The female reproductive systemPresentation Transcript
The Female reproductive system By Natasha Braswell Bio 120
The organ in which the developing fetus resides in is called the uterus. The uterus is a hollow, pear shaped, organ which contain a thick muscular wall, it has a mucous membrane lining, and a rich blood supply. It lies in the middle of the pelvic cavity, it is about 7.5cm in length, 2.5 cm in thickness and weighs 30 to 40 grams.
Each month the inner lining of the uterus called the endometrium prepares itself to receive a fertilized ovum or egg. In a normal pregnancy the ovum is implanted in the lining where it can receive nourishments and protection to develop into a baby. If the ovum is not fertilized and pregnancy does not occur, then the lining of the uterus sheds resulting in menstruation.
The time required for the development of a fetus is called gestation. During the first trimester(week 1-12) the structure that will be the neck and face starts to develop. The heart, blood vessels, stomach and liver are starting to develop. The fetus measures about 2 inches, and start to move around.
During the second trimester (week 13-27) the fetus measures 4.3 to 4.6 inches and weighs about 3.5 ounces. The heart and blood vessels are fully formed. During the 20 week the doctors usually wants to do an ultra sound to see if the baby is growing properly and checking the baby’s heartbeat. The baby’s sex can be determined also.
The third trimester (week 28-42) the baby has fewer wrinkles as layers of fat starts to form under the skin. The baby goes through a growth spurt, the heart and brain is fully developed and the lungs are almost developed. The baby would have a good chance of survival if it was born prematurely.
The three stages of labor and delivery are the dilationstage, the expulsion stage, and the placental stage.
Dilation stage The first stage can last up to 20 hours. It begins when the cervix starts to open or dilate. At this point you uterus muscles contracts strongly to push the fetus out of the womb. When the cervix is completely dilated at 10 cm we enter into the next phase.
Expulsion stage At this point the baby passes through the birth canal, vagina and is born. Usually the baby comes out heard first which is called crowning. Once delivered the baby’s mouth and nose is suctioned to prevent amniotic fluid, mucus and blood from entering the baby’s lungs, shortly after the umbilicial cord is cut.
Placental stage The last stage begins after the birth of the baby, when the placenta or afterbirth separates from the wall of the uterus. It lasts a few minutes and it feel like contractions but not as painful.