Human Growth and Development / Unit 3 HGD 0315 short lesson, about 20 seconds
Reflexes and the Brainstem
Captions available
The idea
A reflex is an involuntary movement originating in the brainstem; most newborn reflexes later give way to movements the child controls.
In practice
A newborn's grasp reflex giving way, around six months, to deliberate grasping.
Where people slip
The brain begins as a tube about three millimetres long and holds an estimated one hundred billion neurons at birth.
Your place on the trail
Every lesson rests on earlier ones and opens later ones. Tap any to jump.
Builds on
Unlocks
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