Male and Female Reproductive Systems

Male Reproductive System It includes both internal and external organs Two main functions: Production and storage of sperm – The male reproductive cells And the transfer of sperm to the female’s body during sexual intercourse.

Male Reproductive System Early teen years (12-15 years old), the male reproductive reaches maturity. Testosterone – The male sex hormone Produced in the pituitary gland

Testosterone Initiates physical changes that signal maturity: Broadening of the shoulders Development of muscles Facial and body hair Deepening of the voice Controls the production of sperm

External Male Reproductive Organs Testes (singular, testis) Scrotum Penis

Testis Located in the scrotum Divided into tiny tubules in which sperm are formed Part of both the reproductive and endocrine system Produce male sex hormones (testosterone) Temperature regulation – Ideal right below body temperature Cremasteric muscle and reflex When this muscle contracts, the spermatic cord is shortened and the testicle is moved closer up toward the body, which provides slightly more warmth to maintain optimal testicular temperature. When cooling is required, the cremasteric muscle relaxes and the testicle is lowered away from the warm body and is able to cool. Located in the scrotum

Scrotum Skin and muscle containing the testicles It is an extension of the abdomen An external skin sac

Penis Tube-shaped organ that extends from the trunk of the body just above the testes. Composed of spongy tissue that contains many blood vessels. When blood flow to the penis increases, it becomes enlarged and erect. Also called an erection

Semen Released by the penis It is a thick fluid containing sperm and other secretions from the male reproductive system.

Internal Male Reproductive Organs Vas deferens Urethra Seminal vesicles Prostate gland Cowper’s gland

Vas Deferens Tubes that extend from each epididymis to the urethra During ejaculation smooth muscle walls contract Propel sperm to urethra Vasectomy

Urethra Passageway which both semen and urine leave the male body

Seminal Vesicle Provides nourishing fluid for sperm Fluid eventually creates semen Fluid is high in proteins, enzymes, fructose, mucus, vitamin C The high fructose concentrations provide nutrient energy for the spermatozoa

Prostate Gland To store and secrete a clear, slightly alkaline fluid that constitutes 10-30% of the volume of the seminal fluid Rest of the seminal fluid is produced by the two seminal vesicles The alkalinity of seminal fluid helps neutralize the acidity of the vaginal tract, prolonging the lifespan of sperm. Contain smooth muscles that help expel semen during ejaculation. A healthy human prostate is slightly larger than a walnut It surrounds the urethra just below the urinary bladder and can be felt during a rectal exam.

Cowper’s Glands Bulbourethral gland During sexual arousal each gland produces a clear secretion known as pre-ejaculate. Fluid helps to lubricate the urethra for spermatozoa to pass through Helps flush out any residual urine or foreign matter

Epididymis Where sperm mature and are stored They lack the ability to swim forward (motility) and to fertilize an egg

Female Reproductive System Produces female sex hormones Stores female reproductive cells Ova (singular, ovum)

Ovaries Female sex gland Produce female sex hormones Store ova (egg) 400,000 at birth 1 matures each month Ovulation – process of releasing a mature ovum into the fallopian tube each month The right ovary will release a mature ovum one month, and the left ovary will release one the next month.

Fallopian Tubes A pair of tubes with fingerlike projections that draw in the ovum Eggs travel from the ovaries to the uterus via the fallopian tubes Tiny hair-like structures called cilia line the tubes and move egg along Ectopic pregnancy

Vagina A muscular, elastic passageway that extends from the uterus to the outside of the body Sperm from the male enter the female reproductive system through here.

Fertilization If sperm are present in the fallopian tubes, a sperm cell may unite with an ovum. Fertilization of an egg by a sperm is called a zygote. When the zygote leaves the fallopian tube, it enters the uterus. Attaches itself to the uterine wall and begins to grow.

Uterus Hollow, muscular, pear-shaped organ Nourishes and protects the fertilized egg

Menstruation Each month the uterus prepares for possible pregnancy If pregnancy doesn’t occur, the thickened lining of the uterus, called the endometrium, isn’t needed, and it breaks down into blood, tissue, and fluids. These materials pass through the cervix and into the vagina.

Cervix Opening of the uterus The lower, narrow portion of the uterus where it joins with the top end of the vagina It’s a cylindrical shape During menstruation the cervix stretches open slightly to allow the endometrium to be shed During childbirth, contractions of the uterus will dilate the cervix up to 10 cm in diameter to allow the fetus to pass through.

Endometrium Tissue that lines the uterus Menstrual cycle Day 1-8: after seven days, if the egg is not fertilized, menstruation begins Day 9-23: A new egg is maturing inside the ovary Day 24: The mature egg is released into one of the fallopian tubes Day 25-28: The egg travels through the fallopian tube to the uterus.

Vulva labia majora labia minora clitoris vaginal orifice The region of the external genital organs of the female, including the: labia majora labia minora clitoris vaginal orifice