Reproductive System Learning Objectives

Penis

Composed of erectile tissue (corpus cavernosum and corpus spongiosum) and contains the urethra for the passage of urine and semen.

Urethra

A tube running through the penis that carries urine and semen.

Prostate

A gland located below the bladder, providing secretions that nourish and protect sperm.

Vas Deferens

A muscular tube that transports sperm from the epididymis to the ejaculatory duct.

Ejaculatory Duct

A duct formed by the union of the vas deferens and seminal vesicle, delivering sperm and seminal fluid to the urethra.

Seminal Vesicles

Glands that produce a significant portion of the seminal fluid, providing nutrients and energy to sperm.

Scrotum

A muscular pouch that houses the testes, regulating their temperature for optimal sperm production

Testes

Organs that produce sperm and hormones mainly testosterone

Circumcision

A surgical procedure that removes the foreskin from the penis, often performed for religious, cultural, or medical reasons.

Vasectomy

A surgical procedure that involves cutting and sealing the vas deferens to prevent sperm from entering the semen, primarily used for male sterilization.

Sperm and Semen Production Process

Sperm is produced in the seminiferous tubules of the testes through spermatogenesis, followed by maturation in the epididymis. Semen is produced through the secretions of the prostate and seminal vesicles, combining sperm with fluids to form semen for ejaculation.

Diploid (2n)

Cells with two complete sets of chromosomes (46 total in humans)

Haploid (n)

Cells that contain only one set of chromosomes (23 total in human sperm and egg)

Hormones in Male Reproductive System

• GnRH

• LH

• Testosterone

• Inhibin

GnRH

Stimulates the release of FSH and LH from the pituitary gland

FSH

Stimulates Leydig cells to produce testosterone

Testosterone

Responsible for development of male secondary sexual characteristics and sperm production

Inhibin

Regulates FSH levels, providing feedback to maintain sperm production

Journey of Sperm from Generation to Ejaculation

Sperm is produced in the seminiferous tubules, matures in the epididymis, travels through the vas deferens, merges with seminal fluid in the ejaculatory duct, and is expelled through the urethra during ejaculation.

What are the accessory glands

• Seminal Vesicles

• Prostate Gland

• Bulbourethral Glands

Seminal Vesicles function

produce seminal fluid containing nutrients for sperm

Prostate Gland

Produces a fluid that nourishes and protects sperm; contributes to semen volume

Bulbourethral Glands (Cowper’s Glands)

Secretes pre-ejaculatory fluid that lubricates the urethra and neutralizes any urinary acidity

Erection

Mediated by the parasympathetic nervous system, leads to smooth muscle relation and increased blood flow to the penis

Ejaculation

Controlled by the sympathetic nervous system, causing muscle contraction to expel semen

Vulva

External genitalia, including the labia, clitoris and vaginal opening

Uterus

A muscular organ where a fertilized egg implants and a fetus develops

Ovaries

Glands that produce oocytes and hormones (estrogen and progesterone).

Associated Structures of the female reproductive system

• Fallopian tubes

• Vagina

Fallopian tubes

transport eggs

vagina

birth canal

Ovarian Cycle

FSH and LH regulate follicle development and ovulation; estrogen and progesterone prepare the uterus for implantation

Menstrual Cycle

involving changes in the endometrium, regulated by ovarian hormones

pH of vagina

Normally acidic to inhibit microbial growth

microbiota

Maintains a balance of beneficial bacteria to protect against infections

Oogenesis

The process by which oocytes are produced in the ovaries

Folliculogenesis

The maturation of ovarian follicles encompasses hormone regulation and cellular changes.

Menopause

The cessation of menstrual cycles, marking the end of a woman's reproductive years, usually occurring between 45-55 years of age.

What are the hormonal regulations of ovulation

• LH Surge

• Menopause

What are the early embryologic milestones

• fertilization

• implantation

Fertilization

Sperm fertilizes the egg in the uterine tube

Implantation

The blastocyst attaches to the uterine lining around 6-10 days post-fertilization.

Key hormones of early pregnancy

• HCG

• Progesterone

HCG (Human Chorionic Gonadotropin)

Produced by the placenta, it is the hormone detected in pregnancy tests.

Progesterone

Maintains the uterine lining and supports early pregnancy

What are the anatomic changes in pregnancy

• increased blood volume

• enlarged uterus

• hormonal changes

• breast development

What are the stages of labor

• Dilation of the cervix

• Delivery of the baby

• Delivery of the placenta

Barrier methods

Condoms and diaphragms that physically block spperm

Spermicides

Chemicals that kill sperm or block their motility

Rhythm Method

Avoiding intercourse during ovulation

Withdraw Method

Withdrawing before ejaculation

Hormonal methods

• birth control pills

• patches

• implants IUD

All prevent ovulation