favicon here hometagsblogmicrobio cvtech cvgpg keys

Understanding the Immune System

#biology #science #medicine #notes

Soc Virnyl Estela | 2023-04-15 | reading time: ~5min

The immune system is a host defense system and comprises many biological structures ranging from white blood cells to entire organs.

The function of the immune system is to protect the host against foreign invaders called pathogens. Pathogens can be anything from a virus, to a bacterium, and even a multicellular parasite including cancer cells.

Layered Immunity§

There are two subsystems of the immune system:

These subsystems provide a layer of defenses against pathogens that keep our body lessen the chances of infection or further damage if otherwise.

Cells involved in the immune system§

The cells involved in the immune system are called leukocytes or "white blood cells". Some of these cells are developed in the bone marrow, whereas others are further developed in the lymphatic system, hence, a subset of leukocytes are called lymphocytes. To destroy pathogens, leukocytes perform phagocytosis, thereby calling some of them as phagocytes.

Innate Immune System§

The innate immune system usually begins with the physical barriers that prevents pathogens from entering the body. These includes our own skin barrier, mucus membranes and the acidity of the stomach. Cells involved in the innate immune system are of the following:

  • Eosinophil
  • Basophil
  • Neutrophil
  • Monocyte
  • Mast Cell
  • Macrophage
  • Dendritic Cell
  • Natural killer cells

This link contains descriptions for each of these cells.

Inflammation and Fever§

Inflammation is the part of the response of the immune system, also called inflammatory response. The purpose of this is to increase blood flow to the damaged site through vasodilation. Inflammation is triggered by either of the two substances: histamine, and cytokine. These substances are released by the phagocytic cells.

Fever is the most misunderstood immune response. But it is believed that a body temperature that is higher than normal discourages pathogen reproduction. A normal temperature can vary from person to person, but it is usually around 98.6 °F (37 °C). A fever is not a disease. It is usually a sign that your body is trying to fight an illness or infection.

Infections cause most fevers. You get a fever because your body is trying to kill the virus or bacteria that caused the infection. Most of those bacteria and viruses do well when your body is at your normal temperature. But if you have a fever, it is harder for them to survive. Fever also activates your body's immune system.

Adaptive Immune System§

The adaptive immune system specializes on stopping or killing pathogens using specific methods of attack. The difference between innate and adaptive immunity is the fact that the latter is specific. This means that the cells involved for this pathogen differs for another pathogen. Cells involved in adaptive immunity are many but these are the most notable in literature: B cells and T cells (both are lymphocytes).

B Lymphocyte§

B lymphocytes are cells in the adaptive immune system that specializes in the production of antibodies. Antibodies is a chemical substance (usually Y-shaped in structure) that acts as a "plug" or "missile" to kill or stop a pathogen in its tracks e.g. stopping metabolic functions or perforation of the pathogen's outer membrane.

T Lymphocyte§

T lymphocytes are cells in the adaptive immune system that are specialized to kill a specific pathogen. Each T lymphocyte are unique from each other and finding the right T lymphocyte may take longer during the symptomatic phase of the infection. While these cells also kill and engulf pathogens, they also revive macrophages and natural killer cells to kill pathogens again.

"Memory" Cells§

After the immune system finally finishes off the last remaining invader, the remnant T and B cells become "memory" cells. "Memory" cells are so called because they are used to "remember" what to do when such a pathogen that was encountered before invades again. This reduces the risk of damage and prevents most reinfections of which we all know as immunity or acquired immunity.

Other purpose of the immune system§

The immune system has another role to prevent bodily damage. This one is to prevent our own cells to become tumors or cancer cells or kill them before they overwhelm our body. This is what we call as immune surveillance.

Self and Non-Self§

The body has the ability to identify which cells are "self" and which are "non-self". In biological and medical terms, cells use antigens to identify "self" and "non-self". Antigens are chemical markers on a cell's surface e.g. pathogens. Our immune system use these chemical markers to detect foreign cells in the body and destroy them.

Allergies§

Sometimes our body overexaggerates immune responses. Pollen, dust, and other types of mostly harmless substances, our body just destroyes them no problem. But other's immune systems are overzealous when trying to remove these allergens. Hence, allergies exist as a "bug" of our immune system.

Further Reading§

Read the following. Don't skip. Most of the exam is based on this blog and the links below.

Review§

  1. What is an allergy?
  2. What will be the first response of your body when it's stung by a bee?
  3. Find out the cells that release histamines.
  4. What is a cytokine?
  5. Research about the complement system.
  6. Describe all pathogen types.

Articles from blogs I follow around the net

Leaktracer: A Rust allocator to trace memory allocations

A few days ago, I had a memory issue in one of my Rust applications. The application was huge, and for some reason the memory kept growing with hundreds of gigabytes of memory allocated, but I couldn't find the source of the leak. Of course I know there…

via Christian Visintin BlogJune 26, 2025

Status update, June 2025

Hi all! This month, two large patch series have been merged into wlroots! The first one is toplevel capture, which will allow tools such as grim and xdg-desktop-portal-wlr to capture the contents of a specific window. The wlroots side is super simple becau…

via emersionJune 20, 2025

Contra Ptacek's Terrible Article On AI

A few days ago, I was presented with an article titled “My AI Skeptic Friends Are All Nuts” by Thomas Ptacek. I thought it was not very good, and didn't give it a second thought. To quote the formidable Baldur Bjarnason: “I don’t recommend reading it, but…

via LudicityJune 19, 2025

Exploiting Erlang OTP with Zip files: CVE-2025-4748

There’s a new Erlang OTP vulnerability, CVE-2025-4748. It’s an Absolute Path Traversal vulnerability involving a Zip archive, which I have a lot of practice with. It affects Erlang OTP, which a coworker has already written about recently and noted the nece…

via GreyNoise LabsJune 17, 2025

Furries Need To Learn That Sunlight Is The Best Disinfectant

Next month, AMC+ is premiering a new series about furries that tracked down sexual abusers hiding within the furry fandom. It’s called, The Furry Detectives: Unmasking A Monster. You can watch the trailer for this below. And I do recommend watching the tra…

via Dhole MomentsJune 12, 2025

Unionize or die

Tech workers have long resisted the suggestion that we should be organized into unions. The topic is consistently met with a cold reception by tech workers when it is raised, and no big tech workforce is meaningfully organized. This is a fatal mistake – an…

via Drew DeVault's blogJune 09, 2025

#FckICE 2025 - cumulative leaks and data

let the games begin

via maia blogJune 09, 2025

Recently

A little late on this one, but I got around to it! Reading I got stuck on two books: books that I want to enjoy but can’t get any momentum on. So my reading “stats” are suffering and this is a light year for books so far. But I switched gears to read Gla…

via macwright.comJune 06, 2025

Elevate hover/focus effects with transitions across multiple elements

You can elevate hover/focus effects by triggering transitions on more than one element. With the right orchestration, you can create more nuanced effects.

via Rob O'Leary | BlogJune 01, 2025

Generative AI will probably make blogs better

Generative AI will probably make blogs better. Have you ever searched for something on Google and found the first one, two, or three blog posts to be utter nonsense? That's because these blog posts have been optimized not for human consumption, but rather …

via pcloadletterMay 30, 2025

The everlasting now

Continuing the experiment. My first post in this series was manually crafted, but coding a static almost-a-site generator, without having to worry about all the interrelationships on the old site was quick, & in Rust terms at least, relatively easy. This i…

via Mike KreuzerMay 23, 2025

The Date that wasn't

A tale of lakes, dates and random results.

via Technically PersonalMay 03, 2025

Body::poll_progress

This describes a proposal for a cancelation problem with hyper’s request and response bodies. hyper is an HTTP library for the Rust language. Background: what is the Body trait? The Body trait used by hyper is meant to represent a potentially streaming (…

via seanmonstarApril 22, 2025

#Rx Writing Challenge 2025

This is a short reflection on my experience of the recent writing challenge I took part in. Over the past two weeks, I have participated in the #RxWritingChallenge 1—a daily, 30-minute writing group starting at 9 AM every morning. Surrounded by fellow doct…

via Ul-lingaApril 05, 2025

My coffee workflow

My coffee workflow by Clement Delafargue on April 1, 2025 Tagged as: coffee, espresso, flair58, v60. It is my first April cools’ and I guess I could start by talking about coffee. If you’ve seen me in person, it won’t be a surprise, I guess. This po…

via Clément Delafargue - RSS feedApril 01, 2025

LLDB's TypeSystems: An Unfinished Interface

Well, it's "done". TypeSystemRust has a (semi) working prototype for LLDB 19.x. It doesn't support expressions or MSVC targets (i.e. PDB debug info), and there are a whole host of catastrophic crashes, but it more or less proves what it needs to: Rust's de…

via Cracking the ShellMarch 28, 2025

Simple Web Augmented Generation

A guide to building a simple web application using augmented generation.

via Ishan WritesMarch 10, 2025

Backup Yubikey Strategy

After a local security meetup where I presented about Webauthn, I had a really interesting chat with a member about a possible Yubikey management strategy. Normally when you purchase a yubikey it's recommended that you buy two of them - one primary and one…

via Firstyear's blog-a-logFebruary 28, 2025

Generated by openring-rs

favicon here hometagsblogmicrobio cvtech cvgpg keys