There are actually only three types of bone cells: osteocytes, osteoclasts, and osteoblasts.  Osteoblasts are the "builders" (think "blasts build") and are responsible for laying down new bone for the constant bone remodeling that goes on throughout all your life as well as initial bone growth. Osteoclasts are the opposite of osteoblasts and are also active in bone remodeling by taking old bone away (think "clasts kill"). Osteocytes are the third and final type that are inactive and are found in individual lacunae (think "cytes sit"). Chondrocytes are cartilage cells. 

Osteoclasts break bone and cause calcium to be reabsorbed into the blood stream whereas osteoblasts lay foundations for new bone mineralization. 

During muscle contraction, the muscle deemed the agonist will contract while the antagonist will stretch. The agonist will cause the primary action and the antagonist would cause an opposite action. Synergists assist the agonist by stabilizing the origin bone, which facilitates movements and posture.

For example, the biceps brachii (agonist) is used to flex the arm, while the triceps brachii (antagonist) is used to straighten the arm. The brachialis is also used to flex the arm, but in a different way, making it a synergist to the biceps brachii.

Tendons are separate from muscle, and are used to secure a muscle attachment to bone.

No chemical digestion occurs in the esophagus. The esophagus is used in order to move food into the stomach using peristaltic motion.

Amylase is introduced in the mouth and begins breaking down carbohydrates. Pepsin in the stomach helps digest proteins. Lipase, trypsin, and other digestive enzymes are introduced in the small intestine, where the majority of chemical digestion takes place.

The duodenum is the first section of the small intestine. It is the site of the most digestion in the small intestine (and the digestive tract in general) because pancreatic enzymes and bile are released into its lumen. These enzymes break down proteins and carbohydrates, while the bile helps to digest lipids and fats. The jejunum and ileum are primarily involved in absorbing nutrients. The cecum is part of the large intestine.

While the pancreas is responsible for the secretion of the majority of digestive enzymes, the liver is responsible for the creation of bile. The gall bladder is responsible for the storage of bile. When the gall bladder is stimulated, bile is released into the small intestine, where it helps with the emulsification and digestion of fats.

The liver has a variety of functions, including blood detoxification, glycogen formation, and blood filtration. The liver is not responsible for chemical digestion, but is needed to synthesize and store key nutrients and macromolecules. Protein digestion primarily takes place in the small intestine, though the process begins in the stomach.

The digestive system consists of the organs that food passes through, from the mouth to the anus, as well as the accessory organs that influence digestion. This includes organs that produce materials aiding in digestion, for example the liver, which produces bile the digest fats. The mouth is the first step in the digestive tract, the duodenum is a region of the small intestine, and the colon is a region of the large intestine.

The lymph nodes are part of the lymphatic system and do not play a role in the digestive system.

The large intestine is located near the end of the gastrointestinal tract. Its primary function is to reabsorb water and nutrients prior to elimination of waste. Mechanical digestion of food occurs in the mouth and stomach. Chemical digestion of food occurs in the mouth (saliva has amylase), stomach, and early in the small intestine. Blood glucose levels are maintained by the pancreas.

Bile is a dark greenish brown substance continuously produced by the liver. It is stored and concentrated in the gallbladder, and is released into the small intestine after eating. In the small intestine, bile aids in the digestion of lipids (this is a very important part of the absorption of fat soluble substances such as certain vitamins).