Which structure is a ball and socket joint?

The quadriceps femoris group is a group of four muscles located in the anterior compartment of the thigh. These muscles are responsible for extending the leg at the knee joint. The four muscles that make up the quadriceps femoris group are the rectus femoris, vastus medialis, vastus intermedius, and vastus lateralis.

The vastus lateralis is the largest of the four muscles and is located on the lateral side of the thigh. It originates from the greater trochanter of the femur, the lateral lip of the linea aspera, and the lateral intermuscular septum. It inserts into the patella and the tibial tuberosity via the patellar tendon. The vastus lateralis is responsible for extending the leg at the knee joint and is also involved in stabilizing the patella.

Digestion begins in the oral cavity, also known as the mouth, where food is ingested and broken down into smaller pieces through mechanical digestion by the teeth and chemical digestion by enzymes in saliva, such as amylase. Once the food is sufficiently broken down, it forms a bolus and is then swallowed, passing through the esophagus and into the stomach. In the stomach, the food is further broken down by stomach acid and enzymes before passing into the small intestine for the absorption of nutrients.