Know More..

Category Human Body

What is the common cause of cataract, the clouding of the eye’s natural lens?

A cataract is a cloudy area in the lens of your eye. Cataracts are very common as you get older. In fact, more than half of all Americans age 80 or older either have cataracts or have had surgery to get rid of cataracts. 

Most cataracts are age-related — they happen because of normal changes in your eyes as you get older. But you can get cataracts for other reasons — for example, after an eye injury or after surgery for another eye problem (like glaucoma).

No matter what type of cataract you have, the treatment is always surgery.

Most cataracts are caused by normal changes in your eyes as you get older.

When you’re young, the lens in your eye is clear. Around age 40, the proteins in the lens of your eye start to break down and clump together. This clump makes a cloudy area on your lens — or a cataract. Over time, the cataract gets more severe and clouds more of the lens.

 

Picture Credit : Google

If a deaf person stands next to the loudest noise in the world do their ears get damaged or would they be unaffected?

If a Deaf person stands next to the loudest noise in the world, they would die just like any other person would. Did I say die? I meant that they would be pulverized.

The loudest sound ever produced in recorded history came about due to the Krakatoa volcanic eruption in 1883. It is estimated to have made a sound equivalent to 310 dB.

It was so loud, that it could be heard 3100 miles away, 4 hours later! That’s like hearing something that happened in California from New York.

It was directly responsible for the death of more than 36,000 people all over the world.

It created a gigantic tsunami that destroyed hundreds of boats and killed thousands of people.

It cooled the Earth and affected the weather for 5 years.

Let’s put this into perspective.

The nearest location that could record the explosion was 100 miles away, and measured the sound at 170 decibels. At that level, it sounds like a piece of dynamite exploding in your face.

At 190 dB, sound waves become shock waves. You can experience permanent hearing loss or become Deaf due to your eardrums rupturing

At 202 dB there is a chance that you can die from the shock.

235 dB is equivalent to 31,624 tons of TNT exploding in your face.

248 dB is equivalent to the sound that the atomic bombs dropped on Hiroshima and Nagasaki made.

286 dB is the equivalent of the sound Mt. Saint Helens made during its eruption in 1980.

The sound Krakatoa made was a whopping 310 dB.

 

Credit : Quora

Picture Credit : Google

What is sleep apnoea?

Sleep apnea is a potentially serious sleep disorder in which breathing repeatedly stops and starts. If you snore loudly and feel tired even after a full night’s sleep, you might have sleep apnea.

The main types of sleep apnea are:

  • Obstructive sleep apnea, the more common form that occurs when throat muscles relax
  • Central sleep apnea, which occurs when your brain doesn’t send proper signals to the muscles that control breathing
  • Complex sleep apnea syndrome, also known as treatment-emergent central sleep apnea, which occurs when someone has both obstructive sleep apnea and central sleep apnea

Obstructive sleep apnea is caused by a blockage of the airway, usually when the soft tissue in the rear of the throat collapses during sleep. Central sleep apnea is usually observed in patients with central nervous system dysfunction, such as following a stroke or in patients with neuromuscular diseases like amyotrophic lateral sclerosis (ALS, Lou Gehrig’s disease). It is also common in patients with heart failure and other forms of heart, kidney or lung disease.

 

Picture Credit : Google

What is pneumonia?

Pneumonia is an infection in one or both lungs. Bacteria, viruses, and fungi cause it.

The infection causes inflammation in the air sacs in your lungs, which are called alveoli. The alveoli fill with fluid or pus, making it difficult to breathe.

Bacteria, viruses, or fungi can cause pneumonia.

Common causes include:

  • Flu viruses
  • Cold viruses
  • RSV virus (the top cause of pneumonia in babies age 1 or younger)
  • Bacteria called Streptococcus pneumoniae and Mycoplasma pneumoniae

Some people who are in the hospital get “ventilator-associated pneumonia” if they got the infection while using a ventilator, a machine that helps you breathe.

If you get pneumonia while you’re in a hospital and aren’t on a ventilator, that’s called “hospital-acquired” pneumonia. But most people get “community-acquired pneumonia,” which means they didn’t get it in a hospital.

 

Picture Credit : Google

What causes asthma?

What we do know is that asthma is a chronic inflammatory disease of the airways. The causes can vary from person to person. Still, one thing is consistent: When airways come into contact with a trigger, they become inflamed, narrow, and fill with mucus.

Allergies with asthma is a common problem. Eighty percent of people with asthma have allergies to things in the air, like tree, grass, and weed pollens, mold, animal dander, dust mites, and cockroach droppings. In one study, children with high levels of cockroach poop in their homes were four times more likely to have childhood asthma than children with low levels. An allergy to dust mites is another common asthma trigger.

For about 80% of people with asthma, a heavy workout can cause airways to narrow. Exercise is often the main asthma trigger. If you have exercise-induced asthma, you will feel chest tightness, cough, and have trouble breathing within the first 5 to 15 minutes of an aerobic workout. For most people these symptoms go away in the next 30 to 60 minutes of exercise. But up to 50% of people with exercise-induced asthma may have another attack 6 to 10 hours later. A slow warm up may help prevent this.

 

Picture Credit : Google

What can emphysema contribute to?

Emphysema is a type of COPD (chronic obstructive pulmonary disease). COPD is a group of lung diseases that make it hard to breathe and get worse over time. The other main type of COPD is chronic bronchitis. Most people with COPD have both emphysema and chronic bronchitis, but how severe each type is can be different from person to person.

Emphysema affects the air sacs in your lungs. Normally, these sacs are elastic or stretchy. When you breathe in, each air sac fills up with air, like a small balloon. When you breathe out, the air sacs deflate, and the air goes out.

In emphysema, the walls between many of the air sacs in the lungs are damaged. This causes the air sacs to lose their shape and become floppy. The damage also can destroy the walls of the air sacs, leading to fewer and larger air sacs instead of many tiny ones. This makes it harder for your lungs to move oxygen in and carbon dioxide out of your body.

The cause of emphysema is usually long-term exposure to irritants that damage your lungs and the airways. In the United States, cigarette smoke is the main cause. Pipe, cigar, and other types of tobacco smoke can also cause emphysema, especially if you inhale them.

Exposure to other inhaled irritants can contribute to emphysema. These include secondhand smoke, air pollution, and chemical fumes or dusts from the environment or workplace.

Rarely, a genetic condition called alpha-1 antitrypsin deficiency can play a role in causing emphysema.

 

Picture Credit : Google

Why does our respiratory system produce sputum (mucus)?

Mucus is secreted from two distinct areas within the lung tissue. In the surface epithelium, which is part of the tissue lining of the airways, there are mucus-producing cells called goblet cells. The connective tissue layer beneath the mucosal epithelium contains seromucous glands which also produce mucus.

The respiratory tract produce about two litres of mucus a day from these glands (Martini, 2003), and this is composed of water, carbohydrates, proteins and lipids. The high water content helps to humidify the passing inspired air. Mucus contains glycoproteins (or mucins) as well as proteins derived from plasma, and products of cell death such as DNA.

Mucus is sticky and this helps to trap dust particles, bacteria and other inhaled debris. Mucus also contains natural antibiotics, which help to destroy bacteria – the epithelial cells secrete a substance called defensis. Mucus also contains lysozyme, which is an antibacterial enzyme. 

 

Picture Credit : Google

Where does the foetus begin to grow?

Once a sperm cell and an egg cell join, the fertilized egg begins to grow inside the woman’s uterus. During pregnancy the female body becomes a complete support system for the unborn baby.

It takes almost nine months for the fertilized egg to become a fully formed baby. Throughout this time, the uterus provides protection and warmth. As the baby develops, the uterus stretches until it is larger than any other organ in the body. The growing foetus shows in the pregnant woman’s “bump” at the front of her abdomen.

Your baby will change a lot throughout a typical pregnancy. This time is divided into three stages, called trimesters. Each trimester is a set of about three months. Your healthcare provider will probably talk to you about your baby’s development in terms of weeks. So, if you are three months pregnancy, you are about 12 weeks.

 

Picture Credit : Google

What happens when sperm meets egg?

Each sperm cell has a head made up of genetic material and a tail that enables speedy swimming. Up to 300 million sperm can be released at one time, and they compete to be first to fertilize the female egg.

Inside a woman’s fallopian tube, her egg is surrounded by perm, but only one will gain entry to the egg. As the winning sperm pushes through the outer case of the egg, a chemical reaction shuts out all the other sperm. The successful sperm then fuses with the nucleus of the egg, and fertilization is complete. An embryo is formed, which will eventually develop into a baby.

The term “gestational age” basically means how far along into a pregnancy you are. Gestational age is counted by starting with the first day of your last menstrual period (called LMP).

Gestational age can be kind of confusing, since it measures pregnancy from your last period — about 3-4 weeks BEFORE you’re actually pregnant. Common knowledge about pregnancy says it lasts 9 months, and it’s true that you’re usually pregnant for about 9 months. But the way pregnancy is measured makes it a little longer. A typical full-term pregnancy ranges from 38-42 weeks LMP — around 10 months.

 

Picture Credit : Google

What are the stages of fertilization in humans?

To join with an egg, sperm cells must complete 20-30 cm (8-12 in) journey from the woman’s vagina, via the uterus, to the egg in her fallopian tube. This is the equivalent of a 10-km (6-mile) swim for a human, millions of sperm begin the journey, but just a few survive to reach the egg – and only one will fertilize it.

Stage 1

The race begins

The vagina is an acidic environment for the sperm. Millions don’t make it beyond this stage.

Stage 2

Through the gap

The surviving sperm swim through the entrance to the uterus, which is slightly open.

Stage 3

The race gets rough

Many sperm fail to get through the cervix’s protective mucus. The successful ones now face attack from immune system cells in the uterus.

Stage 4

The last effort

Uterus muscles contract to push the sperm towards the fallopian tubes. Half of them swim towards the correct tube, where the egg is.

Stage 5

Fertilization

A handful of sperm arrive at the egg. Only one succeeds in burrowing through the egg’s outer layer to fertilize it.

 

Picture Credit : Google