Lesson_6_Developmental_biology_Oocytes_Spermatozoa_Oogenesis_and.pptx

1. Subject: Biology
General medicine, KFU IFMB
1st semester
Module: Developmental biology

3. Mammalian testis (testicles)

4. The structure of the testis of a mammal
Seminal
tubule
lumen
Spermatids
Spermatocytes
Sertoli cell
Sperm
Spermatogonium

5. Depending on the amount of yolk,
4 types of oocytes are distinguished:
1) Alecitic (the yolk is almost absent).
2) Oligolecital (a small amount of yolk);
3) Mesolecital (average amount of yolk);
4) Polylecital (a lot of yolk;);

6. By the nature of the distribution of the yolk,
the eggs are divided into 3 types:
1) Isocytal or homolecital (with a uniform
distribution of the yolk over the ovum), by the
amount of yolk they are more often oligo- or
alecitic. Examples: eggs of echinoderms, lower
chordates, mammals.
2) Telolecital (the yolk is concentrated at the
vegetative pole; Greek end); In terms of yolk
content, these eggs are most often poly- or
mesolecitic. Examples: eggs of molluscs, fish,
amphibians, reptiles, birds.
3) Centrolecytic (the yolk is concentrated in the
center of the cell, and the cytoplasm is along the
periphery and inside the nucleus). Examples:
insect eggs, in terms of yolk content, these are
most often oligo- or mesolecitic eggs.

8. Ovary with eggs at various stages of maturation
Corpus
luteum
Graafian
follicle
Secondary
follicle
Theca
interna
Primary follicle
Zona
pellucida
Oocyte
Corona
radiata

9. Comparison of spermatogenesis and oogenesis
1. Reproduction period:
spermatogonia and oogonia
(mitosis)
2. Growth period:
spermatocytes and oocytes
(meiosis)
3. Maturation period:
four spermatids and only one
oocyte (three polar bodies
die off)
4. Formation period:
spermatozoa (not in
oogenesis)