Presentation on theme: "Growth and development From the time of conception (the implantation of the fertilised egg) it takes about 9 months or 40 weeks, to become a fully formed."— Presentation transcript:
Growth and development From the time of conception (the implantation of the fertilised egg) it takes about 9 months or 40 weeks, to become a fully formed baby. This progress involves: a) Growth: the repeated division of the zygote to provide the many cells that make up the baby b) Development: the organisation of the cells into tissues and organs
Pregnancy is the period of time between fertilisation and birth, which in humans is 9 month. This period of time is called the gestation period The developing fetus needs a stable environment which is provided by the placenta
The placenta After implantation, part of the embryo grows into finger-like projections or villi that penetrate the lining of the uterus. They are surrounded by blood vessels which supply nutrients and oxygen that will continue to grow to form the placenta.
The placenta The villi give the placenta a very large surface area for diffusion. In the placenta, the blood of the fetus flows close to the blood of the mother and do not mix: a) the mother’s blood flows under high pressure that could harm the delicate blood vessels of the fetus if they did mix b) if the mother has different blood groups with the fetus it can cause blood clot of the fetal blood if the mother’s blood flowed into it’s blood vessels.
The placenta The fetus is attached to the placenta by the umbilical cord as shown below. It is surrounded by the amniotic sac which is filled with amniotic fluid; this protects the fetus from knocks and bumps.
The placenta continues to grow during fetus developing. After the baby has been born the placenta, amniotic sac and umbilical cord are expelled from the uterus as the afterbirth.
The role of placenta This disc-shaped organ has a number of functions: 1. Exchange of soluble materials such as foods, wastes and oxygen between mother and fetus 2. Protection: a) of fetus from mother’s immune system b) Againts dangerous fluctuations in mother’s blood pressure 3. Secretion of hormones which maintain the lining of the uterus
The role of placenta Umbilical cord: contains blood vessels which carry materials for exchange between mother and fetus. The cord connects the fetus to placenta Amnion: the membrane that encloses the amniotic fluid. This is ruptured just before birth. Amniotic fluid: protect the fetus against: a) Mechanical shock b) Drying out c) Temperature fluctuations.
The placenta protects and nourishes the developing fetus
Ante-natal care and birth Care before birth is vital for the health of the fetus while it is in the womb. The mother needs to have a balanced diet so the fetus obtains all the nutrients it needs for fetus growth and development
Nutritions A pregnant woman need to ensure that she gets adequate quantities of: 1. Calcium : for the bones of the fetus 2. Iron :both mom and fetus need extra iron to make more haemoglobin, the substance in red blood cells that carries oxygen 3. Carbohydrate :give energy to move around the heavier body of the mother 4. Protein: provide amino acid to make new tissues for both fetus and mom (the mother make muscle tissue in the uterus while the fetus is also grow and develop)
Birth A few weeks before birth the fetus will turn over inside the uterus. This position its head above the cervix an oxytocyn hormone that released from pituitary gland of the mother will stimulate the uterus muscles to contract
Birth The mother starts to feel small contraction of the uterus wall. This is the beginning of labour The contraction becomes stronger and more frequent that slowly strech the opening of the cervix and the amnion breaks, allowing the amniotic fluid to escape.
Birth The muscles of the uterus wall now contract very strongly and start to push the baby toward the cervix. The cervix widens and push the baby’s head through the vagina As soon a it is born the baby breathes for the first time The umbilical cord is tied and cut above the point where it attaches to the baby.
Birth After a few minutes the placenta comes away from the uterus wall. It is pushed out of the vagina as the afterbirth.
Breastfeeding During pregnancy, the gland in the mother’s breasts will enlarge to produce milk. Breastmilk contains antiodies as a passive immunity to the diseases that the mother has had recently The antibodies remain in the child’s blood while it is breastfed and for a short time afterwards. Breastfeeding also enables a close bond between mom and the baby
Breastfeeding Children who are breastfed are less likely to develop certain diseases such as childhood cancers and diabetes Mothers are less likely to develop cancers of breast, womb and ovaries Unlike breast milk that does not cost money and always in sterile condition, formula milk (powdered milik) is quite expensive and needs to be mixed with water in sterile condition.
NoBreastfeedingBottle-feeding (formula mik) 1.Create a close bond between mother and baby No close bond 2.Costs less or no moneyCosts money or expensive 3.Provide antibodies as passive immunity No passive immunity 4.Need private placeConvenient in every place even in public place 5.Ready to serveNeeds to be mixed with sterile water and placed in sterile bottle