Human Reproduction and Development Process

Human reproduction is sexual. Two individuals from different sexes are needed. Each produces a type of gamete (reproductive cell).

Embryo development: Zygote undergoes cell division until it becomes an embryo that continues development up to being a fetus.

Childbirth: Baby is born, alive and fully formed

Development: The baby grows until maturity is reached (adulthood)

Changes leading to sexual maturity

• Primary sex characteristics: The reproductive organs
• Puberty: Stage from the ages 10-16, when majority occurs
• Adolescence: From puberty to adulthood, physical maturity and physiological and social changes, sexual desire appears
• Sex hormones: Estrogens and testosterone, responsible for the development and regulation of the reproductive system and secondary sex characteristics
• Secondary sex characteristics: -Girls: the breasts and external genitalia develop, hips widen and pubic and underarm hair grows -Boys: bones thicken and the muscles grow, the voice deepens: pubic and underarm hair grows, hair grows on the chest and on the face.

Human sexual response

• Sex: Determined by the presence of a female or male reproductive system
• Sexuality: The way we feel as a person, including emotions, thoughts, and sexual behaviors
• Libido: Sexual desire, body responds physically to this
• Reproduction and sexuality: Not the same, reproduction's goal is to have children, sexuality is the ability to have or express sexual feelings
• Sexual intercourse: The sexual contact between two people, it can be heterosexual and homosexual

Male reproductive system:

• Testes: Male glands, produce sperm in the scrotum, cool temperature
• Penis: Male copulation organ, glands covered by the foreskin, Blood vessels dilation causes blood to fill them and erection
• Reproductive tracts: Tubes, epididymis, for sperm maturation and urethra for expulsion
• Accessory glands: Seminal vesicles, prostate, and cowper's glands secrete substances inside the reproductive system
• Sperm: (spermatozoon-spermatozoa) are small mobile cells male gametes
• Spermatogenesis: Sperm production process takes place in the seminiferous tubules inside the testes
• Semen: Whitish fluid made up of spermatozoa and the secretion of the accessory gland

Female reproductive system

• External genital organs (vulva): Vaginal orifice, labia majora and labia minora folds of skin and the clitoris (sensitive erectile organ)
• Internal genital organs: Ovaries and reproductive tracts, Fallopian tubes, uterus, and vagina
• Mammary glands: Produce milk when a baby is born
• The ova: Large, spherical cells, not mobile, female gametes
• Oogenesis: Ova production process takes place in the ovarian follicles. Every month from puberty on. Each follicle contains a single oocyte, when it develops and between the ovary is called ovum
• The female reproductive cycle: Lasts 28 days involving changes in the sex organs caused by pituitary and ovaries hormones
• Ovaries cycle: Changes in the ovary caused by pituitary hormones, LH and FSH
• Uterine cycle: Changes in the endometrium of the uterus caused by estrogens and progesterone produced by ovaries. This lets the ovum to be fertilized, if not, menstruation begins