Pathophysiology 5160: Reproduction 2 Quiz

Course Information

• Course name: Pathophysiology 5160
• Topic: Reproduction 2
• Instructor: Dr. Maiyon Park
• Institution: California University of Science and Medicine (CUSM)
• Course materials protected by copyright

Session Learning Outcomes (SLOs)

• Students able to describe male reproductive system:
  • Testes and spermatogenesis
  • Sperm storage and ejaculation, capacitation
  • Male accessory reproductive glands
  • Testicle descent and cryptorchidism
• Students able to describe female reproductive system:
  • Female reproductive physiology
  • Oogenesis and stages of ovarian follicle development
  • Oocyte attrition
  • Estrogen and progesterone synthesis and secretion

SLO 1a: Structure and Function of Testes

• Testes function in spermatogenesis and testosterone secretion
• Located outside the body cavity in the scrotum, at 35-36°C
• Testicular arteries and veins have a counter-current layout to regulate temperature
• Seminiferous tubules make up ~80% of the adult testis.
• Spermatogonia (2n2c) are undifferentiated male germ cells
• Spermatocytes (2n2c) are cells derived from spermatogonia, becoming mature sperm
• Spermatids are haploid (1n1c) cells from meiotic division, forming spermatozoa in spermiogenesis
• Important process in spermatogenesis

SLO 1a: Spermatogenesis

• Multiplication phase: Spermatogonia (2n2C, 46), stem cells at the basal lamina, proliferate via mitosis.
• Growth phase: One daughter spermatogonium grows and enters meiosis, becoming primary spermatocyte (2n2C,46), and further dividing in the process
• Meiosis I: Primary spermatocyte becomes secondary spermatocytes (1n1C, haploid)
• Meiosis II: Secondary spermatocytes produce 4 spermatids (1n1C, haploid, 23) from each primary spermatocyte
• Maturation phase (Spermiogenesis): Spermatids differentiate into mature spermatozoa or sperms (1n1c) with flagella enabling movement.

SLO 1b: Storage of Sperm, Ejaculation, and Fertilization

• Sperm maturation proceeds primarily in the epididymis
• During sexual arousal, smooth muscle contractions propel mature spermatozoa
• Following ejaculation, there is transportation of sperm from epididymis to vas deferens where seminal vesicles, and prostate glands provide fluid to make semen.
• Prostaglandins from seminal vesicles help with sperm motility and counteract vaginal acidity, inducing peristaltic contractions for optimal sperm penetration.
• 15 million sperms per milliliter are considered a normal count

SLO 1b: Capacitation, Acrosomal Reaction, and Fertilization

• Sperm require capacitation to be able to fertilize an ovum which occurs in the female reproductive tract for about 10 hours
• During capacitation, sperm are released from seminal plasma proteins and undergo reorganization of plasma membrane proteins and lipids with increased cAMP and decreased pH.
• Motility increases, resulting in a "whip-like" motion.
• Acrosomal reaction occurs when the sperm's acrosome (a vesicle at the head) fuses with the cell membrane.
• Enzymes released from the acrosome help the sperm penetrate the ovum's protective layers.

SLO 1c: Male Reproductive Accessory Organs - Seminal Vesicle & Prostate Gland

• Seminal vesicles secrete alkaline viscous fluid containing fructose, citrate, prostaglandins (aid in sperm motility)
• Prostate gland adds milky fluid with enzymes, calcium, and prostate-specific antigen (PSA)
• These fluids combined form semen (providing nutrition and aiding fertilization).
• Prostaglandins help to neutralize acidic vaginal conditions and induce peristaltic contractions in the uterine tubes.

SLO 1d: Testicle Descent and Cryptorchidism

• Normally, testicles descend into the scrotum in boys by 9 months of age.
• Undescended testicles are common in premature infants.
• Cryptorchidism refers to incomplete or undescended testicles.
• Cryptorchidism can occur in the abdomen, inguinal canal, or prescrotal locations.
• Potential for infertility or testicular cancer

SLO 2a: Female Reproductive Physiology

• Ovaries produce eggs (ova) and female hormones (estrogen and progesterone)
• Fallopian tubes capture the egg from the ovary and transport it to the uterus, site of fertilization
• Uterus provides a suitable environment for the fertilized egg
• Cervix secretes mucus regulating sperm entry
• Vagina conducts sperm to the uterus and acts as the birth canal

SLO 2b: Oogenesis & Follicle Development of Female Reproduction

• Oogenesis is the process of creating eggs (ova) in the ovaries, which happens during fetal development and continues into a woman's reproductive life.
• Oogonia develop into primary oocytes, arrested in prophase I of meiosis.
• At puberty, some follicles mature, and primary oocytes complete meiosis I, producing secondary oocytes.
• Secondary oocytes arrest in metaphase II, ready for fertilization.
• Follicle development involves a series of changes in the follicle surrounding the oocyte.
• These changes involve granulosa cells and theca cells.

SLO 2b: Ovaries & Follicle Development for Female Reproduction

• Cortex is the outer layer of the ovary, housing oocytes within follicles.
• Medulla is the inner layer, containing blood vessels and nerves.
• Ovarian follicles are functional units of the ovary containing oocytes surrounded by follicular cells; this produces primordial follicle
• Primordial follicle develops into a growing or primary follicle over a period of several years.
• This process continues until a mature follicle (Graafian follicle) develops, which releases an ovum (egg) at ovulation

SLO 2b: Follicle Development for Female Reproduction

• One follicle matures during each menstrual cycle.
• Follicle continues to grow with the maturation of Granulosa and Theca cells, preparing it for ovulation.
• Primary oocytes remain arrested in prophase I of meiosis until puberty, one at a time per menstrual cycle.
• Primary oocytes are enveloped in layers of follicle to form the mature Graafian follicle, which then releases the ovum (egg) through the process of ovulation.

SLO 2b: Follicle Development for Female Reproduction

• A single Graafian follicle becomes dominant and the others regress.
• Ovulation occurs about 14 days after menstruation; this causes the dominant follicle to rupture and release the secondary oocyte into the peritoneal cavity.
• Fertilization occurs in the fallopian tubes; if successful, the secondary oocyte completes meiosis.
• If fertilization does not occur, the remnants of the ruptured follicle form the corpus luteum, which supports early pregnancy.

SLO 2c: Unequal Cytokinesis during Oogenesis

• Oogonia (2n) are formed via mitosis.
• During fetal development, Meiosis I begins forming primary oocytes, arrested in prophase I.
• After puberty, primary oocytes complete meiosis I, producing a secondary oocyte and a polar body.
• The secondary oocyte arrests in metaphase II, waiting for fertilization.
• Upon fertilization, meiosis II completes, creating an ovum and a second polar body.

SLO 2c: Attrition of Oocytes in Female Lifetime

• At birth, females have a large pool of primary oocytes, but most will undergo atresia (degeneration).
• During fetal development, about 7 million oogonia are present.
• By the time of birth, only about 2 million remain.
• Around puberty, about 400,000 oocytes remain. Only 400-500 will be released during a woman's reproductive lifetime.
• New oocytes are not produced, therefore, a woman's reproductive lifespan declines after puberty.

SLO 2d: Steroid Hormone Production in Ovary

• Steroid hormones produced in ovaries support ovulation and embryonic development.
• Primary follicles produce estrogen.
• Secondary follicles produce both estrogen and progesterone.
• Corpus luteum mainly produces progesterone.
• LH and FSH stimulate different steroidogenic enzymes in theca cells and granulosa cells, leading to the production of androgens and estrogens.
• Androgens produced in theca cells are converted into estrogens in the granulosa cells through enzymatic processes (17ßHSD and aromatase).

Summary of Parts and Functions of Female Reproductive System

• Includes a diagram of the female reproductive system with labeled parts.
• Oogenesis is presented with stages (mitosis, meiosis phases).
• Follicle development with stages and graphical representation.