What is the function of formaldehyde?
Formaldehyde is a strong-smelling, colorless gas used in making building materials and many household products. It is used in pressed-wood products, such as particleboard, plywood, and fiberboard; glues and adhesives; permanent-press fabrics; paper product coatings; and certain insulation materials.
Where does formaldehyde come from?
Formaldehyde is also a byproduct of combustion. When burning natural gas, kerosene, gasoline, wood, or tobacco, formaldehyde is produced. Automobile exhaust is a common source of formaldehyde in our environment. Tobacco smoking in the home is another source of the chemical in the indoor environment.
Where is formaldehyde found?
It is found in gas stoves and open fireplaces, as well as outdoors in automobile emissions. Since formaldehyde is used in the manufacturing of many household items—from furniture to cosmetics—it is present in every home.
Why is formaldehyde toxic?
The exact mechanism of action of formaldehyde toxicity is not clear, but it is known that it can interact with molecules on cell membranes and in body tissues and fluids (e.g., proteins and DNA) and disrupt cellular functions. High concentrations cause precipitation of proteins, which results in cell death.
Why is formaldehyde used in preservation?
The chemical formaldehyde is used to preserve bodies. Formaldehyde changes the tissue on a molecular level so that the bacteria can’t feed on the tissue.
What does formaldehyde do to bacteria?
Formaldehyde is a cold sterilant that effectively kills all microorganisms, including spores and resistant viruses, when used in proper concentrations and given adequate contact time.
How does formaldehyde affect the environment?
What effect does formaldehyde have on the environment? In the atmosphere, formaldehyde usually breaks down quickly to create formic acid and carbon monoxide, which can also be harmful substances. When animals are exposed to formaldehyde it can make them sick, affect their ability to breed, and reduce their life spans.
How much formaldehyde is in the human body?
Formaldehyde is essential in human metabolism and is required for the synthesis of DNA and amino acids (the building blocks of protein). Therefore, all humans have detectable quantities of natural formaldehyde in their circulation (about 2.5 ug of formaldehyde per ml of blood).
What happens when formaldehyde enters the body?
What are the short-term health effects of formaldehyde exposure? When formaldehyde is present in the air at levels exceeding 0.1 ppm, some individuals may experience adverse effects such as watery eyes; burning sensations in the eyes, nose, and throat; coughing; wheezing; nausea; and skin irritation.
Can formaldehyde cause nerve damage?
However, exposure to high concentrations of exogenous formaldehyde that exceeds the peripheral formaldehyde oxidation capacity will elevate the normal tolerable concentration of formaldehyde in the blood and could lead to neural damage.
Why is formaldehyde used as a preservative for biological specimens?
Formaldehyde hardens tissues. The natural appearance of the tissues with respect to color and texture is generally quickly lost and the specimen solutions become cloudy. Specimens preserved in alcohol also lose their natural color very quickly, particularly, when exposed to light.
What are the actions of the extraocular muscles?
The Actions and Innervation of Extraocular Muscles. Three antagonistic pairs of muscles control eye movements: the lateral and medial rectus muscles, the superior and inferior rectus muscles, and the superior and inferior oblique muscles.
What muscles are involved in eye movement?
Three antagonistic pairs of muscles control eye movements: the lateral and medial rectus muscles, the superior and inferior rectus muscles, and the superior and inferior oblique muscles.
What muscle is responsible for eye elevation and depression?
Elevation is due to the action of the superior rectus, and depression is due to the action of the inferior rectus. When the eye is adducted, the oblique muscles are the prime vertical movers.
Which extraocular muscle has the longest tendon in the eye?
Resection of the inferior rectus muscle results in lower lid narrowing (eyelid moves up). The superior oblique muscle has the longest tendon of all the extraocular muscles (26 mm).