The basic structure and function of the human immune system from a scientific perspective.

Question 1: The human body "sky net" is a kind of "net" that appears around bacteria in the human body and is composed of some filamentous substances entwined with each other, which can capture bacteria and poison or devour them and protect healthy cells in the human body. Question 1:

Proteases accidentally injure healthy cells when they fight bacteria. When neutrophils fight bacteria to the point of exhaustion, they "disintegrate" on their own, and their lifespan is only a few hours. Question 1:

When the neutrophils in the human body fight with the bacteria to exhaustion, they "disintegrate" by themselves, and the filamentous substance thrown from the body, DNA, is entangled together, forming a human "sky net" that bacteria cannot escape. Question 1: The "sky net" of the human body always appears around the bacteria quickly after they enter the human body; It can capture, poison, and devour bacteria; It plays a protective role in healthy cells in the human body; It mysteriously disappears after killing enemy protectors; Its filamentous substance is the DNA inside neutrophils.

Question 1: Definition is a common way of explaining the essential characteristics of things and things. Question 1:

They all use vivid explanatory language to vividly illustrate the characteristics of things, which is the characteristic of popular science expository language. Question 1: Learn to use the information in the original text to answer.

Question 1: Simply find the central sentence that indicates the characteristics of the object.

The structure and function of the human immune system.

Immune cells are made up of T lymphocytes and B lymphocytes.

T lymphocytes include surface markers and T cell subsets of T cells.

B lymphocytes include surface markers and B cell subsets of B cells.

1. Composition: The immune system is composed of immune organs (bone marrow, spleen, lymph nodes, thymus, etc.), immune cells (lymphocytes, mononuclear phagocytic cells, neutrophils, etc.) and immune molecules (immunoglobulin, interferon, interleuchin, etc.).

2. Function: 1) Discover and remove foreign bodies, foreign pathogenic microorganisms and other factors that cause internal environment fluctuations.

2) Identify and remove mutated tumor cells, senescent cells, dead cells, or other harmful components in the body. This ability to detect and remove the "non-self" components that appear in the body at any time is called immune surveillance.

3) Removal of metabolic waste products and the dead and wounded bodies of the virus left by immune cells during the battle with the virus must be removed by immune cells.

Answer] Xiao Chanheng: c

The immune system has three major functions: Immune defense: refers to the body's prevention of the invasion of external pathogens and the removal of invading pathogens and other harmful substances.

Immune homeostasis: refers to the body's efforts to achieve stability in the immune system through autoimmune tolerance and immune regulation. Immune surveillance:

It refers to the body's discovery and removal of "non-ready" components from the body at any time.

The immune system has three major functions: defense, stability, and monitoring

1. Defense function: protect the body against the invasion of pathogens and their toxic products, help the body eliminate foreign bacteria and viruses, and prevent people from infectious diseases.

2. Stable function: human tissue cells are constantly metabolized, and a large number of new cells are replacing senescent and damaged cells at any time. The immune system can recognize the aging and dead cells in time and remove them from the body, so as to maintain the stability of the human body, and autoimmune diseases will occur when the function is abnormal;

3. Monitoring function: the immune system has the function of timely identification, killing and timely removal of chromosomal aberrations or gene mutations of cells, preventing the occurrence of tumors and cancers.

Answer] :d The three major functions of the immune system are immune defense, immune monitoring, and immune self-stability. Immune defense is to prevent the invasion of external pathogens and remove invading pathogens (such as bacteria, viruses, fungi, mycoplasma, chlamydia, parasites, etc.) and other harmful substances.

Immune surveillance is the detection and elimination of the appearance of the body at any time"Not yourself"components, such as tumor cells and senescent and apoptotic cells that occur as a result of genetic mutations. Immune autostabilisation is achieved through two main mechanisms of attrition, autoimmune tolerance and immune regulation. Tips: The three major functions of the immune system.

The immune system is composed of immune organs (bone marrow, thymus, spleen, lymph nodes, tonsils, appendix, etc.), immune cells (lymphocytes, mononuclear phagocytic cells, granulocytes, mast cells, platelets), and immune molecules (complement, immunoglobulin, interferon, interleukin, tumor necrosis factor, etc.).