The central nervous system appears at the beginning of the third week of embryonic development as a slipper-shaped plate of cells, called the neural plate. The other edges of the plate develop further, elevating to form the neural folds. As the folds become more elevated, they approach each other in the midline and eventually fuse, thus forming the neural tube. This fusion begins in the neck region and proceeds in a head ward and tail ward direction. Final closure of the tube occurs at approximately 25-27 days.
The upper (cranial) end of the neural tube has three dilations known as the primary brain vesicles. The prosencephalon, or forebrain, will eventually give rise to the cerebrum. The mesencephalon becomes the midbrain (part of the brainstem). The rhombencephalon, or hindbrain, consists of two parts, the metencephalon, which later forms the pons and cerebellum, and the myelencephalon, which forms the medulla oblongata (brainstem).
Most defects of the spinal cord result from abnormal closure of the neural folds in the third to fourth week of development. Spina bifida is one example of such a neural tube defect, which may also involve the covering of the spinal cord (meanings), vertebra, muscles, and skin. A number of closure defects can now be diagnosed prenatally by the detection of elevated levels of alpha-fetoprotein in the blood or amniotic fluid, or by ultrasound scanning.
Folic acid is a B-vitamin that helps build healthy cells. During periods of rapid growth, such as pregnancy and fetal development, the body's requirement for this vitamin increases. Research has shown that if all women who could possibly become pregnant were to take a multivitamin with folic acid, the risk of neural tube defects like spina bifida could be reduced by up to 70% (Spina Bifida Association 2009 http://www.spinabifidaassociation.org). Since spina bifida occurs early in pregnancy, often before a woman knows she is pregnant, it is important to take folic acid every day. Taking folic acid before and during early pregnancy reduces the risk of spina bifida and other neural tube defects.
Goals: This activity aims to teach children about the areas of the brain, the formation of the brain and spinal cord during prenatal development, and the consequences of incomplete fusion of the neural plate in utero. The unit may be connected to elementary students' personal experiences with spina bifida, or their questions about prenatal development and recent news stories on prenatal surgery.
Objectives The students will:
Share their background knowledge (and naive conceptions) related to brain
structure and development.
Construct models to represent areas of the brain and spinal cord.
Identify areas of the brain.
Impairments that result from spina bifida Science Content
The brain consists of four distinct regions.
Different parts of the brain are responsible for different functions.
The spinal cord and brain may not fully develop before birth, resulting in impairment.
Science Process Skills
Models or illustrations of brain
Illustrations of spina bifida
disposable sanitation gloves for everyone
2 uncooked crescent rolls per student group
1 cannoli form
oven or toaster oven(s)
oven mitts and hot pads
extra trash bags
Prepare edible items wearing disposable sanitation gloves.
Handle hot objects with care.
Do not require students to eat their finished model.
Make and bake one crescent roll model that is not completely covered with dough to represent spina bifida caused by incomplete fusion of the neural plate.
Sketch a K-W-L-H chart to indicate what Students K, What they would like to know, what they learned and how they could obtain additional information.
Discuss the student's prior knowledge of the brain and spinal cord, its regions, functions and development.
Discuss the students' prior knowledge or experience with spina bifida
Using models or diagrams clarify or extend their background knowledge. Give each child or small group of children sanitary gloves, a paper plate with 2 uncooked crescent rolls in the shape of a rectangle, and a wiener with an incomplete transverse cut in the middle. The dough represents the neural plate. The cut wiener represents the bendable spinal cord.
Have students place their models on a baking sheet in such a way that they can get their own back. Bake for approximately 10 minutes at the temperature indicated on the crescent roll package.
While the brain models are baking, explain the concept of spina bifida using the pre-made model. Use pictures, illustrations and personal examples to clarify what spina bifida looks like and how it affects people. Briefly explain that not everyone's spinal cord is completely enclosed as it should be at birth, and that many physical problems can result for the person. Explain that there are varying degrees, and that people can be helped through physical therapy. Stress that persons challenged with the effects of spina bifida should be treated with sensitivity.
After the wieners are done, distribute them to their owners. The four condiments can then be used to cover the appropriate areas of the brain and spinal cord, as illustrated on your chart.
Assess students' learning by asking them to explain their models and by following up on the K-W-L chart. Students who can respond correctly or add appropriate comments to the discussion may consume their finished product, if desired. Have students be responsible for cleaning up with paper towels, wet-wipes, and trash bags.
Embryo - a developing baby within the mother
In utero - in the uterus (mother) before birth
Spinal cord- a cable of nerve tissue in the backbone connected to the brain at the base of the skull.
Spina bifida- means an open or incomplete spine and it is one of the most serious of all birth defects. The condition may affect a small region of the spine or a much larger area. In case of spina bifida, portions of the spinal cord are pushed outward, making them vulnerable to injury or infection.
Neural tube- neural plate folds up to become the neural tube.
Neural plate -the structure that becomes the entire nervous system,
Cerebrum - large part of the brain consisting of two large lobes or hemispheres, certain areas of which control particular processes of thought and voluntary muscular movement
Cerebellum - part of the brain that controls the coordination of the muscles.
Brain stem - is the base of the brain lying beneath the cerebrum and the cerebellum, which connects the spinal cord with the forebrain.