Lecture 14: Reproductive System Flashcards
What are reproductive system functions?
- Produce gametes (sperm and egg)
- Fertilization
- Nurture the development of zygote into an embryo then fetus.
What are the gonads?
Testes in males
Ovaries in females
Which two products are produced by the gonads?
- Gametes made through meiosis.
- Sex hormones (Testosterone, estrogen and progesterone)
What is scrotum and it’s function?
Testes contained within a sac of skin located outside the abdominopelvic cavity.
Optimal temperature for producing viable sperm is lower than internal body temperature.
Which two tissues are contained within the testes?
- Seminiferous tubules (network of tubes where sperm are made)
- Leydig (Interstitial endocrine cells) Produce the hormone testosterone - located within the connective tissue between the seminiferous tubules.
What is the difference between spermatogenesis and spermiogenesis?
Spermatogenesis: Sperm are made within the seminiferous tubules.
Spermiogenesis: Complete their maturation process in the epididymis.
How does spermatogenesis occur?
Firstly, mitotic cell division allows for identical copies of original cell.
Some of the daughter cells undergo meiosis where immature sperm cells (spermatids) are produced. These cells migrate closer to the lumen of seminiferous tubule.
What happens during spermiogenesis (epididymis)?
- Forms an acrosome (penetrates the eggs outer layer and contains digestive enzymes)
- Cytoskeleton extends to form a flagellum
- Produce extra mitochondria (enough energy to swim and fertilize the egg)
- Lose extra cytoplasm to streamline
What is the function of the penis?
- Deliver semen to the female reproductive tract
- Serve in the elimination of urine
(Contains 3 cylindrical bodies of erectile tissue)
Erectile tissue - Filled with blood when stimulated.
What are some causes to erectile dysfunction?
- Blood vessel damage
- Nerve damage
What are the accessory glands and their function?
- Seminal gland: Location on posterior surface of the bladder. Produces fructose sugar to nourish the sperm.
- Prostate gland: Doughnut shaped; protects the sperm from acidic environments.
- Bubo - urethral gland: Pea sized inferior to the bladder; releases mucus into the urethra that neutralizes any leftover urine.
What is Benign Prostatic Hyperplasia:
Enlargement of the prostate gland leads to reduced ability to urinate due to compression of its walls.
Define the pathway for sperm?
- Epididymis: Stores matured sperm.
- Ductus (Vas) Deferens: Long tube
- Ejaculatory duct: Sperm is mixed with fluids from seminal and prostate glands to form semen.
- Urethra
Describe the external and internal parts of the mammary gland?
External: Surrounding the nipple is a pigmented area called areola which contains sebaceous glands.
Internal: 15-25 lobes and each lobe is subdivided into lobule which contains glandular alveoli where milk is produced. Milk is transported to nipple through lactiferous ducts.
What is clitoris and it’s function?
Erectile tissue which is innervated and sensitive to touch. Homologous to penis in males.
What is labia and its function?
Folds of skin around the opening of the vagina.
Labia majora (outer larger folds) and labia minora (inner smaller folds)
Protects from bacteria and dirt.
What is the hymen?
Typically ruptures by first tampon usage or sexual intercourse.
What is the function of ovaries?
- Produce and release gametes (oocytes)
- Produce and release female sex hormones estrogen and progesterone.
What do the ovaries consist of?
Ovarian follicles: Tiny sacs that contain immature eggs (oocytes)
Follicular cells: Cells that surround and nourish the egg.
How are follicles selected for maturation?
- Increasing the number of follicle cells that surround the oocyte.
- Completion of meiosis I
- Development of a fluid filled cavity surrounding the oocyte.
Define the pathway for an ovulated oocyte:
- Ovary (Egg stored and matured)
- Oviduct (Carry the eggs from ovary to uterus)
- Uterus (Develops into fetus during pregnancy)
- Vagina (Connects the uterus to the outside of the body)
Describe parts of the uterine tube
Distal end expands around the ovary (Infundibulum) which has ciliated finger like projections called fimbriae.
Lined with smooth muscle and ciliated cells.
What is Ectopic pregnancy?
Fertilized egg implants into uterine tube lining or elsewhere instead of the uterus.
Define the anatomical position of the uterus.
Superior and posterior to the urinary bladder and anterior to the rectum. Houses and supports the development of the baby.
Describe the uterine structure.
Fundus: Rounded region superior to where oviduct enters.
Body: Main portion
Cervix: Narrow outlet that connects into the vagina.
Uterine wall from deep to superficial
- Endometrium - Exposed to the cavity of the uterus.
- Myometrium - Middle layer of smooth muscle that contracts during labor and delivery.
- Perimetrium - Outermost supportive layer
What is the function of the cervix?
Contains glands that produce mucus which fills the cervical canal. Mucus blocks entry of microbes from vagina and sperm most of the time. Estrogen levels allow sperm to pass through and progesterone has the opposite effect.
What is the function of vagina?
- Passageway for delivery of menstrual flow and infants.
- Site of semen deposition during intercourse.
How are sperm lost in their journey?
- Acidic vaginal environment
- Inability to get through cervix
- Choosing the wrong uterine tube
What is the difference in meiosis between sperm and egg formation?
Female only produce 1 viable egg in comparison to 4 sperm cells.
Describe the embryonic development.
Morula formation occurs 3 days after ovulation. By day 4 after the embryo reaches the uterus, it is transformed into a blastocyst.
What is the difference between dizygotic and monozygotic twins?
Dizygotic: Mother ovulated two eggs at the same time and both were fertilized.
Monozygotic: 2 inner cell masses are formed instead of one in the blastocyst.
