Ovaries and Follicles

What are ovaries?

Paired glands that provide for the development of oocytes and production of hormones

What is ovulation?

The release of mature oocytes

Where are the ovaries located?

To its respective right or left kidney and is suspended form the dorsal wall of abdomen

Parts of the Ovary

• What covers the ovary 

• What is the periphery of ovary called 

  • Function 

• What is the middle of ovary called 

  • Function

What covers the ovary: Tunica albuginea

What is the periphery of ovary called: Cortex (functional part) 

• Function: Contains large mass of follicles in various stages of development

What is the middle of ovary called: Medulla (supportive part)

• Function: Contains loose connective tissue, blood vessels, lymphatics and nerves

Picture of 

What are the 3 types of follicles in oocyte?

• Primordial follicle #ffb3c6

• Growing follicle #ff8fab

• Graafian follicle #fb6f92

Primordial Follicle #ffb3c6

• What does it contain 

• Where do the oocyte in primordial follicle come from?

What does it contain: A single oocyte surrounded by.a single layer of granulosa cells

Where do the oocyte in primordial follicle come from: 

• Derived from mitosis of oogonia in the embryonic genital ridge 

• Which then migrates to the ovary 

Growing Follicle #ff8fab

• What 

• What structures are absent in a growing follicle 

What: A follicle that has begun developing from the primordial stage but not yet formed thecal layer or antrum

Structures absent: Thecal layer or antrum 

Graafin Follicle? #fb6f92

• What

• What controls the formation of Graafian follicles

• When does the formation start

What: A mature follicle with a visible antrum and 2 thecal layers

• Theca interna 

• Theca extera

What controls the formation of Graafian follicles:

• Its hormone dependent

Formation starts: At puberty when LH and FSH levels start to rise and fall with each estrous cycle

Zona pellucida

• What

• Its function to fertilisation

What: A glycoprotein layer surrounding the oocyte

Function to fertilisation: Sperm must recoginse, bind and travel through zona pellucida to reach oocyte plasma membrane

What is follicle regression?

• The periodic process in which immature ovarian follicles degenerate

• And are re-absorbed during the follicular phase of the menstrual cycle

What happens to the multiple follicles that mature each month?

• Only 1 follicle is ovulated 

• Remaining undergo atresia 

What happens to the single dominant follicle after ovulation?

It becomes corpus luteum