Birth (parturition) (8) Flashcards
What is birth?
Birth is the expulsion of the foetus, its surrounding membranes and the placenta from the uterus.
Approximately ___ months after fertilisation the baby is ready to be born
nine
What is known, however, is that at the end of the gestation period the ____ is less efficient. For this reason alone birth must take place.
placenta
What is distinctive about birth in humans? (2)
• The human baby is born at a relatively immature and very helpless stage. If the human foetus grew any larger it would not be able to leave the body successfully for the following reasons. − In the process of becoming upright and bipedal, the pelvis had to be narrower in humans, which also made the birth canal narrower than any other primate or mammal.
− The brain, even in the foetal stage, is much larger than that in other primates. If it enlarged any more the head would not be able to pass through the birth canal. • The baby is usually born headfirst; the head circumference of the baby at (or before birth) is the largest diameter of its body.
How does birth occur?
Two or three weeks before birth the foetus moves into position for birth. For a normal birth to take place, the foetus must lie with its head pointing downward towards the cervix. Just before the baby is born, the very high levels of oestrogen in the mother’s blood cause the hypophysis to release a hormone called oxytocin. This hormone promotes contraction of the uterine wall. The entire birth process may take from a few hours to well over a day.
What are the three stages of birth?
- Dilation of the cervix
- Delivery of the baby
- Expulsion of the placenta
What happens during the dilation of the cervix?
During this stage the myometrium starts contracting. Contractions are at first slow and rhythmic but later become intense and more frequent.
The uterine muscle contractions: (2)
- force the amnion and foetus towards the cervix.
* cause the cervix of the uterus to dilate.
How does the female’s water break?
About the time that the cervix becomes fully dilated (about ten centimetres) the increased pressure causes the amnion to break and release amniotic fluid, which passes out through the birth canal (vagina). This is commonly called ‘breaking of the waters’.
How is the baby delivered?
After the cervix is fully dilated the baby is pushed out through the vagina, usually head first, by the very powerful contractions of both the uterine and abdominal muscles. Immediately after birth the umbilical cord is tied and cut. The part of the umbilical cord still connected to the baby shrivels up and becomes its navel or belly button.
What is the final stage of child birth?
The expulsion of the placenta: The final stage happens about ten to twenty minutes after delivery when the placenta with the remaining bit of the umbilical cord comes away from the uterine wall. Uterine contractions will force it out as the afterbirth. This stage of labour is short, seldom lasting longer than 15 minutes.
What are the different birth options? (2)
- Vaginal childbirth – natural (drug-free) or with pain medication
- Cesarean section - if a normal birth puts the life of the mother or her baby at risk or if there are complications (e.g. awkwardly positioned baby) a woman may have her baby delivered by Caesarean section (C-section). This involves cutting open the abdomen and uterus of a woman, removing the baby from the uterus and stitching up the cut.
What are mammary glands?
Mammary glands are organs in female mammals that produce milk to feed young offspring. In humans, the mammary glands are situated in the breasts and are made up of milk-secreting cells.
What is lactation?
Milk production is called lactation.
During pregnancy ____ and ____ stimulate the growth and development of the milk glands and milk ducts in the breasts.
oestrogen
progesterone
