| Questions | 5 |
| Topics | Central & Peripheral Nervous Systems, Exoskeleton, Health Benefits of Vitamins & Minerals, Infiltration, Veins |
The nervous system consists of the brain and spinal cord (central nervous system) and the peripheral nervous system which is the network of nerve cells (neurons) that collect and distribute signals from the central nervous system throughout the body.
An exoskeleton (external skeleton) is common in arthropods like insects, spiders, and crustaceans.
| Vitamin / Mineral | Sources | Health Benefits |
|---|---|---|
| Calcium | Dairy products (milk, yogurt, cheese), spinach. | Aids bone growth and repair, muscle function. |
| Iron | Red meat, beans, whole grains. | Allows red blood cells to transfer oxygen to body tissues. |
| Magnesium | Nuts, whole grains, green leafy vegetables. | Muscle, nerve, and enzyme function. |
| Potassium | Bananas, nuts, seeds. | Helps balance fluid levels in the body. |
| Vitamin A | Liver, milk, eggs, carrots. | Vision, immune system, cell growth. |
| Vitamin C | Green and red peppers, citrus fruits, broccoli. | Collagen formation, immune system function, antioxidant (helps protect cells from damage). |
| Vitamin D | Exposure to sunlight. | Helps calcium strengthen bones, muscle, nerve, and immune system function. |
The water then accumulates as runoff and eventually returns to bodies of water or is absorbed into the Earth (infiltration) and becomes part of the water table, an underground resevoir of fresh water.
Veins carry blood back to the heart from the body. While arteries are thick-walled because they carry oxygenated blood at high pressure, veins are comparatively thin-walled as they carry low-pressure deoxygenated blood. Like the heart, veins contain valves to prevent blood backflow.