Human Reproduction

Sexual Reproduction in Human testis ovary sperms eggs (ova) fertilization zygote Blastocyst embryo fetus baby

External Male Reproductive Organs Penis Testes Scrotum

The Penis Tube-shaped organ that extends from trunk of the body just above the testes Part of the body where semen is released (ejaculation) Semen- thick fluid containing sperm and other secretions from the male reproductive system

Male Reproductive System Scrotum – sac of skin that holds testes. Hangs below body to keep testes cool. Sperm cannot be produced if body is too warm. Testes move into scrotum just before birth. Testis/testes –Made up of small, coiled tubes seminiferous tubules. 300-600 per testis. Immature sperm made here. Secrete testosterone

Testis and epididymis epididymis vas deferens (sperm duct) sperm tubules

Internal Male Reproductive Organs Epididymis Vas Deferens Seminal Vesicles Prostate Gland Cowpers Gland Urethra

Epididymis For temporarily storage of sperms Where sperm Mature During intercourse, muscles of epididymis contract to release sperms

Internal Organs Vas deferens – tubes that extend from each epididymis to the urethra Cowper’s gland, Prostate Gland, & Seminal vesicles –secretions from these glands combine with sperm-containing fluid to form semen

Male Reproductive System seminal vesicle secrete seminal fluid prostate gland Cowper’s gland

Functions of Seminal Fluid To provide a medium for the sperms to swim To activate and nourish the sperms To neutralize the acidity in the female reproductive tract Seminal Fluid Semen Sperms +

Male Reproductive System 8. Urinary bladder – stores urine 9. Rectum- holds waste 10. Urethra – passageway for excretion of urine and sperm to leave body. Vas deferens empties into urethra

Male Concerns Hernia- Part of body pushes through the muscle wall Sterility- Sperm weak, may not be able to fertilize egg Prostate Cancer- Uncontrolled growth of cells (radiation therapy/removal of prostate) Testicular Cancer- Frequent in males 15-35 (self-check)

Hernia

Preventing Problems Prevent STI’s Prevent trauma (athletic cups) Prevent hernias (don’t lift things that are too heavy)

Male Reproductive System Urinary Bladder Seminal Vesicles Prostate Gland Urethra Penis Rectum Epididymis Cowper’s gland Testes Vas Deferens Scrotum

Functions of Ovary Produce female gametes (ova/eggs) For production of female sex hormones Estrogen and Progesterone

Ovary A female’s ovaries contain 400,000 immature eggs at birth. (all the eggs they will ever have) Once a month during puberty, a mature egg is released into the fallopian tubes. This process is called ovulation.

Fallopian Tubes Carries the ovum (egg) forward by the beating action of the cilia on its inner surface the contraction of muscles of fallopian tube

Female Reproductive System Fallopian tube – Each ovary is near but not connected to oviduct. Tube with funnel-like opening. Cilia line it to create a current that draws the egg into the tube. Egg is fertilized in the fallopian tube 3. Uterus – thick, muscular, pear-shaped organ. Once egg is fertilized it finishes its development in uterus attached to uterine wall

Female Reproductive System Urinary bladder – storage of urine Urethra – passage of urine to outside of body Vagina (birth canal) – leads to outside of body from the uterus Cervix – narrow neck of uterus Rectum – passage for wastes

Ovulation The release of an ovum (egg) from an ovary Every month, the fallopian tubes take turns releasing an egg. Right one month, left the next month

Female Reproductive System Fallopian tube ovary uterus cervix vagina

Menstrual Cycle Menstruation occurs once a month, due to the uterus preparing itself for possible pregnancy. If pregnancy doesn’t occur, the uterine lining breaks down into blood, tissue, and fluids and is released through the vagina.

Female Concerns Infertility- Inability for female to become pregnant Problems that can cause infertility STD’S--PID Infection of the Fallopian Tubes Blocked Fallopian Tubes- PID, Abdominal Surgery, Leading Cause Of Infertility Endometriosis- Uterine tissue grows outside the uterus, often appearing on the ovaries, fallopian tubes and abdominal cavity

Other Female Reproductive Disorders Vaginitis: Most common Vaginal infection in women of child bearing age. Caused by bacteria, accompanied by discharges, pain, itching… Ovarian Cysts: Fluid filled sacs on the ovaries. Small and non-cancerous, usually they will disappear on their own. Larger cysts may require surgery

Problems related to menstruation: Concerns Problems related to menstruation: Menstrual cramps- Cramps in abdominal occur during menstrual period Dysmenorrhea- Painful contractions lasting 1-2 days Amenorrhea- Lack of menstruation by age of 16 or stopping of cycle for 3 or more months (PMS) Premenstrual Syndrome- Symptoms are: nervous tension, anxiety, irritability, bloating, wt gain, depression, mood swings (TSS) Toxic Shock Syndrome- Caused by using tampons during period ~Bacteria produce a toxic poison that affects liver and the immune system Symptoms: vomiting, dizziness, rash, kidney and liver damage, diarrhea

Pap Smear- Test to detect for abnormal cells in cervix Trichomoniasis- A vaginal infection that can lead to urethra and bladder infections Vaginitis- Most common vaginal infection in women of childbearing age Symptoms: Discharge, odor, itching, pain Ovarian Cysts- Fluid-filled sacs on the ovary. Small non-cancerous, usually disappear on their own. Larger cysts may need surgery

Self Exam should be performed once per month Concerns continued… Yeast Infection- Fungus, thick white cheesy discharge, foul odor, and severe itching Sterility- Untreated STD, blockage of tubes, fertilization can not occur Breast Cancer- Change in breast or nipple, lump or swelling in breast or armpit Self Exam should be performed once per month Mammogram- X-ray of the breast to locate any mass or tumor. Cervical Cancer- Causes can include many sexual partners, early sexual activity, effects women between 20-30

Mammogram

Mammogram of breast

Preventing Problems Prevent STD’s Prevent vaginal irritation Bathe regularly Exercise regularly

Events Happened after Fertilization Egg is fertilized in fallopian tubes Fertilized ovum is carried to the uterus by the beating cilia on the inner wall of oviduct the contraction of muscles of fallopian tube After reaching the uterus, the fertilized ovum fixed firmly onto the thick uterine wall----Implantation

Development of Human Foetus uterus foetus placenta umbilical cord amnion amniotic fluid Video on foetus development Click here

Functions of the Uterus During embryo development Protect the embryo Provide a constant environment for the embryo to develop Allow placenta to attach on During birth of baby Push the baby out by muscular contraction Click here

Functions of the Amniotic Fluid To keep the foetus moist to prevent dessication As a water cushion to support the foetus allow it to move freely absorb shock protect the foetus from mechanical injuries To reduce temperature fluctuation To lubricate the vagina during birth Click here

The Placenta oxygenated blood from mother’s artery deoxygenated blood to mother’s vein villus umbilical vein umbilical artery

Functions of the Placenta As a place of exchange of materials between mother and the foetus For secreting hormones

Adaptations of the Placenta Finger-like villi to increase the surface area for efficient diffusion Maternal blood and foetal blood flows in opposite direction to speed up diffusion of materials between them Maternal blood capillaries and foetal blood capillaries are separated by thin membrane to shorten the distance of diffusion of materials

Adaptations of the Placenta Maternal blood is separated from foetal blood by capillary wall to prevent high pressure of maternal blood to break the delicate foetal blood vessels to prevent harmful substances to enter the foetus to prevent clotting of maternal and foetal blood if their blood groups are incompatible Click here

The Birth Process Onset of labour Uterine muscles begin to make rhythmic contractions Contractions gradually become stronger and closer

The Birth Process Further contractions push the placenta out of the body “After birth” Muscular contractions push the foetus head first through the vagina, and the umbilical cord is cut and tied Uterine contractions causes amnion to break and amniotic fluid to escape out of the vagina Dilation of cervix allow the head of the foetus to pass through

Could you survive after birth without the care of your parents?

Parental Care To increase the chance of survival of the young Mother feeds milk to the baby Milk provides the babies with a balanced diet It also contains antibodies which defend the babies against infection

Birth Control Human population increases exponentially leads to storage of resources problem of pollution becomes more serious overcrowding

Using contraception methods What can we do?

Rhythm Method Prevent copulation during 7 days before and after ovulation (fertile period)

Condom Male and female condom As a barrier to prevent sperms from entering the vagina

Diaphragm Fitted over the cervix To be used together with spermicides

Contraceptive Pills Contains hormones which inhibit ovulation Must be taken regularly May have side effect

Surgical Methods Tubal ligation Vasectomy Cutting and tying of oviducts Vasectomy Cutting and tying of sperm ducts