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Gardnerella vaginalis

Gardnerella Vaginalis

Definition Gardnerella vaginalis is the name of a micro-aerophilic coccobacillus found in the vaginal flora. Gardnerella vaginalis does not cause bacterial vaginosis (vaginal infection) unless...
Acetic Acid

Acetic Acid

Definition Acetic acid is a mildly corrosive monocarboxylic acid. Otherwise known as ethanoic acid, methanecarboxylic acid, hydrogen acetate or ethylic acid, this organic compound is...
Amino Acids

Amino Acids

Definition Amino acids are the building blocks of polypeptides and proteins and play important roles in metabolic pathway, gene expression, and cell signal transduction regulation....
BCAA supplements: a muscle myth?

Branched Chain Amino Acids

Definition The branched-chain amino acids or BCAAs, leucine, isoleucine, and valine are three of the nine nutritionally essential amino acids. These three ingredients form a...
Sulfuric acid

Sulfuric Acid

Definition Sulfuric acid (sulphuric acid) is a corrosive mineral acid with an oily, glassy appearance that gave it its earlier name of oil of vitriol....
Bile salt action in the gut

Bile Salts

Definition Bile salts are found in bile, a secretion produced by liver cells to aid digestion. Although bile is 95% water, bile salts are its...
The salivary glands

Submandibular Gland

Definition Submandibular glands are the second-largest salivary gland type, producing around 65% of our saliva when unstimulated (at rest). Located under the jaw, the exocrine...
Metaphase I

Metaphase I

Definition The first metaphase of meisosis I encompasses the alignment of paired chromosomes along the center (metaphase plate) of a cell, ensuring that two complete...
Prophase II

Prophase II

Definition During prophase II of meiosis II, four important steps occur. These are the condensing of chromatin into chromosomes, disintegration of the nuclear envelope, migration...


Definition Aldosterone (C21H28O5) is a mineralocorticoid hormone compound secreted by the adrenal gland cortex. It is part of the renin angiotensin aldosterone system or RAAS...

Nervous System Fun Facts

The nervous system is the body’s communication system. It processes everything from sight to taste and interprets the information from its surroundings. The main organs of your nervous system are the brain and spinal cord. Some organisms have a much simpler nervous system consisting of just a few cells, such as a jellyfish. This system determines what is going on around the body and helps to facilitate a response.

The below image shows a diagram of the cross-section of a brain.

cross-section of a brain

Top 20 Fun Facts

  1. The basic unit of the nervous system is the neuron. These specialized cells have a cell body or soma, axons, and dendrites.
  2. The brain uses more of the body’s energy than the rest of the organs, using over 20% of the energy reserves in the body.
  3. The brain is hard at work even when you’re sleeping.
  4. The brain’s structure is constantly changing as we learn. New neuronal connections are made which increases the density of the brain.
  5. Some neurons have an insulating layer known as the myelin sheath. This allows nervous impulses to travel faster, with less energy lost.
  6. Involuntary reflexes are not controlled by your brain. They are controlled by a reflex arc.
  7. The fastest signal transmission in the body occurs in the alpha motor neurons within the spinal cord. They transmit a signal at 268 miles per hour. The slowest signal transmission is within the skin at 1 mile per hour.
  8. Neurons can’t divide or replace themselves. This means that nerve damage is often permanent.
  9. We lose neurons as we age, starting at around 20 years old in humans. 1/10 of our neurons are gone by the time we turn 75.
  10. Electrical impulses within the nervous system are triggered by ions or chemical signals that pass through channels in the neuron.
  11. Ions that are important in chemical signaling include sodium, potassium, chloride, and calcium.
  12. As we age, our brain shrinks by about 1-2 grams every year due to the loss of neurons.
  13. Males and females have different brain compositions. Males have more grey matter, while females have more white matter.
  14. The optic nerve crosses over in the brain. This means that the right optic nerve crosses to the left side of the brain and vice versa. This allows an image to be produced by the brain.
  15. Primates, including humans, have a group of neurons called mirror neurons. These are responsible for some behaviors being contagious, such as yawning.
  16. The longest nerve in the body is the sciatic nerve. It runs from the spinal cord to the toes on each side of the body.
  17. Neurons can look very differently from each other depending on their function. For example, sensory neurons have dendrites on both sides of their body, rather than on one side.
  18. The bowel is controlled by a separate part of the nervous system known as the enteric nervous system. It regulates digestion and bowel movements.
  19. Glial cells are support cells for neurons. They can make myelin to surround part of the neuron. They can also get rid of microbes and help supply nutrients to the neurons.
  20. The brain has approximately 100 billion neurons. In contrast, the spinal cord only has roughly 13.5 million neurons throughout its length.