List the principles of development
- 1. Development requires change
- 2. Early development is essential for later development
- 3. The pattern of development is orderly & predictable
- - development proceeds from the head downwards (cephalocaudal law)
- -development proceeds from body's centre outward (proximodistal)
- -general to specific development
- -simple to complex
- 4. Development involves maturation & learning
- 5. Growth and development are continuous
- 6. Rates of development are unique
Explain what is meant by the term conception
- Conception is the beginning of human development.
- It is the moment when the sperm and ovum meet to combine genetic information.
Where is the best place for conception to occur?
High in the fallopian tubes
Describe what is meant by the term "ectopic pregnancy"
Implantation occurs inside the fallopian tubes and the baby develops there instead of the uterus
List the 3 stages of prenatal development and the associated time frame
- Germinal stage: conception - implantation (approx. end of 2nd week)
- Embryonic stage: implantation - end of week 10-12
- Foetal stage: end of week 10-12 - until birth
Give 3 examples of physical development that occur in the germinal stage:
- The process of cell division begins as the newly formed cell splits into identical cells.
- Differentiation occurs as the cells begin to distinguish between seperate functions and roles they will carry out
- Implantation of the blastocyst (ball of cells) in the endometrium of the uterus
Gve 3 examples of physical development that occur in the embryonic stage:
- The cells form three layers that will later become different organs and tissues depending on their location
- The heart appears, before it begins to function & divide into chambers
- Limb buds that will later form the arms and legs begin to sprout
Give 3 examples of physical development that occur in the foetal stage
- Furthur development of the organ systems (established in embryonic stage)
- The webbed appearence of the feet begins to disappear
- The baby continues to grow in length and gain weight steadily during this stage
Outline what is meant by the term "teratogen"
A substance or factor that can influece, or have an affect upon, the developing baby if the mother is exposed to it
Identify 3 teratogens that can impact in the growth and development of a foetus during pregancy
- Tobacco Smoking
How does tobacco smoking impact on the growth and development of a foetus?
- Smoking during pregnancy has a negative impact on the growth and development of a baby because:
- It reduces the oxygen supply and bloodflow to foetus - baby's cells can't grow - babies are smaller in size and weight
- It effects proper growth of organs and structures
- It effects healthy development of the umbilical cord and placenta
How does alcohol impact on the growth and development of a foetus?
- Alcohol consumption during pregnancy has a very negative impact because:
- It can cause Foetal Alcohol Syndrome (babies are smaller than average, have abnormal facial feautures, and sometimes at risk of dying)
- It effects the developing brain of the baby and can result in intellectual retardation
- It reduces the amount of oxygen available to the baby
Explain the role of the placenta during pregnancy
- The placenta is an organ that:
- provides nourishment to the baby
- removes waste
- is responsible for gas exchange through the bloodstream
- However it is not a complete barrier as substances such as alcohol and nicotine can pass through the placenta
How long does each trimester of pregancy last?
- Trimester 1: weeks 1-13
- Trimester 2: weeks 14-27
- Trimester 3: weeks 28-40
Identify the 3 stages of birth
Desribe what occurs during the stage of labour
- Dilation of cervix
- Waters burst
- Regular contractions to open cervix and retract lower uterus to form birth canal
- Labour ends when cervix is fully dilated
Describe what occurs during the stage of delivery
- Contractions force foetus into vagina
- Head/face should be facing spine
- Crowning when head comes out
- Head is rotated to allow one shoulder to come out and then the other
- Final push and delivery is complete
- Umbilical cord is clamped and cut
Describe what occurs during stage of after-birth
- Delivery of the placenta and membrane
- Placenta is examined to ensure it is all there
List the 5 adaptions of the neonate after birth
- Removal of waste
- Temperature control
Describe the adaption of circulation
- Before birth, the chamber that directs blood to the lungs is not needed and is bypassed via a hole in the atria. This is because the baby's lungs are full of fluid, and oxygen is supplied by the placenta.
- After birth, the umbilical cord is cut and this causes a change in blood pressure. When the lungs infalte, it causes the blood to be channeled to the lungs and the hole between the atria is forced shut. The flap of skin covering it eventually grows closed.
- Blood then follows the normal route.
Describe the adaption of digestion
- Prior to birth, the baby obtained nutrients via the placenta. The baby must now adapt to drinking and digesting milk.
- The first food supply to the baby is almost immediately after birth, and this fluid is called colustrum (high in protein, low in fat)
- Sucking reflex allows the baby to feed, but as baby develops this refelx is lost and it becomes a learned action.
- The baby then has to digest its own food, specific to its needs.
Describe the adaption of waste removal
- Removal of waste including urine and solid waste.
- The first faeces is called meconium- very dark in colour. It is the waste product from the baby swallowing amniotic fluid
- The baby's bowels now begin to process waste from breast milk
- Blood is filtered now by the kidneys, and urine is extreted by the child itself
Describe the adaption of temperature control
- Once out of the womb and the surrounding amniotic fluids, the baby's temperature will drop but should return to normal over the next few hours. The neonate has a large surface area and loses heat quickly, especially through the head.
- There is a thick layer of fat on its chest and back to keep the heart and major organs protected with warmth.
- Careful parental control of the baby's environment and clothing is needed.
Describe the adaption of respiration.
- In pregnancy, the baby's lungs are filled with amniotic fluid, but during birth a lot of this is pushed out of the lungs.
- The rest is absorbed into the lungs so once outside of the mother's body, the baby can begin to breathe.