Hm Shander Popular Books
Hm Shander Biography & Facts
Red blood cells (RBCs), scientific name erythrocytes (from ancient Greek erythros 'red' and kytos 'hollow vessel', with -cyte translated as 'cell' in modern usage), also known as red cells, erythroid cells, and rarely haematids, are the most common type of blood cell and the vertebrate's principal means of delivering oxygen (O2) to the body tissues—via blood flow through the circulatory system. Erythrocytes take up oxygen in the lungs, or in fish the gills, and release it into tissues while squeezing through the body's capillaries. The cytoplasm of a red blood cell is rich in hemoglobin, an iron-containing biomolecule that can bind oxygen and is responsible for the red color of the cells and the blood. Each human red blood cell contains approximately 270 million hemoglobin molecules. The cell membrane is composed of proteins and lipids, and this structure provides properties essential for physiological cell function such as deformability and stability of the blood cell while traversing the circulatory system and specifically the capillary network. In humans, mature red blood cells are flexible biconcave disks. They lack a cell nucleus (which is expelled during development) and organelles, to accommodate maximum space for hemoglobin; they can be viewed as sacks of hemoglobin, with a plasma membrane as the sack. Approximately 2.4 million new erythrocytes are produced per second in human adults. The cells develop in the bone marrow and circulate for about 100–120 days in the body before their components are recycled by macrophages. Each circulation takes about 60 seconds (one minute). Approximately 84% of the cells in the human body are the 20–30 trillion red blood cells. Nearly half of the blood's volume (40% to 45%) is red blood cells. Packed red blood cells are red blood cells that have been donated, processed, and stored in a blood bank for blood transfusion. Structure Vertebrates The vast majority of vertebrates, including mammals and humans, have red blood cells. Red blood cells are cells present in blood to transport oxygen. The only known vertebrates without red blood cells are the crocodile icefish (family Channichthyidae); they live in very oxygen-rich cold water and transport oxygen freely dissolved in their blood. While they no longer use hemoglobin, remnants of hemoglobin genes can be found in their genome. Vertebrate red blood cells consist mainly of hemoglobin, a complex metalloprotein containing heme groups whose iron atoms temporarily bind to oxygen molecules (O2) in the lungs or gills and release them throughout the body. Oxygen can easily diffuse through the red blood cell's cell membrane. Hemoglobin in the red blood cells also carries some of the waste product carbon dioxide back from the tissues; most waste carbon dioxide, however, is transported back to the pulmonary capillaries of the lungs as bicarbonate (HCO3−) dissolved in the blood plasma. Myoglobin, a compound related to hemoglobin, acts to store oxygen in muscle cells. The color of red blood cells is due to the heme group of hemoglobin. The blood plasma alone is straw-colored, but the red blood cells change color depending on the state of the hemoglobin: when combined with oxygen the resulting oxyhemoglobin is scarlet, and when oxygen has been released the resulting deoxyhemoglobin is of a dark red burgundy color. However, blood can appear bluish when seen through the vessel wall and skin. Pulse oximetry takes advantage of the hemoglobin color change to directly measure the arterial blood oxygen saturation using colorimetric techniques. Hemoglobin also has a very high affinity for carbon monoxide, forming carboxyhemoglobin which is a very bright red in color. Flushed, confused patients with a saturation reading of 100% on pulse oximetry are sometimes found to be suffering from carbon monoxide poisoning. Having oxygen-carrying proteins inside specialized cells (as opposed to oxygen carriers being dissolved in body fluid) was an important step in the evolution of vertebrates as it allows for less viscous blood, higher concentrations of oxygen, and better diffusion of oxygen from the blood to the tissues. The size of red blood cells varies widely among vertebrate species; red blood cell width is on average about 25% larger than capillary diameter, and it has been hypothesized that this improves the oxygen transfer from red blood cells to tissues. Mammals The red blood cells of mammals are typically shaped as biconcave disks: flattened and depressed in the center, with a dumbbell-shaped cross section, and a torus-shaped rim on the edge of the disk. This shape allows for a high surface-area-to-volume (SA/V) ratio to facilitate diffusion of gases. However, there are some exceptions concerning shape in the artiodactyl order (even-toed ungulates including cattle, deer, and their relatives), which displays a wide variety of bizarre red blood cell morphologies: small and highly ovaloid cells in llamas and camels (family Camelidae), tiny spherical cells in mouse deer (family Tragulidae), and cells which assume fusiform, lanceolate, crescentic, and irregularly polygonal and other angular forms in red deer and wapiti (family Cervidae). Members of this order have clearly evolved a mode of red blood cell development substantially different from the mammalian norm. Overall, mammalian red blood cells are remarkably flexible and deformable so as to squeeze through tiny capillaries, as well as to maximize their apposing surface by assuming a cigar shape, where they efficiently release their oxygen load. Red blood cells in mammals are unique amongst vertebrates as they do not have nuclei when mature. They do have nuclei during early phases of erythropoiesis, but extrude them during development as they mature; this provides more space for hemoglobin. The red blood cells without nuclei, called reticulocytes, subsequently lose all other cellular organelles such as their mitochondria, Golgi apparatus and endoplasmic reticulum. The spleen acts as a reservoir of red blood cells, but this effect is somewhat limited in humans. In some other mammals such as dogs and horses, the spleen sequesters large numbers of red blood cells, which are dumped into the blood during times of exertion stress, yielding a higher oxygen transport capacity. Human A typical human red blood cell has a disk diameter of approximately 6.2–8.2 µm and a thickness at the thickest point of 2–2.5 µm and a minimum thickness in the centre of 0.8–1 µm, being much smaller than most other human cells. These cells have an average volume of about 90 fL with a surface area of about 136 μm2, and can swell up to a sphere shape containing 150 fL, without membrane distension. Adult humans have roughly 20–30 trillion red blood cells at any given time, constituting approximately 70% of all cells by number. Women have about 4–5 million red blood cells per microliter (cubic millimeter) of blood and men about 5–6 million; people living at high altitude.... Discover the Hm Shander popular books. Find the top 100 most popular Hm Shander books.
Best Seller Hm Shander Books of 2024
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Journey to Cheshire Bay
HM ShanderA homeless dropout with nothing to live for. A socially inept astrophysicist with a detailed future. A crosscountry journey that will forever alter their lives.Iris is ready to cle...
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Noel
HM ShanderWho needs holiday magic when your life is almost perfect?Britannia Edwards thinks she has it made. A highprofile career, a corner office with a view, and a private weekly meeting w...
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Accidentally in Love
HM ShanderFeatures three previously released fulllength novels in one perfect boxed set:It All Began with a NoteOne mistaken note brought them together. Their geography will tear them apart....
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Serving Up Innocence
HM ShanderDo opposites really attract?Desperately broke, Shayne will do whatever it takes to turn things around. She has a plan. She'll keep her head down, work her tail off at both of her j...
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Adrift in Cheshire Bay
HM ShanderShe’s ready to surprise her boyfriend. Turns out she’s going to be the one in shock.Tonight’s the night. Cedar couldn’t be more excited to announce to her longtime sweetheart, at t...
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Charmed in Cheshire Bay
HM ShanderNo kissing, no dating, and no matter what, absolutely no falling in love.These are three rules Summer Bates has vowed to honour after losing her one true love. Used as a pawn since...
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It All Began with a Note
HM ShanderOne note.Two strangers.Seven days in paradise.The scribbled message was supposed to be for Tess’s best friend and travel companion. In no way, shape or form was it meant for the ho...
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Serving Up Hope
HM ShanderA failure at love in the real world, but totally in love online.In the world of online dating and hidden identities, Meghan Carter finds herself facing the ultimate dilemma. When a...
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If You Say Yes
HM ShanderAurora may have got her man, but she hasn’t claimed her happily ever after yet.With the help of her best friend Lucas and a summer of battling her anxieties, Aurora finally believe...
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It All Began with a Wedding
HM ShanderWeddings in Vegas aren’t real, are they?Did Izabella get married in Vegas or not? She can't seem to remember. A drunken haze of a midnight wedding almost seven months ago starts to...
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Serving Up Secrecy
HM ShanderPassion, Secrets, and a Love Beyond ImaginationIn a moment of passion, Josephine's life takes an unexpected turn, and she finds herself pregnant. As an adopted child with no knowle...
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Unforgiven in Cheshire Bay
HM ShanderErin has learned to guard her heart and keep her secrets safely stashed away. When she’s asked to design a huge mural and collaborate on the project with a handsomely rugged man, s...
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It All Began with a Mai Tai
HM ShanderOne magical trip inspires her to change her life. When she gets home, making a change is much harder than she bargains for...Before Camille left for vacation, she knew her relation...
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That Summer
HM ShanderWhen all seems lost, do you give up forever or fight with all you have?After a car crash tore them apart, Nate makes a heartbreaking decision to walk away from his dream to win bac...
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Dreamers in Cheshire Bay
HM ShanderMia MacDonald loves Cheshire Bay more than she loves herself – just ask her former fiancé. Between the landscape, the people, and the idyllic setting, it’s her whole world. She’s h...
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Serving Up Devotion
HM ShanderHer house may need repairs, but it's her heart that's broken.Since her mother’s death, Audrina’s become her adult brother’s legal guardian. While her home suited her, it’s not for ...
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Flirty in Cheshire Bay
HM ShanderLibby learns her donated kidney is no longer prolonging her estranged father’s life. He needs another, and preferably from the sister she doesn’t remember. Shocked, she’s now taske...
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Christmas in Cheshire Bay
HM ShanderMona has never gotten over her last visit to the family's summer beach home thirteen years ago. That was the heartbreaking day her beloved mother passed away. Now, with her sister ...
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Welcome to Cheshire Bay
HM ShanderWelcome to Cheshire Bay, a smalltown community on the western edge of Vancouver Island. You'll come for the views of the Pacific Ocean, but you'll stay for the hospitality.The Ches...
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Second Chances in Cheshire Bay
HM ShanderIn a small town, the list of goodlooking, ageappropriate, and single guys is already slim. Being the only doctor for miles, those choices become even narrower. When a speed dating ...
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Duly Noted
HM ShanderOn the cusp of adulthood, Aurora met tragedy and darkness in a horrifying car crash. Death snatched her mom and sister away, destroying her family in a heartbeat. In its wake, it l...
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Awake in Cheshire Bay
HM ShanderAn emergency landing, a sexy stranger, and a night she’s never going to forget.Amber has never been lucky in love, that’s why her guard is way up. Her bar and her smalltown life ar...
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Return to Cheshire Bay
HM ShanderIt’s hard to start over, and find love, when no one forgets your past.Pregnant and suddenly jobless, Lily is desperate to figure out what she wants from life before the baby comes....