Answer:
B
Explanation:
The circulatory system is a network consisting of blood, blood vessels, and the heart. This network supplies tissues in the body with oxygen and other nutrients, transports hormones, and removes unnecessary waste products.
Answer:
Carbohydrates are made of hydrogen and oxygen with the general formula of Cm(H2O)
1. Contraction
2. Actin
3. Tendons
4. Epidermis
5. Dermis
6. Acne
7. A nerve signal from the brain arrives at the intersection of the nerve and muscle cells and releases acetylcholine from the neuron. This triggers chemical changes in the muscle cell involving ions, including Ca2+. Calcium triggers the thick filaments, made of myosin, to attach to the thin filaments, made of actin, in the muscle cell, and the myosin pulls the actin toward the center of the muscle cell. ATP causes the release of the actin fibers, allowing the muscle to relax and the process to begin again.
For Penn Foster.