Formation of specific tissues, organs and organ systems from three germ layers is called Organogenesis.

Transfer of sperms by the male into the female genital tract is called Insemination.

Gametogenesis is the process of formation of gametes i.e., Sperms from primary spermatocytes and ova from primary oocyte in testes and ovaries respectively. Meiosis plays the most significant role in the process of gametogenesis.

Human Chorionic Gonadotropin (hCG), Human Chorionic Somatotropin (hCS) (or) Human Placental Lactogen (hPL), oestrogens and progesterone.

In testes Sertoli cells secrete inhibin, a hormone which is involved in the negative feedback control of sperm production. (Spermatogenesis).

Placenta during pregnancy secretes hormones such as human chorionic gonadotrophic (hcG) estrogen, progesterone and human placenta lactogen. So, placenta is regarded as an endocrine tissue.

Spermiogenesis Spermatogenesis lt is a process of formation of sperms from immature germ cells It is a process of transformation of a non-motile spermatid into a motile
spermatozoan Number of cells increased as each spermatogonium produces four spermatids No change in number of cells as only one spermatid develops into a spermatozoa

Clean and safe absorbable clothing materials, sanitary napkins, pads, tampons, and menstrual cups have been identified as materials used to manage menstruation

During the ovulatory phase of the menstrual cycle, maximum secretion of leutinising hormone occurs during the mid cycle (about 14^th day) which is called LH surge and induces ovulation.

Human Ovum
a - Vitelline membrane
b - Nucleus
c - Zona Pellucida
d - Corona radiata

Relaxin  
(i) It is a hormone secreted by the placenta and also by the corpus luteum during pregnancy.
(ii) It promotes parturition by relaxing the pelvic joints and by dilation of cervical ligaments with continued powerful contractions.
Oxytocin:
(i) It causes the "Let-Down" reflex.
(ii) The actual ejection of milk from the alveoli of the mammary glands.
(iii) During lactation, oxytocin also stimulates the recently emptied uterus to contract, helping it to return to pre-pregnancy size..

Colostrum is the yellowish fluid produced from the mother's mammary glands during initial few days of location, after parturition.
Significance:
1. It has less lactose than milk and almost no fat, but it contains more proteins, vitamin A and minerals.
2. Colostrum is also rich in IgA antibodies.
3. This helps to protect the infant's digestive tract against bacterial infection.
4. Breast milk is the ideal food for infants as it contains all the constituents in suitable concentration and is easily digestable.
5. It is fully sufficient till about 6 months of age and all infants must be breast fed by the mother to ensure the growth of a healthy baby.