Simple diffusion is the process by which a substance moves across a cell membrane from an area of high concentration to an area of low concentration. Substances that move by simple diffusion are able to diffuse directly across the phospholipid bilayer of the cell membrane. These substances are generally small and neutral, as large or charged particles cannot cross the phospholipid bilayer. Some examples of molecules that move by simple diffusion are carbon dioxide and oxygen.
Facilitated diffusion is the process by which a substance moves across a cell membrane from an area of high concentration to an area of low concentration with the aid of a membrane protein. Substances that move by facilitated diffusion are not able to diffuse directly across the phospholipid bilayer of the cell membrane. These substances are generally large and/or charged. They therefore travel through a protein channel in the cell membrane along their concentration gradient. Some examples of substances that can move by facilitated diffusion are glucose, sodium ions and chloride ions.
The similarities between facilitated diffusion and simple diffusion are:
They both involve the movement of a substance across a cell membrane along its concentration gradient (from an area of high concentration to an area of low concentration).
They are both examples of passive transport, as neither requires energy from the cell to move the substance across the membrane.
Retina allows the eye to regulate how much lint can enter.
Answer:
Hypothalamus
Explanation:
The hypothalamus is a part of the brain which possesses temperature receptor cells that detect changes in the man’s temperature, thereby sending signals in the form of electrical nerve impulses to the man’s muscles and nervous system, which in turn respond in counteracting the drop in the normal temperature of the body.
Once the muscle cells of this man receive these signals, they produce heat through thermogenesis by shivering when the muscle cells begin to contract. This is one of the mechanisms by which thermoregulation is achieved as controlled by the hypothalamus in the brain of the man.
The next thing for the nurse to do is to write down the normal breath sound in the patient's record. Soft, low pitched sound over the base of the lungs indicate normal breathing. The sound heard will be different if the lungs are infected. Thus, the lungs of the patient been examined is working perfectly; this should be documented in the patient's record.
