Female Reproductive System - Cervix, Breast, Vagina & Placenta

What cells line the TDLU?

A dual layer of epithelial and myoepithelial cells

Function of lactiferous sinus

Accumulates milk before expulsion

Metaplasia usually occurs in response to...

Chronic irritation or hormonal stimuli

Lamina propria of the Vagina

Contains many elastin fibres. Very rich in thin walled blood vessels, which speeds up diffusion of vaginal fluid across the epithelium

How are the bands of smooth muscle arranged, in relation to the lactiferous sinus (of the breast)?

Parallel and circularly

Main functions of the cervix

Provides tight, muscular opening to uterus. It allows sperm to enter but provides a barrier to infection

The vagina contracts after coitus and this helps...

Retain semen

Function of breast glands

Secrete milk

Function of the inner layer of epithelial cuboidal cells of the TDLU

Secretes milk

Endocervix

Simple, mucous secreting, columnar cells. Mucus protects the cervix from bacterial infection

The endocervical canal is lined by...

Single layer, tall, mucus-secreting columnar epithelium

What layers overlie the lamina propria of the vagina?

Smooth muscle and outer adventitial layer

What type of epithelium lines the vagina?

Stratified Squamous Epithelium

Interlobular Stroma

Surrounds large ducts and TDLUs, denser, more collagenous, fat content post puberty increases

Intralobular Stroma

Surrounds the TDLUs and contains scattered fibroblasts, plasma cells, macrophages and vessels

Vagina

Thin walled, fibromuscular tube located between bladder and rectum. It connects the uterus to the outside of the body

Placenta

Trophoblast forms finger-like projections or chorionic villi that protrude into maternal vessels. A mass of these villi forms the placenta.

How many breast lobes are there?

15 - 25

The nipple projects from the...

Anterior surface of the breast

Transformation zone

Area of epithelium where metaplastic change has occurred. This is where most cervical cancers originate from

Terminal duct-lobular unit (TDLU)

Basic functional unit of the breast

The two main layers of the cervix are called the...

Ectocervix and Endocervix

The intralobular stroma does not contain...

Elastin

How is the breast affected by lactation?

Oestrogen and progesterone levels fall. Prolactin stimulates secretion of milk and oxytocin causes contraction of myoepithelial cells propelling the milk into the sinuses, and then out of the nipple.

How is the breast affected by pregnancy?

Oestrogen, progesterone and prolactin cause the terminal epithelium to proliferate and the number of secretory acini increases

The placenta is connected to the...

Foetus via the umbilical cord

What glands are found within the breast?

Highly modified apocrine glands

Breast lobe

Independent glandular unit of a breast. It is a complex branching tubulo-acinar gland.

What happens to the glycogen after the layer has been shed?

It gets broken down into lactic acid by bacteria in the vagina. This causes the pH to decrease

How is the vagina adapted for parturition?

It is capable of considerable stretching because it has an elastin-rich lamina propria, a smooth muscle layer and an adventitial layer

Function of lactic acid

It lowers the pH within the vagina, which prevents the bacteria from growing and, it reduces the amount of time that sperm can survive in the vagina

Function of Vagina's epithelium

It stores glycogen. The level of glycogen is at its maximum during ovulation. This layer is shed during menstruation

Squamous-columnar junction

Junction where squamous epithelium (ectocervix) meets columnar epithelium (endocervix)

Each breast lobe drains into a...

Lactiferous duct

Before the nipple opening, the lactiferous ducts dilate to form a...

Lactiferous sinus

The squamous-columnar junction is the site of...

Metaplastic change

Cervix

Neck of womb, projects into upper vagina via the endocervical canal

Function of breast milk

Nourish newborn

Ectocervix

Thick, protective, stratified squamous epithelium

TDLUs open into...

The main duct

Metaplasia

The process by which one fully differentiated type of epithelium, becomes another type fully differentiated type of epithelium, which is more suited/adapted to its environment

TDLUs consist of...

The terminal duct and a cluster of glands or acini which form the lobule

Function of the outer layer of myoepithelial cells of the TDLU

They maintain the glandular structure of the breast and have the capacity to contract and squeeze the ducts. This aids the expulsion of milk