cause follicles to enlarge and
mature
- 2. Follicle cells produce
estrogen which causes the
endometrium of the uterus to
thicken
- Uterus
- Endometrium:
thickens and is shed
in the menses
- Myometrium:
smooth
muscle layer
- 3. Primary oocyte
completes meiosis I and
begins meiosis II
- 4. LH surge causes ovulation. Secondary
oocyte (metaphase II) moves into the
fallopian tube
- 5. Ruptured follicle or corpus luteum produces estrogen and progesterone. These hormones cause the uterine lining to thicken
- 6. Fertilization occurs in the
fallopian tubes.
- If fertilization does not occur, the
corpus luteum degenerates and
uterine lining is shed
- 7. After fertilization occurs,
the secondary oocyte
completes meiosis II
- 8. Ootid
matures
into an
ovum
- 9. Fusion of the male
pronucleus with the
female pronucleus -
2N zygote
- 10. Corpus luteum continues to
produce estrogen and progesterone
to keep the endometrium thick and
ready for implantation
- 11. Zygote divides
mitotically as it travels
to the uterus
- 12. Embryo
implants into the
endometrium of
the uterus
- 13. The embryo produces the hormone
choriogonadotropin which maintains the
corpus luteum. Corpus luteum produces high
quantities of progesterone to maintain the
endometrium
- 14. Formation of the placenta
- Chorio-allantoic membrane of foetus
+ endometrium of mother
- Site of oxygen/carbon dioxide
exchange; nutrient/waste
exchange; hormone production
- Prenatal Diagnosis
- Indications for Prenatal Diagnosis
- Family history of a genetic disease;
ethnic background with known risk;
paternal or maternal disease; adverse
outcome of previous pregnancy; maternal
age; exposure to teratogens, radiation,
etc.
- Can provide information on:
chromosomal abnormalities, protein
levels (enzymes or structural
proteins), identification of a specific
mutation through DNA analysis, other
metabolite levels
- Ultrasound
- Accurate date of pregnancy, multiple gestations, size &
position of placenta, amount of amniotic fluid, some
internal abnormalities and skeletal defects can be seen,
foetal sex, foetal growth and development
- Chorionic Villi Sampling (CVS)
- Tiny pieces of
chorionic villi
removed and villi
cells are cultured