Reproductive System Lecture Notes

Previous exam review: Tuesday, April 29, 10:00 AM - 3:00 PM
- Location: RCE 134
- No phones or computers allowed.
- Most recent exam and all previous exams will be available.
Exam scores: Will be emailed sometime today.
Course evaluations: Please complete.
- Forward completion verification email for extra credit points.

Meiosis:
- Watch and take notes on 2 animations on Moodle.
- Complete questions #23-31 on the activity using the animations and the textbook.
- Due Monday.
Reproductive Assignment:
- Posted to Moodle.
- Due next Friday by 9 AM.
- Covers both male and female reproductive systems.
- Open book and open internet allowed.

Both male and female reproductive systems have primary sex organs called gonads.
- Ovaries in the female.
- Testes in the male.
Gonads produce sex cells called gametes.
- Oocytes in the female.
- Sperm in the male.
Both systems have ducts to transport gametes from gonads to the site of fertilization.
Both systems also contain accessory sex organs.

Accessory tissues share developmental origins.
In simplest terms, female is the default developmental pathway.
- In the sexually indifferent stage (around week 6), embryos have:
  - Genital tubercle
  - Labioscrotal swelling
  - Urogenital fold
Differentiation:
- Female (XX):
  - No TDF (Testis Determining Factor).
  - Indifferent gonads develop into ovaries.
  - Follicles do not develop until the third trimester.
  - Forms clitoris, labia minora, labia majora, vaginal orifice.
- Male (XY):
  - TDF present.
  - Indifferent gonads develop into testes.
  - Seminiferous tubules and interstitial cells develop in the early embryo.
  - Forms glans of penis, scrotum.

Female Organ - Male Organ - Common Function
- Ovaries - Testes - Produce gametes and sex hormones
- Clitoris - Glans of penis - Contain autonomic nervous system axons that stimulate feelings of arousal and sexual climax
- Labia majora - Scrotum - Protect and cover some reproductive structures
- Vestibular glands - Bulbourethral glands - Secrete mucin for lubrication

Societal term = intersex
- More accepted scientific term for outdated terms hermaphroditism and pseudohermaphroditism
- Also referred to as "Differences in Sexual Development" (DSD) as a more encompassing term.
Prevalence:
- 1:1500 births are significant enough to utilize consultation.
- 1:66 people show intersex characteristics at some point in life (more common later).
Term "hermaphrodite" describes animal species, negative stigma in humans, shouldn’t be used

Both ovarian and testicular tissue can exist together.
Some people have an ovary on one side and a testis on the other, while others have fused ovotestes.
Due to issues during zygotic mitosis, not every cell receives the full Y chromosome.
Hundreds or thousands of possible variations exist, creating a "spectrum" or "gradient" of sex (Wiersma and Ramdial, 2009).

Seeing the normal variation that occurs, it is easy to see why there is no simple definition of "biological sex" (Nature, 2015).
Similar to other varying characteristics, the lecture will discuss the simplified version of male and female anatomy and physiology.

The primary sex organs are the testes.
- Some animals have internal testes (birds, elephants, whales), and this is the default evolutionary pathway.
Scrotum: Provides the testes with a cooler environment than body temperature.
- Human sperm develop best $3^{\circ}C$ below body temperature.
- Temperature controlled via dartos (wrinkling) and cremaster (retraction) muscles.
Accessory organs: Set of ducts, tubules, and glands leading from the testes and the penis.

Testis
Epididymis
Ductus (vas) deferens
Efferent ductules
Ampulla of ductus deferens
Seminal vesicle
Ejaculatory duct
Prostate gland
Bulbourethral gland
Urethra
- Prostatic urethra
- Membranous urethra
- Spongy (penile) urethra
Penis
- Root of penis
- Shaft of penis
- Corpus cavernosum
- Corpus spongiosum
- Glans of penis
- Prepuce
- Bulbospongiosus muscle
- Crus
- Bulb
Scrotum
Urinary bladder
Rectum
Pubic symphysis
Ureter

Bulbourethral glands are located in the urogenital diaphragm on either side of the membranous urethra.
Alkaline mucin is secreted from these glands and enters the spongy urethra in pre-ejaculate to buffer urine and lubricate the glans.

Located on the posterior surface of the urinary bladder, lateral to the ampulla of the ductus deferens.
Secrete a viscous, whitish-yellow, alkaline fluid containing:
- Fructose (energy).
- Bicarbonate (buffer).
- Prostaglandins (immune suppressor).

Located immediately inferior to the urinary bladder.
Produces substances secreted directly into the urethra.
Contains:
- Mucin.
- Citric acid (nutrient for sperm).
- Seminalplasmin (antibacterial).
- Prostatic-specific antigen (PSA, an enzyme that helps liquefy semen).