As to the brain, the outer layer is the cerebral cortex whose tens of millions of cells communicate your present awareness.
The brain’s medulla oblongata controls your automatic functions such as breathing and digestion. The cerebellum helps maintain your balance and keeps your muscle motion smooth. Some small organs deep inside your brain allow you to experience emotions.
The thalamus manages the flow of sensory information. The hippocampus is essential to remembering and learning. The hypothalamus tells our bodies how to react to different emotions. The amygdala sends a signal to your body when you are fearful or anxious.
The HUMAN BODY’s overlays allow you to see your heart both from the back and the front. The heart contracts and relaxes about 100,000 times a day. It is by far the hardest working muscle in your body, “never going on vacation” or saying, “I’m just too tired to contract, I want to take a nap.” Babies have no fingerprints at birth. The embryo is called a fetus at 8 weeks (after conception). A typical fetus is 5 inches long at 12 weeks. At 38 weeks, the fetus turns itself upside down, in preparation for its passage through the birth canal.
Your biggest bone is the thighbone or femur, which is one-quarter of your height, no matter what your age.
The average person walks 79,500 miles during his lifetime, more than three times the circumference of the Earth.
The image of the outside world is upside down on your retina in the rear of your eye. On the retina, the rods sense light and the cones detect color and detail. The sclera is the white of the eye, the iris is the colored part of the eye and the pupil is the dark dot in the middle of the eye where light penetrates onto the retina. (To be continued next week.)