Chemical weathering is caused by rain water reacting with the mineral grains in rocks to form new minerals (clays) and soluble salts. These reactions occur particularly when the water is slightly acidic.
Hemoglobin is a special protein in the blood that captures and carries oxygen.
Similar to the other types of muscle, smooth muscle contraction is caused by the sliding of myosin and actin filaments over each other. Calcium initiates contractions in a different way in a smooth muscle than in a skeletal muscle.
Smooth muscles use less energy to generate the given amount of force, can substain contractile force without fatigue & uses calcium from the sarcoplasic reticulum & extracellular space.
The nervous system consists of things like the spinal cord, brain, and all the nerves that connect the sensory organs. Basically, the nervous system helps different parts of the body communicate with each other; thus leading to control of the body.