The neuromuscular junction is the site of the signal exchange. The steps of this process in vertebrates occur as follows:(`) The action potential reaches the axon terminal. (2) Voltage-dependent calcium gates open, allowing calcium to enter the axon terminal.he neuromuscular junction is the site of the signal exchange. The steps of this process in vertebrates occur as follows:(`) The action potential reaches the axon terminal. (2) Voltage-dependent calcium gates open, allowing calcium to enter the axon terminal.
Sudden onset pain on the outer side of the foot can be from a fracture of the 5th Metatarsal and injuries to this bone are a common sports injury. Causes of pain on the outside of the foot are listed here: 1  Midtarsal Joint Sprain A mid tarsal joint sprain is an injury to the ligaments holding the mid tarsal joint together causing pain in the outside middle of the foot. 2  Peroneus Brevis Tendon Injury The Peroneus Brevis tendon inserts into the 5th matatarsal bone on the outside of the foot.
People with high arches or who walk on the insides of their feet (known as pronating) are particularly susceptible. You know you have plantar fasciitis if you feel pain in your heel or arch first thing in the morning, because the fascia stiffens during the night. If the problem is left untreated, it can cause a buildup of calcium, which may create a painful, bony growth around the heel known as a heel spur.