Sexual Reproduction & Development

What are the primary sex organs in males and females and what are their 2 main jobs

Males → testes

Females → ovaries

1. produce gametes (sperm ; ova/egg)

2. produce steroid sex hormones (androgens; progesterone and estrogen)

WhaT are the secondary/ accessory reproductive organs (3)

ducts, glands, and external genitalia

Gonads

primary sex organs (testes and ovaries) that produce gametes and sex hormones

How many pairs of chromosomes and what is one of the pairs

23 pairs
1 pair = sex chromosomes - X + Y

male and female chromosomes

How are sperms split
how are eggs split

male - xy → sperm → 50% X 50% Y

female - xx → egg → 100% X

Which gamete determines chromosomal sex (gender)

the sperm because it has the y → all eggs have x

How does teste development initiate

The SRY gene initiates teste development → located on the Y chromosome → hormone for male reproductive development

no SRY → usually ovaries develop no testes

What are these 4 things from top to bottom

embryonic structures that develop into external genitalia

genital tubercles (yellow)

urogenital/ urethra folds (pink)

labioscrotal folds (blue)

tail

Genital tubercle develops into what

Glans of penis (tip)

clitoris

Urethral folds/ urogenital folds develop into what

male urethra

female - labia minora (small inner outside fold)

Labioscrotal folds develeop into what

male - scrotum (ball sac)

female - labia majora

When do the gonads begin to descent

2 months before birth

Male descent of gonads

testosterone stimulate migration of testes towards scrotum

Female descent of gonads

ovaries descend → movement stopped by broad ligament of pelvic brim

Gubernaculum

fibrous cord that guides gonad descent

• males - testes to gonad

• females - ovaries to labium majus

What triggers puberty and what does it do (3)

rising levels of gonadal hormones

hormones cause

• reproductive organs to grow to adult size and become functional (earliest that reproduction is possible)

• secondary sexual characteristics (other physical changes like hair voice breast etc)

STIs/ STDs/ VDs

sexually transmitted infections/ diseases/ venereal diseases

Name 5 STIs

gonorrhea, syphylis, chlamydia, genital warts, genital herpes