BIOM3010 Lecture Notes - Lecture 15: Circulatory System, Arteriole, Osmotic Concentration
Document Summary
Local factors in the immediate vicinity of arterioles are powerful regulators of blood flow. Blood flow in tissues is normally determined by these local factors. Especially important in extreme situations exercise, blood loss, etc. The major local factors: decreased local o2. Increased k+ (from actively contracting muscle/nerve [brain]) increased metabolic activity: osmolarity (concentration of solutes rises during, adenosine (released during increased use of atp for, local hormones energy [atp adp + pi adenosine +pi]) All these factors include relaxation of arterioles close by: the vasodilation increases blood flow to the capillaries supplied by the arterioles. Whenever the availability of oxygen to the tissues decreases, the blood flow through the tissues increases markedly. In carbon monoxide poisoning (poisons the ability of haemoglobin to transport oxygen: 4. In cyanide poisoning (poisons the ability of the tissue to use oxygen: 5. Vitamin b deficiencies 2-3x higher blood flow (beriberi, pellagra)
