Langerhans cells are dendritic cells (antigen-presenting immune cells) of the skin, and contain organelles called Birbeck granules. They are present in all layers of the epidermis and are most prominent in the stratum spinosum.
Answer:
The answer to the question: The movement of ions through their channels require a discharge of the capacitance, is, true.
Explanation:
In order for cells, muscular and neuronal, to perform their activities, they need to generate action potentials, that will permit these activities. In order for an action potential to happen, a cell´s membrance must be charged, or rather, its polarity must be changed, so that the cell can be charged and then fire. Usually, cells remain in a resting membrane state, in which, the extracellular matrix remains positive, while the intracellular space remains positive, due to ion, and anion presence in either. In order for the action potential to happen, these polarities are reversed through a series of steps in which ions, particularly potassium and sodium, sometimes calcium, will enter and exit the cell´s membrane to change this polarity. But in order for this process to take place, first a current, or stimulation, must motivate the cell to start the process. The capacitance is the capability of a cell to be ready to be activated or de-activated when stimulated, meaning, to be charged and discharged, when necessary. In order for this capacitance to permit the process of action potential formation, it needs to be discharged first, and this is done through the stimulus, which orders the cell´s membrane to initiate depolarization by opening up the ion channels. This is why the answer is true.
Answer:
The truth about the hormone leptin and obesity. It's been called the " obesity hormone" or "fat hormone" -- but also the "starvation hormone." When scientists discovered leptin in 1994, excitement arose about its potential as a blockbuster weight loss treatment. Even today, the Internet is loaded with sites that sell leptin supplements.
Explanation:
Answer:
D
Explanation:
Stem cell research is controversial because the use of embryonic cells requires the destruction of an embryo.
