Final answer:
Loss of 20% of capillaries would reduce the surface area for diffusion, impairing the delivery of oxygen and nutrients to tissues, and removal of waste, potentially resulting in weakness and lethargy. Oxygen transportation relies on red blood cells with hemoglobin; conditions like anemia, sickle cell anemia, and thalassemia impede this process, leading to similar symptoms.
Step-by-step explanation:
If 20% of a tissue's capillaries were lost, transport to and from that tissue would be adversely affected due to the laws of diffusion. Diffusion is a process where substances move from an area of higher concentration to one of lower concentration. Capillaries are the smallest blood vessels and are critical for the exchange of oxygen, nutrients, and waste products between the blood and the tissues. With fewer capillaries, there would be a reduced surface area for diffusion, leading to decreased oxygen and nutrient delivery to the cells. Consequently, less waste would be removed from the tissues. This can lead to tissue injury, impaired metabolism, and potentially contribute to diseases characterized by weakness and lethargy.
Oxygen is transported to the cells of the body primarily through red blood cells, which contain the oxygen-carrying molecule hemoglobin. In conditions such as anemia, the number of red blood cells or their oxygen-carrying capacity is reduced. As a result, less oxygen reaches the body's tissues, causing symptoms like weakness and fatigue. Diseases like sickle cell anemia and thalassemia further decrease the blood's oxygen-carrying ability and its capacity to deliver oxygen to tissues due to abnormal red blood cell shapes and low hemoglobin levels, respectively.