Lesson 6.3Terms:•Fertilization – merging of two sexcell-male spermatozoon and femaleovum (egg).•Ovulation –hormones stimulate anovum to ripen and separate itself fromthe ovary at regular intervals.
Lesson 6.3•Fertilization – merging of two sex cell-male spermatozoon and female ovum (egg).•Ovulation –hormones stimulate an ovum to ripen and separate itself from the ovaryat regular intervals.•Fallopian tube – tube ovum(egg cell) travels down tothe uterus.
What happens to the Ovum?One of Two things can happen:1. If the ovum is not fertilized it will be shed along with the lining of the uterus. or
What happens to the Ovum?One of two things can happen:1. If the ovum is not fertilized it will be shed along with the lining of theuterus. or2. If the ovum is fertilized it willattach it self to the uterus and theembryo will begin to develop.
If the ovum is fertilized it will attach it self to the uterus and the embryo will beginto develop.
If the ovum attaches a pregnancy begins.Now sit and listen and look for afew minutes! You don’t have towrite!!
Weeks One through FourGender is determinedNeural tube forms - It will developinto the nervous system (Brain, spinalcord, hair, and skin). Already yourbaby has the foundation for thought,senses, feeling, and more!Heart and primitive circulatorysystem rapidly form - While still in itsbeginning stages, this is the very lifesupport system that will carry yourchild throughout his or her life.
Week Five First heartbeats begin Umbilical cord develops Blood is now pumpingMost other organs begin to develop Arm and leg buds appear [ <>
Week Six The arms and legs continue to develop - Brain is growing well - Lenses of the eyes appear - Nostrils are formed- Intestines grow -Pancreas - now equipped to deal with digestive enzymesand take on processing the insulin and glucagons the body needs to function.
Week Seven Elbows form Fingers start to developFeet start to appear with tiny notches for the toes Ears eyes and nose start to appear Intestines start to form Teeth begin to develop under the gums
•Week Eight•Cartilage and bones begin to form -•The basic structure of the eye is wellunderway -•The tongue begins to develop•Intestines move out of the umbilical cordinto the abdomen.•Body grows and makes room - Two monthsalong and this little one is growing inside andout by leaps and bounds!•The fingers and toes have appeared but arewebbed and short•Babys length (crown to rump) is 0.61 inch(1.6cm) and weight is 0.04 ounce (1gm)
Week Nine •Baby has begun movement •Most joints are formed now•Fetus will curve its fingers around an object placed in the palm of its hand•Fingerprints are already evident in the skin •Average size this week -- length 0.9 inch (2.3cm), weight 0.07 ounce (2gm)
Week Ten •Baby is now called a fetus •The most critical part of the infants development is complete. •Eyelids fuse shut and irises begin todevelop - Eye color is also determined by this point. Write this down:•Placenta begins to function at10 – 11 weeks The placenta is the organ responsible for boththe provision of nutrients along with the removal of waste.
Week Eleven•Nearly all structures and organs are formed.•Fingers and toes have separated •Hair and nails begin to grow •Amniotic fluid begins toaccumulate as the kidneys begin to function •The muscles in the intestinal walls begin to practice contractions that digest food.
Week Twelve •Vocal cords begin to form •Ears shift to their normal place on the side of the head•Intestines move farther in to your childs body •His or her liver begins to function •The pancreas begins to produce insulin
Back to writing!! The point is:By the twelve week ofdevelopment every detailof a person’s basicstructures are developed.The baby has brainactivity and responds totouch by the 7 th wk.
Back to terms:•Gestation period – the periodbetween fertilization and birth.Gestation period for humans is38 – 40 weeks.
Umbilical cord - the bundle ofthree blood vessels thatattaches the baby to themother’s placenta.•Has two blood vessels bringingnutrients and oxygen to the fetus•Has one blood vessel carrieswaste and carbon dioxide fromthe baby
More about the umbilical cord: •Has two blood vessels bringing nutrients and oxygen to the fetus •Has one blood vessel carries waste and carbon dioxide from the baby•exchange of waste and nutrientssuch as O2 happens at theplacenta, but the mother andbaby’s blood never mixes.
•Amniotic sac – is a fluid filledsac that protects the developingbaby during gestation.