Explain the structure and function of human blood

The heart pumps blood through a vast network of arteries and veins. Blood is a living fluid. It transports oxygen and other essential substances throughout the body, fights sickness, and performs other vital functions. Below are 8 important facts about blood. 1. Blood Is Fluid Connective Tissue Blood is composed of 55% plasma and 45% “formed elements,” including red blood cells, white blood cells, and platelets. Because of these living cells suspended in the plasma, blood is considered a fluid connective tissue (not a fluid). It is the only fluid tissue in the body. 2. Blood Provides the Body's Cells with Oxygen and Removes Carbon Dioxide Blood absorbs oxygen from air in the lungs. It transports the oxygen to cells throughout the body, and it removes waste carbon dioxide from the cells. In the lungs, the carbon dioxide moves from the blood to the air and is exhaled. 3. Blood Transports Nutrients and Hormones Blood plays a large role in digestion and endocrine system functions. Digested nutrients are absorbed into the bloodstream through capillaries in the villi that line the small intestine. These nutrients include glucose, amino acids, vitamins, minerals, and fatty acids. Blood also transports some hormones secreted by endocrine system glands to target organs and tissues. 4. Blood Regulates Body Temperature Blood absorbs and distributes heat throughout the body. It helps to maintain homeostasis through the release or conservation of warmth. Blood vessels expand and contra...

The circulatory system (cardiovascular system) pumps blood from the heart to the lungs to get oxygen. The heart then sends oxygenated blood through arteries to the rest of the body. The veins carry oxygen-poor blood back to the heart to start the circulation process over. Your circulatory system is critical to healthy organs, muscles and tissues. Overview What is the circulatory system? Your heart and blood vessels make up the circulatory system. The main function of the circulatory system is to provide oxygen, nutrients and hormones to muscles, tissues and organs throughout your body. Another part of the circulatory system is to remove waste from cells and organs so your body can dispose of it. Your The circulatory system provides blood to all the body's tissues so they can function. Function What does the circulatory system do? The circulatory system’s function is to move blood throughout the body. This blood circulation keeps organs, muscles and tissues healthy and working to keep you alive. The circulatory system also helps your body get rid of waste products. This waste includes: • Carbon dioxide from respiration (breathing). • Other chemical byproducts from your organs. • Waste from things you eat and drink. How does the circulatory system work? Your circulatory system functions with the help of blood vessels that include arteries, veins and capillaries. These • The heart’s bottom right pumping chamber (right ventricle) sends blood that’s low in oxygen (oxygen-poor b...

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Learning Objectives By the end of this section, you will be able to: List and describe the functions of the skeletal system • Attribute specific functions of the skeletal system to specific components or structures The skeletal system is the body system composed of bones, cartilages, ligaments and other tissues that perform essential functions for the human body. Bone tissue, or osseous tissue, is a hard, dense connective tissue that forms most of the adult skeleton, the internal support structure of the body. In the areas of the skeleton where whole bones move against each other (for example, joints like the shoulder or between the bones of the spine), cartilages, a semi-rigid form of connective tissue, provide flexibility and smooth surfaces for movement. Additionally, ligaments composed of dense connective tissue surround these joints, tying skeletal elements together (a ligament is the dense connective tissue that connect bones to other bones). Together, they perform the following functions: Figure 6.1.1 Functions of the skeletal system. Support, Movement, and Protection Some functions of the skeletal system are more readily observable than others. When you move you can feel how your bones support you, facilitate your movement, and protect the soft organs of your body. Just as the steel beams of a building provide a scaffold to support its weight, the bones and cartilages of your skeletal system compose the scaffold that supports the rest of your body. Without the skel...

CONTENTS • Blood Definition • Function of Blood • Bringing Vital Substances to Cells • Removing Dangerous Wastes • Contains and Transports Immune Factors • Contains and Transports Clotting Factors • Components of Blood • Plasma • Red Blood Cells • White Blood Cells • Platelets • Blood Types • Quiz Index Blood Definition Blood is the body fluid in humans and other animals that delivers the essential materials for life to the body’s cells. It has sometimes been called a fluid “tissue,” because like solid tissues it contains several types of cells which perform complex functions for the human body. The components of blood are produced mainly in the bone marrow, where special cells produce red cells, white cells, and platelets. So-called “blood cancers” such as leukemia are actually cancers of the bone marrow. As cancerous tissue replaces healthy bone marrow tissue, healthy red blood cells, white blood cells, and platelets cannot be made. Despite looking like a simple red fluid, blood is as complex as any tissue in the body. Here we will discuss its functions, its components, and some clinically important characteristics of blood. Function of Blood Important functions of the blood include: Bringing Vital Substances to Cells Complex multicellular organisms need complex circulatory systems; that’s because we have many cells, and these cells have high metabolisms. Without highly efficient means of delivering vital substances like oxygen, water, and nutrients, complex and active l...

Enter search terms to find related medical topics, multimedia and more. Advanced Search: • Use “ “ for phrases o [ “pediatric abdominal pain” ] • Use – to remove results with certain terms o [ “abdominal pain” –pediatric ] • Use OR to account for alternate terms o [teenager OR adolescent ] Search A-Z The skin keeps vital chemicals and nutrients in the body while providing a barrier against dangerous substances from entering the body and provides a shield from the harmful effects of ultraviolet radiation emitted by the sun. In addition, skin color, texture, and folds ( see Descriptions of Skin Marks, Growths, and Color Changes Doctors use specific terms to describe various types of marks and growths on the skin. Some skin disorders and infections can cause color changes in the skin. (See also Structure and Function... read more ) help mark people as individuals. Anything that interferes with skin function or causes changes in appearance ( see Effects of Aging on the Skin Aging results in thinning of the dermis and epidermis. The underlying fat layer can be lost as well. The decrease in volume and overall effectiveness of all three skin layers results in a number... read more ) can have major consequences for physical and mental health. Many problems that appear on the skin are limited to the skin. Sometimes, however, the skin provides clues to a disorder that affects the entire body. Consequently, doctors often must consider many possible diseases when evaluating skin probl...