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.
Find out more about the common causes, symptoms, diagnosis and treatment options for pain on outside of foot in the ankle sprain section. 3) Cuboid Syndrome Cuboid Syndrome is a less common cause of lateral foot pain (i.e. outer side of foot pain) but it frequently goes undiagnosed which can lead to symptoms being present for long periods.