HUMAN REPRODUCTION

REPRODUCTIVE SYSTEM OF HUMAN MALE SCROTUM TESTES EPIDIDYMIS VAS DEFERENS COWPER’S GLAND RECTUM SEMINAL VESICLES URINARY BLADDER PROSTATE GLAND URETHRA PENIS 8. 7. 9. 6. 10. 5. 3. 11. 4. 2. 1.

REPRODUCTIVE SYSTEM OF HUMAN FEMALE OVARY OVIDUCT (FALLOPIAN TUBE) UTERUS URINARY BLADDER URETHRA VAGINA CERVIX RECTUM 1. 2. 1. 4. 3. 5. 8. 6. 7.

MALE REPRODUCTIVE SYSTEM TESTES Produces sperm cells Secretes testosterone Secondary male sex characteristics Body hair Muscle development Deep voice SCROTUM Sac that holds testes Muscles control temperature Muscles contract – pull the testes up (cold temp) Muscles relax – drops the testes down (warm temp) 1. (3) 2.

MALE REPRODUCTIVE SYSTEM SEMINIFEROUS TUBULES Inside the testes Produces sperm EPIDIDYMIS Sperm stored here VAS DEFERENS Sperm travels through here to the urethra SEMINAL VESICLES (nourishment) COWPER’S GLAND (lubricant) PROSTATE GLAND (alkaline) These glands secrete fluids into the vas deferens that make up the fluid called semen URETHRA bladder 8. 6. 5. 7. 9. 4. 1. (3) 2.

FEMALE REPRODUCTIVE SYSTEM OVARY Produces the egg Secretes estrogen Secondary sex characteristics Develop breasts Broaden pelvis Distribute body fat Follicles – contain immature eggs (200,000) only 500 eggs mature in a lifetime Ovulation – when one follicle breaks out to the ovary 1.

FEMALE REPRODUCTIVE SYSTEM OVIDUCT (FALLOPIAN TUBE) Cilia create a current and draws the egg down the tube Usually fertilization occurs here UTERUS Thick walled muscular organ Where the embryo develops CERVIX Narrow neck of the uterus VAGINA (birth canal) URETHRA 1. 2. 3. bladder 4. 6. 5.

MALE REPRODUCTIVE SYSTEM vas deferens bladder seminal vesicle prostate gland Cowper’s gland urethra penis epididymis testes

FEMALE REPRODUCTIVE SYSTEM oviduct uterus cervix follicles ovary vagina uterus (endometrium)

THE MENSTRUAL CYCLE CHARACTERISTICS Involves interaction of hormones from the hypothalamus, pituitary gland, and ovary Cycle lasts about 28 days Females begin at puberty (ages 10-14) and ends at menopause (ages 45-50) Cycle stops during pregnancy

Stages of the Menstrual Cycle Follicle stage (10 – 14 days) Pituitary secretes FSH (follicle stimulating hormone) Follicle secretes estrogen which causes thickening of the uterine lining Ovulation High levels of estrogen causes ↓ FSH and starts the secretion of LH (luteinizing hormone) Egg breaks out of the follicle Corpus luteum stage LH causes corpus luteum to form around the egg (yellow body of cells) Corpus luteum secretes progesterone which stops the development of new eggs Menstruation If no fertilization takes place - ↓ LH and ↓ progesterone Lining of the uterus and blood pass out through the vagina

THE MENSTRUAL CYCLE

FERTILIZATION Fusion of sperm and egg nuclei In vitro fertilization – 2 days after fertilization in a glass dish – zygote then implanted in the uterus

Reproductive Technology In vitro fertilization (IVF): This is one of the most commonly used procedures. Eggs are combined with sperm in a dish in a laboratory. Once fertilization has occurred, the resulting embryos develop for 3 to 5 days before being placed in the uterus.

Implantation and Development Cleavage – develops into blastula while in the oviduct 5-19 days later – embryo in the uterus Implantation – embryo fastens itself onto the wall of the uterus Ectopic pregnancy – embryo implants itself into the oviduct or abdominal wall After 8-10 weeks it is called a fetus

EXTRAEMBRYONIC MEMBRANES CHORION Outer most membrane PLACENTA Forms between chorion and wall of the uterus Allows exchange of nutrients and wastes between mom and baby BLOOD DOES NOT MIX!! BUT NOT A COMPLETE BARRIER!! Allows diffusion of some viruses (German measles), alcohol, nicotine, drugs UMBILICAL CORD Formed from the yolk sac and allantois Connects fetus to the placenta AMNION Inner most membrane Filled with amniotic fluid Shock absorber 1. 2. 3. 4.

BIRTH Gestation period – length of the pregnancy Rhythmic contractions – contractions of the uterus called labor Cervix dilates (opens) Mom pushes baby out the birth canal Placenta and amnion are expelled after the baby is born (after birth)

BIRTH Premature birth – birth before full term Cesarean section – surgically removing the baby Identical twins – same genetic material – come from the same egg Fraternal twins – 2 different eggs fertilized by 2 different sperm

Testing during pregnancy What is ultrasound? A prenatal ultrasound test uses high-frequency sound waves, inaudible to the human ear, that are transmitted through the abdomen via a device called a transducer to look at the inside of the abdomen. With prenatal ultrasound, the echoes are recorded and transformed into video or photographic images of your baby. The ultrasound can be used during pregnancy to show images of the baby, amniotic sac, placenta, and ovaries. Major anatomical abnormalities or birth defects can show up on an ultrasound.

Ultrasound images

Testing during pregnancy What is an amniocentesis? An amniocentesis is a procedure used to obtain a small sample of the amniotic fluid that surrounds the fetus to diagnose chromosomal disorders and open neural tube defects such as spina bifida.