Spermatogenesis
Where are sperm produced?
In the seminiferous tubules
Outline the Oogenesis cycle
Hormones are secreted from pituitary gland and is sent to the ovaries where immature egg is located. Then the follicle secretes a hormone to the pituitary to continue sending hormones till oocyte matures and leaves ovaries.
Number of gametes produced.
Spermatogenesis- Life long
Oogenesis- Fixed amount
Similarity?
Both produce gamete cells
Name a part of a mature egg and give an annotation
Zona Pellucida- Barrier to Sperm entry
Cortical Granule- Prevent Polyspermy
Corona Radiata- Provide support and nourishment to the egg cell
When does spermatogenesis start? Does it end?
Starts at puberty and never ends, but production reduces as age increases
What hormones are used in Oogenesis and where are they secreted from?
GnRH- Hypothalamus
FSH and LH- Pituitary Gland
Estrogen- Follicles
Timing of gamete formation.
Spermatogenesis- Continuous
Oogenesis- Once a month
Similarities?
Both produce haploid cells from diploid cells
Name a part of a mature sperm and give an annotation
Acrosome- Produces enzymes to help sperm penetrate the egg
Mitochondria- Produces ATP to allow for mobility for sperm
Flagellum- Allows the sperm to swim
What cells undergo cell growth, then what does it become?
Spermatogonia becomes spermatocytes
What is the target of each hormone?
FSH and LH- The ovaries to stimulate the growth of the follicle and oocyte
Estrogen- The pituitary gland to continue the growth of the follicle and oocyte till it is fully mature
Where does the complete maturation of gametes occur?
in the epididymis
What are the 4 stages of spermatogenesis?
Multiplication, growth, maturation, metamorphosis
The cap-like acrosome is filled with enzymes that help to break down the zona pellucida
hyaluronidase, acrosin
How many meiotic divisions does spermatocytes undergo? What is the result?
Undergoes 2 meiotic divisions to produce 4 haploid cells
Where does Oogenesis take place?
Ovaries
what is the sudden increase in the LH called?
LH surge
what does the growing follicale starts to secrete in the folllicular phase and tell whether it is high or low level?
low levels of estrogen
During oogenesis, the primary oocyte is arrested in prophase I until puberty. What triggers its resumption of meiosis?
A surge in luteinizing hormone (LH)
In which stage of oogenesis is the secondary oocyte arrested before fertilization occurs?
Metaphase II
What is the primary reason why oogenesis results in only one viable ovum instead of four, as seen in spermatogenesis?
The process of cytokinesis during meiosis is unequal, giving most of the cytoplasm to one cell.
Proteins help to propel the sperm toward the egg
dynein proteins
if no fertilization occurs in the menstrual phase what happens to the corpus luteum, uterine line, and progesterone?
the corpus luteum degenerate and progesterone levels drops. the uterine lining starts to shed.
Contains the nucleus, which holds haploid highly condensed DNA (23 chromosomes).
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