It also protects your reproductive chances: Without a foreskin, the glans rubs against objects, like your clothes, and develops a thick layer of skin to desensitize itself, Weinhaus says. We'll notify you here with news about. Turn on desktop notifications for breaking stories about interest? Comments 0. Top Stories. This organ sits on the left side of the abdomen, towards the back under the ribs. It is most commonly removed as a result of injury.
Because it sits close the ribs, it is vulnerable to abdominal trauma. It is enclosed by a tissue paper-like capsule, which easily tears, allowing blood to leak from the damaged spleen. If not diagnosed and treated, it will result in death. When you look inside the spleen, it has two notable colours. A dark red colour and small pockets of white. These link to the functions. The red is involved in storing and recycling red blood cells, while the white is linked to storage of white cells and platelets.
You can comfortably live without a spleen. This is because the liver plays a role in recycling red blood cells and their components. Similarly, other lymphoid tissues in the body help with the immune function of the spleen. The stomach performs four main functions: mechanical digestion by contracting to smash up food, chemical digestion by releasing acid to help chemically break up food, and then absorption and secretion. The stomach is sometimes surgically removed as a result of cancer or trauma.
In , a British woman had to have her stomach removed after ingesting a cocktail that contained liquid nitrogen. While the appendix is found between the small intestine and large intestine it plays no role in digestion.
Experts suggest it may have served a purpose when the human diet was mostly made up of plants. Now it only becomes inflamed and infected before finally rupturing when someone develops appendicitis. Why do men have nipples anyway?
All human fetuses develop nipples even before our gender is determined. While it is rare, men are capable of lactating. Years of research suggest that vision, lung function, immune system performance, and even sperm count can all be improved by omega-3s. Do you know how to prevent head lice infestations? Or what to do if you find the critters?
Apple Picking, a Perfect Fall Activity. The tonsils are another vestigial organ that have been the subject of debate in terms of necessity. It has been argued that the tonsils play an important role as the front defensive lines against harmful pathogens that may be ingested or inhaled. It is this penchant to became dangerously infected that has led experts to believe that if immune response was their actual purpose, the benefits of that response have been certainly—and easily—outweighed by the need to have them removed.
Are you able to wiggle your ears? These muscles are responsible for the movement of the visible parts of the ear, and are much more useful to other mammals, including our feline, canine, and larger farm animal friends. As humans evolved and moved up the food chain, the need to prick our ears for sound detection decreased, and our neck flexibility increased, allowing us to more easily turn our heads to observe the source of sounds.
Palmaris Longis is a long muscle that runs the inner length of the forearm from wrist to elbow. In the days where the primary route of transport for our ancestors was through the treetops, the muscle is believed to have played a significant role in their grips. Once we began walking upright, the necessity for a powerful grip to hang on so tightly became abysmal.
However, even though the muscle no longer serves its original intended purpose, it has potential to be repurposed in the medical field. The muscle functions well for folks who need tendon grafts, as it can be completely cut out and relocated elsewhere in the body, without affecting function and movement of the hand and wrist. Think you might have it? To check, turn your palm up and touch your thumb and pinky together.
Be sure to use it wisely. Another lingering hint at our evolutionary past, the coccyx is all that remains of our ancestral tails. In many creatures, tails can serve several beneficial functions by way of balance, communication, and in the case of some primates, are even prehensile. As humans gradually evolved to walk upright, our tails became unnecessary for our balance, and began to disappear altogether, leaving our tailbone as the only evidence of their previous existence.
However, there are many well-documented cases involving the surgical removal of the tailbone, which all resulted in little to no side effects for the patient, which suggests this evolutionary leftover may be totally unnecessary. A lesser known vestigial feature, known as the fabella, has actually shocked scientists by making a surprising comeback, after being considered a feature that was initially lost to evolution.
The fabella is a teeny, tiny bone that sits inside the tendon behind the knee, and was found to be present in a mere The bone provides a smooth surface for the tendon in the back of the knee to slide on, reducing the amount of friction and stress our larger calf muscles and longer shin bones put on our knees. Either way, it remains up for debate if the bone presence is truly necessary.
Ever wish you had self-cleaning eyes? Another Fun Fact : Not all vestigial features are necessarily bodily organs or structures! They can also present as behaviors, reflexes, and even biochemical processes!
This is due to the primitive reflex known as the palmar grasp reflex. In my research for this article, I stumbled across this not-exactly-scientific, though undoubtedly amusing dispute of the vestigiality of this reflex, made by a parent.
It has been proposed that the hiccups might be attributed to an ancient amphibian ancestor. The motor reflex that allows tadpoles to take in air and water through their gills is apparently quite comparable to the reflexes observed when we hiccup.
Natalie is a Science Writer at Promega. She earned her B.
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