Corpus Luteum

Ovulation → ruptured Graafian follicle→ corpus luteum

4 stages :

• Proliferation
• Vascularization
• Maturation
• Regression

Collapsed walls of empty follicle form convolutions

Opening - ovum escapes → plugged with fibrin

Granulosa cells→ hypertrophy without multiplication

Cells → larger , polyhedral with pale vesicular nuclei & fatty cytoplasm→ Granulosa lutein cells

Color of the corpus luteum : Greenish yellow → due to presence of lipids

Within 24 hours of rupture of the follicle

• small capillaries grow into granulosa layer
• sprouting vessels may rupture & bleed in the cavity

4th day

• luteal cells have attained the maximum size

7-8 days

• attains a size of about 1-2 cm & reaches its secretory peak

Theca lutein cells → 'K' cells → invade granulosa cells

Lutein cells

• greatly enlarged→ develop lipid inclusion 
• distinctive yellowish colour
• color is due to the pigment carotene ​​​​​​​