The Immune System – Introduction [HD]

Опубликовано: 11 Март 2025
на канале: SebWeo

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Learn about the immune system.

There are two major types of the immune system: the innate immune system and the adaptive immune system.
• Innate #immunity: Everyone is born with innate (or natural) immunity. The body's most important defense is the skin, which acts as a physical barrier to keep pathogens out.
• Adaptive immunity: Adaptive (or active) immunity develops throughout our lives. We develop adaptive immunity when we're exposed to diseases or when we're immunized against them with vaccines.

The innate immune system – is the first line of defense against invaders (pathogens and infection).
• The skin
• The cornea of the eyes
• Membranes lining the respiratory, digestive, urinary, and reproductive tracts

These barriers are defended by secretions containing enzymes that can destroy bacteria. Examples are sweat, tears in the eyes, mucus in the respiratory and digestive tracts.

The next line of defense involves white blood cells (#leukocytes) that travel through the bloodstream and into tissues, searching for and attacking microorganisms invaders.

When a pathogen does make it into the body, white blood cells leak from the vessels to invade the infected tissue. These white blood cells (phagocytes) engulf and destroy bacteria.
When a pathogen has invaded, the immune system may also release chemicals that increase body temperature, producing a fever. Increased body temperature may slow or stop pathogens from growing and helps speed up the immune response.

When pathogens are able to bypass innate immune defenses, the adaptive immune system is activated.
The immune system uses cellular and chemical defenses to attack pathogens. The immune responses are triggered by antigens, that are usually found on the surface of pathogens and are unique to that particular pathogen.
The immune system responds to antigens by producing cells that directly attack the pathogen, or by producing special proteins called antibodies. Antibodies attach to an antigen and attract cells that will engulf and destroy the pathogen.
Antibodies alone are often not enough to protect the body against pathogens. In these instances, the immune system uses cell-mediated immunity to destroy infected body cells.
The main cells of the immune system are #lymphocytes known as B cells and T cells, which are produced in bone marrow.

While the innate immune response is immediate, the adaptive immune response is not. However, the effect of the adaptive immune response is long-lasting, highly specific, and is sustained long-term by memory T cells.

After an encounter with a new pathogen, the adaptive immune system often "remembers" the pathogen, allowing for a faster response if the pathogen ever attacks again.

The immune system is incredibly complicated and utterly vital for our survival. Several different systems and cell types work in perfect synchrony throughout the body to fight off pathogens. Buy Me A Coffee ☕😊💕 https://www.buymeacoffee.com/SebWeo