Microbiology and Human Physiology Fundamentals
Microorganisms and Their Characteristics
Micro-organisms are life forms that have small main characteristics: they can only be seen through a microscope, are abundant in nature, can multiply quickly, and can be either beneficial or harmful.
Types of Microorganisms
- Eukaryotes: These include fungi (such as mushrooms).
- Prokaryotes: These include cyanobacteria and algae.
- Viruses: These have a subcellular organization.
Bacteria vs. Viruses
Bacteria have a cellular organization including ribosomes, genetic material, and a cell wall. They can be autotrophs or live on organic substances. While some cause disease, many are beneficial, such as intestinal bacteria. In contrast, viruses have a subcellular organization consisting of genetic material and a protein coat; they are obligate parasites and disease-producing agents in other cells.
Immune System Definitions
- Antigen (Antixeno): Any foreign body or molecule.
- Antibody: These are substances that bind to antigens to remove them. White blood cells are responsible for producing antibodies.
- Serum: An antibody preparation.
- Vaccine: A preparation of weakened or less active germs that stimulates the body to produce the antibodies necessary to fight a specific disease.
- Infectious Disease: A disease produced by microbes such as viruses, bacteria, etc.
- Immunity: The resistance of the organism to any infectious agent. The cells responsible for immunity are lymphocytes.
The Human Respiratory System
The respiratory system involves the exchange of oxygen and carbon dioxide.
Inspiration and Expiration
- Inspiration: This occurs when air enters the lungs and reaches the alveoli. There, the oxygen from the air passes into the blood, and carbon dioxide from the blood passes into the air.
- Expiration: This occurs when air rich in carbon dioxide is expelled from the lungs.
The Path of Air
Air enters the body through the mouth and nose, where it is heated and hydrated. It then passes through the pharynx, the larynx, and the trachea, reaches the bronchi, and finally enters the alveoli in the lungs. This is where gas exchange takes place: oxygen passes from the air to the blood, and carbon dioxide passes from the blood into the air.
Circulatory System Basics
Difference Between Veins and Arteries
Veins carry blood toward the heart, while arteries carry blood away from the heart. In humans, the most important artery is the aorta, and the most important vein is the vena cava.
Division of the Heart
The heart is divided into four parts: two atria and two ventricles, which are connected through valves.