Week 1 - B - Histology of the female reproductive system Flashcards
What is the lower part of the uterus known as where a narrowing occurs to form the cervix?
This is the internal os (internal orifice of the uterus)
The lower part of the uterus is known as the cervix The opening of the cervix is known as the internal os - where the uterus narrows and the opening of the cervix into the vagina is known as what?
The external os
What are the two main functions of the ovary?
They produce gametes - oogenesis - formation of eggs
Produce steroids - mainly oestrogens and progestogens (mainly progesterone)
Structure: the ovary has a medulla and a cortex: The medulla forms the core of the organ and contains loose connective tissue, contorted arteries, veins and lymphatics, and is continuous with the hilum of the organ. The cortex has scattered ovarian follicles in a highly cellular connective tissue stroma. What is the dense connective tissue layer which is the outer shell of the cortex?
This is the tunica albuginea
What colour is the tunica albuginea?
The tunica albuginea is white hence the name the white coat
What is the thin layer that covers the tunica albuginea (tunica albuginea - outer shell of dense connective tissue)? Give both names for this single layer
This is a single layer of cuboidal cells called the germinal epithelium - also known as ovarian surface epithelium
What is the difference in tissue types between the tunica albuginea and the germinal (ovarian surface) epithelium?
Tunica albuginea is the dense connective tissue outer coat of the ovary
Germinal epithelium is a single layer of cuboidal cells that cover the tunica albuginea
What is the earliest recognisable female germ cell? It can undergo mitosis
This is the primordial germ cell
At what week in embry development do the primordial germ cells invade the ovary and undergo mitosis to form oogonia? What are the oogonia a precursor to? Do they form this via mitosis or meisosis?
The primordal germ cells invade the ovary in week 6 of development to undergo mitosis to form the oogonia
The oogonia divides in the process of meisosis to form oocytes
What is the difference between oogenesis and folliulogenesis?
Oogenesis is the development of the oocytes, the female germ cells, from the oogonia (which develops from the primordial germ cell at 6 weeks)
Folliculogenesis is the development of the follice , which cosnsits of the oocyte and any supporting cells
When oogonia are formed in utero, there are millions and progressivley there becomes less and less until menopauase What is the loss of oogonia and oocytes by the apoptosis based process known as?
This is known as follicular atresia
Before birth meiosis begins in the occytes but what stage is this halted and until when?
The primary occytes are suspended in prophase 1 until puberty where one oocyte (usually) is chosen per month to undergo ovulation
How many follicles mature each month and how many are actually ovulated? When does the primary oocyte suspended in prophase 1 begin mieisosis again?
Around 20 follicles mature per month but only one is ovulated
The primary oocyte undergoes meisosis again during puberty when one egg is ovulated each month
What stage does the secondary oocyte arrest in and when does it complete meisosis? What signifies the fertilization of the egg?
Secondary oocyte arrests in metaphase II and a polar body is formed - the egg is then ovulated
When fertilisation occurs the secondary oocyte divides and a second polar body and fertiised egg is formed
The formation of two polar bodies signifies fertilisation
The pregranulosa cells here are squamous but once the follicle enters the growth phase, what are the hallmark cells of the primary follilce known as?
The hallmark cells of the primary follicle are the cuboidal follicular (granulosa) cells
What do the inner and outer stromal cells that surround the primary follicle divide to become?
The inner stromal cells divide to become the theca interna and the outer stromal cells divide to become the theca externa
The theca interna produces oestrogen precursors which are converted to oestrogen by which cells?
The theca interna produces the oestrogen precursors which are converted to oestrogen by the granulosa (follicular) cells