Answer:
Identify how the physical barriers of the immune system protect the body against pathogens?
skin contains tightly packed cells
•skin is tough, flexible, and waterproof
Explanation:
<h2>Membrane potential </h2>
Explanation:
- Membrane potential represents charge difference across the membrane, all biological cells are negative inside (cytoplasm) and positive outside (due to difference in ionic distribution)
- In a typical neuron cell membrane potential of cytoplasm is negative at rest (when no stimulus is applied) hence called resting membrane potential
- Resting membrane potential of excitable cells is established by Na+ and K+pump
- Repolarization starts with the efflux of K+ by the opening of voltage gated K+ channels
- Voltage gated K+ channels starts to open when voltage gated Na+ channels becomes inactive
- Hyperpolarization occurs due to excessive efflux of K+ by voltage gated K+ channels
- Additional efflux of K+ occurs due to slow inactivation of voltage gated K+ channels