Following scenarios. Alfredo was born with a genetic disease that causes a defec
ID: 85168 • Letter: F
Question
Following scenarios. Alfredo was born with a genetic disease that causes a defect in calcium channels in his cells. The channels' normal job is to allow calcium to move across membranes in cells. What effects do you think this disease will have on Alfredo's muscles, and why? Your biceps brachii muscles are capable of helping you lift a light piece of tissue paper or helping you pick up a very heavy piece of luggage. How is it possible for your biceps brachii to create such a wide range of tensions in different situations? One day, you arrive at home to find your front door stuck shut. You place the palms of your hands flat on the door, and push forcefully to move the door. Which muscles did you just use to push the door open, and what actions did they perform? Respond to 2Explanation / Answer
1. Alfredo was born with a genetic disease that causes a defect in calcium channels in his cells.This disease may have the following effects on Alfredos muscles.
*Calcium ions bind to troponin and change its shape; change of calcium moves tropomyosin from the myosin-binding site on the actin molecule, which allows the myosin to bind to actin, causing a muscle contraction. As alfredo has defects in calcium channels, the above process is delayed leading to disturbances in skeletal muscle contraction or excitability.
*The action potential of cardiac myocytes is extremely long , since a continuous influx of calcium during
the plateau phase is needed for cardiac contraction. Defects in the intracellular calcium ion channels may result in cardiac arrythmias.
Therefore, dysfunction of calcium ion channels can cause broad spectrum of symptoms ranging from hypertension to endocrine disorders, kidney stones etc.
2. Bicep brachii muscle is the agonist for flexion and antagonist for extension. The total tension created by a muscle during lifting or picking up an object is the combination of passive and active tensions. Stretching builds up passive tension involving the noncontractile units of muscle, where as releasing builds up active tension involving contractile units of muscle and movement of active and myosin.
When the biceps brachii muscle contracts (elbow flexion), the forearm moves toward the humerus.
The forearm is more movable because it is attached to the hand. The humerus is more stable because it is attached to the axial skeleton at the shoulder joint. Therefore, in this way biceps brachii muscles are capable of helping you lift a light piece of tissue paper or help you pick up a very high piece of luggage.
3. Pushing the door open requires supination which is achieved by concentric activity in the
supinator, brachioradialis, and biceps brachii, followed by the triceps brachii and anconeus muscles to extend the elbow. The actions that these muscles performed include flexion, extension, horizontal abduction.