125 Facts About Capillaries For The Budding Doctor In You

The human blood flow system is also called the cardiovascular system, or simply the circulatory system.

It is made up of blood vessels which transport blood through the body with necessary nutrients, hormones, oxygen, and also carry waste, carbon dioxide, and other such substances to and fro. Blood flow keeps up the nourishment of our bodies and helps fight diseases and maintain temperature.

The lymphatic system falls under the cardiovascular system. The blood has white blood cells, red blood cells, and platelets. The system is made up of the heart, blood, and blood vessels. Arteries, veins, and capillaries carry the blood to its respective destination.

Now let’s have a sneak peek into the capillaries which form an important component of the human circulatory system. Read further to know how capillaries connect to blood vessels to perform in our human bodies!

Afterwards, also check out how many nerves are in the human body and how many ribs does a human have.

Fun Facts About Capillaries

The smallest blood vessels in the body, capillaries transport blood between arterioles and venules. These microvessels (small blood vessels) surrounded by interstitial fluid act as a transit point for many substances.

Substances like water, oxygen, carbon dioxide, uric acid, creatinine, glucose, lactic acid, and urea are taken around the body by capillaries.

These tiny blood vessels help in connecting arteries and veins and exchange certain substances between blood and tissues. Tissues in muscles, the liver, and kidneys act the way they do because of the presence of these capillaries. Connective tissues, the ones that are less metabolically active, don’t have enough capillaries.

The smallest vessels in the lymphatic system and minute channels for bile in the liver are also called capillaries.

Capillaries are so tiny that they are a tenth of the diameter of a human hair. It’s astonishing to note that blood cells squeeze to fit and pass through capillaries, which are just one cell thick.

Facts About Capillaries’ Functions

These tiny capillaries perform innumerable functions. Have a glance into the function and impacts of dysfunction of capillaries in the human body by reading on.

They connect the arterial system with the venous system. The arterial system has blood vessels that transport blood all through your body right from the heart.

The venous system, on the other hand, has blood vessels that carry blood back to the base: the heart. All those substances, oxygen, nutrients, or waste, are exchanged between blood and tissues via capillaries.

There are two important processes tied with this: passive diffusion and pinocytosis. Passive diffusion is the movement of a substance from an area of higher concentration to an area of lower concentration and pinocytosis is the process by which cells in the body acquire fats and proteins in small molecules.

There are thin walls made of endothelial cells that are composed of tunica intima.

This thin layer of endothelial cells is again surrounded by another thin layer called the basement membrane. The composition of thin layered endothelial cells and basement membranes is arranged in such a way that oxygen and other molecules reach cells of the body with ease.

White blood cells in your blood are responsible for fighting against diseases and infections, thereby shielding your body against foreign invaders and boosting your immunity system. These white blood cells employ the capillaries to reach sites of infection or inflammation.

What if the capillaries fail to function? The unusual functioning of capillaries results in serious medical conditions.

The widening of capillaries in the skin results in port wine stains. The skin turns pink or dark red in color owing to this. The good part about port wine stains is that they don’t spread to other areas and don’t necessarily require any treatment.

To lighten the color of skin, laser treatments are often opted for. Flat, round tiny spots that appear on the skin, mostly red or purple in color, mark the condition of petechiae.

The leaking of blood into the skin by the capillaries causes petechiae. These are usually the symptoms of underlying infectious diseases such as scarlet fever, leukemia, scurvy, or falling platelet levels. This can also be caused by taking medications such as penicillin.

Then there is the systemic capillary leak syndrome. This is a rare condition and the cause is still unknown.

Although experts haven’t reached a conclusion, they believe that particular substances in the blood that damage the capillary wall result in systemic capillary leak syndrome (SCLS). Patients under this condition are at risk of cardiac attacks and a drop in blood pressure. Nasal congestion, nausea, cough, headache, abdominal pain, lightheadedness, swelling, and fainting are symptoms.

Then there is the arteriovenous malformation syndrome. This is caused when arteries and veins get tangled together without capillaries in between them. This syndrome mainly affects the brain and spinal cord as tangles occur mostly there.

This badly hampers the blood flow and oxygen delivery resulting in internal bleeding at times. AVM doesn’t show up with symptoms.

When a person is diagnosed with some other disease that has headaches, pain, weakness, vision issues, and seizures as their symptoms, there is a high probability for the person to have AVM. This condition is often present at birth.

Some prefer medications to deal with headaches and pains while there are treatments that endorse surgical closing of arteriovenous malformation (AVM) lesions.

Microcephaly capillary malformation syndrome is another condition when capillaries don't function correctly. This is a very rare condition. People with myelocortical multiple sclerosis (MCMS) are likely to have smaller heads and brains. Capillaries in this condition are so wide that blood flow increases towards the skin surface, giving pinkish-red spots to the skin.

Seizures, difficulty in eating, unusual movements, slower growth, smaller stature, finger or toe abnormalities, and distinct facial features are the apparent symptoms of this medical condition. Mutation in a gene causes this particular syndrome. Stimulations and therapies constitute the treatment, which help balance posture and manage seizures.

Facts About Capillaries' Network

The network of capillaries is known by different names in different parts of the body. Here are a few facts on networks and types of capillaries that constitute the capillary network in the human body. The network of the capillary blood vessels is called capillary beds.

Capillary networks are nothing but the final destination of arterial blood carried from the heart.

Known as a tuft, the network of small blood vessels located at the beginning of the nephron in the kidney is called a glomerulus.

The smallest of the arteries branch into arterioles to form the capillaries. There are around 10 billion capillaries in the human body, constituting the capillary bed.

Except for cartilage and cornea, capillary beds are found in each and every part of the body.

There are various types of capillaries such as continuous capillaries, fenestrated capillaries, and sinusoid capillaries.

Continuous capillaries, the most commonly found capillaries, have a slight change in structure and composition of the endothelial cells. They have small gaps in between the endothelial cells that allow the easy exchange of gasses, water, sugar, and some hormones to travel easily.

The continuous capillaries found in the brain are an exception for this characteristic feature.

Those found in the brain do not allow an exchange of everything, but only the essential nutrients required. Continuous capillaries found in the brain, therefore, have endothelial cells with the least gaps and thicker basement membranes.

The fenestrated capillaries have an altogether different structure. These are not only leakier than the continuous blood capillaries but also contain small pores.

Their capillary walls enable an exchange of larger molecules. They are vigorously involved in exchanging elements between blood and tissues and are found in the small intestine and kidneys.

Whether it's absorption of nutrients from food or filtering out waste products from the blood, which are the respective tasks of the small intestine and kidneys, fenestrated capillaries have a big job!

Sinusoid capillaries are the rarest and leakiest of all. They easily allow the movement of large molecules to and from blood cells and tissues.

There are wider gaps in their capillary walls which enable them to do so. Apart from these wide gaps, these capillaries are featured by small gaps and pores. Openings are also present in the basement membranes.

Found in the tissues of the liver, spleen, and bone marrow, they perform important functions. Blood cells enter the bloodstream and kick off their circulation process through the capillaries present in the bone marrow.

Facts About Veins

Blood vessels in humans and several other animals that carry blood towards the heart are called veins.

Except for the pulmonary and umbilical veins that carry oxygenated blood, the smallest veins transport deoxygenated blood from the tissues back to the heart.

Veins carry blood under low or negative pressure. They have thin walls and fewer muscular tissues in comparison to the smallest arteries.

A single vein has three layers: tunica adventitia, tunica media, and tunica intima.

You might be astounded to know that human bodies contain up to 100,000 mi (160,934km) of blood vessels. Regular rigorous exercising causes veins to pop out.

Veins that transport oxygenated blood from the lungs to the left atrium of the heart are called pulmonary veins and veins that carry blood from the body tissue to the right atrium of the heart with much less oxygen are called systemic veins.

Here at Kidadl, we have carefully created lots of interesting family-friendly facts for everyone to enjoy! If you liked our suggestions for 125 facts about capillaries for the budding doctor in you then why not take a look at bones in the human body or are humans bioluminescent?