Category Archives: Science

The Glory of the Cat

The Glory of the Cat – The Adored Pet!!!

Two Short Pieces of Poetry, From the Pen of an Earnest Biologist (Aditya Sardana aka Adidarwinian), Dedicated To the Glory of the Cat for the Pet Lovers around the Globe:

 For some the cat is Hilarious,

For others the cat is Furious,

For me the cat is Prestigious and Glorious.”  

 “For the Ages,

The Cats form the Divine Images,

In the Minds of the Sages.”

Domestic Cat - adidarwinian

A photograph of a Domestic Cat – adidarwinian

The Glorious Cat – Its History, Fame, and the Never Ending Legends

“A lame cat is better than a swift horse when rats infest a palace” – an ancient Chinese saying

The cat is too glorious as an animal not only in its unique biology that blesses it with the amazing physical abilities unrivaled by other animals but also in its long and interesting history. The bones of a cat have been found near the human bones in a ninety five hundred years old grave, which was unearthed in Cyprus, dating from 7,500 to 7,000 years B.C., making it the oldest known evidence of the domestication or taming of the cats. This is much earlier in time than the domestication of these wonderful animals by the Egyptians.

Reference to this celebrated mammal has been made in the ancient Sanskrit writings of the mythological and mystical land of India, which are more than two thousand years old, and still more early references are found in the inscriptions, monumental figures, and the cat mummies of the ancient Egypt. These preserved relics shed a bright light on the answer to one of the most difficult questions in the field of zoology that how this least tameable of the animals was domesticated and adored as a pet.

Felis catus or the domestic cat (also called as the house cat) can be found on every continent of the planet Earth, except the continent of Antarctica, usually in the human populated areas. These animals, due to their ubiquity and familiarity with us, are often treated as our companions.

The cats have always acquired a prominent place in the human culture. There are many legends about them and their mystical powers that are dispersed within the extensive literature created by the human beings for ages. Evidences show that even more than thirty five hundred years ago, the cat flourished as a beloved and revered animal along the banks of the great river Nile. Egyptians used to call cats as Mau-Mai, Maau, Mau, or Maon. The ancient Egyptian kingdom of the Pharaohs paid homage to them and regarded them as the sacred animals. Cat was decorated with jewels and worshiped in the temples. In the Egyptian civilization, this animal was so much adored that the figures of cats were placed in the Egyptian homes, and even their death was respected by burying them in the tombs. To show veneration, trinkets or ornaments representing both the goddess and cat were worn.

Egyptians protected their cats from getting injured, took great care of these beloved mammals when they were alive, and mourned their death with expressions and signs of grief. To express grief, they even shaved off their eyebrows. The Egyptian’s idea of a respectful and correct burial of a human being involved the practice of Mummification (process of the mummification was used by the ancient Egyptians in order to preserve body parts of the dead from degradation until the day of resurrection), and this same process was used for their beloved cats. If a dead cat’s owner was wealthy, his or her cat was very elaborately mummified by using the finest linen and enclosing the body in a bronze box with a statue of cat placed on the top. The richest paid special reverence to their dead cats and buried their dearest dead cats with the pomp and magnificence of a royal personage.

Since the ages, cats have been a part of many mystical legends. They have been associated with the occult, evil, witchcraft, and magic, especially, the so-called black magic, but now these false perceptions have lost their value, at least, for the rational minds. Not only the pet lovers and biologists adore these great animals, but even the Hollywood has made a lot of wealth by selling cat-centered movies; how can one forget the cat named Tom in the famous “Tom and Jerry” cartoon films.

Click this image to enlarge –

Wild Cat - adidarwinian

Lynx - adidarwinian

A photograph of a Lynx – adidarwinian

The Glorious Cat – Its Place in the Menu of Life

The cat is a mammal which belongs to the order Carnivora, that is, the flesh-eaters. The zoologists divide the order Carnivora into the two suborders, viz., – the Caniformia (the dog-like or caniform carnivores) and the Feliformia (the cat-like or feliform carnivores).

Before knowing where exactly the taxonomists have put our glorious and beloved cats in the long list under the menu of carnivorous animals, we should at least give a keen glance at the classification of the dog-like carnivorous animals or the Caniformia. The order Caniformia (the dog like or caniform carnivores) consists of the following families –

  • Canidae – The family Canidae contains the dogs, wolves, coyotes, foxes, and the jackals.
  • Ailuridae – Red Panda (Ailurus fulgens)
  • Mephitidae – The family Mephitidae contains Skunks and the Stink Badgers.
  • Mustelidae Mustelidae is the largest family within the order Carnivora, and is comprised of weasels, polecats, mink, stoats, marten, wolverines, fishers, badgers, otters, and others.
  • Odobenidae – Walruses (Odobenus rosmarus)
  • Otariidae – The family Otariidae contains Sea lions and the fur seals.
  • Phocidae – Seals (they are also called the hair seals or true seals or earless seals)

Note: Seals, fur seals, sea lions, and walruses are collectively referred to as the Pinnipeds (wing-footed).

  • Procyonidae – This family comprises of Cacomistle, Coatis, raccoons, and relatives.
  • Ursidae – It is the family of theBears (Polar Bear, Black Bear, Brown Bear, Spectacled Bear, Sloth Bear, Giant Panda, and the Sun Bear).

Now, let us move to the suborder that contains our much cherished cats and other cat-like mammals. The order Feliformia (the cat-like or feliform carnivores) consists of the following families –

  • Eupleridae – This family consists of the Malagasy carnivores which are restricted to the island of Madagascar.
  • Herpestidae – This family consists of the Mongooses including the Meerkats.
  • Hyaenidae – Striped hyena, Aardwolf (Proteles cristata), brown hyena, and spotted hyena (Crocuta crocuta)
  • Nandiniidae – African palm civet (Nandinia binotata)
  • Viverridae – It consists of the civets, genets, linsangs, binturong, and relatives.
  • Felidae This family consists of the cats; a member of this family is called a feline or felid. The family Felidae consists of two subfamilies – Pantherinae and Felinae.
  • Pantherinae – This subfamily consists of the roaring cats (leopards, lions, tigers, and jaguars).
  • FelinaeThis subfamily consists of the small cats:
  • Cheetah (Acinonyx)
  • Caracal
  • Small cats – Chinese desert cat, domestic cat, jungle cat, Pallas’ cat, sand cat, wild cat, black-footed cat
  • Catapuma – Asiatic golden cat and Bay cat
  • Small American cats – Colocolo, pantanal cat, Geoffroy’s cat, kodkod, ocelot, pampas cat, Andean mountain cat, little spotted cat, margay
  • Serval
  • Lynxes – Lynx, bobcat
  • Marbled cat
  • Asian small cats – Leopard cat, fishing cat, rusty-spotted cat, flat-headed cat, Iriomote cat
  • African golden cat
  • Puma – Cougar or Mountain lion, Florida panther, and Jaguarundi

Click these images to enlarge –

Fishing Cat - adidarwinian

Margay - adidarwinian

A photograph of a Margay – adidarwinian

Jaguarundi - adidarwinian

A photograph of a Jaguarundi – adidarwinian

The Glorious Cat – An Evolutionary Marvel

Extraordinarily Flexible, Swift, and Athletic!!

“Cats’ stunning acrobatic feats have been the envy of even the finest of our gymnasts” – Aditya Sardanaaka Adidarwinian

Cats show extraordinary mobility and flexibility due to the fluidity of its body’s design. They show stunning acrobatic feats unparalleled by other animals, such as:

  • A cat can twist itself into unusual positions.
  • It can very easily curl itself into a perfect circle during sleep, twitching its tail in a rhythmic fashion across its nose.
  • It can jump up about six times its length or more than eight feet in a single bounce.
  • It can jump from great heights without being hurt.
  • From a sitting start, it can bounce up to nine times its height.
  • It can make sudden changes in direction when pursuing and capturing its prey.
  • It can narrow its shoulders and chest to squeeze easily through very tight spaces.
  • In a wink of eye, it can reorient itself in midair and land on its feet.

Powerful muscles in the hind legs of a cat and the flexible nature of the joints in its limbs and vertebrae, helps it to jump up about six times its length or more than eight feet in a single bounce. This amazing animal uses its tail as a highly specialized tool for communication, and also, for balancing its body while climbing, jumping, etc. Its tail allows it to maintain its orientation during sharp turns made while running, for example, when hunting a prey. The structure of its body gives it a marvelous flexibility. Its supple spine makes it very fast, flexible, allows it to perform elegant gymnastic feats, and also makes it a high-speed runner. Between its spinal vertebrae, are present the elastic, cushioning and thick fibrocartilaginous discs. These discs are very pliable (bendable) and resilient (rebounding). In order to reach top speed, a cat lengthens its stride, and thereby increases its speed, by extending and flexing its spine in succession. When starting a new stride, using claws as spikes for traction, it stretches its body to its maximum length, with every stride driving it about three times its body-length.

A cat’s shoulder blades or scapulae are attached to the sides of its body by muscles only and not by any bone, therefore, allowing movement in almost every direction. This feature allows the shoulder blade or scapula much enhanced freedom to move with the cat, thereby increasing its running stride. Moreover, unlike the motion-restricting, long and anchored clavicles or collarbones of human beings, a cat possesses small, rudimentary, muscle-attached “floating collarbones or clavicles”. This provides narrow chest to these animals which accounts for the amazingly long stride of these animals and contributes to their ability to squeeze through tight spaces or openings.

Click these images to enlarge –

Pallas' Cat - adidarwinian

A photograph of a Pallas’ Cat – adidarwinian

Ocelot - adidarwinian

A photograph of an Ocelot – adidarwinian

caracal - adidarwinian

A photograph of a caracal – adidarwinian

The Righting Reflex: Falls from Great Heights without Landing Dead!!   

Cats possess an innate ability called as “the righting reflex”. They possess an uncanny righting reflex, in which they orient or adjust their bodies to prepare for the impact of falling from a height. This impeccable ability imparts these animals the excellent survival instincts. The giant counterparts of domestic cats hunt on and above the ground. Domestic cat, following its giant counterparts, shows a remarkable sense of balance, nimbleness, and ability in order to spring up and land from high levels.

When a cat falls from a high elevation, it instantly rotates its head in the right direction. If, for example, a cat is upside-down (that is its spinal or dorsal or back is facing down) during a fall, it turns its head in the order that its face sees downwards (towards the floor) and the back of the head upwards. This systematic righting reflex of cat occurs due to its natural or evolutionary orienting nervous mechanisms in its eyes and inner ears. This adjustment of the head brings the forequarters (the part of the body of a four-legged animal that consists of its forelegs, shoulders, and the adjoining parts) also in the downward direction. Next, its spine twists in response to the above reorientation, and then the hindquarters or the rear portion gets are similarly aligned. Moreover, its tail helps in balancing and propelling its body during the act of reorientation. Cat also bends its back before touching the ground. This helps in dissipating the force of landing. The impact of landing is reduced by the soft cushions of the foot-pads.

Domestic cat is quite lighter in body weight. This animal at reaching the terminal velocity (the maximum uniform velocity reached by a body falling through a medium such as air, when the force of resistance of the medium is equal and opposite to the force of gravity) during a free fall is significantly less heavy than a human being. Moreover, if it falls from a greater height it would have more time to complete adjustment or reorientation due to its innate righting reflex before landing on ground, than if it falls from a lower height. After it has adjusted itself and if is able to reach the free falling at terminal velocity, cat spreads its legs, adding to the drag that helps in slowing it down. During the free fall, this mammal is able to relax it muscles, and this relaxation of muscles reduces the impact of the injuries that otherwise would have happened with tensed muscles.

Cats jumping down, towards the ground, from the high-rise buildings is a not an infrequent phenomenon. Open windows at the higher stories of buildings pose danger to them, as they fall out of them so frequently that the veterinary doctors have named this condition as the High-Rise Syndrome. Such falls can result in broken limbs and pelvises, head injuries, punctured lungs, shattered jaws, and even death. These mammals do not deliberately jump off from high places but most cats fall accidentally. These accidents occur as our beloved cats get highly focused on the objects of their interests. A moving car, a bird, or any other animal can distract them so much that they can lose their balance and fall.

It is a misconception that cats would not be injured if they fall only from one or two stories of buildings. They may actually get more injury when falling from shorter heights than by falling from greater heights. Lower heights do not give these carnivorous mammals enough time to reorient or adjust their body in order to fall correctly. So, the cats have a higher chance of suffering less severe injuries if they fall off from a great height. This is so as they would be able to reorient their body by virtue of their uncanny righting reflex. Also, there are more chances of achieving the terminal velocity when falling from a greater height against the lower heights.

Caution!!

It should be remembered that cats do not have nine lives as has been portrayed by the cat legends. When a cat falls from a high-rise building, it is quite probable that it may end up severely injured or dead. It should never be assumed that it has not survived the fall; rather it should be immediately rushed to the nearest veterinary hospital. Statistics have revealed that there is ninety percent survival rate for the one of the best pets of man – cats – when they fell from high-rise buildings and receive instant medical attention.

Click these images to enlarge –

Serval - adidarwinian

Bobcat - adidarwinian

Geoffroy's Cat - addarwinian

 

Cougar -adidarwinian

 

Kodkod - adidarwinian

 

Jaguar - Panthernae - adidarwinian

 

Sand Cat - adidarwinianSnow Leopard - Panthernae - adidarwinianCheetah - Acinonyx - adidarwinianLeopard Cat - adidarwinianLeopard - Panthernae - adidarwinianAsiatic Golden Cat - adidarwinianJungle Cat - adidarwinian

Complications of High Blood Pressure or Hypertension

This research article or paper focuses on the complications of Hypertension or High Blood Pressure. Complications of High Blood Pressure involve a multitude of deadly diseases. The author of this paper has tried to emphasize on the mechanism of development of complications, i.e., how the complications develop due to Hypertension. Pathophysiology of Hypertension resulting in the development of complications is investigated.

Complications of High Blood Pressure or Hypertension

“High Blood Pressure or Hypertension is a Key to a Multitude of Deadly Diseases”

Rationally Coping with High Blood Pressure or Hypertension is the Choice of the Wise”

High Blood Pressure or Hypertension or HBP is a common medical condition. Usually, people suffering from this condition have no signs and symptoms until complications develop in the vital organs. So, if you have Hypertension, it will keep on damaging your organs without your knowledge. That’s why High Blood Pressure is aptly called as The Silent Killer. A person can have it for many years without knowing it. While a person may be unaware of his or her High Blood Pressure status, High Blood Pressure can damage his or her blood vessels, heart, kidneys, brain, eyes, and other organs of the body. Therefore, regularly getting your blood pressure checked is important, even if you are feeling healthy. If your blood pressure is already normal, then your health care professional or team can guide you how to maintain it. If a person’s blood pressure is high, treatment can help prevent damage to the organs.

complications of high blood pressure or hypertension - adidarwinian

High Blood Pressure or Hypertension or HBP when left untreated, over the time, can cause many complications as described below –

Damage to Heart and Arteries

High Blood Pressure or HBP or Hypertension places a higher workload on your heart and arteries, and can damage and block your arteries, can cause heart attack and heart failure. Arteries throughout the body get narrowed, which limits the blood flow, this can result in heart attack, kidney failure, stroke, amputation of part of leg, or loss of vision, and other problems.

  • Hypertension damages and blocks your arteries. If you have Hypertension, the force on your arteries is very high. This high force creates microscopic tears in the walls of your arteries. These microscopic damages form the scar tissues, which in turn, lead to formation of the Plaques (Atherosclerosis). Substances found in the blood such as fat, cholesterol, fibrin (a clotting material), calcium, etc., collectively form plaque. Plaques narrow and harden the arteries. The narrowing or thickening of arteries limits the supply of the oxygen-rich blood to the body organs. Hypertension also speeds up the narrowing and hardening of arteries which is a part of the natural process of aging. When your arteries get narrowed, you have a greater chance for the formation of Blood Clots. Blood clots can get carried away with your blood until they get stuck in narrow spaces. These stuck blood clots can significantly or totally block the blood supply to various parts of your body.
  •  As High Blood Pressure causes narrowing of arteries, blood supply to the heart muscle gets reduced. This can cause Angina (Chest Pain or Discomfort).
  •  Hypertension or High Blood Pressure can cause Heart Attack. Heart attack occurs as a result of blocked blood supply to the muscle tissue of the heart. Hypertension makes the arteries that supply blood to the heart muscle (coronary arteries) thicker and harder as a result of formation of plaques (Coronary Heart Disease or CHD).  These arteries supply oxygen-rich blood to your heart muscle. High Blood Pressure makes arteries prone to blood clots. When a plaque or a blood clot or both completely blocks a coronary artery, the blood flow to the heart muscle fed by that artery stops and heart muscle begins to die.
  • The narrowed arteries interfere with blood’s ability to flow smoothly. This places a higher workload on your heart. Eventually, the heart thickens, becomes larger, and weaker. This can cause Heart Failure. Heart failure is a medical condition in which the heart is unable to pump enough blood to meet your body’s requirements.

Stroke

A Stroke occurs when an artery that supplies oxygen-rich blood to the brain gets blocked (Ischemic Stroke). Hypertension can cause such a blockage of arteries. Without oxygen and blood supply, brain cells starts dying within a few minutes. High Blood Pressure or Hypertension can also cause sudden bleeding in the brain (Hemorrhagic Stroke). The bleeding causes swelling and increased pressure in a person’s skull; this process damages brain cells.

Kidney Damage

High Blood Pressure causes arteries supplying blood to the kidneys to narrow and harden. When the arteries get narrowed, the nephrons (a nephron is a structural and functional unit of the kidney involved in the filtration of the wastes and excess fluids from the blood) do not get adequate amount of the blood and oxygen. This causes damage to them. When the blood vessels in the kidneys get damaged, they stop eliminating wastes and extra fluid from a person’s body. The extra fluid further raises the blood pressure, thus, a vicious circle starts. Hypertension is one of the main causes of Kidney Failure or End-Stage Renal Disease (ESRD).

Vision Loss

Hypertension can strain the blood vessels in the eyes, and the optic nerve. Hypertension can cause the blood vessels of eyes to either narrow or bleed due to too much blood pressure force. This may result in Vision Problems or Blindness. HBP or High Blood Pressure can also reduce the ability to see by causing swelling of the optic nerve. Optic nerve carries visual information from the retina of the eye to the brain. Disease or damage of the optic nerve can lead to Partial or Total Blindness. Hypertension can cause damage to the retina (Hypertensive Retinopathy). Hypertensive Retinopathy occurs as a result of damage to the blood vessels in the retina. Untreated High Blood Pressure can cause permanent vision problems or blindness.

Aneurysms

Hypertension can lead to the formation of Aneurysms. An aneurysm is an abnormal (balloon-like) bulge in the wall of an artery. Arteries have thick walls to withstand normal blood pressure. The force of High Blood Pressure or Hypertension by pushing against the weakened or injured walls of the arteries can cause an aneurysm. An aneurysm can burst or rupture, and thereby, can cause severe bleeding inside the body. An aneurysm may undergo a dissection, which is defined as a split in one or more artery wall’s layers. The split results in bleeding into and along the layers of the artery wall. Both the rupture of aneurysm and dissection of aneurysm are often fatal.

Common spot for aneurysms is the aorta which is the main artery that carries oxygen-rich blood from the heart to all the body parts except the lungs. Many people die annually from Aortic Aneurysm. Most of the deaths occur from Aortic Aneurysm Rupture or Aortic Dissection (also known as Aortic Aneurysm – Dissecting). Aneurysms also can occur in other arteries though less commonly. For example aneurysm can occur in the artery leading to the spleen; and the arteries in the brain, intestines, and legs.

Erectile Dysfunction

High Blood Pressure or Hypertension can cause Erectile Dysfunction or ED or Impotence. Erectile Dysfunction or ED is the inability of a man to get or keep an erection firm enough to have sexual intercourse. High Blood Pressure damages, hardens, and narrows the arteries carrying blood to the male sexual organ. This reduces blood flow and makes it difficult to achieve and sustain erection.

Dementia

Dementia is a brain disease that involves impaired intellectual functioning, loss of ability to solve problems, inability to maintain emotional control, memory loss, and impairment of language skills. Dementia may involve personality changes and behavioral problems like agitation, delusions, and hallucinations. High Blood Pressure or Hypertension or HBP can cause Dementia by narrowing and blocking the arteries that supply blood to the brain

Diabetes and Metabolic Syndrome

Metabolic Syndrome is the name given to a group of risk factors that raises a person’s risk for developing Heart Disease, Diabetes, and Stroke. High Blood Pressure or Hypertension or HBP, being a metabolic risk factor, increases the risk for developing Diabetes and other health problems.

Rationally Coping With High Blood Pressure or Hypertension

Posted on 2 October 2012

Rationally Coping With High Blood Pressure or Hypertension

How To Cope With High Blood Pressure or Hypertension?

“High Blood Pressure or Hypertension Is A Multifaceted Menace; It’s Best To Control It At Its Very Beginning”

High Blood Pressure or HBP or Hypertension has been aptly called by the author of this article as a Multifaceted Disease because it does not damage a single organ or part of your body but it can cause damage to multiple organs of your body including heart, blood vessels, kidney, brain, eyes, and others. Also, this disease is a Silent Killer as it can silently (without any symptoms) damage your organs or even can kill you.

High Blood Pressure or Hypertension Silent Killer - AdidarwinianIf you have High Blood Pressure, then in order to cope with this menace there are two proven strategies. High BP or Hypertension can be normalized with lifestyle changes and by the use of certain medicines. When lifestyle changes are not sufficient enough to keep your blood pressure or BP in control, your doctor will likely add medication to your treatment regimen. Most people who have High Blood Pressure or Hypertension need lifelong treatment. Adhering to the treatment plan is vital not only to keep a person healthy but also to prevent or delay health problems related to Hypertension. For most adults, the goal of treatment is to achieve and maintain blood pressure below 140/90 mm Hg. For adults suffering from the diabetes or the chronic kidney disease, the goal of treatment is to achieve and maintain blood pressure below 130/80 mm Hg.

Lifestyle Changes Are a Must to Control Hypertension / High Blood Pressure

“Healthy lifestyle habits are the basis of a long and active life”

Lifestyle Changes Are a Must to Control Hypertension - AdidarwinianThere are certain healthy lifestyle habits that help control Hypertension. These healthy lifestyle habits include –

Healthy Diet

Balanced and flexible eating plans, such as, DASH (Dietary Approaches to Stop Hypertension) eating plan can help control High Blood Pressure. In order to control High BP, DASH eating plan advocates the limited use of cholesterol, saturated fat, total fat, salt, sweets, sugary beverages, added sugars, red meat, and hard drinks.

Maintain a Healthy Weight

A healthy weight can help you control your blood pressure, lower the strain on the heart, and lessen your risk for other health problems.

Maintain a Healthy Weight - AdidarwinianBe Physically Active

Physical activity helps control your blood pressure, weight, and strengthens your heart and reduces stress. A strong heart, healthy weight, and good emotional health are beneficial for your blood pressure. Discuss with your doctor before starting a new exercise plan. Your doctor will suggest how much and what types of physical activities are safe for you.

Quit Smoking and Avoid Secondhand Smoke

“Each cigarette that a person smokes, temporarily increases his or her blood pressure for many minutes after he or she finishes”.

Quit Smoking and Avoid Secondhand Smoke - AdidarwinianSmoking harms nearly every organ in your body, including your heart, the blood vessels, your lungs, mouth, eyes, reproductive organs, bladder, bones, and the digestive organs. Smoking raises your risk for High BP. Discuss with your doctor about the community programs, support groups, and products that are available to help you quit smoking. Also, avoid secondhand smoke as secondhand smoke also harms the heart and blood vessels in the same way by which active smoking harms. For a healthy life, and to reduce risks for heart attack and stroke, one should avoid all forms of smoking including secondhand smoke.

Manage / Control Stress

Managing stress can improve both the emotional and physical health of a person. Physical activity, meditation, listening to music, yoga, relaxation, and tai chi can help reduce stress levels. Certain support groups and healthy lifestyle programs are available which teach you how to cope with the common problems of life without getting stressed.

Medicines Used To Treat High BP / Hypertension  

Medicines Used To Treat High Blood Pressure or Hypertension - AdidarwinianMedicines play a major role in controlling Hypertension. Different types of High Blood Pressure medicines reduce blood pressure by different actions or mechanisms. Some medicines lower BP (blood pressure) by eliminating extra water and salt from the body; some medicines slow down the heart rate; some relax and widen your blood vessels; etc. Generally, combination-therapy of two or more medicines works better than a single medicine.

Beta Blockers

Beta Blockers slow down the heart rate and reduce heart muscle’s contractility, thus reducing High Blood Pressure.

Diuretics

Diuretics reduce the amount of fluid in your blood by helping kidneys to eliminate the excess of water and salt from the body. This causes lowering of High BP or Hypertension.

Calcium Channel Blockers

Calcium channel blockers prevent calcium entry into the muscle cells of the blood vessels, thereby, causing relaxation of blood vessels. Thus, High BP or Hypertension comes under control.

Angiotensin-Converting Enzyme (ACE) Inhibitors

Angiotensin-converting enzyme (ACE) inhibitors dilate blood vessels by blocking the action of angiotensin-converting enzyme (ACE). Angiotensin-converting enzyme (ACE) helps in the formation of a chemical called angiotensin II. Angiotensin II causes blood vessels to constrict. Thus, inhibiting the formation of angiotensin II lowers High BP.

Angiotensin II Receptor Blockers (ARBs)

Angiotensin II receptor blockers (ARBs) class of medicines lowers blood pressure by blocking angiotensin II receptors. Angiotensin II requires angiotensin II receptors to constrict blood vessels, so blocking these receptors blocks the action of angiotensin II, and this results in relaxation of blood vessels.

Direct Vasodilators

Vasodilators work directly on the muscles in blood vessel walls and causes dilation of blood vessels, thus, Hypertension comes under control.

Alpha Blockers

Alpha blockers interfere with the conduction of nerve impulses resulting in relaxation of the muscle tone of the walls of the blood vessels. This lowers the High BP.

Alpha-Beta Blockers

This class of medicines interferes with the conduction of nerve impulses like alpha blockers, and also, slows down the heart rate like beta blockers. Thus, High BP or Hypertension is normalized by double mechanisms.

Centrally Acting Medicines

These medicines stimulate specific receptors in the brain. This, in turn, sends nerve signals to the blood vessels, causing them to relax and widen. This causes lowering of High Blood Pressure or HBP.

Direct Renin Inhibitors

Renin is a protein (enzyme) secreted by the kidney in response to decreases in blood volume and other reasons. Renin converts angiotensinogen to form angiotensin I. Direct renin inhibitor decreases plasma renin activity (PRA), and hence, inhibits the conversion of angiotensinogen to angiotensin I. Suppression of angiotensin I causes decrease in the formation of angiotensin II which is a potent blood pressure-elevating chemical. This way, direct renin inhibitors lowers High BP or Hypertension.