Here, learn about its anatomy, functions, and the kinds of health problems that can occur. The fimbriae of the uterine tube, also known as fimbriae tubae, are small, fingerlike projections at the end of the fallopian tubes, through which…. The bladder, like the stomach, is an expandable saclike organ that contracts when it is empty.
The inner lining of the bladder tucks into the folds…. Combined with the cardiovascular system, the circulatory system helps to fight off disease, helps the body maintain a normal body temperature, and….
Health Conditions Discover Plan Connect. Read this next. Nose Medically reviewed by the Healthline Medical Network. Depressor septi nasi Medically reviewed by the Healthline Medical Network. Strotmann J, Breer H Formation of glomerular maps in the olfactory system. Fairless R, Barnett SC Olfactory ensheathing cells: their role in central nervous system repair. Nedelec S, Dubacq C, Trembleau A Morphological and molecular features of the mammalian olfactory sensory neuron axons: what makes these axons so special?
Schwob JE Neural regeneration and the peripheral olfactory system. Matthew S. Anosmia or hyposmia can result from a head injury, which is called post-traumatic olfactory loss PTOL. The loss is connected to both the severity of the injury as well as the part of the head that's damaged.
Injuries to the back of the head are the most likely ones to cause loss of smell. That might seem odd since the olfactory nerves are in the front of the brain. When there's an impact on the back of the head, the brain can come forward and collide with the inside front of the skull—right where the olfactory nerve is. Then, as the brain bounces back, it yanks on the delicate nerve fibers, which can snag on the rough edges of the tiny holes in the skull that they extrude through.
The olfactory nerves can become severed in this way, but often the smell loss is due to bruising of the olfactory bulb. PTOL also can be caused by damage to the face, such as a blow to the nose, as well. A decreased sense of smell can also occur due to tumors, such as meningiomas of the olfactory groove as well as be an early feature of some neurological diseases such as Parkinson's disease, Alzheimer's disease, and Lewy body dementia.
If you've lost your sense of smell to a known cause that's treatable—such as by surgically removing nasal polyps, straightening the septum, or clearing out the sinuses—it's possible that your sense of smell will improve over time. That's what happens in many cases of post-viral olfactory loss, although the sense may never be fully restored. A study published in found that more than 80 percent of participants reported improvement in olfactory ability one year after they were diagnosed with loss.
If your decreased sense of smell is due to a Parkinsonian syndrome or Alzheimer's disease, the treatment is usually directed towards the condition itself, often with no significant impact on the diminished ability to smell. Several studies suggest that smell training may be beneficial to some people. Researchers believe that could be due to the brain stimulation that results from repeatedly detecting or even imagining particular scents.
Most studies have used essential oils that people are familiar with. The prognosis is generally worse for people with post-traumatic olfactory loss.
Some will never regain their sense of smell, but others may see some improvement over time. Usually, the degree of recovery depends on the severity of the damage. While olfactory nerve cells can grow new nerve fibers, scar tissue may prevent them from ever being able to re-connect to the olfactory bulb. The new fibers also may be unable to find their way through the tiny holes in the bone behind the nose. Second, the olfactory sensory neurons, whose axons integrate the olfactory nerve, connect the nasal cavity and the brain without any relay.
Third, the olfactory nerve is composed by unmyelinated axons. Fourth, the olfactory nerve contains neither Schwann cells nor oligodendrocytes wrapping its axons. But it contains olfactory ensheathing glia, which is a type of glia unique to this nerve.
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