Answer: In order to compensate for the low partial pressure of oxygen at altitude, the human body undergoes a number of physiological changes. A vital component in this process is the increase in the concentration of circulating haemoglobin. The role of HIF‐1α, erythropoietin and red blood cells in this acclimatisation process is described, together with the fall in plasma volume that increases the concentration of haemoglobin in the early stages of hypoxic exposure.
Explanation:
So its acquired immunity and the cells responsible are the B lymphocytes that produces antibodies against the virus. Memory is keep since first encounter of the virus by the immune system by way of the antibodies that was initially produced. The antibodies are there already, which makes it fast to act upon when expose again.
Answer:
B
Explanation:
Get a referral from his primary care physician.
