Feathers (Bulu)

Feather evolution

Nail structure (Struktur kuku)

Muscle Structure and Functions (Struktur dan Fungsi Otot)

Musculature system

Skeletal muscle

Integumentary system (Sistem kulit)

Structure and Functions of Integumentary system…

Cantiknya mawar merah yang sedang mekar….

Lihat ini…

Bagi yang berminat untuk mengetahui lebih lanjut tentang pola variasi genom manusia terkini, sila baca artikel berikut:

human microsatelite variation

Taring ular berbisa

Biasanya ular berbisa mempunyai taring yang tajam yang digunakan sebagai senjata untuk memasukkan bisa ke dalam tisu mangsanya. Taring dikatakan berasal atau berkembang daripada gigi.

Artikel di bawah ini memuatkan informasi tentang taring ular berbisa dan struktur yang berkaitan dengannya.

Fangs Venomous snakes

The fangs of venomous snakes, which evolved from teeth, are among “the most advanced bioweapon systems in the natural world,” says Freek Vonk of Leiden University in the Netherlands. “There is not a comparable structure as advanced, as sophisticated, as for example a rattlesnake fang and venom gland.”

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Bagaimanakah perkembangan taring ular??

How Snakes Got Their Fangs

By Jeanna Bryner, Senior Writer
30 July 2008

Biologists have sunk their teeth into the question of snake fang development, revealing how these poison prickers have evolved from regular teeth and allowed snakes to become such champion biters.

The research suggests that both rear and front fangs in venomous snakes developed from separate teeth-forming tissue at the rear of the mouth — unlike the situation for non-venomous snake dentition and human teeth. This finding, detailed in the July 31 issue of the journal Nature, could explain why snakes flourished beginning some 60 million years ago, geologically soon after non-avian dinosaurs went extinct.

“The snake venom system is one of the most advanced bioweapon systems in the natural world,” said lead researcher Freek Vonk of Leiden University in the Netherlands. “There is not a comparable structure as advanced, as sophisticated, as for example a rattlesnake fang and venom gland.”

Fang factors

Snake fangs are sharp, enlarged teeth positioned along the upper jaw at the front or rear of a snake’s mouth and connected to venom glands. Only the venomous snakes, which are considered advanced snakes, sport such fangs, while the non-venomous snakes like pythons are equipped with only the normal rows of teeth.

The Asian vine snake (Aheatulla prasina) sports rear fangs. The enlarged teeth in front of the jaw are not fangs, but teeth used for grabbing their prey, which are fast lizards. Credit: © Freek Vonk.

And sometimes even a venomous snake will impart a “dry” bite, not delivering the potent venom.

Most venomous snakes, including grass snakes, have fangs positioned in the rear of the mouth, while a few groups, including rattlesnakes, cobras and vipers, have fangs jutting down from their upper jaws in the front of the mouth.

“If you want to eat a very dangerous prey, like a big rat with razor-sharp rat teeth, then it would be more advantageous to have your fangs in front of the mouth so you can just bite it quickly and then let go,” Vonk told LiveScience, “instead of biting it and holding on and then chewing the venom into the tissue, because then the rat can bite back.

Fang development

To figure out how both types of snake fangs evolved from non-fanged species, Vonk and his colleagues looked at fang development in 96 embryos from eight living snake species. Here are their names:

Non-venomous snakes:

* Water python (Liasis mackloti)

Venomous front-fanged snakes:

* Indonesia pit viper or Hageni’s treeviper (Trimeresurus hageni)
* Rhombic Night Adder (Causus rhombeatus)
* Malayan pit viper (Calloselasma rhodostoma)
* Asian spitting cobra (Naja siamensis)
* Cape Coral Snake (Aspidelaps lubricus infuscatus)

Rear-fanged venomous snakes:

* Rat snake (Elaphe obsolete)
* Grass snake (Natrix natrix)

The team’s analyses showed that the front and rear fangs develop from a separate teeth-forming tissue at the back of the upper jaw. For all front-fanged venomous snake species, the front fangs displaced forward during embryo development by rapid growth of the embryonic upper jaws. The rear fangs stayed put where they formed.

That’s unlike the dental development scenario for humans and non-venomous snakes, such as pythons. As an embryo, all of our teeth in the upper jaw sprout from one tooth-forming tissue, while all the bottom teeth develop from another tooth-forming tissue.

“The uncoupled rear part of the teeth-forming tissue evolved in close association with the venom gland, thereafter forming the fang-gland complex,” Vonk said. “The uncoupling allowed this to happen, because the rear part of the teeth-forming tissue did not have constraints anymore from the front part.”

Super snakes

The separate development of the rear part of the tissue, Vonk said, may have played a major role in snakes’ ability to diverge into the 3,000 species found throughout the world today.

“It sheds light on one of those nagging questions in herpetology — how did a diversity of fang types among snakes evolve?” said David Kizirian, a herpetologist at the American Museum of Natural History in New York who was not involved in the study.

The research was funded by the Netherlands Organization for Scientific Research, Dutch government, Dutch Technology Foundation, Curatoren fund, LUSTRA fund, Australian Research Council, Australian Academy of Science, Whitman College and Leiden University Fund.

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Mengenal Penyakit Jantung

Penyakit jantung merupakan pembunuh yang utama di negara ini, dan juga di negara-negara lain. Terdapat pelbagai jenis penyakit yang berkaitan dengan jantung, dari peringkat awal dikesan hingga ke tahap kritikal yang membawa kematian.

Berikut adalah penerangan asas tentang pelbagai penyakit jantung yang biasa terjadi di kalangan kita, bertujuan untuk menambah pengetahuan dan kesedaran tentang penyakit yang bahaya ini. Faktor penyebab sakit jantung, tanda atau simptom penyakit jantung, ujian untuk mengetahui tahap sakit jantung, dan rawatan serta langkah berjaga-jaga juga diterangkan. Dengan adanya pengetahuan dan kesedaran ini, setiap orang bolehlah mengambil langkah-langkah drastik (jika perlu) untuk mengelakkan penyakit jantung (jika belum terkena) atau merawatnya supaya pulih atau sekurang-kurangnya tidak bertambah teruk.

Heart Disease

Reviewed by Louise Chang, MD on September 01, 2010

What Is Heart Disease?

Bring up heart disease, and most people think of a heart attack. But there are many conditions that can undermine the heart’s ability to do its job. These include coronary artery disease, cardiomyopathy, arrhythmia, and heart failure. Keep reading to find out what these disorders do to the body and how to recognize the warning signs.

What Is a Heart Attack?

Every year, more than 1 million Americans have a heart attack – a sudden interruption in the heart’s blood supply. This happens when there is a blockage in the coronary arteries, the vessels that carry blood to the heart muscle. When blood flow is blocked, heart muscle can be damaged very quickly and die. Prompt emergency treatments have reduced the number of deaths from heart attacks in recent years.

Heart Attack Symptoms

A heart attack is an emergency even when symptoms are mild. Warning signs include:

* Pain or pressure in the chest.
* Discomfort spreading to the back, jaw, throat, or arm.
* Nausea, indigestion, or heartburn.
* Weakness, anxiety, or shortness of breath.
* Rapid or irregular heartbeats.

Heart Attack Symptoms in Women

Women don’t always feel chest pain with a heart attack. Women are more likely than men to have heartburn, loss of appetite, tiredness or weakness, coughing, and heart flutters. These symptoms should not be ignored. The longer you postpone treatment, the more damage the heart may sustain.

Signs of Coronary Artery Disease

A precursor to a heart attack, coronary artery disease or CAD occurs when sticky plaque builds up inside the coronary arteries. This narrows the arteries, making it more difficult for blood to flow through. Many people don’t know they have CAD until a heart attack strikes. But there are warning signs, such as recurring chest pain caused by the restricted blood flow. This pain is known as angina.

Inside a Heart Attack

The plaque deposited in your arteries is hard on the outside and soft and mushy on the inside. Sometimes the hard outer shell cracks. When this happens, a blood clot forms around the plaque. If the clot completely blocks the artery, it cuts off the blood supply to a portion of the heart. Without immediate treatment, that part of the heart muscle could be damaged or destroyed.

Don’t Wait to Be Sure

The best time to treat a heart attack is as soon as symptoms begin. Waiting to be sure can result in permanent heart damage or even death. If you think you may be having a heart attack, call 911. And don’t try driving yourself to the hospital. When you call 911, the EMS staff can start emergency care as soon as they reach you.

Sudden Cardiac Death

Sudden cardiac death (SCD) accounts for half of all heart disease deaths in the U.S., but it’s not the same as a heart attack. SCD occurs when the heart’s electrical system goes haywire, causing it to beat irregularly and dangerously fast. The heart’s pumping chambers may quiver instead of pumping blood out to the body. Without CPR and restoration of a regular heart rhythm, death can occur in minutes.

Arrhythmia: Erratic Heart Beat

Regular electrical impulses cause your heart to beat. But sometimes those impulses become erratic. The heart may race, slow down, or quiver. Arrhythmias are often harmless variations in rhythm that pass quickly. But some types make your heart less effective at pumping blood, and that can take a serious toll on the body. Let your doctor know if you’ve noticed your heart beating abnormally.

Cardiomyopathy

Cardiomyopathy is a disease involving changes in the heart muscle. These changes may interfere with the heart’s ability to pump effectively, which can lead to a chronic condition called heart failure. Cardiomyopathy is sometimes associated with other chronic conditions, such as high blood pressure or heart valve disease.

Heart Failure

Heart failure doesn’t mean your heart stops working. It means the heart can’t pump enough blood to meet the body’s needs. Over time, the heart gets bigger to hold more blood, it pumps faster to increase the amount of blood moving out of it, and the blood vessels narrow. The heart muscle may also weaken, reducing the blood supply even more. Most cases of heart failure are the result of coronary artery disease and heart attacks.

Congenital Heart Defect

A congenital heart defect is one that’s present at birth. The problem could be a leaky heart valve, malformations in the walls that separate the heart chambers, or other heart problems. Some defects are not found until a person becomes an adult. Some need no treatment. Others require medicine or surgery. People with congenital heart defects may have a higher risk of developing complications such as arrhythmias, heart failure, and heart valve infection, but there are ways to reduce this risk.

Testing: Electrocardiogram (EKG)

An EKG (also ECG) is a painless test that uses electrodes placed on the skin to record the heart’s electrical activity. The test provides information about your heart rhythm and damage to the heart muscle. An EKG can help your doctor diagnose a heart attack and evaluate abnormalities such as an enlarged heart. The results can be compared to future EKGs to track changes in the condition of your heart.

Testing: Stress Test

The stress test measures how your heart responds to exertion. If you have an exercise stress test, you’ll either walk on a treadmill or ride a stationary bike while the level of difficulty increases. At the same time, your EKG, heart rate, and blood pressure will be monitored as your heart works harder. Doctors use a stress test to evaluate whether there is an adequate supply of blood to the heart muscle.

Testing: Holter Monitor

A Holter monitor is a portable heart rhythm recorder. If your doctor suspects a heart rhythm problem, she may ask you to wear one for 1 or 2 days. It records the heart’s continuous electrical activity day and night, compared with an EKG, which is a snapshot in time. The doctor will probably also ask you to keep a log of your activities and to note any symptoms and when they occur.

Testing: Chest X-ray

A chest X-ray is a picture of your heart, lungs, and chest bones that’s made by using a very small amount radiation. Chest X-rays can be used to look for heart and lung abnormalities.

In this image, the bulge seen on the right side is an enlarged left ventricle, the heart’s main pumping chamber.

Testing: Echocardiogram

An echocardiogram uses sound waves (ultrasound) to generate moving images of the heart. The test can assess the chambers and valves of your heart and how well your heart muscle and heart valves are working. It’s useful in diagnosing and evaluating several types of heart disease, as well as evaluating the effectiveness of treatments.

Testing: Cardiac CT

Cardiac computerized tomography (known as cardiac CT) takes detailed images of the heart and its blood vessels. A computer stacks the images to create a 3-D picture of heart. A cardiac CT can be used to look for plaque or calcium buildup in the coronary arteries, heart valve problems, and other types of heart disease.

Living With Heart Disease

Most forms of heart disease are chronic. In the beginning, symptoms may be too mild to affect everyday life. And in many cases, long-term treatment can keep symptoms under control. But if the heart begins to fail, patients may develop shortness of breath, fatigue, or swelling in ankles, feet, legs, and abdomen. Heart failure can be managed with medication, lifestyle changes, surgery, and in certain cases, a heart transplant.

Treatment: Medicines

Medications play a huge role in treating heart disease. Some drugs help lower blood pressure, heart rate, and cholesterol levels. Others can keep abnormal heart rhythms under control or prevent clotting. For patients who already have some heart damage, there are medications to improve the pumping ability of an injured heart.

Treatment: Angioplasty

Angioplasty is used to open a blocked heart artery and improve blood flow to the heart. The doctor inserts a thin catheter with a balloon on the end into the artery. When the balloon reaches the blockage, it is expanded, opening up the artery and improving blood flow. The doctor may also insert a small mesh tube, called a stent, to help keep the artery open after angioplasty.

Treatment: Bypass Surgery

Bypass surgery is another way to improve the heart’s blood flow. It gives blood a new pathway when the coronary arteries have become too narrow or blocked. During the surgery, a blood vessel is first moved from one area of the body — such as the chest, legs, or arms — and attached to the blocked artery, allowing it to bypass the blocked part.

Who’s at Risk for Heart Disease?

Men have a higher risk of having a heart attack than women, and at an earlier age. But it’s important to note that heart disease is the No. 1 killer of women, too. People with a family history of heart ailments also have a higher risk of heart trouble.

Risk Factors You Can Control

High cholesterol and high blood pressure are major risk factors for heart disease. Being overweight, obese, or physically inactive all increase your risk. So does diabetes, especially if your glucose levels are not well controlled. Discuss your risks with your doctor and develop a strategy for managing them. There are many steps you can take to protect your heart.

Smoking and Your Heart

If you smoke, your risk of heart disease is 2 to 4 times greater than a nonsmoker’s. And if you smoke around loved ones, you’re increasing their risk with secondhand smoke. Each year in the U.S., more than 135,000 people die from smoking-related heart disease. But it’s never too late to quit. Within 24 hours of quitting, your heart attack risk begins to fall.

Smoking and Your Heart

If you smoke, your risk of heart disease is 2 to 4 times greater than a nonsmoker’s. And if you smoke around loved ones, you’re increasing their risk with secondhand smoke. Each year in the U.S., more than 135,000 people die from smoking-related heart disease. But it’s never too late to quit. Within 24 hours of quitting, your heart attack risk begins to fall.

Heart Disease Prevention

The key to preventing heart disease is a healthy lifestyle. This includes a nutritious diet, at least 30 minutes of exercise most days of the week, not smoking, and controlling high blood pressure, cholesterol, and diabetes. If you drink alcohol, do so in moderation – no more than one drink a day for women, two drinks a day for men. Ask your friends and family for help in making these changes. They’ll benefit, too.

Diet and Your Heart

What you eat makes a difference. Be sure you get plenty of whole grains, vegetables, legumes, and fruits to help keep your heart healthy. Plant oils, walnuts, other nuts, and seeds can also help improve cholesterol levels. And don’t forget to eat fish at least a couple of times each week for a good source of heart-healthy protein.

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Terkini: Kafein berkait dengan masalah pundi kencing perempuan

Kajian terkini menunjukkan bahawa pengambilan kafein yang berlebihan dalam makanan dan minuman berkait rapat dengan risiko mendapat masalah pundi kencing bagi perempuan. Oleh itu, langkah-langkah untuk mengurangkan pengambilan kafein perlulah dilakukan, terutamanya kepada orang perempuan yang telah lanjut usia.

Artikel berikut memberi perincian tentang laporan kajian ini….

Caffeine and Bladder Problems Linked

For Women, Excess Caffeine Increases Risk of Urinary Incontinence, Study Finds

By Kathleen Doheny
Reviewed by Laura J. Martin, MD

Sept. 30, 2010 — Excess caffeine increases the likelihood of urinary incontinence in women, according to a new study that echoes the findings of previous research.

”Women who consume high levels of caffeine are 70% more likely to have urinary incontinence than women who don’t,” says Jon Gleason, MD, an instructor and fellow at the University of Alabama at Birmingham Medical School’s Division of Women’s Pelvic Medicine and Reconstructive Surgery.

He is slated to present the findings Friday at the American Urogynecologic Society’s annual meeting in Long Beach, Calif.

Caffeine sources include coffee, tea, beverages, foods, and some pharmaceuticals.

In Gleason’s study, women who reported taking in 329 milligrams of caffeine a day — about three cups of coffee — or more had a 70% higher likelihood of having the bladder problem.

Urinary incontinence, or the unintentional loss of urine, affects more than 13 million Americans, mostly women. Women are most likely to develop it either during pregnancy or childbirth or with menopause and its hormonal changes, due to pelvic muscle weakness. But it’s not a natural consequence of aging, experts say.

Caffeine and Bladder Problems: The Study

Previous research has produced conflicting findings about caffeine and bladder problems, Gleason says. So he looked at a larger group of women than those studied in previous research.

Gleason evaluated data on 1,356 women, aged 20 to 85, who had participated in the 2005-2006 National Health and Nutrition Examination Survey, a large nationally representative survey.

The women kept food diaries on two separate days and also answered questions about bladder function.

Moderate caffeine intake, defined as about 182 milligrams a day, was not linked to urinary incontinence. But higher intakes — 329.5 milligrams or higher — were.

People who had a high caffeine intake were more likely to be aged 40-59, to drink alcohol, and to be non-Hispanic white.

Gleason found no links between urinary incontinence and body mass index, vaginal childbirth, or high intake of water.

What’s Behind the Link?

”Only high levels of caffeine were associated with urinary incontinence,” Gleason says.

What is it about the caffeine? “There is evidence that caffeine has a diuretic effect,” he says. The diuretic effect increases the amount of urine you make.

Caffeine may also make the muscles that contract when you void overactive, he says.

Caffeine and Bladder Problems: Second View

The study findings are similar to those found by Lilly Arya, MD, an associate professor of obstetrics and gynecology at the University of Pennsylvania School of Medicine in Philadelphia, who published a study on caffeine and incontinence nearly a decade ago.

”What these studies are really finding [is that] high levels of caffeine are associated with urinary incontinence,” she says.

Does it cause or aggravate the condition? “That’s not known,” says Arya, who reports doing consultant work for Pfizer, Astellas, and Duramed, makers of incontinence drugs or products.

Caffeine and Bladder Problems: Advice

The new study findings lend weight to advice many doctors already give, Arya says.

”For the woman with [bladder] problems, it should ideally be zero caffeine,” she says. But she’s realistic, knowing ”you have to be able to get through the day.” So she tells these women, “Have a cup, one small cup, but make it as small as you can, definitely less than 8 ounces.”

For women without bladder problems? “Up to two cups a day is generally fine. No bigger than 12 ounces, and the second cup should preferably be decaf.”

“If you review all the caffeine literature, it seems like, in the U.S., up to two cups of coffee a day is considered moderate.” What’s more difficult, she says, is defining a cup.

Years ago, she tells WebMD, researchers considered 5 ounces to be a ”standard” cup. “That’s your grandma’s china cup,” she says.

These days, many researchers view an 8-ounce cup standard, she says. But coffee sold at outlets is often served in a much bigger cup.

At Starbucks, for instance, a short is 8 ounces but a tall is 12, a grande is 16, and a venti, 20 ounces.

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Rawatan kelemumur

Banyak orang menghadapi masalah kelemumur, tapi tahapnya berbeza-beza kerana lain orang lain kadar terjadinya kelemumur di atas kulit kepala. Pada mereka yang mempunyai masalah kulit kepala yang kering, kelemumur memang banyak, kerana lapisan korneum pada kulit kepala berganti dengan cepat dan menghasilkan kelemumur yang banyak.

Berikut ada beberapa saranan untuk merawat kelemumur dengan menggunakan beberapa jenis shampoo yang sesuai….

Understanding Dandruff — Treatment

Reviewed by Norman Levine, MD

What Are the Treatments for Dandruff?

Mild cases of dandruff may need nothing more than shampooing more frequently. Daily cleansing with a dandruff shampoo to decrease oil and cell buildup can keep moderate dandruff in check, but consult your doctor about more stubborn forms such as seborrheic dermatitis.

Not all dandruff shampoos are alike, so you may need to experiment with them to find the one that works best for you. Here are some examples of some effective over-the-counter shampoos you can try.

* Coal-tar preparations (Neutrogena T/Gel, Tegrin)

* Pyrithione zinc (Suave Dandruff Control, Pert Plus Dandruff Control, Head & Shoulders)

* Salicylic acid and sulfur (T-Sal, lonil T, Sebulex)

* Selenium sulfide (Selsun Blue)

* Ketoconazole (Nizoral A-D) available as a 1% over-the-counter shampoo and a 2% prescription-strength shampoo.

You may need to alternate between types of shampoos if one type initially controls the dandruff but later loses its effectiveness. If you find that you are still scratching and shedding after trying over-the-counter preparations, see your doctor. You may be using the wrong shampoo for your condition. For really stubborn dandruff cases you may need to use a prescription lotion or shampoo.

Most doctors recommend that dandruff sufferers use a medicated shampoo daily, rubbing your scalp well and leaving the lather on for at least five minutes. Be sure to rinse thoroughly; shampoo and soap residue can actually aggravate skin problems. Brush your hair from your scalp outward with steady, firm strokes. This will carry oil from your scalp, where it can cause dandruff, along the hair strands, which need the oil to stay shiny and healthy.

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