Reproductive - fellas nd makin bebes Flashcards
What are the two components of the testis?
Tubular components
Interstitial components
What type of cells compose Tubular components?
Sertoli cells
Germ cells
What type of structures compose Interstitial components?
Leydig cells
Capillaries
What do Sertoli cells do?
Supporting germ cells in development
What do Germ cells do?
Precursor cells for sperms
What are the two main features of a sperm cell?
- An acrosome, contains digestive enzymes that gobble up egg’s outer shell
- Tail for motility
What intracellular structure forms the acrosome?
golgi apparatus
What intracellular structure forms the flagellum?
Centriole
What happens to the premature sperm cell once acrosome and flagellum are established? (3)
- Excess materials ‘eaten up’ by sertolli cells
- DNA repackaged
- tail develops from flagellum
Where does fertilisation occur?
The fallopian tube
Prefertilization events? 4
- Changes in the cervical mucus – becomes thin
- Muscular contractions of the uterus and the fallopian tube
- The fimbrial end comes into contact with the ovary
- Peristaltic movements brings it to the ampulla
What is capacitation?
Functional maturation of the spermatozoon, occurs in the female genital tract
What happens after capacitation?
Acrosome reaction
How does the sperm penetrate the corona radiata?
Flagellar action, enzymes
What does the cortical reaction in the zona pellucida prevent
polyspermy
How does sperm binding to the zona pellucida prevent polyspermy? (2)
- Na+ influx changes membrane potential = fast block
2. Kinase stimulation and increase in level of Ca2+ leads to formation of hyaline layer
What effects does sperm binding (and consequently rise in intracellular Ca2+) result in? 3
- Triggers the egg to complete meiosis
- Triggers a cytoplasmic rearrangement
- Causes a sharp increase in protein synthesis and metabolic activity in general
What is the final stage of fertilisation?
Haploid sperm and haploid egg nuclei fuse to form diploid nucleus of the zygote
Most human sperms do not survive longer than 48 hours in the female genital tract.
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Fertilisation is Completed within 24 hours of ovulation
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Some sperm are held up by the folds of the cervix and are gradually released into the cervical canal; this gradual release increases the chances of fertilization.
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Why are egg cells bigger than sperm cells?
Egg cells are considerably larger than sperm cells because they carry the cytoplasm and organelles necessary for cell division and growth to begin, while sperm cells are basically a cell nucleus and a tail.
