Ch. 28 - Female Reproductive System

What is the broad ligament and what does it support

A mesentery sheet extending laterally from the uterus; supports the ovaries, uterine tubes, and uterus in the pelvic cavity

Where is the recto-uterine pouch located

Posterior space between the uterus and rectum

Where is the vesico-uterine pouch located

Anterior space between the uterus and the urinary bladder

What are the functions of ovaries

Produce oocytes, estrogen, and progesterone. (Female gonads)

What ligament connects the ovary to uterus

The ovarian ligament

What ligament contains the ovarian artery and vein and attaches the ovary to the lateral pelvic wall

The suspensory ligament

Describe the regions of the uterine tube

Fimbriae → Infundibulum → Ampulla → Isthmus; lined with ciliated columnar epithelial cells that sweep the oocyte toward the uterus

What are the major regions of the uterus

Fundus, body, and cervix (which contains the cervical os leading to the vagina)

What are the layers of uterine wall

Perimetrium (outer)

Myometrium (smooth muscle)

Endometrium (inner)

The endometrium has

Basal layer (retained)

Functional layer (proliferates & sheds during menstruation)

What is the vagina and its major actions

Muscular canal connecting cervix to external genitalia. Functions:

Birth canal

Receives sperm

Passage for menstrual flow

What is the fornix

Superior region of the vagina that encircles the cervix

What is the hymen

A thin membranous fold covering the external vaginal opening; stretched or torn by activity or penetration

What is the vulva

Collective term for the external female genitalia (labia, vestibule, clitoris)

What structures are found in vestibule

The external urethral opening and vaginal opening

Describe the labia minor and labia majora

Labia minora: thin folds lateral to vestibule

Labia majora: adipose-rich skin folds lateral to labia minora

What is the clitoris

Sensory erectile organ containing a glans and prepuce. Homologous to the glans penis

What are mammary glands and their structure

Glands in breast tissue that produce milk.

Organized into lobes surrounded by adipose tissue

Supported by Cooper Ligaments (suspensory)

Connected to nipple via lactiferous ducts

What is oogenesis and when are primary oocytes formed

Production of oocytes.

All primary oocytes form before birth and remain arrested in prophase I until puberty

When does the secondary oocyte complete meiosis II

Only after fertilization

What is a primordial follicle

A primary oocyte surrounded by follicular cells

What happens during follicular development

Follicular cells enlarge → primary follicle

Estrogen production increases

Zona pellucida forms

Follicle advances to secondary → tertiary stages

What is the ovarian cycle and its phases

28-day cycle:

Follicular phase (days 1-14)

Ovulation

Luteal phase (days 14-28)

What occurs during the follicular phase

Rising FSH → follicle development

Primary oocyte completes meiosis I → secondary oocyte

Ends with ovulation

What triggers ovulation

A spike in LH due to high estrogen → + feedback on hypothalamus/pituitary

What happens during the luteal phase

Corpus luteum forms

Progesterone increases

Endometrium thickens

Ends when corpus luteum becomes corpus albicans

What happens during the menstrual phase

The functional layer of the endometrium is shed. Lasts 1–7 days

What happens during the proliferative phase

Estrogen from developing follicles rebuilds the functional endometrium

What happens during the secretory phase

Progesterone from corpus luteum thickens and maintains the endometrium for possible implantation

What does GnRH do

Hypothalamic hormone that regulates FSH and LH based on estrogen/progesterone levels

What does FSH do in females

Stimulates follicle development; inhibited by inhibin

What does LH do in females

Triggers ovulation and formation of corpus luteum

What does estrogen do

Low levels → inhibit LH

High levels → stimulate LH surge

Supports secondary sex characteristics, bone/muscle maintenance, reproductive organ health

What does progesterone do

Maintains the endometrium

Suppresses GnRH (prevents new follicles)

Used in many birth control pills

What does sexual differentiation occur

Around week 7 (requires testosterone for male structures).

Week 8 → female structures by default if no testosterone

List homologous structures (male ↔ female)

Glans penis ↔ Clitoris

Body of penis ↔ Labia minora

Testes ↔ Ovaries

Scrotum ↔ Labia majora

Bulbourethral glands ↔ Greater vestibular glands

What stabilizes ovaries

Ovarian ligament, suspensory ligament, mesovarium, broad ligament

Regions of ovary

Cortex (follicles), medulla (blood vessels/nerves), germinal epithelium, tunica albuginea

What part of uterine tube does fertilization take place

Ampulla

What is vaginal epithelium

Nonkeratinized stratified squamous epithelium; rugae; acidic environment

What is the milk pathway

Lobules → lactiferous ducts → lactiferous sinus → nipple

When do oogonia complete mitosis

Before birth

Primary oocyte characteristics

Arrested in prophase I until puberty

Each cycle, some resume meiosis I → secondary oocyte + polar body

At what stage is the secondary oocyte arrested

Metaphase II

When does meiosis II finish

Only after fertilization

Stages of follicles

Primordial

Primary

Secondary

Tertiary (antral)

Ovulation

Corpus luteum

Corpus albicans

Key events in follicular phase

FSH stimulates follicle growth; follicles release estrogen; estrogen inhibits LH until threshold

How long after LH peak does ovulation occur

~9 hours

What does corpus luteum secrete

Progesterone (dominant) + some estrogen

What happens if fertilization doesn’t occur

Corpus luteum degenerates → progesterone falls → menstruation begins

3 phases of uterine cycle

Menstrual (shedding)

Proliferative (estrogen rebuilds functional layer)

Secretory (progesterone → glands enlarge, secretion

What enzyme converts testosterone → estradiol

Aromatase

What determines genital differentiation

Presence of testosterone → male pathway; absence → female pathway