Bioelements, Biomolecules, and Cellular Nutrition: A Comprehensive Look
Bioelements and Biomolecules
Bioelements are the chemical elements that constitute the material of living things. Biomolecules are formed when bioelements combine to create the molecules of living things.
Properties of Water
- Solvent Power: Water is a great solvent for many substances, allowing them to be transported throughout the body or incorporated into cells in a dissolved state.
- Chemical Reactivity: Water provides the H+ and OH- required for hydrolysis reactions, as well as O2 and H2 in oxidation-
Dental Abscesses, Ulcers, and Radiography: Common Questions
Dental Abscesses: Common Questions and Answers
Where can a dental abscess form? In the teeth or in the gums.
Where are the blood vessels and nerves of a tooth located? At the very centre of the tooth (pulp).
What is the function of the periodontal ligament? To attach the tooth to the jaw.
How is plaque described? Plaque is a by-product of food and saliva.
What is the most common form of abscess? A periapical abscess.
How is later infection prevented in a periapical abscess? With antibiotics and a permanent
Read MoreSkin, Hair, and Nail Structure and Function
The Skin: Structure and Function
The skin is an organ with cutaneous annexes, such as hair and nails, and exocrine glands, including sebaceous and sweat glands.
Structure of the Skin
Epidermis
The epidermis is composed of stratified epithelial tissue. Its cells, called keratinocytes, divide by mitosis. Keratinocytes generate cell layers and produce keratin.
- Melanocytes: These cells have extensions that lie between nearby cells.
Layers of the Epidermis:
- Stratum Basale (Basal Layer): The deepest layer,
Digestive and Respiratory Systems: Functions and Processes
The Digestive System
It consists of the gastrointestinal tract and accessory glands. The gastrointestinal tract is a long tube that varies along its route, widening in some places and narrowing in others. It begins at the mouth and ends at the anus. The following parts are distinguished:
- Pharynx
- Esophagus
- Intestine
The accessory glands are organs that pour their secretions into the digestive tube. These are:
- Salivary glands (located in the mouth)
- Stomach
- Intestinal glands (in the intestine)
- Liver
- Pancreas
The
Read MoreNeuron Activation, Synapses, and Nervous System
Neuron Activation
A membrane also has channels through which ions pass. Na+ channels are closed, but upon appropriate stimulation, they open, and Na+ enters massively. The entry of Na+ changes the polarity of the membrane; the inside of the neuron becomes positive, and the outside becomes negative. This potential difference is called the nerve impulse, and the membrane is said to be depolarized. The opening of Na+ channels takes a short time, and when they close, K+ channels open, becoming positive
Read MoreCirculatory System: Heart, Blood, Vessels, and Function
Circulatory System: Composition and Function
The circulatory system consists of the heart and blood vessels. Blood is composed of 45% blood cells and 55% plasma, which is a liquid.
Blood Plasma
Blood plasma is a yellowish liquid consisting of water and a great variety of dissolved substances.
Blood Cells
Blood cells are formed in the red bone marrow. There are three types:
- Red blood cells: The most abundant cells in the blood.
- White blood cells: Several types of white blood cells exist, and all have a