Human Circulatory System: Blood, Heart, and Vessels PDF

Okay, I will do my best to convert the attached document or image into a structured markdown format. Here's the conversion: # Circulatory System in Humans In higher animals, a well-developed transportation system called the **circulatory system** is present. In humans, the circulatory system is the...

Okay, I will do my best to convert the attached document or image into a structured markdown format. Here's the conversion: # Circulatory System in Humans In higher animals, a well-developed transportation system called the **circulatory system** is present. In humans, the circulatory system is the life support system that provides their body cells with food and oxygen and takes away waste products from the body cells. The human circulatory system consists of blood, blood vessels, and the heart. ## Blood Blood is a specialized body fluid that flows inside blood vessels. It is red in color and transports various substances, including oxygen, within the human body. In a healthy adult human being, the volume of blood is about 5 liters. Blood is mainly composed of two components - plasma and blood corpuscles (blood cells). ### Plasma Plasma is the fluid part of the blood in which different types of blood cells remain suspended. It is pale yellow in color and constitutes about 55% of the blood. Plasma mainly contains water (about 90%) but other contents like minerals, salts, nutrients, proteins, enzymes, fats, vitamins, hormones, etc., are dissolved in it. ### Blood Corpuscles (Blood Cells) Blood cells account for 45% of the blood tissue by volume. There are three types of blood cells present in the blood: * Red blood cells (RBCs) * White blood cells (WBCs) * Blood platelets #### 1. Red Blood Cells (RBCs) RBCs, also known as erythrocytes, are produced in **bone marrow**. These are biconcave, disc-shaped structures which contain a red-colored iron-rich pigment called **hemoglobin**. Due to the presence of hemoglobin pigment, RBCs are red in color. Hemoglobin combines with oxygen to form **oxyhemoglobin** and transports it to various body parts. When this oxygen-rich blood reaches the body cells, oxyhemoglobin dissociates, releasing oxygen and hemoglobin. The oxygen is used by the cells for respiration. Hemoglobin again becomes available to transport the oxygen. Hemoglobin also combines with carbon dioxide and transports it from the body cells to the lungs, from where it is breathed out. #### 2. White Blood Cells (WBCs) WBCs, also known as leucocytes, are colorless, slightly larger in size, and are fewer in number than RBCs. Their main function is to protect us against diseases by destroying harmful bacteria and other foreign materials that enter into our body. They can change their shape just like amoeba and are thus capable of amoeboid movement. This helps them to pass through the walls of blood vessels and to reach infected parts of the body. The WBC count goes up when there is any infection in the body. They provide us with immunity and help in fighting against infections, allergies, and foreign particles. Hence, WBCs are called **soldiers of the body**. #### 3. Blood Platelets These are also called thrombocytes. Platelets are colorless and smaller in size than both RBCs and WBCs. They help the blood to clot whenever there is a cut or wound on the body. This blocks the flow of blood and prevents blood loss. Blood in some animals like crab, lobsters, octopus, squid, etc., is blue in color due to the presence of a copper-rich pigment called hemocyanin. Just like hemoglobin, it carries oxygen. ## Functions of Blood Blood performs the following functions in the human body: 1. It helps in the transportation of oxygen from the lungs to body cells, and carbon dioxide from body cells to lungs. 2. It helps in the absorption of digested food and transports it to all cells of the body. 3. It plays an important role in the transportation of excretory materials such as urea, uric acid, etc. 4. It helps in regulating body temperature. 5. It contains cells and antibodies that fight against infection. ## Blood Vessels Inside the human body, blood flows through a network of tubes called **blood vessels.** There are three types of blood vessels: * Arteries * Veins * Capillaries ### 1. Arteries Arteries carry oxygen-rich (oxygenated) blood away from the heart and distribute it to all parts of the body. The Pulmonary artery is the only exception as it carries deoxygenated blood from the heart to the lungs. Arteries have thick elastic walls to allow stretching and to deal with the high pressure of blood coming from the heart. Arteries are usually deep-seated under the skin. Valves are absent in arteries. ### 2. Veins Veins carry carbon dioxide-rich (deoxygenated) blood from various body parts back to the heart. The Pulmonary vein is the only exception as it carries oxygenated blood from the lungs to the heart. Veins have thin elastic walls. The diameter of veins is greater than that of arteries. These are superficially placed, i.e., they lie closer to the surface of the skin and can be seen as greenish-blue lines in our hands and legs. The blood pressure in the veins is low. There are a series of valves present in veins which prevent back flow and allow blood to flow only in one direction, i.e., towards the heart. ### 3. Capillaries Capillaries are the tiny and the finest blood vessels, branching out from arteries that join to form veins. Capillaries form a network around the body cells so that all cells have blood passing close to them. Capillaries have extremely thin walls which help in the exchange of gases and diffusion of materials between blood and body cells. ## Differences Between Arteries and Veins | Feature | Arteries | Veins | | :--------------------- | :------------------------------------------------- | :--------------------------------------------- | | Blood Carried | Carries blood away from the heart | Carries blood toward the heart | | Wall Thickness | Thick-walled tubes | Comparatively thinner walls | | Placement | Deeply placed under the skin | Superficially placed, blood doesn't move under pressure | | Blood Pressure | Blood moves under high pressure | Lower blood pressure | | Valves | No valves inside arteries | Valves present to prevent backflow | ## Heart The description is of a diagram of a heart. Heart is a highly muscular organ, about the size of the fist, located in the chest cavity, between the two lungs slightly to the left behind the breast bone. It is one of the most important organs that functions throughout a person's life span tirelessly. It beats continuously to pump the blood through the blood vessels to all the parts of the body. The heart is made of cardiac muscles and is divided into four chambers. The two upper chambers are called the atria (singular: atrium) or auricles and the two lower chambers are called ventricles. Atria are the blood-receiving chambers of the heart. Their walls are thinner than those of the ventricles. The right atrium receives deoxygenated blood from the body parts, while the left atrium receives oxygenated blood from the lungs. Ventricles are the blood-distributing chambers of the heart. The right ventricle receives deoxygenated blood from the right atrium and pumps it to the lungs for oxygenation. The left ventricle is the largest heart chamber and has the thickest walls. It receives oxygenated blood from the left atrium and pumps it to the body parts. The left and right sides of the heart are completely separated from each other by a thin-walled tissue, called the septum, which prevents mixing of oxygenated and deoxygenated blood in the left and right side of the heart respectively. The heart has a number of valves that prevent the back flow of blood from ventricles to atria and allow the blood to flow in one direction only. Human heart works tirelessly from the moment it begins to beat in the mother's womb until it stops at Ideath. The heart is made up of cardiac muscles that work continuously and never get tired. On average, human hearts beat around 2.5 billion times in its lifetime. **Atherosclerosis** is a thickening or hardening of arteries caused by the buildup of fats, calcium, fibrin, cholesterol, and cellular wastes in the inner lining of the artery. ## Circulation of Blood Two large veins (vena cava) bring deoxygenated blood from all over the body (except lungs) to the right atrium. The right atrium, on contraction, pumps this blood to the right ventricle, which then pumps it to the lungs through the pulmonary artery to pick up oxygen. The oxygenated blood is received by the left atrium through two pairs of pulmonary veins (one pair from the right lung and one pair from the left lung). It is then pumped into the left ventricle, which, in turn, pumps the oxygenated blood into the largest artery called the aorta, through which it is supplied to the rest of the body. The deoxygenated blood from different body parts again enters the right side of the heart and is pumped to the lungs through the pulmonary artery for the exchange of gases (carbon dioxide is given off and oxygen is picked up). This oxygen-rich blood then travels back to the left side of the heart and is again sent to different parts of the body. In this way, the process is repeated again and again, and blood circulates through the body, 72 times in a minute, the same as the heartbeat rate and pulse rate. ## Heartbeat The walls of different chambers of the heart are made of special muscles called cardiac muscles. These muscles contract and relax rhythmically to pump the blood throughout the body. One complete contraction and relaxation of the heart is called one heartbeat. Human heart beats about 72 times per minute. This is called the heart rate (i.e., number of times the heart beats in one minute). The heartbeat consists of two sounds: "lub" and "dub." A doctor uses the stethoscope as a medical device to amplify the sound of the heart. It consists of a chest piece that carries a sensitive diaphragm, two ear pieces, and a tube joining the parts. Doctors can get clues about the condition of your heart by listening through a stethoscope. ## Pulse and Pulse Rate Pulse is the throbbing movement caused by the flow of blood, under pressure, in the arteries. The number of pulses per minute is called the pulse rate. A resting person usually has a pulse rate of 72 pulses per minute. The pulse can be felt at various points on the body where the arteries are just under the skin, such as the temples, neck (over carotid artery), crook of the elbow, wrist, back of the knee, and inside back of the ankle. Females have higher pulse rates than males. Pulse rate increases during emotional distress, heavy exercise, etc. | Feature | Heartbeat | Pulse | | :------------------------- | :------------------------------------------------------- | :----------------------------------------------------------------- | | Definition | Rhythmic contraction and relaxation of chambers | Rhythmic contraction and relaxation in aorta & main arteries | | Regulation | Regulated by Nervous and Endocrine systems | Dependent on rate of Heartbeat. | | One Complete unit | One Consists of One construction and takes for about 0.8 seconds. |Regular jerk ofan artery| ## Excretion Our body cells accomplish their operations through several biochemical reactions. These biochemical reactions, collectively referred to as metabolism, produce certain waste products. Accumulation of these waste products is harmful, as these are toxic in nature. Thus, these waste products need to be removed from the body. The biological process by which harmful metabolic waste is expelled from the body is called excretion. Major waste products that are produced in the human body are carbon dioxide, urea, water, salts, uric acid, etc. The parts or organs involved in excretion form the excretory system. In lower animals, waste is removed by the process of simple diffusion. However, higher animals possess specialized organs for excretion. Plants produce various metabolic wastes but they do not possess any specialized organs for their removal. Gaseous wastes are expelled through the stomata, water vapor from the leaves through transpiration, solid wastes stored in the plant body through the shedding of leaves, peeling of bark falling. Human Excretory System The human excretory system consists of a pair of kidneys, a pair of ureters, urinary bladder, and urethra. Kidneys are bean-shaped organs that are positioned in the abdominal cavity, just below the diaphragm, one on either side of the backbone. When the blood reaches the kidneys, it contains both useful and harmful substances. the useful substances are absorbed back into the blood, whereas the wastes dissolved in the water removed as urine. If glucose is present in the urine of a person what health condition does it indicate? Diabetes The kidneys are made up of a large number of coiled tubes called nephrons. Each kidney contains about one million nephrons. A nephron is the structural and functional unit of the kidney. They filter the blood by removing excess water, salts, and urea from it. The clean and purifies blood leaves the kidneys and continues circulating in the body. Wastes removed by the kidneys form a liquid called urine. A narrow tube called the ureter runs from the inner side of each kidney. The two ureters from each kidney are connected to a large sac called the bladder. Ureters transport the generated urine into the urinary bladder, where it is stored. From the bladder, urine passes through another muscular tube called the urethra and is finally passed out through a urinary opening at the end of the urethra. *An adult human being normally passes about 1-1.8 L of urine. The urine that passes of an addult human being consists of 95% water, 2.5% urea and 2.5% of other waste products.* Other Organs of Excretion: Apart from kidneys, there are other organs/parts in the human body that also helps in excretion which has to be noted: * Lungs: This Removes carbon dioxid and vapour, which produced during respiration. * Skin: This removes urea, salts and excesss of water in the form of sweat through sweat glands. helps in regulating body temperature and keeps de body cool * Liver: This removes toxins and excretes to make sure the amount excreted in bile produced in liver. *Ammonotelism, Ureotelism and Uricotelism is the way in which animals the amount they depend. Kidney Failure: Kidney filature is dondition which in kidney both the kidneys will the of the person stop working this is done with the help of machies to filtering blood. *To keep exess of salt Sweat glands * The unet of kedney -Nephreon * Stores in unvary Bloddas *The machine used to feeler for waste and uterer*. ## Transportation in Plants All the plant parts need minerals, water, and food to carry out basic life processes. Water and minerals absorbed by roots, need to be transported to different plant parts, including leaves. Leaves synthesize food by the process of photosynthesis the prepared food is also need to be carried to the other parts if the plant. For the transportation of these substances across the plant body, plants possess a well-developed transport system called a vascular system the vascular system comprises of vascular tissues. A tissue is a group of cells perform specialized function in an organism. Xylem and pholem are vascular tissues. Transportation of water and minerals from the roots to all the aerial parts a plant occurs through example transplantation of food synthesized in the leaves to all the other parts. Transportation of water and minerals what are long with mineral salts dissolved in it enters the plan through the thin roots here is present in root root hairs or extension and roots that increase for the absorption of water in between the soil particles by Omosis. Omoss is the protein moves of water molecules across the semipermeable membrane it allows certain molecule to cross and high concentrate to from a low where it Is no close with the water molecules are more concrntrated. The leaves form a continuous network of channels to connect the leaves to the tree which is in this manner that a transport. *Water pass across a route through the stem. Excretory systems from our body and animals. There is what will help. * Deforestation-To cut down trees.* ## Artificial Methods of Vegetative Propagation The process of new plants by artificial method is known as artificial propagation some of these methods are as follows: ### Cutting In this method, and healthy new plants are cut into segments like Bougainvillea and Sugarcane. and plant in moist soft they cutting will grow ### Layering. In this method young birds and covered moist of some soil the brain will cut by plants is called layering . ### **Crafting** This is the common method called hybrid varieties where some new ornamental plants are created and has a common with fruits and other. plants are grown such as Apple, guava and mango. ### Tissue Cultural To large to produce the quantity are used to conserve endangered and rare varieties of plants. *Some plants use the root and other plant parts to do vegetative in the function for the plant such a water storage from soil.* Process by to get help in tissue culture to do different plant types and other. ### Parts of some Plants * Roots * Stem. * Leaves.* ## Vegetative Propagation This helps to produce new plants in the best way for the plants. ### Asexual Reproduction The new plants formed through a number of cells is asexual production. Rhizomes are the most form by which new plants or vegetaries is formed like Ginger. *The leaves have new plant buds are Bryophyllum.* ## Transpiration The process by which water vapor escapes from a living organism, typically a plant, from internal parts to the atmosphere This method creates to help move the material and all parts. ## Step by Step *You must do this Some time it has to get rid get off or go so that a new way can help for growth Some cases it has to get away.*.