The circulatory system delivers oxygen, nutrients, and waste products from cells back into circulation, as well as hormones, and removes carbon dioxide produced during metabolism.
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Circulatory System Diseases
The blood circulatory system (also referred to as cardiovascular) provides oxygen and nutrients to all of your body’s cells. This system consists of your heart and the blood vessels running throughout your entire body, with your heart pumping blood into large arteries that branch off into smaller and smaller arteries until reaching capillaries, where they provide blood for delivery to tissues where oxygen is released and carbon dioxide collected before returning through veins back to the heart.
Circulatory system diseases interfere with this complex process and prevent your body from working efficiently. They can develop quickly or slowly over time; to be aware of which illnesses fall under this category so you can discuss it with your physician is key.
In 2004, approximately one out of six hospital stays and approximately $71.2 billion in costs in the US were attributable to circulatory disorders, according to this statistical brief. These hospital stays and diseases that caused them were broken down by payer and type of disorder; coronary artery disease, peripheral vascular disease, and phlebitis were the three most frequently mentioned circulatory conditions; additionally, it explored rates of hospital admission for transient cerebral ischemia among insured and uninsured populations.
Veins
Like arteries, veins have three layers, but their walls tend to be less muscular due to not needing to endure high levels of pressure like an artery does. About 70% of your blood can be found within veins at any given time; like their counterparts, they also contain valves that open and close periodically to regulate flow control and prevent it from flowing back the other way.
Capillaries connect to the ends of veins, carrying oxygen and nutrients directly to cells throughout your body, while waste from these same cells is carried off to be disposed of via veins. Together, these vessels form closed systems of tubes that lead back to your heart.
Blood vessels are typically named according to which organ or tissue they serve; some, like the pulmonary veins, bring oxygenated blood from your lungs through to other parts of your body before returning it again to them.
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Arteries
Your arteries are the largest blood vessels in your body, boasting thick walls and muscular layers to keep the blood moving efficiently. Beginning with your aorta (which receives blood from the heart), they branch off into smaller vessels, which distribute it throughout your body; finally, the pulmonary artery transports deoxygenated blood directly to your lungs for oxygenation.
Your arteries are composed of smooth muscle cells and elastic tissue that allow blood to bend around corners when it flows through them, with muscular tissue providing support to maintain the shape of the artery, while an outermost thin membrane protects blood from leaking out of it.
Arteries tend to have higher blood pressure than other parts of your circulatory system due to wall thickness and elasticity, as they contribute to pressure variation between systolic (SP) and diastolic (DP) pressures throughout each cardiac cycle—known as pulse pressure variation.
Veins have thinner walls than arteries, helping them move more blood faster while having lower pressures than arteries. Veins also feature one-way valves to prevent backflow of blood into them from your arteries; capillaries serve as intermediaries that transport oxygen, food nutrients, and waste between these blood vessels.
Capillaries
Capillaries are the smallest blood vessels, linking arterioles to veins to facilitate exchanges of oxygen and other materials between your blood and tissues. Their thin walls allow nutrients, gases, and waste products to pass through via passive diffusion; in addition, active transport occurs whereby cells take up sugars or proteins directly from capillary walls.
Your immune system uses capillaries to send white blood cells directly to sites of infection or inflammation, helping you fight disease and remain healthy. This allows your white blood cells to quickly repair damaged areas while keeping you on the road to wellness.
Your capillaries are lined by endothelial cells supported by a tunica intima basement membrane that contains cells called pericytes that partially encase each endothelial cell.
Your body is filled with continuous nonfenestrated capillaries known as blood-brain barriers that protect and regulate water, oxygen, and other substances between your blood and brain, keeping harmful toxins out. Fenestrated capillaries contain small gaps in their endothelial cells that allow certain substances, including oxygen, carbon dioxide, salt, and glucose, to pass into tissue cells. Osmotic pressure closes the gap when blood returns to your heart for circulation back out again, drawing excess fluids back into fenestrated capillaries for elimination from your body.
FAQ’S
1. What is the main function of the circulatory system?
The circulatory system delivers oxygen and nutrients to cells and removes waste products like carbon dioxide.
2. What organs make up the circulatory system?
The circulatory system includes the heart, arteries, veins, and capillaries.
3. What are common diseases affecting the circulatory system?
Common circulatory system diseases include coronary artery disease, peripheral vascular disease, and phlebitis.
4. How do veins differ from arteries?
Veins have thinner walls and lower pressure compared to arteries and contain valves to prevent backflow of blood.
5. What is the role of capillaries in the circulatory system?
Capillaries facilitate the exchange of oxygen, nutrients, and waste products between blood and tissues.
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