The Circulatory System
And how it maintains Homeostasis
Your circulatory system is absolutely necessary for your survival. Its job is to transport blood and other nutrients to all of the organs and tissues in your body. The exchange of oxygen and nutrients between your blood and your body's cells is facilitated by capillaries, which are small blood vessels (ER Services, 2022). Your capillaries exchange carbon dioxide and other waste materials that are discharged from your body. These tiny capillaries are dispersed throughout your body in order to reach all of your cells.
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Let's follow blood through the circulatory system in a basic loop to demonstrate how it works:
1. Through the veins, oxygen-depleted blood returns to your heart (on the right side).
2. This blood is pumped to the lungs by your heart. The blood removes carbon dioxide from the lungs and replaces it with fresh oxygen.
3. The newly oxygenated blood travels to the left side of the heart, where it is pushed into the arteries.
4. The blood eventually enters the capillaries. It delivers oxygen and nourishment to the organs and tissues of your body here. The carbon dioxide and other waste products are then collected.
5. Through the veins, oxygen-depleted blood returns to the heart, and the cycle begins all over again.
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The circulatory system can also respond to a variety of stimuli in order to control blood flow. Changes in blood volume, hormones, and electrolytes are examples of these stimuli. The circulatory system transports oxygen, nutrients, and hormones to cells while also eliminating waste products such as carbon dioxide (Admin, 2022). To keep things moving in the right direction, these roads only go in one direction.
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Maintaining Homeostasis:
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Blood flow must be redirected continuously to the tissues as they grow more active in order to maintain homeostasis in the circulatory system and deliver adequate blood to the tissues. Because there isn't enough blood flow to distribute blood evenly to all tissues at the same time, the circulatory system engages in resource allocation in a very real sense. When a person exercises, for example, more blood is sent to the skeletal muscles, the heart, and the lungs. More blood is delivered to the digestive system after a meal. Only the brain receives a rather continuous supply of blood, regardless of whether you are exercising, resting, thinking, or doing anything else.
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How does the Circulatory System support theNervous System (and vice versa)?
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The nervous system regulates the heart and peripheral circulation through control centres in the medulla, which receive descending information from higher neural areas in the brain as well as afferent input from mechanically and chemically sensitive receptors throughout the body. The Nervous System is aided by the Circulatory System: The blood-brain barrier is maintained by endothelial cells, baroreceptors give blood pressure information to the brain, and cerebrospinal fluid drains into the venous blood supply (Admin, 2022). Heart rate and blood pressure are controlled by the brain. The circulatory system ensures a steady flow of oxygen-rich blood to your brain, while your brain controls your heart rate and blood pressure. Even systems of the body that appear to be unrelated are linked.
The cardiovascular centres of the medulla oblongata are responsible for the neurological regulation of blood pressure and flow. This group of neurons reacts to variations in blood pressure as well as oxygen, carbon dioxide, and hydrogen ions concentrations in the blood. There is also a tiny population of neurons that relax the smooth muscle fibres in the vessel tunics to control vasodilation in the vasculature of the brain and skeletal muscles. Many of these are cholinergic neurons, which release acetylcholine, which induces endothelial cells in the arteries to release nitric oxide (NO), causing vasodilation. Others secrete norepinephrine, which interacts to two different receptors. Only a few neurons directly release NO as a neurotransmitter. Muscle tone is maintained by moderate stimulation of the skeletal muscles. Vascular tone in vessels exhibits a similar behaviour. Arterioles are naturally somewhat constricted, as previously mentioned: with maximal stimulation, their radius can be lowered to one-half of its resting state. Sympathetic stimulation must be turned off in order for most arterioles to fully dilate. An arteriole can grow by up to 150 percent when this happens. Resistance, pressure, and flow can all be drastically affected by such a large increase (Admin, 2022).