Human rudimentary organs: a list and their functions

Doctor of Medical Sciences, Professor, Medical Director of Medical On Group (Medscan Group of Companies)

“Most of the rudimentary organs do not carry any load on the body, and a person does not notice them.”

Table of Contents

What are rudimentary organs

Rudimentary organs are those organs without which the body can function. They have lost their functions during human evolution and are considered residual parts of past ancestors. Nevertheless, these body parts continue to form during embryonic development and persist throughout a person’s life.

There are many rudimentary organs in the human body, but we will consider only 10 of them.

1. Muscle fibers responsible for the appearance of “goosebumps”

When these muscles contract, during times of acute stress and fear or when the ambient temperature is low, the hair stands up and the “gooseflesh” effect appears. In evolution, these muscles took part in thermal insulation: air is kept between the raised hairs, which helps the body to keep warm.

Animals thanks to this function visually appear larger, which looks intimidating in the eyes of the enemy. Modern man has no need for these muscle fibers.

We have long been able to dress warmly and heat our homes.

2. Ear muscles

In ancient times ear muscles were important: they helped to catch various sounds and better orient on the terrain. This increased the efficiency of hunting, and in times of danger allowed to hide in a safe place in time.

About 10% of people still have ear muscles, and it is not uncommon to find people who are able to move their ears.

Ear muscles are well developed in pets, and by the movement of the ears we can often catch their emotions.

3. Wisdom Teeth

All adults know what problems wisdom teeth can cause when they erupt – it causes a lot of suffering. In ancient times, people needed a strong jaw and strong teeth to chew rough food (raw meat of wild animals, rough plants, hard food). This function was exactly what the “eights” helped to fulfill.

In the modern world, people eat more thermally processed food, and this does not require strong chewing muscles and strong teeth. As a result, this has led to the loss of the primary function of wisdom teeth: a person can do without them.

4. Long palmar muscle

Some people have this muscle, others lack it completely, but this does not change the function of the hand in modern man. In the past centuries, this muscle allowed to form a more tenacious grip on the hand, which helped to deftly climb trees and overcome various obstacles. Since then, a lot of time has passed: man walks on two legs, and his hands are no longer adapted to strong grip. This has led to a gradual atrophy of this muscle.

How to check its presence in yourself? You can connect the thumb and little finger and bend the hand – under the palm will be located an elongated swollen tubercle. This is the long palm muscle.

5. Pyramidal muscle

Next to the appendix (an important part of immunity) is the pyramidal muscle. It looks like a small triangle and is located in the lower abdomen. In humans, this muscle does not carry a functional load, and some do not have it at all. It is important for marsupial animals, as it is an additional protection when carrying cubs.

6. epicanthus

An overhanging fold over the upper eyelid can be observed in northern peoples and the Mongoloid race; it is absent in the Caucasoid race. This skin fold may have been created by nature to further protect the eye from cold, wind, dust and the blindingly bright sun.

In the modern world, we use sunglasses, so gradually it is no longer necessary.

7. Vomeronasal organ

This formation is located in the nasal cavity. It is called the accessory olfactory organ. It is developed in animals, as they search for their mate by pheromones, which forms sexual attraction.

Man in the modern world is more oriented to active social interaction. The formation of sexual desire is made up of many factors.

But still the preservation of this organ has its additional, although poorly developed to date, function. For example, we can feel attracted to a complete stranger, at the level of instincts.

8. The third eyelid

This is a transparent film located at the inner corners of the eyes. In reptiles and birds it has an important function: it moistens the eye, protects it from dust and wind. In humans, it is not present, it is represented in the form of a rudiment – a kind of mucous point in the corners of the eyes. The functions of the third eyelid are now performed by the upper and lower eyelids.

9. Morgans ventricles of the larynx

These are specific sac-like recesses located to the right and left of the larynx, next to the vocal cords. They are involved in creating the resonant sounds of our voice.

In ancient times, sounds were especially important when communicating in hunting and scaring away dangerous animals. In the modern world, the need for such communication is gradually diminishing.

10. Male nipples

At an early stage of embryonic development, nipples and breasts are laid down in everyone. With the further development of the fetus and the change in hormonal background there is a division into boys and girls, there is the formation of genitalia, but the nipples to this process of development are already there. For this reason, everyone has them.

Sometimes, with a large production of the hormone prolactin, men may have a small lactation, but this is already a pathology.

Do vestigial organs have a negative impact on the human condition?

According to the doctor, most of the rudimentary organs do not carry any load on the body, people do not notice them. But there are cases of formation of cancerous tumors from these tissues – this is a real threat to human health and life.

And inflammation of the wisdom teeth can bring not only severe pain, but also become a source of odontogenic (dental) sepsis. This is a deadly condition that requires inpatient treatment, often in intensive care.