When oxygen uptake is low, a high proportion of the total amount of blood pumped goes to the intestines. When oxygen uptake is high, a small proportion of blood goes to the intestines. Explain the differences in terms of the needs of the body during rest and during exercise.
Is it because during exercise, the body is more occupied with breathing and improving the muscles, and so the intestines are not as "important"?
Also, why does blood volume supplied to the skin increase as oxygen uptake increases? I'm confused on how more blood flow to the skin would help during exercise (sweating?)
Our skin is the largest organ of our body. An increased blood flow to the skin allows the body to cool off more effectively. Our body temp is 98.6, warmer than the average air temp. Bringing a larger volume of blood closer to the surface of out body, along with sweating, helps keep the body from over heating. Digestion is not the body's main concern during increased activity, especially if it's "fight or flight". Therefore blood flow to the intestines decreases while respiration and pulse increase during activity, allowing better oxygenation of vital systems.
That did not help
During rest, the body's energy demands are relatively low, and the primary focus is on essential functions such as digestion and maintenance of organ systems. At this time, oxygen uptake is low, meaning the body requires only a limited amount of oxygen to meet its energy requirements. As a result, a high proportion of the blood pumped by the heart is directed towards the intestines to support digestion and absorption of nutrients.
On the other hand, during exercise, the energy demands of the body increase significantly. The muscles need more oxygen to generate energy for movement and sustain physical activity. Consequently, there is a higher oxygen uptake during exercise. To meet this increased demand, the body adjusts the distribution of blood flow to prioritize the delivery of oxygen-rich blood to the working muscles. As a result, a lesser proportion of the blood is directed to the intestines since digestion becomes less critical during exercise.
Regarding blood flow to the skin, an increase in oxygen uptake during exercise promotes several physiological adaptations. As the body becomes more active, it generates extra heat that needs to be dissipated to maintain an optimal body temperature. One of the ways the body regulates temperature is through vasodilation, which is the widening of blood vessels in the skin. This expansion allows more blood to flow near the skin's surface, facilitating the transfer of heat from the internal organs to the external environment.
Additionally, this increased blood flow to the skin also aids in cooling the body through perspiration or sweating. As sweat evaporates from the skin's surface, heat is drawn away from the body, helping to prevent overheating. Therefore, the increased blood volume supplied to the skin during exercise serves as a means to regulate body temperature and facilitate the cooling process.