Muscles move body parts by contracting and then relaxing. Muscles can pull bones, but they can't push them back to the original position. So they work in pairs of flexors and extensors. The flexor contracts to bend a limb at a joint.
In addition to a high body temperatures, the symptoms of heatstroke include altered mental state or behavior, nausea and vomiting, flushed skin, rapid breathing and racing heart rate. "Generally with heat exhaustion, a patient is sweating a lot, whereas with heat stroke, they've stopped sweating and are actually dry.
Exoskeleton and Endoskeleton
Multicellular organisms e.g. man meet their needs through use of specialized systems that they have in their bodies. Examples of such include:
1. cardiovascular system composed of heart, veins and arteries which facilitate transport of nutrients to all parts of the body .
2. Skeletal system composed of bones, joints, ligaments and cartilage whose function is support and protection of the body. <span>
3. Digestive system composed of mouth, esophagus, stomach , small and large intestines whose function is breakdown of food and absorption of nutrients.</span>
