The Female Reproductive System

What are the 5 functions of the female reproductive system?

• Produce female sex cells

• Transport egg cell for fertilization

• Provide environment for developing offspring

• Move offspring

• Production of sex hormones

Describe the structure of the ovaries

Small, paired, almond shaped organs near lateral walls of pelvic cavity

What are two functions of the ovaries?

Production of female gametes (ova)

Secretion of female sex hormones

Oogenesis

Production of ovum (egg)

Starting with primordial germ cell, what is the order of cells that will form during development of an ovum?

Primordial germ cell

Oogonium

Primary oocyte

Secondary oocyte

Ovum

Oogonia

Diploid (2n) precursor cells in the ovaries

Formed from primordial germ cells that undergo mitosis to development in females

Primary oocytes

Diploid cells formed from oogonia in the ovaries, which begins the first meiotic division but arrest in prophase I until puberty, when they resume development during each menstrual cycle

Secondary oocyte

A haploid cell resulting from the completion of the first meiotic division of a primary oocyte

It begins the second meiotic division but arrests in metaphase II

Released during ovulation to be fertilized by a sperm cell

What event triggers the secondary oocyte to complete meiosis II?

Fertilization

What is a polar body?

Is a small cell that results from the unequal distribution of cytoplasm during meiosis during oogenesis

Where does the oogenesis occur?

Occurs in the cortex of the ovaries, specifically within the ovarian follicles located in this outer layer

Primordial follicle

Follicle cells the surround a primary oocyte

Earliest stage of follicle development in the ovaries

Ovarian cycle

Cycle of follicle growth resulting in ovulation and corpus luteum formation

List the steps of the ovarian cycle

• Formation of primary follicles

• Formation of secondary follicles

• Formation of tertiary follicle

• Ovulation

• Formation of corpus luteum

Ovulation

Release of egg from the ovary into a uterine tube

Which hormone helps to trigger ovulation?

Luteinizing hormone (LH)

Which hormone will trigger the development of the follicles in the ovary?

Follicle-stimulating hormone (FSH)

What is the function of the corpus luteum?

To produce progesterone to maintain the uterine lining while it waits for implantation

What happens to the corpus luteum about 12 days after ovulation of fertilization doesn’t happen

It will degrade

(progesterone levels will decrease)

Describe structure of uterine tubes

Uterine tubes end closet to the ovary to form an expanded tunnel called infundibulum with numerous projections called fimbriae that extend into the pelvic cavity

What helps move the egg through the uterine tube (fallopian tubes)

Tube is lined with ciliated epithelium that beat to move the egg

Peristaltic contractions by smooth muscle also help move egg

Describe the structure of the uterus

Muscular chamber with two regions - the body and cervix

Fundus

Superior portions of the uterus

Cervix

Inferior portions of uterus

Endometrium

Inner layer of uterus

Myometrium

Muscular layer of uterus

Perimetrium

The tough, membranous outer layer of the uterus

Uterine (menstrual) cycle

Cyclic series of changes in endometrium that occur in response to fluctuating ovarian hormone levels

Where does fertilization typically take place?

Uterine tubes

How long does the window of fertilization last for a secondary oocytes?

about 12-24 hours

Menarche

First menstrual period at puberty

List the 3 stages of the menstrual cycle and what days then span

• Menstruation - days 1-7

• Proliferative - days 7-14 (day 14 ovulations)

• Secretory - days 15-28

Menstruation

Degeneration and shedding of superficial layer of endometrium

Triggered by decline in progesterone and estrogen levels as corpus luteum disintegrates

Proliferative Phase

Surviving endometrial epithelial cells multiply and spread across the surface of endometrium

Stimulated by rising estrogen levels

Secretory Phase

Uterine glands enlarge and endometrial lining reaches mac thickness - stimulated by progestins and estrogens from corpus lutuem

Describe the structure of the vagina

Elastic, muscular tube extending between uterus and vestibule (a space bounded by external genitalia)

Vaginal walls contain a network of blood vessels and layers of smooth muscle

Moist lining is maintained by secretions from cervical glands

pH is slightly acidic

Labia majora

Folds of skin that enclose external reproductive organs

Labia minora

Flattened longitudinal folds between labia majora

Clitoris

Small projection of sensitive erectile tissue that correspond to penis in males

Define lactation

Milk production

Mammary gland function

Specialized to secrete milk after pregnancy