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#176 Re: This is Cool » Miscellany » 2025-08-26 22:19:30
2375) Strait
Gist
A strait is a narrow body of water that connects two larger bodies of water and separates two landmasses. It serves as a natural waterway, often crucial for navigation and shipping. For example, the Strait of Gibraltar connects the Atlantic Ocean and the Mediterranean Sea.
Summary
A strait is a narrow channel of water between two land areas. A strait connects two bodies of water. Straits often connect two seas. Many straits are economically and strategically important. Straits may be part of important shipping routes. So, someone who controls a strait can control the shipping. Wars have been fought to control them. Although rivers and canals often connect two large lakes or a lake and a sea, they are not straits. Straits are much larger and wider and do not have water running in a single direction.
Well-known straits
Well-known straits in the world are:
* Bosporus and the Dardanelles, which connect the Mediterranean and the Black Sea
* Strait of Dover, between England and France, which connects the North Sea with the English Channel
* Strait of Gibraltar, the only natural passage between the World Ocean and the Mediterranean Sea
* Bering Strait between Alaska and Siberia, which connects the Pacific and Arctic Oceans
* Strait of Magellan, connecting the Atlantic and Pacific Oceans north of Tierra del Fuego
* Palk strait, between India and Sri Lanka, the location of Ram Sethu and rich in natural resources
* Strait of Hormuz connecting the Persian Gulf and the Oman Sea, through which Persian Gulf petroleum is shipped to the world
* Strait of Malacca, which separates the Malay Peninsula from Sumatra, and connects the Indian Ocean with the South China Sea. (It is one of the highest-volume shipping lanes in the world.)
* Bass Strait, which is between mainland Australia and Tasmania, and connects the Indian Ocean with the Pacific Ocean.
* Torres Strait which is between Australia and New Guinea.
* Cook Strait, between New Zealand's North and South Islands, and connects the Tasman Sea and the South Pacific Ocean.
Details
A strait is a water body connecting two seas or water basins. The surface water is, for the most part, at the same elevation on both sides and can flow through the strait in either direction, although the topography generally constricts the flow somewhat. In some straits, there is a dominant directional current. Most commonly, the strait is a narrow channel that lies between two land masses. Straits are loci for sediment accumulation, with sand-sized deposits usually occurring on the two strait exits, forming subaqueous fans or deltas. Some straits are not navigable because, for example, they are too narrow or too shallow, or due to the presence of a reef or archipelago.
Terminology
The terms channel, pass, or passage can be synonymous and used interchangeably with strait, although each is sometimes differentiated with varying senses. In Scotland, firth or Kyle are also sometimes used as synonyms for strait.
Many straits are economically important. Straits can be important shipping routes and wars have been fought for control of them.
Numerous artificial channels, called canals, have been constructed to connect two oceans or seas over land, such as the Suez Canal. Although rivers and canals often provide passage between two large lakes, and these seem to suit the formal definition of strait, they are not usually referred to as such. Rivers and often canals, generally have a directional flow tied to changes in elevation, whereas straits often are free flowing in either direction or switch direction, maintaining the same elevation. The term strait is typically reserved for much larger, wider features of the marine environment. There are exceptions, with straits being called canals; Pearse Canal, for example.
Comparisons
Straits are the converse of isthmuses. That is, while a strait lies between two land masses and connects two large areas of ocean, an isthmus lies between two areas of ocean and connects two large land masses.
Some straits have the potential to generate significant tidal power using tidal stream turbines. Tides are more predictable than wave power or wind power. The Pentland Firth (a strait) may be capable of generating 10 GW. Cook Strait in New Zealand may be capable of generating 5.6 GW even though the total energy available in the flow is 15 GW.
Navigational (legal) regime
Straits used for international navigation through the territorial sea between one part of the high seas or an exclusive economic zone and another part of the high seas or an exclusive economic zone are subject to the legal regime of transit passage (Strait of Gibraltar, Strait of Dover, Strait of Hormuz). The regime of innocent passage applies in straits used for international navigation (1) that connect a part of high seas or an exclusive economic zone with the territorial sea of a coastal nation (Straits of Tiran, Strait of Juan de Fuca, Strait of Baltiysk) and (2) in straits formed by an island of a state bordering the strait and its mainland if there exists seaward of the island a route through the high seas or through an exclusive economic zone of similar convenience with respect to navigational and hydrographical characteristics (Strait of Messina, Pentland Firth). There may be no suspension of innocent passage through such straits.
Additional Information
A strait is a narrow body of water that connects two larger bodies of water.
It may be formed by a fracture in an isthmus, a narrow body of land that connects two bodies of water. Tectonic shifts can lead to straits like this. One strait that was formed by tectonic activity is the Strait of Gibraltar, the only link between the Mediterranean Sea and the Atlantic Ocean. The Strait of Gibraltar is actually closing, as the African tectonic plate slides north. In a few thousand years, the Strait of Gibraltar will be the Isthmus of Gibraltar, and the Mediterranean will be a large, salty, inland sea.
If fractures in an isthmus are created by human activity, the straits are usually called canals. The Suez Canal was constructed in 1869 as a waterway between the Mediterranean Sea and the Red Sea. The Suez Canal allows transportation between Europe and Asia without having to go around the entire continent of Africa. It is an important economic strait.
A strait can also be formed by a body of water overflowing land that has subsided or has been eroded. The Bosporus, which links the Black Sea and the Aegean Sea, was formed this way. Land at the southwestern edge of the Black Sea eroded and crumbled, creating a strait. Although scientists know that the Black Sea was once an enclosed lake, they do not know for sure whether the Black Sea flooded into the Aegean, or the Aegean flooded into the Black Sea. The Bosporus is an extremely important strait, separating the continents of Europe and Asia. Besides two entire continents, the Bosporus also separates a single country. It splits the European part of Turkey, called Thrace, and the Asian part, called Anatolia.
Strategic Straits
Historically, straits have had great strategic importance. Whoever controls a strait is likely to control the sea and shipping routes of the entire region.
The Strait of Hormuz connects the Persian Gulf and a part of the Arabian Sea called the Gulf of Oman. Great quantities of petroleum from Middle Eastern states are shipped through the Strait of Hormuz.
The strait is jointly controlled by Oman, the United Arab Emirates, and Iran. These countries, which all export oil, are rarely in dispute with each other. They all have military centers in the region. Countries that import oil from the region also patrol the Strait of Hormuz. Sometimes, these military patrols can lead to conflict. In 2008, the United States accused Iran of harassing U.S. warships with small speedboats. Iran denied the allegations. The two countries were close to conflict for months before the dispute was settled without violence.
Their narrow passages can make some straits difficult to navigate. The Strait of Magellan is a very thin waterway between the southern tip of South America and the group of islands known as Tierra del Fuego. The strait links the Pacific and Atlantic Oceans. The stormy waters south of Tierra del Fuego (close to Antarctica) made the Strait of Magellan, to the north, more attractive to mariners. Although the landmasses protect the strait from harsh Antarctic weather, the Strait of Magellan is still difficult to navigate. It is narrow and the islands of Tierra del Fuego can lead to confusion in stormy weather. The temperatures can reach freezing. Strong wind and waves make visibility and steering complex.
Whaling ships of the 19th century, sailing from the East Coast of the United States to the whaling grounds of the South Pacific, would sometimes stay for weeks around the Strait of Magellan, waiting for calm, clear days for passage.
#177 This is Cool » White Blood Cells » 2025-08-26 21:42:13
- Jai Ganesh
- Replies: 0
White Blood Cells
Gist
White Blood Cells are components of the immune system that protect the body from infection and disease. They circulate in the blood and lymph, and are produced in the bone marrow from stem cells. The main types of white blood cells include lymphocytes (T cells and B cells), monocytes, and granulocytes (neutrophils, eosinophils, and basophils), each with a distinct role in detecting and destroying pathogens, producing antibodies, and engulfing foreign materials.
White blood cells (WBCs), or leukocytes, are a crucial part of the immune system, produced in the bone marrow and circulating in the blood and lymph tissue to fight infections, other diseases, and foreign invaders. There are five main types—neutrophils, eosinophils, basophils, lymphocytes, and monocytes—each with specific roles in the body's defense. A white blood cell count (WBC count) is a common blood test that measures the number of WBCs, with an elevated count often indicating an infection or inflammatory condition.
Summary
White blood cells (scientific name leukocytes), also called immune cells or immunocytes, are cells of the immune system that are involved in protecting the body against both infectious disease and foreign entities. White blood cells are generally larger than red blood cells. They include three main subtypes: granulocytes, lymphocytes and monocytes.
All white blood cells are produced and derived from multipotent cells in the bone marrow known as hematopoietic stem cells. Leukocytes are found throughout the body, including the blood and lymphatic system. All white blood cells have nuclei, which distinguishes them from the other blood cells, the anucleated red blood cells (RBCs) and platelets. The different white blood cells are usually classified by cell lineage (myeloid cells or lymphoid cells). White blood cells are part of the body's immune system. They help the body fight infection and other diseases. Types of white blood cells are granulocytes (neutrophils, eosinophils, and basophils), and agranulocytes (monocytes, and lymphocytes (T cells and B cells)). Myeloid cells (myelocytes) include neutrophils, eosinophils, mast cells, basophils, and monocytes.[6] Monocytes are further subdivided into dendritic cells and macrophages. Monocytes, macrophages, and neutrophils are phagocytic. Lymphoid cells (lymphocytes) include T cells (subdivided into helper T cells, memory T cells, cytotoxic T cells), B cells (subdivided into plasma cells and memory B cells), and natural killer cells. Historically, white blood cells were classified by their physical characteristics (granulocytes and agranulocytes), but this classification system is less frequently used now. Produced in the bone marrow, white blood cells defend the body against infections and disease. An excess of white blood cells is usually due to infection or inflammation. Less commonly, a high white blood cell count could indicate certain blood cancers or bone marrow disorders.
The number of leukocytes in the blood is often an indicator of disease, and thus the white blood cell count is an important subset of the complete blood count. The normal white cell count is usually between 4 billion/L and 11 billion/L. In the US, this is usually expressed as 4,000 to 11,000 white blood cells per microliter of blood. White blood cells make up approximately 1% of the total blood volume in a healthy adult, making them substantially less numerous than the red blood cells at 40% to 45%. However, this 1% of the blood makes a huge difference to health because immunity depends on it. An increase in the number of leukocytes over the upper limits is called leukocytosis. It is normal when it is part of healthy immune responses, which happen frequently. It is occasionally abnormal when it is neoplastic or autoimmune in origin. A decrease below the lower limit is called leukopenia, which indicates a weakened immune system.
Details
White blood cells are a part of your immune system that protects your body from infection. These cells circulate through your bloodstream and tissues to respond to injury or illness by attacking any unknown organisms that enter your body.
What are white blood cells?
White blood cells, also known as leukocytes, are responsible for protecting your body from infection. As part of your immune system, white blood cells circulate in your blood and respond to injury or illness.
Function:
What do white blood cells do?
White blood cells protect your body against infection. As your white blood cells travel through your bloodstream and tissues, they locate the site of an infection and act as an army general to notify other white blood cells of their location to help defend your body from an attack of an unknown organism. Once your white blood cell army arrives, they fight the invader by producing antibody proteins to attach to the organism and destroy it.
Anatomy:
Where are white blood cells located?
Your white blood cells are in your bloodstream and travel through blood vessel walls and tissues to locate the site of an infection.
What do white blood cells look like?
Contrary to their name, white blood cells are colorless but can appear as a very light purple to pink color when examined under a microscope and colored with dye. These extremely tiny cells have a round shape with a distinct center membrane (nucleus).
How big are white blood cells?
You can only see white blood cells under a microscope, as they are extremely small.
How many white blood cells are in my body?
White blood cells account for 1% of your blood. There are more red blood cells in your body than white blood cells.
How are white blood cells formed?
White blood cell formation occurs in the soft tissue inside of your bones (bone marrow). Two types of white blood cells (lymphocytes) grow in the thymus gland (T cells) and lymph nodes and spleen (B cells).
What are white blood cells made of?
White blood cells originate from cells that morph into other cells in the body (stem cell) within the soft tissue of your bones (bone marrow).
What are the types of white blood cells?
There are five types of white blood cells:
* Neutrophils: Help protect your body from infections by killing bacteria, fungi and foreign debris.
* Lymphocytes: Consist of T cells, natural killer cells and B cells to protect against viral infections and produce proteins to help you fight infection (antibodies).
* Eosinophils: Identify and destroy parasites, cancer cells and assists basophils with your allergic response.
* Basophils: Produce an allergic response like coughing, sneezing or a runny nose.
* Monocytes: Defend against infection by cleaning up damaged cells.
Conditions and DisordersWhat are the common conditions and disorders that affect white blood cells?
If you have a low white blood cell count, you are likely to get infections (leukopenia). If your white blood cell count is too high (leukocytosis), you may have an infection or an underlying medical condition like leukemia, lymphoma or an immune disorder.
What are common signs or symptoms of white blood cell conditions?
Symptoms of white blood cell conditions, where you may have a count that is too high or too low, include:
* Fever, body aches and chills.
* Wound that is red, swollen, oozes pus or won’t heal.
* Frequent infections.
* Persistent cough or difficulty breathing.
What is a normal white blood cell count?
It is normal for you to produce nearly 100 billion white blood cells each day. After completing a blood draw, a test counts your white blood cells, which equals number of cells per microliter of blood. The normal white blood cell count ranges between 4,000 and 11,000 cells per microliter.
What are common tests to check the number of white blood cells?
A complete blood count (CBC) test identifies information about the cells in your blood. A lab completes this test after a medical professional draws your blood and examines your white and red blood cell count.
White blood cells scan is a test to detect infection or abscesses in your body’s soft tissues. This test involves withdrawing your blood, separating the white blood cells from the sample, tagging them with a radioactive isotope, returning those white blood cells back into your body, then an imaging test will identify areas that show infection or abscess on your body.
What causes a low white blood cell count?
Causes of low white blood cell count include:
* Bone marrow failure (aplastic anemia).
* Bone marrow attacked by cancer cells (leukemia).
* Drug exposure (chemotherapy).
* Vitamin deficiency (B12).
* HIV/AIDS.
A blood test with fewer than 4,000 cells per microliter of blood diagnoses low white blood cells.
What causes a high white blood cell count?
Causes of high white blood cell count include:
* Autoimmune disorders (lupus, rheumatoid arthritis).
* Viral infections (mononucleosis).
* Bacterial infections (sepsis).
* Physical injury or stress.
* Leukemia or Hodgkins disease.
* Allergies.
A blood test with more than 11,000 cells per microliter of blood diagnoses high white blood cells.
What are common treatments for white blood cell disorders?
Treatment for white blood cell disorders vary based on the diagnosis and severity of the condition. Treatment ranges from:
* Taking vitamins.
* Taking antibiotics.
* Surgery to replace or repair bone marrow.
* Blood transfusion.
* Stem cell transplant.
Care:
How do I take care of my white blood cells?
You can take care of your white blood cells by:
* Practicing good hygiene to prevent infection.
* Taking vitamins to boost your immune system.
* Treating medical conditions where white blood cell disorders are a side effect.
White blood cells serve as your first line of defense against injury or illness. Keep your white blood cells healthy by taking vitamins to boost your immune system and practicing good hygiene to prevent infection. If you experience any symptoms like fever and chills, frequent infection, persistent cough or difficulty breathing, contact your healthcare provider to test if your white blood cell count is abnormal.
Additional Information
A white blood cell is a cellular component of the blood that lacks hemoglobin, has a nucleus, is capable of motility, and defends the body against infection and disease by ingesting foreign materials and cellular debris, by destroying infectious agents and cancer cells, or by producing antibodies.
Characteristics of white blood cells
In adults, the bone marrow produces 60 to 70 percent of the white cells (i.e., the granulocytes). The lymphatic tissues, particularly the thymus, the spleen, and the lymph nodes, produce the lymphocytes (comprising 20 to 30 percent of the white cells). The reticuloendothelial tissues of the spleen, liver, lymph nodes, and other organs produce the monocytes (4 to 8 percent of the white cells). A healthy adult human has between 4,500 and 11,000 white blood cells per cubic millimetre of blood. Fluctuations in white cell number occur during the day; lower values are obtained during rest and higher values during exercise.
The survival of white blood cells, as living cells, depends on their continuous production of energy. The chemical pathways utilized are more complex than those of the red cells and are similar to those of other tissue cells. White cells, containing a nucleus and able to produce ribonucleic acid (RNA), can synthesize protein.
Although white cells are found in the circulation, most occur outside the circulation, within tissues, where they fight infections; the few in the bloodstream are in transit from one site to another. As living cells, their survival depends on their continuous production of energy. The chemical pathways utilized are more complex than those of red blood cells and are similar to those of other tissue cells. White cells, containing a nucleus and able to produce ribonucleic acid (RNA), can synthesize protein. White cells are highly differentiated for their specialized functions, and they do not undergo cell division (mitosis) in the bloodstream; however, some retain the capability of mitosis. On the basis of their appearance under a light microscope, white cells are grouped into three major classes—lymphocytes, granulocytes, and monocytes—each of which carries out somewhat different functions.
Major classes of white blood cells
Lymphocytes, which are further divided into B cells and T cells, are responsible for the specific recognition of foreign agents and their subsequent removal from the host. B lymphocytes secrete antibodies, which are proteins that bind to foreign microorganisms in body tissues and mediate their destruction. Typically, T cells recognize virally infected or cancerous cells and destroy them, or they serve as helper cells to assist the production of antibody by B cells. Also included in this group are natural killer (NK) cells, so named for their inherent ability to kill a variety of target cells. In a healthy person, about 25 to 33 percent of white blood cells are lymphocytes.
Granulocytes, the most numerous of the white cells, rid the body of large pathogenic organisms such as protozoans or helminths and are also key mediators of allergy and other forms of inflammation. These cells contain many cytoplasmic granules, or secretory vesicles, that harbour potent chemicals important in immune responses. They also have multilobed nuclei, and because of this they are often called polymorphonuclear cells. On the basis of how their granules take up dye in the laboratory, granulocytes are subdivided into three categories: neutrophils, eosinophils, and basophils. The most numerous of the granulocytes—making up 50 to 80 percent of all white cells—are neutrophils. They are often one of the first cell types to arrive at a site of infection, where they engulf and destroy the infectious microorganisms through a process called phagocytosis. Eosinophils and basophils, as well as the tissue cells called mast cells, typically arrive later. The granules of basophils and of the closely related mast cells contain a number of chemicals, including histamine and leukotrienes, that are important in inducing allergic inflammatory responses. Eosinophils destroy parasites and also help to modulate inflammatory responses.
Monocytes, which constitute between 4 and 8 percent of the total number of white blood cells in the blood, move from the blood to sites of infection, where they differentiate further into macrophages. These cells are scavengers that phagocytose whole or killed microorganisms and are therefore effective at direct destruction of pathogens and cleanup of cellular debris from sites of infection. Neutrophils and macrophages are the main phagocytic cells of the body, but macrophages are much larger and longer-lived than neutrophils. Some macrophages are important as antigen-presenting cells, cells that phagocytose and degrade microbes and present portions of these organisms to T lymphocytes, thereby activating the specific acquired immune response.
Diseases of white blood cells
Specific types of cells are associated with different illnesses and reflect the special function of that cell type in body defense. In general, newborns have a high white blood cell count that gradually falls to the adult level during childhood. An exception is the lymphocyte count, which is low at birth, reaches its highest levels in the first four years of life, and thereafter falls gradually to a stable adult level.
An abnormal increase in white cell number is known as leukocytosis. This condition is usually caused by an increase in the number of granulocytes (especially neutrophils), some of which may be immature (myelocytes). White cell count may increase in response to intense physical exertion, convulsions, acute emotional reactions, pain, pregnancy, labour, and certain disease states, such as infections and intoxications.
A large increase in the numbers of white blood cells in the circulation or bone marrow is a sign of leukemia, a type of cancer of the blood-forming tissues. Some types of leukemia have been related to radiation exposure, as noted in the Japanese population exposed to the first atomic bomb at Hiroshima; other evidence suggests hereditary susceptibility. A number of different leukemias are classified according to the course of the disease and the predominant type of white blood cell involved. For example, myelogenous leukemia affects granulocytes and monocytes, white blood cells that destroy bacteria and some parasites.
An abnormal decrease in white blood cell numbers is known as leukopenia. The count may decrease in response to certain types of infections or drugs or in association with certain conditions, such as chronic anemia, malnutrition, or anaphylaxis.
Certain types of infections are characterized from the beginning by an increase in the number of small lymphocytes unaccompanied by increases in monocytes or granulocytes. Such lymphocytosis is usually of viral origin. Moderate degrees of lymphocytosis are encountered in certain chronic infections, such as tuberculosis and brucellosis. Infectious mononucleosis, caused by the Epstein-Barr virus, is associated with the appearance of unusually large lymphocytes (atypical lymphocytes). These cells represent part of the complex defense mechanism against the virus, and they disappear from the blood when the attack of infectious mononucleosis subsides.
#178 Jokes » Lawyer Jokes - VI » 2025-08-26 19:52:27
- Jai Ganesh
- Replies: 0
Q: How many lawyer jokes are there?
A: Just two, all the rest are true.
* * *
Q: How many lawyers does it take to stop a moving bus?
A: Never enough.
* * *
Q: Did you hear about the new microwave lawyer?
A: You spend eight minutes in his office and get billed as if you'd been there eight hours.
* * *
Q: What's the difference between a law firm and a circus?
A: At a circus, the clowns don't charge the public by the hour.
* * *
Q: How many lawyers does it take to change a lightbulb?
A: None, they'd rather keep their clients in the dark.
* * *
#179 Re: Maths Is Fun - Suggestions and Comments » Confused » 2025-08-26 19:21:04
Let's close the topic here. Let us go forward.
#180 Re: Jai Ganesh's Puzzles » General Quiz » 2025-08-26 18:47:02
Hi,
#10535. What does the term in Biology Cell membrane mean?
#10536. What does the term in Biology Cell nucleus mean?
#181 Re: Jai Ganesh's Puzzles » Doc, Doc! » 2025-08-26 18:32:39
Hi,
#2454. What does the medical term Facial nerve paralysis signify?
#182 Re: Jai Ganesh's Puzzles » English language puzzles » 2025-08-26 17:56:29
Hi,
#5725. What does the adjective frantic mean?
#5726. What does the noun fraudster mean?
#183 Re: Jai Ganesh's Puzzles » 10 second questions » 2025-08-26 17:29:30
Hi,
#9722.
#184 Re: Jai Ganesh's Puzzles » Oral puzzles » 2025-08-26 17:06:47
Hi,
#6227.
#185 Re: Exercises » Compute the solution: » 2025-08-26 16:32:32
Hi,
2568.
#186 Re: Maths Is Fun - Suggestions and Comments » Confused » 2025-08-26 16:18:58
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#187 Re: Maths Is Fun - Suggestions and Comments » Confused » 2025-08-26 12:02:25
See Forum Rules.
#188 This is Cool » Red Blood Cells » 2025-08-25 22:29:12
- Jai Ganesh
- Replies: 0
Red Blood Cells
Gist
Red blood cells (RBCs), or erythrocytes, are the most abundant type of blood cell, responsible for transporting oxygen from the lungs to the body's tissues and carbon dioxide back to the lungs for exhalation. These cells are produced in the bone marrow and contain hemoglobin, an iron-rich protein that binds to oxygen. RBCs are small, biconcave (disc-shaped), and lack a nucleus when mature in mammals, allowing them to be flexible enough to pass through narrow blood vessels and maximize their oxygen-carrying capacity. A deficiency in red blood cells, known as anemia, can lead to symptoms like fatigue and shortness of breath.
Red blood cells (RBCs) primarily function to transport oxygen from the lungs to the body's tissues and to carry carbon dioxide, a waste product, from the tissues back to the lungs to be exhaled. This gas exchange occurs thanks to hemoglobin, a protein within the RBCs that binds to oxygen and carbon dioxide. RBCs also contribute to maintaining blood pH, help regulate body temperature, and determine a person's blood type by carrying surface antigens.
Summary
Red blood cells (RBCs), referred to as erythrocytes (from Ancient Greek erythros 'red' and kytos 'hollow vessel', with -cyte translated as 'cell' in modern usage) in academia and medical publishing, 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 (Hb), 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.
Details
Red blood cells bring oxygen to the tissues in your body and release carbon dioxide to your lungs for you to exhale. Oxygen turns into energy, which is an essential function to keep your body healthy.
What are red blood cells?
Red blood cells, also known as erythrocytes, deliver oxygen to the tissues in your body. Oxygen turns into energy and your tissues release carbon dioxide. Your red blood cells also transport carbon dioxide to your lungs for you to exhale.
Function:
What do red blood cells do?
Red blood cells are responsible for transporting oxygen from your lungs to your body’s tissues. Your tissues produce energy with the oxygen and release a waste, identified as carbon dioxide. Your red blood cells take the carbon dioxide waste to your lungs for you to exhale.
Do red blood cells carry oxygen?
Yes, a red blood cell takes oxygen from the lungs to the tissues in your body. Your cells use oxygen to produce energy.
Anatomy:
Where are red blood cells made?
Red blood cells develop in your body’s soft bone tissue (bone marrow) and release into your bloodstream after they fully mature, which takes about seven days.
What do red blood cells look like?
Red blood cells get their bright red color from a protein that allows them to carry oxygen from your lungs and deliver it to other tissues in your body (hemoglobin).
Red blood cells are microscopic and have the shape of a flat disk or doughnut, which is round with an indentation in the center, but it isn’t hollow. Red blood cells don’t have a nucleus like white blood cells, allowing them to change shape and move throughout your body easier.
What are red blood cells made of?
Red blood cells grow in your bone marrow. Bone marrow creates almost all of the cells in your body. Red blood cells contain a protein called hemoglobin, which is responsible for carrying oxygen.
Conditions and Disorders:
What are the common conditions that affect red blood cells?
Red blood cell conditions have either a low or high red blood cell count.
Medical conditions that affect a low red blood cell count include:
* Anemia. Your blood carries less oxygen than normal and causes your body to feel cold, tired and weak.
* Blood loss. Your body loses more blood cells than it can produce.
* Bone marrow disorder: You experience damage to your bone marrow, where red blood cells form (leukemia, lymphoma).
* Cancer. Certain cancers and chemotherapy treatment for cancer can affect the number of red blood cells your body produces.
Medical conditions that affect a high red blood cell count include:
* Polycythemia vera. A high red blood cell count causes your blood to thicken, leading to heart attack or stroke.
* Congenital heart disease. One or more structures in your heart is irregular due to not forming completely during fetal development.
* Lung disease. The tissue in your lungs scars due to emphysema, COPD or pulmonary fibrosis.
* Hypoxia. The oxygen level in your blood is low.
* Carbon monoxide. Smoking increases your chance of exposure to carbon monoxide.
What are common symptoms of red blood cell conditions?
Common symptoms of conditions involving red blood cells include:
* Fatigue
* Muscle weakness
* Lack of energy
* Headache or dizziness
* Blurry vision
* Cold hands and feet
What causes a low red blood cell count?
Causes that contribute to low red blood cell count include:
* Vitamin deficiency (iron, B9 and B12)
* Malnutrition
* Preexisting medical conditions or cancer treatment (chemotherapy)
What causes a high red blood cell count?
Causes that contribute to a high red blood cell count include:
* Smoking cigarettes
* Living at a high elevation
* Taking performance-enhancing drugs (anabolic steroids)
* Dehydration
* Medical conditions including heart or lung disease
What are common tests to check the health of my red blood cells?
A complete blood count (CBC) test examines how many blood cells (red and white) are in your blood. A medical professional will sample your blood to count how many red blood cells are present.
What is a normal red blood cell count?
Normal red blood cell counts differ based on the person, but general ranges include:
* Males: 4.7 to 6.1 million red blood cells per microliter of blood
* Females: 4.2 to 5.4 million red blood cells per microliter of blood
* Children: 4 to 5.5 million red blood cells per microliter of blood
If your count is outside of these ranges, it’s either too high or too low and your healthcare provider will offer additional tests or treatments.
What are common treatments for red blood cell disorders?
Treatment for red blood cell disorders varies based on the diagnosis and severity of the condition. Treatment ranges from:
* Taking vitamins
* Eating a well-balanced diet
* Treating existing medical conditions
* Getting a blood transfusion
Care:
How do I take care of my red blood cells?
You can maintain healthy red blood cells by eating a nutritious diet that’s full of vitamins and minerals like iron, B9 (folic acid) and B12, which includes:
* Red meat (beef) and meat from the organs, like liver
* Fish
* Leafy vegetables, like kale and spinach
* Lentils, beans and peas
* Nuts and dried berries
Additional Common Questions:
What is hemoglobin within red blood cells?
Hemoglobin is the protein that carries oxygen and exists within each red blood cell. If your red blood cell was a vehicle, hemoglobin is in the driver’s seat, picking up oxygen at the lungs and transporting it to the tissues throughout your body.
What are interesting facts about red blood cells?
* Red blood cells have a limited lifespan because they don’t have a center membrane (nucleus). When a red blood cell travels through your blood vessels, it uses up its energy supply and only survives an average of 120 days.
* Your blood appears red because red blood cells make up 40% of your blood.
Red blood cells are constantly moving throughout your body to bring oxygen to your tissues, and release carbon dioxide as you exhale. Keep your red blood cells healthy by eating a nutritious diet full of vitamins and minerals, and avoid smoking to reduce your risk of red blood cell disorders.
Additional Information
Red blood cell are cellular component of blood, millions of which in the circulation of vertebrates give the blood its characteristic colour and carry oxygen from the lungs to the tissues. The mature human red blood cell is small, round, and biconcave; it appears dumbbell-shaped in profile. The cell is flexible and assumes a bell shape as it passes through extremely small blood vessels. It is covered with a membrane composed of lipids and proteins, lacks a nucleus, and contains hemoglobin—a red iron-rich protein that binds oxygen.
The function of the red cell and its hemoglobin is to carry oxygen from the lungs or gills to all the body tissues and to carry carbon dioxide, a waste product of metabolism, to the lungs, where it is excreted. In invertebrates, oxygen-carrying pigment is carried free in the plasma; its concentration in red cells in vertebrates, so that oxygen and carbon dioxide are exchanged as gases, is more efficient and represents an important evolutionary development. The mammalian red cell is further adapted by lacking a nucleus—the amount of oxygen required by the cell for its own metabolism is thus very low, and most oxygen carried can be freed into the tissues. The biconcave shape of the cell allows oxygen exchange at a constant rate over the largest possible area.
The red cell develops in bone marrow in several stages: from a hemocytoblast, a multipotential cell in the mesenchyme, it becomes an erythroblast (normoblast); during two to five days of development, the erythroblast gradually fills with hemoglobin, and its nucleus and mitochondria (particles in the cytoplasm that provide energy for the cell) disappear. In a late stage the cell is called a reticulocyte, which ultimately becomes a fully mature red cell. The average red cell in humans lives 100–120 days; there are some 5.2 million red cells per cubic millimetre of blood in the adult human.
Though red cells are usually round, a small proportion are oval in the normal person, and in certain hereditary states a higher proportion may be oval. Some diseases also display red cells of abnormal shape—e.g., oval in pernicious anemia, crescent-shaped in sickle cell anemia, and with projections giving a thorny appearance in the hereditary disorder acanthocytosis. The number of red cells and the amount of hemoglobin vary among different individuals and under different conditions; the number is higher, for example, in persons who live at high altitudes and in the disease polycythemia. At birth the red cell count is high; it falls shortly after birth and gradually rises to the adult level at puberty.
#189 Re: This is Cool » Miscellany » 2025-08-25 19:51:37
2374) Hydrometer
Gist
A hydrometer is an instrument used to measure the specific gravity (or relative density) of liquids; that is, the ratio of the density of the liquid to the density of water. A hydrometer is usually made of glass and consists of a cylindrical stem and a bulb weighted with mercury or lead shot to make it float upright.
In simple terms, a hydrometer tells the user if a liquid is more or less dense than water. It will float higher in a liquid with a greater density – such as one with sugar dissolved in it – compared to one
with a lower density, such as water or alcohol.
Summary
A hydrometer or lactometer is an instrument used for measuring density or relative density of liquids based on the concept of buoyancy. They are typically calibrated and graduated with one or more scales such as specific gravity.
A hydrometer usually consists of a sealed hollow glass tube with a wider bottom portion for buoyancy, a ballast such as lead or mercury for stability, and a narrow stem with graduations for measuring. The liquid to test is poured into a tall container, often a graduated cylinder, and the hydrometer is gently lowered into the liquid until it floats freely. The point at which the surface of the liquid touches the stem of the hydrometer correlates to relative density. Hydrometers can contain any number of scales along the stem corresponding to properties correlating to the density.
Hydrometers are calibrated for different uses, such as a lactometer for measuring the density (creaminess) of milk, a saccharometer for measuring the density of sugar in a liquid, or an alcoholometer for measuring higher levels of alcohol in spirits.
The hydrometer makes use of Archimedes' principle: a solid suspended in a fluid is buoyed by a force equal to the weight of the fluid displaced by the submerged part of the suspended solid. The lower the density of the fluid, the deeper a hydrometer of a given weight sinks; the stem is calibrated to give a numerical reading.
Details
A hydrometer is an instrument used to measure the specific gravity (or relative density) of liquids; that is, the ratio of the density of the liquid to the density of water. A hydrometer is usually made of glass and consists of a cylindrical stem and a bulb weighted with mercury or lead shot to make it float upright. The liquid to be tested is poured into a tall container, often a graduated cylinder, or specially designed hydrometer cylinder, and the hydrometer is gently lowered into the liquid until it floats freely. The point at which the surface of the liquid touches the stem of the hydrometer is noted. Hydrometers usually contain a scale inside the stem, so that the specific gravity can be read directly. A variety of scales exist, and are used depending on the context, this includes Specific Gravity (SG), Baume, Twaddle and mg/L. Below we explain a little about the more specialist types of hydrometers available.
Lactometer A lactometer (or galactometer) is a hydrometer used to test milk. The specific gravity of milk does not give a conclusive indication of its composition since milk contains a variety of substances that are either heavier or lighter than water. Additional tests for fat content are necessary to determine overall composition. The instrument is graduated into a hundred parts. Milk is poured in and allowed to stand until the cream has formed, then the depth of the cream deposit in degrees determines the quality of the milk.
Range 1.025 to 1.035 g/ml.
Alcoholometer
An alcoholometer is a hydrometer which is used for determining the alcoholic strength of liquids. It is also known as a Proof and Tralles hydrometer. It only measures the density of the fluid. Certain assumptions are made to estimate the amount of alcohol present in the fluid. Alcoholometers have scales marked with volume percents of "potential alcohol", based on a pre-calculated specific gravity. A higher "potential alcohol" reading on this scale is caused by a greater specific gravity, assumed to be caused by the introduction of dissolved sugars. A reading is taken before and after fermentation and approximate alcohol content is determined by subtracting the post fermentation reading from the pre-fermentation reading.
Range 0.98 to 1.12 °SG
Saccharometer
A saccharometer is a hydrometer used for determining the amount of sugar in a solution, invented by Thomas Thomson. It is used primarily by winemakers and brewers, and it can also be used in making sorbets and ice-creams. It consists of a large weighted glass bulb with a thin stem rising from the top with calibrated markings. The sugar level can be determined by reading the value where the surface of the liquid crosses the scale. It works by the principle of buoyancy. A solution with a higher sugar content is denser, causing the bulb to float higher. Less sugar results in a lower density and a lower floating bulb.
Thermohydrometer
A thermohydrometer is a hydrometer that has a thermometer enclosed in the float section. For measuring the density of petroleum products, like fuel oils, the specimen is usually heated in a temperature jacket with a thermometer placed behind it since density is dependent on temperature. Light oils are placed in cooling jackets, typically at 15 °C. Very light oils with many volatile components are measured in a variable volume container using a floating piston sampling device to minimize light end losses. As a battery test it measures the temperature compensated specific gravity and electrolyte temperature.
Urinometer
A urinometer is a medical hydrometer designed for urinalysis. As urine's specific gravity is dictated by its ratio of solutes (wastes) to water, a urinometer makes it possible to quickly assess a patient's overall level of hydration.
Range 1 to 1.06 °SG
Soil Analysis
A hydrometer analysis is the process by which fine-grained soils, silts and clays, are graded. Hydrometer analysis is performed if the grain sizes are too small for sieve analysis. The basis for this test is Stoke's Law for falling spheres in a viscous fluid in which the terminal velocity of fall depends on the grain diameter and the densities of the grain in suspension and of the fluid. The grain diameter thus can be calculated from a knowledge of the distance and time of fall. The hydrometer also determines the specific gravity (or density) of the suspension, and this enables the percentage of particles of a certain equivalent particle diameter to be calculated.
Range 0.995 to 1.038 °SG.
Additional Information
A hydrometer is a device for measuring some characteristics of a liquid, such as its density (weight per unit volume) or specific gravity (weight per unit volume compared with water). The device consists essentially of a weighted, sealed, long-necked glass bulb that is immersed in the liquid being measured; the depth of flotation gives an indication of liquid density, and the neck can be calibrated to read density, specific gravity, or some other related characteristic.
In practice, the floating glass bulb is usually inserted into a cylindrical glass tube equipped with a rubber ball at the top end for sucking liquid into the tube. Immersion depth of the bulb is calibrated to read the desired characteristic. A typical instrument is the storage-battery hydrometer, by means of which the specific gravity of the battery liquid can be measured and the condition of the battery determined. Another instrument is the radiator hydrometer, in which the float is calibrated in terms of the freezing point of the radiator solution. Others may be calibrated in terms of “proof ” of an alcohol solution or in terms of the percentage of sugar in a sugar solution.
The Baumé hydrometer, named for the French chemist Antoine Baumé, is calibrated to measure specific gravity on evenly spaced scales; one scale is for liquids heavier than water, and the other is for liquids lighter than water.
#190 Dark Discussions at Cafe Infinity » Climb Quotes - I » 2025-08-25 18:09:20
- Jai Ganesh
- Replies: 0
Climb Quotes - I
1. It isn't the mountains ahead to climb that wear you out; it's the pebble in your shoe. - Muhammad Ali
2. Obstacles don't have to stop you. If you run into a wall, don't turn around and give up. Figure out how to climb it, go through it, or work around it. - Michael Jordan
3. Keep close to Nature's heart... and break clear away, once in awhile, and climb a mountain or spend a week in the woods. Wash your spirit clean. - John Muir
4. After climbing a great hill, one only finds that there are many more hills to climb. - Nelson Mandela
5. Just remember, you can't climb the ladder of success with your hands in your pockets. - Arnold Schwarzenegger
6. Only when you drink from the river of silence shall you indeed sing. And when you have reached the mountain top, then you shall begin to climb. And when the earth shall claim your limbs, then shall you truly dance. - Khalil Gibran
7. It's wonderful to climb the liquid mountains of the sky. Behind me and before me is God and I have no fears. - Helen Keller
8. You cannot climb the ladder of success dressed in the costume of failure. - Zig Ziglar.
#191 Re: Guestbook » Empty » 2025-08-25 16:49:26
Zach Alie,
Don't post irrelevant information in Guest Book.
#192 Science HQ » Erbium » 2025-08-25 16:46:33
- Jai Ganesh
- Replies: 0
Erbium
Gist
Erbium (Er) is a rare-earth, f-block element with atomic number 68, found as a silvery-white solid metal when isolated. It is used to color glass, in metal alloys, and as burnable poison in nuclear reactors. Due to its optical properties, erbium is also crucial for lasers in medical treatments (like resurfacing and tattoo removal) and for amplifying signals in long-distance fiber optic communications.
This metal is used to colour the lenses of glasses. It is also used in the control rods of nuclear reactors. It has a vital application in the production of metal alloys. Erbium ion's unique wavelength aids laser surgery.
Summary
Erbium is a chemical element; it has symbol Er and atomic number 68. A silvery-white solid metal when artificially isolated, natural erbium is always found in chemical combination with other elements. It is a lanthanide, a rare-earth element, originally found in the gadolinite mine in Ytterby, Sweden, which is the source of the element's name.
Erbium's principal uses involve its pink-colored Er3+ ions, which have optical fluorescent properties particularly useful in certain laser applications. Erbium-doped glasses or crystals can be used as optical amplification media, where Er3+ ions are optically pumped at around 980 or 1480 nm and then radiate light at 1530 nm in stimulated emission. This process results in an unusually mechanically simple laser optical amplifier for signals transmitted by fiber optics. The 1550 nm wavelength is especially important for optical communications because standard single mode optical fibers have minimal loss at this particular wavelength.
In addition to optical fiber amplifier-lasers, a large variety of medical applications (e.g. dermatology, dentistry) rely on the erbium ion's 2940 nm emission (see Er:YAG laser) when lit at another wavelength, which is highly absorbed in water in tissues, making its effect very superficial. Such shallow tissue deposition of laser energy is helpful in laser surgery, and for the efficient production of steam which produces enamel ablation by common types of dental laser.
Details
Erbium (Er) is a chemical element, a rare-earth metal of the lanthanide series of the periodic table.
Pure erbium is a silvery white metal that is relatively stable in air. It slowly reacts with water and quickly dissolves in diluted acids, except hydrofluoric acid (HF) because of formation of the protective fluoride (ErF3) layer on the surface of the metal. Erbium is a very strong paramagnet above approximately 85 K (−188 °C, or −307 °F). Between 85 K and 20 K (−253 °C, or −424 °F) the metal is antiferromagnetic, and below about 20 K it is arranged in a conical ferromagnetic structure.
The element was discovered in 1842 as an oxide by Carl Gustaf Mosander, who originally called it terbia; in the confusion arising from the similarity in the properties of the rare-earth elements, the names of two, terbium and erbium, became interchanged (c. 1860). The element occurs in many rare-earth minerals; among the more important are the laterite ionic clays, xenotime, and euxenite. Erbium also occurs in the products of nuclear fission. In Earth’s crust, erbium is as abundant as tantalum and tungsten.
Natural erbium is a mixture of six stable isotopes: erbium-166 (33.5 percent), erbium-168 (26.98 percent), erbium-167 (22.87 percent), erbium-170 (14.91 percent), erbium-164 (1.6 percent), and erbium-162 (0.14 percent). Not counting nuclear isomers, a total of 30 radioactive isotopes of erbium are known. Their mass varies from 142 to 177. All the radioactive isotopes of erbium are relatively unstable: their half-lives range from 1 second (erbium-145) to 9.4 days (erbium-169).
Commercial purification is accomplished by liquid-liquid solvent extraction and ion-exchange methods. The metal itself is prepared by metallothermic reduction of the anhydrous fluoride with calcium. Only one allotropic (structural) form is known for erbium. The element adopts a close-packed hexagonal structure with a = 3.5592 Å and c = 5.5850 Å at room temperature.
When raised to a high-energy state by absorption of infrared light, the Er3+ ion emits photons at wavelengths of 1.55 micrometres—one of the wavelengths commonly employed in fibre-optic signal transmission. Hence, the major use of erbium is in fibre-optic telecommunications as a component of the signal amplifiers in long-distance telephone and data cables. Its compounds are used in lasers and as a pink colouring agent for glasses. Erbium-stabilized zirconia (ZrO2) makes pink synthetic gems. Another small-scale use of erbium is in the intermetallic compound Er3Ni, which has a high magnetic heat capacity around 4 K (−269 °C, or −452 °F), which is needed for effective regenerative heat exchange at low temperatures, and, therefore, the compound is employed as a regenerator material in low-temperature cryocoolers.
Erbium behaves as a typical rare-earth element, forming compounds in which its oxidation state is +3, such as the pink oxide Er2O3. The Er3+ ion is pink in solution.
Element Properties
atomic number : 68
atomic weight : 167.259
melting point : 1,529 °C (2,784 °F)
boiling point : 2,868 °C (5,194 °F)
specific gravity : 9.066 (24 °C, or 75 °F)
oxidation state : +3.
Additional Information:
Appearance
A soft, silvery metallic element.
Uses
Erbium finds little use as a metal because it slowly tarnishes in air and is attacked by water.
When alloyed with metals such as vanadium, erbium lowers their hardness and improves their workability.
Erbium oxide is occasionally used in infrared absorbing glass, for example safety glasses for welders and metal workers. When erbium is added to glass it gives the glass a pink tinge. It is used to give colour to some sunglasses and imitation gems.
Broadband signals, carried by fibre optic cables, are amplified by including erbium in the glass fibre.
Biological role
Erbium has no known biological role, and has low toxicity.
Natural abundance
Erbium is found principally in the minerals monazite and bastnaesite. It can be extracted by ion exchange and solvent extraction.
#193 Re: Guestbook » Empty » 2025-08-25 16:15:58
Zach Alie,
Don't post irrelevant information in Guest Book.
#194 Re: Jai Ganesh's Puzzles » General Quiz » 2025-08-25 16:10:59
Hi,
#10533. What does the term in Biology Cell cycle mean?
#10534. What does the term in Biology Cell division mean?
#195 Re: Jai Ganesh's Puzzles » English language puzzles » 2025-08-25 15:49:10
Hi,
#5723. What does the noun intolerance mean?
#5724. What does the noun intoxicant mean?
#196 Re: Jai Ganesh's Puzzles » Doc, Doc! » 2025-08-25 15:32:48
Hi,
#2453. What does the medical term Minimally invasive procedure signify?
#197 Re: Jai Ganesh's Puzzles » 10 second questions » 2025-08-25 15:09:00
Hi,
#9721.
#198 Re: Jai Ganesh's Puzzles » Oral puzzles » 2025-08-25 14:47:27
Hi,
#6226.
#199 Re: Exercises » Compute the solution: » 2025-08-25 14:25:48
Hi,
2567.
#200 Jokes » Lawyer Jokes - V » 2025-08-25 14:02:28
- Jai Ganesh
- Replies: 2
Q: What's the difference between a lawyer and a catfish?
A: One is a slimy, bottom dwelling, scum sucker. The other is a fish.
* * *
Q. How many law professors does it take to change a light bulb?
A. You need 250 just to lobby for the research grant.
* * *
Q: What do you call a smiling, sober, courteous person at a bar association convention?
A: The caterer.
* * *
Q: Why are lawyers like nuclear weapons?
A: If one side has one, the other side has to get one.
* * *
Q: Why are lawyers like nuclear weapons?
A: Once launched, they can't be recalled.
* * *