Download
1 / 50
500 likes | 508 Vues
Reproduction. Puberty. A time in life when humans become capable of reproduction. Egg cells mature in girls and sperm are produced in boys. The social and emotional maturity necessary for parenting is reached later than physical maturity. Sex.
E N D
Puberty • A time in life when humans become capable of reproduction. Egg cells mature in girls and sperm are produced in boys. The social and emotional maturity necessary for parenting is reached later than physical maturity
Sex • Term used to refer to male or female gender or to the physical part of a relationship
Sexuality • Refers to all aspects of a person’s maleness or femaleness, including thoughts, experiences, roles, feelings and fantasies
Phsyical changes at Puberty • Similar changes in boys and girls • Pituitary gland in brain stimulates pubertal changes • Growth of hair under arms, on legs and in groin • Growth spurt – height and weight • Girls 9-16 (average 10-13) • Boys 10-18 (average 11-14)
Increased gland secretions of oil and sweat… which often results in acne and/or body odor… SOOOOO........
Size of sexual organs varies greatly and usually does not affect sexual or reproductive function
EXTERNAL PARTS • Penis – the male reproductive and urinary organ • Organ size increases and decreases due to blood flow • Size of penis varies • Some penises are circumcised at birth to remove foreskin
Scrotum – contains the testicles • The scrotum keeps the sperm at proper temperature (about 92.6, six degrees below body temperature Changes in size and shape with warmth or cold
INTERNAL PARTS • Testicles – produce sperm and testosterone (male hormone) • Vas Deferens – tubes through which sperm passes out of testicles • Urethra – tube through which semen passes out of the penis and through which urine passes out of the bladder. Urine and semen never flow through the urethra at the same time
Sperm – mixes with milky fluid called semen from the seminal vesicle • Production of sperm and semen is continuous • Sperm is carried into female body by insertion of the penis through the vagina • Sperm matures and can produce pregnancy, beginning at age 12-15 • Each ejaculation contains about one teaspoon of liquid and millions of sperm
EXTERNAL PARTS • Breasts- produce milk for young • Labia- folds of skin that cover the clitoris, urethra and entrance to vagina • Clitoris- small pea-sized organ that is full of sensitive nerve endings • Urethra- opening through which urine passes out of the body • Vulva- term for the outer genital area that includes the labia, clitoris and vaginal opening
INTERNAL PARTS VAGINA Passage from the outside of the body to the uterus Entrance to the vagina is between the legs in front of the anus The entrance is for the penis during intercourse, for sperm into uterus, for birth of baby, and passage for menstrual flow
Uterus – small, muscular, pear shaped organ located in the lower abdomen. The fetus grows in the uterus until it is ready to be born
Ovaries- two organs located in the abdomen that produce eggs and sex hormones – estrogen and proestrogen • Fallopian tubes- tubes through which eggs pass from ovaries to uterus: site of Fertilization • Cervix- narrow end of uterus, opens into the vagina and stretches to allow the baby to be born
the development of a fertilized ovum outside the uterus, as in a Fallopian tube ECTOPIC PREGNANCY
The human body is made up of 46 chromosomes The sperm and the egg each contribute 23 chromosomes Fertilization and Genetic Mix
The mother’s 23 chromosomes pair up with the father’s 23 chromosomes, side by side • The become intertwined tightly and then “unzip” so the each new chromosome contains some genes from the father and some from the mother.
The sperm contains either an X or Y chromosome • The mother’s ova contains only an X chromosome • When the father’s sperm contributes an X chromosome the result is a girl: XX • When the sperm contributes a Y chromosome the result is a boy: XY
The ratio of boys born to girls is 103-107 boys for every 100 girls • After the first year of infancy, approximately the same number of boys are alive as girls, because infant males tend to have a higher death rate than infant females • Because genetics are mixed children do not resemble parents identically
Fertilization of two different eggs by two different sperm. The resulting zygotes contain different genetic combinations. Can be a boy and a girl, a boy and a boy, or a girl and a girl Fraternal twins occur more often than identical twins – 2/3 are fraternal FRATERNAL TWINS
pair of twins who developed from a single fertilized ovum and therefore have the exact same genetics and are always of the same sex The fertilized ovum, the zygote, splits Identical twins
Triplets and larger number of babies may be identical or fraternal, depending on number of eggs fertilized The more fetuses there are, the smaller they usually are at birth Larger Multiple Births
Development of Baby • Day 1: Sperm joins with ovum (egg) to form one cell – smaller than a grain of salt. The new life has inherited 23 chromosomes from each parent, 46 in all. This one cell contains the complex genetic blueprint for every detail of human development – the child’s sex, hair and eye color, height, skin tone.
Days 3-4: The fertilized egg ("zygote") travels down the fallopian tube into the uterus, where the lining has been prepared for implantation.
Days 5-9: The zygote implants itself in the rich lining of the uterus and begins to draw nourishment.
Days 10-14: The developing embryo signals its presence in the mother's body through chemicals and hormones, preventing the mother from menstruating.
DAY 28: Foundations of the brain, spinal cord, and nervous system are already established.The backbone and muscles are forming. Arms, legs, eyes, and ears have begun to grow. Three Weeks - A Beating Heart!
Day 30: At one month old, the embryo is 10,000 times larger than the original fertilized egg – and developing rapidly. The heart is pumping increasing quantities of blood through the circulatory system. The placenta forms a unique barrier that keeps the mother’s blood separate while allowing food and oxygen to pass through to the embryo.
Now the four primitive limb buds appear, first the arms, then the legs. Five fingers can be discerned in the hand. At this stage toxic substances such as Thalomide may alter or hinder limb development despite the highly-protective placenta. The head, disproportionately large at this time, is flexed on the rest of the body, about a quarter inch over all. The eyes darken as pigment is produced. The umbilical cord joins the embryo to the placenta and to the yolk sac, which manufactures blood cells during the first weeks of the embryo’s life. Five Weeks - Tiny Fingers Form
Brain waves can be detected and recorded with an electroencephalogram. The liver is now taking over the production of blood cells, and the brain begins to control movement of muscles and organs. The mother is about to miss her second period and has probably confirmed that she is pregnant. Six Weeks - Brain Waves
At a little more than an inch long, the developing life is now a fetus – Latin for “young one”. Everything is now present that will be found in a fully developed adult. The heart has been beating for more than a month, the stomach produces digestive juices, and the kidneys have begun to function. Forty muscle sets begin to operate in conjunction with the nervous system. The baby’s body responds to touch, although the mother will not be able to feel movement until the fourth or fifth month. Fingerprints are already evident in the skin. The baby will curve his fingers around an object placed in the palm of his hand. 8-9 Weeks - Fully Formed
12-13 Weeks - Baby Can Smile • The baby now sleeps, awakens, and exercises its muscles energetically - turning his head, curling his toes, and opening and closing his mouth. The palm, when stroked, will make a fist. The baby is breathing amniotic fluid to help develop his respiratory system. • Fine hair has begun to grown on the head and sexual differentiation has become apparent.
By the end of this month, the baby is eight to ten inches long and weighs half a pound or more. The mother will probably start to “show” now. The ears are functioning and there is evidence that the baby hears quite a bit: the mother’s voice and heartbeat as well as external noises. Month 4 - Baby Hears Mother's Voice
Half the pregnancy has now passed, and the baby is about 12 inches long. The mother has definitely begun to feel movement by now. If a sound is especially startling, the baby may jump in reaction. Babies are routinely saved when born prematurely at 21 to 22 weeks after fertilization, and in some cases, even younger – babies have lived when born at 19 weeks! Month 5 - Half Way Home!
6th Month:Oil and sweat glands are functioning. The delicate skin of the growing baby is protected from the fetal waters by a special ointment called “vermix”. If the baby were born at this month and given proper care, he would survive. • 7th Month: The baby now uses the four senses of vision, hearing, taste, and touch. She can recognize her mother’s voice. • 8th Month: The skin begins to thicken with a layer of fat stored underneath for insulation and nourishment. Antibodies increasingly build up. The baby absorbs a gallon of amniotic fluid per day; the fluid is completely replaced every three hours. • 9th Month: Toward the end of this month the baby is ready for birth.The average duration of pregnancy is 280 days from the first day of the mother’s last menstrual period, but that varies. Most babies (85-95%) are born somewhere between 266 and 294 days. By this time the infant normally weighs six to nine pounds, and his heart is pumping 300 gallons of blood per day. He is fully capable of life outside the womb.
A cesarean section is also known as a c-section, which is sometimes also written as c/s. This type of birth is done by a surgical incision in the abdomen and uterus to allow a baby or babies to be born safely when a vaginal birth is not the safest route. The current cesarean rate in the United States is over 30% cesarean birth
