HLTH377 Week 3: Reproductive Anatomy, Sexual Characteristics, and Homologous Genitals

Intersex or DSD (Differences in Sexual Differentiation or Disorders in Sexual Development)

A general term used for a variety of conditions in which a person is born:
- with reproductive or sexual anatomy that differs from that typically ascribed to "female" or "male"
- with biological or chromosomal variation from XX or XY

How common is intersex?

Visibly counted by medical professionals: 1 in 1500 to 1 in 2000 births
Most subtle forms: 1-2% of the population (as common as red hair in the US

Transgender vs. Intersex

Transgender is related to gender identity, while intersex is more related to biological characteristics.w

7 Components Associated W/ Sex

1. Chromosomes, 2. Genitals, 3. Internal sex organs, 4. Gonads, 5. Secondary sex characteristics, 6. Hormone production, 7. Hormone response

Issues W/ Intersex Youth

Many doctors lack the understanding and specialized intersex medical knowledge (maybe due to lack of research) and recommend surgeries on infants/ youth to remove intersex characteristics in children.

Primary Sex Characteristics
(Most commonly ascribed to those w/ SAB - Female)

- Sex Chromosomes (XX)
- Sex Hormones (Estrogen and Progesterone)
- External Genitalia (i.e. Labia, Clitoris)
- Internal Sex Organs (i.e. Uterus, Ovaries)

External Genitalia: Vulva

Internal Sex Organs (SAB - Female)

Internal Sex Organs (SAB - Female) - Side View

Clitoris

Homologous Structure of the Clitoris and Penis

Cliteracy

A project by Sophia Wallace, a visual artist, that aims to bring awareness, conversation, and empowerment to the clitoris.

Primary Sex Characteristics
(Most commonly ascribed to those w/ SAB - Male)

- Sex Chromosomes (XY)
- Sex Hormones (Testosterone)
- External Genitalia (i.e. Penis, Testes)
- Internal Sex Organs (i.e. Vas Deferens, Seminal Vesicle)

External Genitalia: Penis

Why are the testicles located outside the body?

To regulate the temperature of the testes. Sperm production is best at a slightly cooler temperature than that of internal body temp.
- Cremaster muscle will pull testes close to body when aroused in preparation for sex (more safe during intense movements during sex)

Internal Sex Organs (SAB - Male) - Side View

Internal Sex Organs - Cross-section of Penis

Note: Corpus cavernosum are critical to protecting urethral pathway during erection and help give penis its "engorged"/"erect" look.

Semen's Pathway

1. Testis (where sperm originates)
2. Vas deferens
3. Seminal vesicle (contribute 70% of seminal fluid)
4. Prostate gland (also contributes some fluid)
5. Bulbourethral gland (contributes last bit of fluid: pre-cum, lubricant, neutralizes urethra)

Homologous means...

similar in structure

Match the homologous parts: Ovaries

Testes

Match the homologous parts: Clitoral hood

Foreskin

Match the homologous parts: Glans clitoris

Glans penis

The glans clitoris is homologous to the glans penis (head of the penis).
There are ___ nerve endings in the clitoris, which is ____ as many as are in the glans penis.

8000; twice

T or F: Both the penis and the clitoris have crura (plural = crus).

True

The cervix..

Is at the end of the vaginal canal and acts as the gate keeper between the vaginal canal and the uterus

Pre-Ejaculate (aka pre-cum) is secreted from the ( _______). Pre-cum neutralizes acidity in the urethra caused by urine - better for passage of sperm.

Bulbourethral Glands