Anatomy of Sex

It is always a good idea to know a little about the machine that you wish to use. There are two main components of sexual system. One is the brain and second is the external and internal genitalia.

Brain

Brain is the central processing unit. It receives signal from vision, hearing, touch etc and also internal signals from stored memory of past. It perceives pleasure and coordinated sexual hormones, nerves, muscles and blood circulation to create sexual response. The sexual thoughts, desires and fantasies are coming from cerebral cortex, the outer layer of brain. The sexual emotions and feelings come from limbic system of the brain. Pituitary gland in brain under the control of hypothalamus releases sexual hormones which are oxytocin, prolactin, follicle stimulating hormone FSH and luteinizing hormone LH. Of these FSH is said to be responsible for relationship bonding. It is released during sexual intercourse at the time of orgasm there called ‘Hormone of Love’. These hormones are also responsible for pregnancy and lactation.

Female anatomy of sex

External anatomy

The soft area over pubic bone located between umbilicus and vagina is monsveneris also called mount of venus. It is sensitive as it has many nerve endings. The entrance starts with labia majora, the outer lips followed by labia minora the inner lips. Labia majora are elongated folds of skin covered with hair. Labia minora meet and form clitoral hood which has clitoris with very high number of nerve endings, it is the seat of pleasure and orgasm. Labia minora contains rich supply of blood vessels and nerves. It covers the vaginal and urethral opening. Lower portion of labia minora contains bartholin’s gland which secrete alkaline fluid. This is essential as sperms can not survive acidic environment.

The vaginal opening is surrounded by bulbocavernosus muscle and vestibular bulb. These help vaginal grip on penis during intercourse. It is flexible to accommodate penis of all size. Inside vaginal opening there is hymen, a thin membrane that partially covers the vaginal opening. It is seen as a sign of virginity although in addition to intercourse it can get broken by other reasons like physical activity.

Breasts are also considered as part of external sexual organs. They contain mammary glands and fatty tissue. Their basic purpose is to prepare and provide milk to infant. Nipples are pink to brown colored and are very sensitive. Breasts too play a role in sexual stimulation.

Internal anatomy

The female internal organs are vagina, uterus, fallopian tubes and ovaries. The vagina is canal like structure from vulva outside to cervix inside. During intercourse penis ejaculates sperm in vagina. The vagina has capacity to expand as it does during intercourse and also during childbirth. Front wall of vagina contains a spot called G Spot which is said to be sensitive and take part in sexual stimulation.

Between vagina and lower end of uterus is the cervix. Uterus is a muscular organ where fetus grows. Uterus occupies the pelvic cavity below abdomen. The fertilized egg is implanted on inner layer of uterus called endometrium which comes out as menstrual cycle every month when there is no fertilization. Fallopian tubes starts from side upper end of uterus both sides and extend sideways towards ovaries. Fallopian tubes pick eggs from ovaries. In these the eggs travel and get fertilized. Ovaries are female gonads and produce egg and female hormones estrogen and progesterone. In ovaries eggs grow inside a capsule called follicle. Every month one or more eggs get mature and egg is released. A female releases about 400 eggs during lifetime.

Male anatomy of sex

External anatomy

The external genitalia contain penis, scrotum and testes. Penis is cylindrical organs and helps in sexual intercourse and also as passage of sperms and urine. In non erect state it is about 3 to 3.75 inch in length and 1 to 1.2 inch in diameter. In erect state it is 4 to 6 inch in length and about 1.5 inch in diameter. The top portion of penis is glans which is covered by foreskin. In some cultures, this foreskin is removed in a process called circumcision. The main body of penis is shaft which has three cylinder shaped bodies of spongy tissue with many tiny blood vessels. These bodies get filled with blood to create erection in penis. Urethra, a tube like structure runs through penis to open outside at meatus as outlet of urine and sperms. The lower end of penis is root that gets attached to pubic bones. Underneath the penis there is a sac like structure called scrotum. It holds testes.

Internal anatomy

It contains testes, prostate gland, cowper’s gland and the duct system.

Testes are male gonads responsible for production of sperm cells and sex hormones, androgens like testosterone. Everyday millions of sperm cells are produced. These are carried in duct system. The duct system from testes to penis consists of epididymis near testes leading to vas deferens which extends into ejaculatory duct passing through prostate gland. Semen is produced in prostate. The ejaculatory duct finally merges into urethra towards penis.