Skeletal Muscle Contraction Case Study

1. Nerve conduction tests of the ulnar, tibial, and peroneal nerves involves testing how well and quickly a nerve can send electrical signals to begin contraction of skeletal muscles. The first step in muscle contraction is excitation of a skeletal muscle fiber by a nerve signal. The nerve signal must be sent to the neuromuscular junction to open the voltage-gated calcium channels. Just like in a muscle fiber, the neuron must reach threshold potential before the action potentials can be propagated down the neuron. After the threshold potential is reached, voltage-gated sodium channels open causing sodium to rapidly move into the cell. This is called depolarization because voltage inside the cell becomes more positive (there is less of a difference in charge inside and outside of the cell). After the action potential has reached the synaptic knob, the sodium channels close and the voltage-gated …show more content…
PTH is one of the two hormones involved in calcium homeostasis. PTH is secreted by the parathyroid hormone and is responsible for increasing osteoclast production. Since osteoclasts break down bone, the calcium stored in the bone is released into the blood, increasing the blood calcium level. This means that Gustavo’s bone density will decrease and he will have greater levels of calcium in the blood. The administration of calcitonin and Vitamin D with calcium supplementation could aid in balancing blood calcium levels and loss of bone density. Vitamin D turns into calcitriol (the variant of Vitamin D) and this calcitriol binds to the PTh in order to help with breaking down the bone and releasing more calcium into the blood. Also, calcitonin will inhibit the osteoclast activity and increase the loss of calcium in urine through the kidneys thereby lowering blood calcium levels and maintaining homeostasis. Calcitonin is also responsible for osteoblast production. Osteoblasts build up bones and therefore remove calcium from the blood supply, which maintains