Systemic & pulmonary circulation
CIRCULATORY SYSTEM ANATOMY
Smooth muscle around arterioles: Increases in temperature result in the smooth muscle in the walls of arterioles being stimulated to relax causing vasodilation increase in diameter of the vessel.
This in turn increases the volume of blood flow to the skin, allowing cooling to occur. We see this is in the adjacent diagram where blood that is normally concentrated around the core organs is shunted to the skin to cool when the body is under heat stress.
If however the thermoreceptors detect a cooling of the blood or skin then the hypothalamus reacts by sending a message to the smooth muscle of the arteriole walls causing the arterioles to vasoconstrict reduce their diameter , thus reducing the blood flow to the skin and therefore helping to maintain core body temperature.
When a drop in blood temperature is recorded the hypothalamus can also react by causing skeletal muscles to start shivering. Shivering is actually lots of very fast, small muscular contractions which produce heat to help warm the blood. The hypothalamus may trigger the release of hormones such as thyroxin, adrenalin and noradrenalin in response to drops in blood temperature. These hormones all contribute to increasing the bodies metabolic rate rate at which the body burns fuel and therefore increasing the production of heat.
When the fluid levels in the body do not balance a state of dehydration or hyperhydration can occur, both of which impede normal body function and if left unchecked can become dangerous or even fatal. Dehydration is the excessive loss of body fluid, usually accompanied by an excessive loss of electrolytes. The symptoms of dehydration include; headaches, cramps, dizziness, fainting and raised blood pressure blood becomes thicker as its volume decreases requiring more force to pump it around the body.
Hyperhydration on the other hand results from an excessive intake of water which pushes the normal balance of electrolytes outside of their safe limits. This can occur through long bouts of intensive exercise where electrolytes are not replenished and excessive amounts of water are consumed. If this swelling occurs in the brain it can put excessive pressure on the brain stem that may result in seizures, brain damage, coma or even death.
Where as hyperhydration or a gain in body fluid intake of water usually results in a reduction of blood tonicity and an increase in blood volume. Any change in blood tonicity and volume is detected by the kidneys and osmoreceptors in the hypothalamus. Osmoreceptors are specialist receptors that detect changes in the dilution of the blood. Essentially they detect if we are hydrated diluted blood or dehydrated less diluted blood. In response hormones are released and transported by the cardiovascular system through the blood to act on target tissues such as the kidneys to increase or decrease urine production.
Another way the cardiovascular system maintains fluid balance is by either dilating widening or constricting tightening blood vessels to increase or decrease the amount of fluid that can be lost through sweat. Make writing personal training programs easy with these custom designed exercise templates, and keep your clients focused and progressing. Pain-free clients are happy clients. Claim your free copy of the client back care guide today. A CBC, including a platelet and a reticulocyte count, will provide information on the severity of anemia and degree of bone marrow response, and also allow for evaluation of other cell lines.
The RBC indices measures of size and hemoglobin concentration are calculated by automated cell counters calibrated for the species in question. RBC size is expressed by the mean corpuscular volume MCV in femtoliters and can reflect the degree of regeneration.
Macrocytosis an increase in the MCV usually correlates with a regenerative anemia. Macrocytosis can be a heritable condition in Poodles without anemia and may be seen in anemic cats infected with feline leukemia virus.
Microcytosis a decrease in the MCV is the hallmark of iron-deficiency anemia. Terms used for description of abnormalities with MCHC include normochromia and hypochromia. Abnormalities in RBC morphology, such as basophilic stippling, can indicate lead intoxication.
Heinz body formation indicates oxidative injury to the RBCs, secondary to toxin exposure see Table: Toxic Causes of Anemia. Cats are more susceptible to Heinz body formation than other species, and cats without anemia can have a small number of Heinz bodies.
The presence of schistocytes or spherocytes may also help identify the pathophysiology associated with the cause of anemia.
Acetaminophen , benzocaine , dapsone , nitrofurans, primaquine , propofol , quinacrine. Cephalosporins, levamisole, penicillin, propylthiouracil , sulfonamides. Amphotericin, azidothymidine, cephalosporins, chloramphenicol , estrogen, fenbendazole, griseofulvin , meclofenamic acid, phenobarbital , phenothiazine, phenylbutazone, propylthiouracil , quinidine , recombinant human erythropoietin, sulfonamides, thiacetarsamide.
The reticulocyte count is usually reported as a percent of the RBC mass. This value should be corrected for the degree of anemia to evaluate the degree of regeneration. To correct the percent reticulocytes, the formula see below can be applied.
After acute blood loss or hemolytic crisis, reticulocytosis usually takes 3—4 days to become evident. A serum chemistry panel and urinalysis evaluate organ function. If GI blood loss is suspected, an examination of the feces for occult blood and parasites can be useful.
Radiographs can help identify occult disease, such as a penny zinc toxicity in the stomach of a puppy with hemolytic anemia. Tubes called veins go into your heart.
Arteries and veins are also called blood vessels. Blood comes into the atria or top chambers of your heart. Your ventricles, or bottom chambers, pump blood out to every part of your body.
Every part of your body needs food and oxygen for energy. You need energy for your body to work and for you to stay alive. Your heart pumps blood carrying food and oxygen through your arteries. Big arteries carry the blood to your legs and arms.
The arteries get smaller and smaller the farther out they go. Little blood vessels called capillaries take blood to your cells. Everything in your body is made of tiny cells. One of these waste products is a gas called carbon dioxide.
The blood in your capillaries picks up the waste products. Capillaries connect to bigger veins. The pumping of your heart pushes the blood through your veins. The chambers on the right side of your heart take care of blood coming back through your veins. First, the blood comes into your right atrium, the top chamber. Your right atrium pumps the blood into your right ventricle, the bottom chamber. Your right ventricle pumps the blood through an artery into your lungs. It has to get a fresh supply of oxygen.
Your lungs take care of both jobs. Carbon dioxide from your blood goes into your lungs. Your lungs get rid of the carbon dioxide when you breathe out. Your lungs get oxygen from breathing in air.