EXAM 6: Reproductive Flashcards
Identify the major gross structures of the female reproductive system.
Ovaries: The primary reproductive organs that produce eggs (ova) and hormones (estrogen and progesterone).
Fallopian Tubes: Tubes that transport the egg from the ovary to the uterus. Fertilization usually occurs here.
Uterus: A hollow, muscular organ where a fertilized egg implants and develops into a fetus.
Cervix: The lower, narrow part of the uterus that connects to the vagina and acts as a barrier during pregnancy.
Vagina: The muscular canal that leads from the cervix to the external genitalia, through which menstrual flow and babies pass.
Describe the general structure of the ovary and follicles.
Ovary Structure: The ovaries are small, oval-shaped organs located on either side of the uterus. They are made up of an outer layer of germinal epithelium, beneath which is the cortex containing ovarian follicles. The medulla is the inner part, which contains blood vessels, lymphatic vessels, and nerves.
Follicles: Ovarian follicles are structures that contain immature eggs (oocytes). They consist of an oocyte surrounded by layers of granulosa cells and a theca. The follicles develop and mature as the oocyte progresses through its maturation stages.
Describe the stages of the follicle as it matures.
Primordial Follicle: The earliest stage, consisting of a primary oocyte surrounded by a single layer of granulosa cells.
Primary Follicle: The granulosa cells increase in number, and the oocyte enlarges.
Secondary Follicle: The follicle develops multiple layers of granulosa cells and begins forming a fluid-filled space (antrum).
Tertiary (Graafian) Follicle: The mature follicle with a large antrum that is ready to ovulate. The oocyte is surrounded by the corona radiata and zona pellucida.
What is the process of ovulation? Name the follicular structures that develop before and after ovulation. What hormones are produced by the follicle? How many follicles typically mature monthly in a post-pubescent female?
Ovulation Process: Ovulation occurs when a mature Graafian follicle ruptures, releasing a secondary oocyte from the ovary into the fallopian tube.
Before Ovulation: The follicle develops from a primordial to a primary and secondary follicle, finally reaching the mature Graafian follicle before ovulation.
After Ovulation: The ruptured follicle transforms into the corpus luteum, which secretes progesterone to prepare the uterus for possible pregnancy. If pregnancy does not occur, the corpus luteum degenerates into the corpus albicans.
Hormones Produced:
Estrogen: Produced primarily by granulosa cells in the follicle, it helps regulate the menstrual cycle and promotes the thickening of the endometrial lining.
Progesterone: Produced by the corpus luteum after ovulation, it helps maintain the endometrial lining for potential embryo implantation.
Number of Follicles: Typically, 1-2 follicles mature fully each month in a post-pubescent female, though many follicles begin developing at the start of each cycle, and only one is selected for ovulation.
What are the stages of oocyte maturation and describe the progression from diploid to haploid number. How is oocyte maturation very different from that of sperm in timing and number?
Stages of Oocyte Maturation:
Oogonium (Diploid): The original germ cells that undergo mitosis to produce primary oocytes.
Primary Oocyte (Diploid): Oocytes that enter prophase I of meiosis and remain arrested until puberty.
Secondary Oocyte (Haploid): After puberty, each month, one primary oocyte completes meiosis I, producing a secondary oocyte and a smaller polar body. The secondary oocyte is haploid (having half the chromosome number).
Fertilization: If fertilization occurs, the secondary oocyte completes meiosis II, producing a mature ovum and a second polar body.
Difference in Oocyte vs. Sperm Maturation:
Oocyte Maturation: Oocyte maturation is discontinuous and occurs over a prolonged period. A female is born with all her primary oocytes, and they do not mature until later stages of life, with only one oocyte maturing each cycle.
Sperm Maturation: Sperm production (spermatogenesis) is continuous throughout the male’s life, with millions of sperm produced each day. Sperm maturation occurs relatively rapidly, typically taking about 64-72 days from spermatogonium to mature sperm.
Describe the anatomy of the uterine (fallopian) tubes. Identify the location and role of the infundibulum and fimbriae. What is the makeup of the mucosal and muscularis layers of these tubes, and how does it aid in propulsion of sperm or egg?
Anatomy of the Uterine Tubes: The uterine tubes (fallopian tubes) are paired tubes that extend from the upper corners of the uterus toward the ovaries. They are responsible for transporting the egg from the ovary to the uterus.
Infundibulum: The funnel-shaped end of the uterine tube near the ovary. It has fimbriae, finger-like projections that help capture the egg released during ovulation.
Fimbriae: These finger-like projections help draw the egg into the infundibulum during ovulation.
Mucosal Layer: Lined by ciliated epithelium that aids in the movement of the egg and sperm through the tube. The mucosa also secretes fluids that nourish the egg.
Muscularis Layer: Comprised of smooth muscle that contracts rhythmically to propel the egg towards the uterus (peristalsis), assisting in sperm transport toward the egg for fertilization.
Identify the regions of the uterus, the 3 layers of its wall, and which of these layers is shed each month during a menstrual period?
Regions of the Uterus:
Fundus: The top, dome-shaped portion of the uterus, above the openings of the fallopian tubes.
Body: The main central portion of the uterus where the fertilized egg implants.
Cervix: The lower, narrow portion of the uterus that connects to the vagina.
3 Layers of the Uterine Wall:
Perimetrium: The outer serous layer, part of the peritoneum.
Myometrium: The thick middle muscular layer, responsible for uterine contractions during menstruation and childbirth.
Endometrium: The innermost mucosal layer that thickens and sheds each month during menstruation if implantation of a fertilized egg does not occur.
Layer Shed During Menstruation: The endometrium is shed during menstruation.
Describe the location of the vagina with respect to urethra and rectum, the regions known as anterior/posterior/lateral fornix, and the composition of the mucosal lining.
Location of the Vagina:
- The vagina is a muscular canal that extends from the cervix to the external genitalia.
- The urethra is located anterior (in front) of the vagina, while the rectum lies posterior (behind) to the vagina.
Regions of the Vagina:
Anterior fornix: The space formed between the front wall of the vagina and the cervix.
Posterior fornix: The space formed between the back wall of the vagina and the cervix.
Lateral fornices: The spaces formed on the sides of the cervix.
Mucosal Lining: The vagina is lined with stratified squamous epithelium, which is designed to withstand friction. It also has rugae (folds) that allow for stretching during childbirth or sexual intercourse. The mucosa is rich in glycogen, which, when metabolized by bacteria, produces lactic acid to maintain an acidic environment that helps prevent infections.
Know the location of and descriptions of external genitalia, the labia, clitoris, and vestibule. Describe the location of the perineum.
External Genitalia (Vulva): The external part of the female genitalia that includes:
Labia Majora: The larger, outer folds of skin that protect the inner structures.
Labia Minora: The smaller, inner folds of skin that enclose the vaginal and urethral openings.
Clitoris: A small, highly sensitive organ located at the anterior junction of the labia minora. It is made of erectile tissue and is a key site of sexual arousal.
Vestibule: The area enclosed by the labia minora, containing the vaginal and urethral openings.
Perineum: The region between the vaginal opening and the anus. It contains muscles that support the pelvic organs and can be involved in childbirth.
What are the ligaments associated with the uterus and ovaries?
Broad Ligament: A large sheet-like ligament that supports the uterus, ovaries, and fallopian tubes in the pelvic cavity.
Ovarian Ligament: Connects the ovary to the lateral surface of the uterus.
Suspensory Ligament of the Ovary: Attaches the ovary to the lateral pelvic wall and contains blood vessels that supply the ovary.
Round Ligament: A ligament that connects the uterus to the anterior pelvic wall and helps maintain the position of the uterus.
Understand the gross anatomy, cellular make-up, and secretions (where applicable), and functions of the following organs: uterus, ovary, uterine tube, vagina.
Uterus:
- Gross Anatomy: A hollow, pear-shaped organ located in the pelvic cavity.
- Cellular Make-Up: The inner lining (endometrium) is made of epithelial cells and glandular tissue.
- Secretions: The endometrium secretes nutrients for the fertilized egg, and the cervix secretes mucus to protect the uterus and facilitate sperm passage.
Function: Houses and nourishes a fertilized egg during pregnancy.
Ovary:
- Gross Anatomy: Paired organs located on either side of the uterus.
- Cellular Make-Up: Composed of an outer cortex containing follicles and an inner medulla with blood vessels.
- Secretions: Produces estrogen and progesterone.
Function: Produces eggs and hormones for the menstrual cycle.
Uterine Tube:
- Gross Anatomy: Paired tubes extending from the uterus to the ovaries.
- Cellular Make-Up: Lined with ciliated epithelium.
- Function: Transports eggs and is the site of fertilization.
Vagina:
- Gross Anatomy: A muscular canal leading from the cervix to the external genitalia.
- Cellular Make-Up: Lined with stratified squamous epithelium.
- Function: Facilitates sexual intercourse and childbirth, and serves as the passage for menstrual flow.
Understand the ovarian cycle vs. the uterine cycle.
Ovarian Cycle:
- The monthly cycle of follicular development, ovulation, and luteal phase. It includes:
Follicular Phase: The maturation of the ovarian follicles, stimulated by FSH.
Ovulation: The release of the secondary oocyte from the mature follicle.
Luteal Phase: The formation of the corpus luteum, which secretes progesterone.
Uterine Cycle:
- The monthly cycle that prepares the endometrium for potential pregnancy:
Menstrual Phase: The shedding of the endometrium when fertilization does not occur.
Proliferative Phase: The endometrial lining thickens in response to estrogen.
Secretory Phase: The endometrium secretes nutrients for the fertilized egg under the influence of progesterone.
Understand the primary sex organs and accessory sex organs: their location, and all structures of their gross anatomy, their functions (and what secretions they make, where applicable), and their gross anatomy (e.g., scrotum, testes, epididymis, vas deferens, ejaculatory ducts, urethra, penis, seminal vesicles, prostate, and bulbourethral glands).
Primary Sex Organs:
Testes: Located in the scrotum, produce sperm and testosterone.
Accessory Sex Organs:
Scrotum: Sac that contains and protects the testes; regulates temperature for sperm production.
Epididymis: Coiled tube atop the testes where sperm mature and are stored.
Vas (Ductus) Deferens: Transports sperm from the epididymis to the ejaculatory duct.
Ejaculatory Ducts: Carry sperm from the vas deferens to the urethra.
Urethra: Tube that carries sperm and urine out of the body.
Penis: Organ for urination and sexual intercourse; delivers sperm into the female reproductive tract.
Seminal Vesicles: Produce a significant portion of semen fluid, providing nutrients and energy for sperm.
Prostate: Produces fluid that helps activate sperm and adds to semen volume.
Bulbourethral Glands: Produce pre-ejaculatory fluid that lubricates the urethra and neutralizes acidic urine.
Describe the location of seminiferous tubules, the cell types (Sertoli, Leydig cells) in and around the tubules, and the function of each. Which produces testosterone? What is the role of testosterone? (What type of molecule is testosterone?)
Seminiferous Tubules: Located within the testes, these coiled tubes are where sperm are produced.
Sertoli Cells: Located within the seminiferous tubules, they nourish and support developing sperm cells.
Leydig Cells: Found outside the seminiferous tubules in the interstitial tissue; they produce testosterone in response to luteinizing hormone (LH).
Testosterone: A steroid hormone that is critical for the development of male sexual characteristics, sperm production, and maintaining libido.
What are the stages of sperm development, and what is meant by a haploid vs. diploid cell? What is the number in human cells? During what cellular process does reduction in chromosome number occur? Know the steps of spermatogenesis (meiosis in the male body).
Stages of Sperm Development (Spermatogenesis):
1. Spermatogonia (diploid) undergo mitosis to produce primary spermatocytes.
2. Primary Spermatocytes (diploid) undergo meiosis I to form secondary spermatocytes (haploid).
3. Secondary Spermatocytes (haploid) undergo meiosis II to form spermatids (haploid).
4. Spermatids mature into spermatozoa (sperm).
Haploid vs. Diploid:
- Diploid: Cells with two sets of chromosomes (46 total chromosomes in humans).
- Haploid: Cells with one set of chromosomes (23 chromosomes in humans).
- Meiosis is the process during which the chromosome number is halved, ensuring that sperm and egg each contain half the genetic material needed to form a complete set upon fertilization.
