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Anonymous users2024-02-08** and mucous membranes belong to the first line of defense of the human body to protect themselves, phagocytic cells and lysozyme belong to the second line of defense, immune cells and immunoactive substances, immune organs belong to the third line of defense of the human body, the first two are called non-specific immunity, the third is called specific immunity, and phagocytic cells play an important role in the recognition of antigens by specific immunity, so they also belong to specific immunity, the two mechanisms of specific immunity, namely cellular immunity and humoral immunity, when pathogenic microorganisms break through the first and second lines of defense, Specific immunity is activated, that is, when the first two lines of defense do not effectively prevent the invasion of pathogenic microorganisms, specific immunity comes into play.
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Anonymous users2024-02-07In general, the human body has 3 lines of defense, the third of which is humoral immunity and cellular immunity, and the 3rd line of defense is specific immunity, while phagocytic cells and lysozyme belong to the 2nd line of defense, and the 1st and 2nd lines of defense are not specific immune responses, because both lines of defense have defense functions against multiple pathogens.
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Anonymous users2024-02-06Humoral immunity in a broad sense refers to the immune response involved by all humoral immune factors; In the narrow sense, it refers to the immune response mediated by B lymphocytes secreting antibodies, so please give a specific topic first.
Generally, it is calculated in a narrow sense, and it depends on the specific question. In general, humoral immunity is specific immunity.
Lysozyme is considered the second line of defense, and in a narrow sense, it is not considered humoral immunity.
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Anonymous users2024-02-05Humoral immunity works first to prevent the spread of parasites, and when the parasites enter the cells, cellular immunity releases antigens from the target cells, and then humoral immunity plays a role.
Is it okay to take the trouble to adopt? It's okay to adopt other people's leaves, but don't adopt them?
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Anonymous users2024-02-04Bacterial exotoxins are mainly humoral immunity, so why not cellular immunity?
Extracellular stuff is mainly cleared by humoral immunity.
Is it because extrabacterial viruses do not invade the host cell?
Bacterial exotoxin is not a bacterial extrabacterial virus. Toxins are not viruses, cannot invade cells, and cannot replicate.
For viruses, first humoral immunity, then cellular immunity, and finally humoral immunity clears it out Why not just clear it with cellular immunity?
As long as the pathogen enters the human body, humoral immunity and cellular immunity will be activated, and it is impossible not to activate it.
So why can Mycobacterium tuberculosis be eliminated by cellular immunity alone?
Mycobacterium tuberculosis does not cause humoral immunity, but it has little effect.
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Anonymous users2024-02-03Answer D examines the relationship between humoral immunity and cellular immunity. Specific immunity consists of a third line of defense, including cellular immunity and humoral immunity. Humoral immunity and cellular immunity not only have their unique roles in the specific immunity deficiency response, but also can cooperate with each other to exert immune effects.
In the process of humoral immunity, the joint participation of B lymphocytes and T lymphocytes is required; For pathogens that invade the human body, if they exist in body fluids, they act through humoral immunity. If it exists in cells, it requires both cellular immunity and humoral immunity to work together, for example, in viral infection, humoral immunity is often used to prevent the spread of the virus first, and then it is completely eliminated through cellular immunity.
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Anonymous users2024-02-02The lymphatic and mononuclear phagocytic cell systems are the body's second line of defense. After microorganisms enter the tissues of the body, most of the lymphatic fluid along the interstitial space of the tissue reaches the lymph nodes through the lymphatic vessels, but the macrophages in the lymph nodes will destroy them and prevent them from spreading in the body, which is the lymphatic barrier effect. If the number of microorganisms is large and the virulence is strong, it is possible to break through the lymphatic barrier, enter the blood circulation, and spread to tissues and organs.
At this point, they are blocked by the mononuclear phagocytic cell system barrier. This is a large class of phagocytic cells. There is also a smaller class of phagocytic cells, the main of which are neutrophils and eosinophils.
They do not belong to the mononuclear phagocytic cell system, but like the mononuclear phagocytic cell system, they are distributed throughout the body and have the effect of phagocytosis, digestion and elimination of invading microorganisms and macromolecular substances.
Some non-specific bactericidal substances in normal body fluids, such as complement, opsonin, lysozyme, interferon, betalysin, phagocytocidal fungicid, etc., are also the second line of defense of the body, like the lymphatic and mononuclear phagocytic cell system barriers, which help to destroy invading microorganisms.
The blood-brain barrier is mainly composed of the pia mater, choroid, and cerebral capillaries, which can prevent microorganisms from invading the cerebrospinal cord and meninges, thereby protecting the central nervous system from damage. The blood-brain barrier gradually matures with ontogeny, and infants and young children are prone to cerebrospinal meningitis and encephalitis, which is the reason for the imperfect development of the blood-brain barrier. The placental barrier is made up of the basal decidua of the maternal endometrium and the cells of the fetal chorionic trophoblast.
This barrier not only does not hinder the exchange of substances between mother and child, but also prevents pathogenic microorganisms in the mother's body from invading the fetus, thereby protecting the normal development of the fetus.
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Anonymous users2024-02-01For example, if you knock your hand open, and after a few hours, it becomes swollen and you squeeze out pus, which is non-specific immunity, and the bacteria go through the wound and kill the body fluids.
Dizzy, buy a reference book.
First, the dominant recessive nature of albinism and sickle anemia was determined, and according to the left half of Figure 1, it can be concluded that anemia is a recessive genetic disease, which is bb; Then look at Figure 2, because if it is normal, it can be cut, and if it is not normal, it can't, so B is normal, C is albino, and both are homozygous, only A is heterozygous (because A can cut out three pieces: DNA is a double helix structure, only one of A can be cut, B can be cut all of them, cut into two short and two long, C is not cut) Because albinism is a recessive genetic disease, it is AA, so it can be known that B is AA and C is AA >>>More
For these two types of immunity you must first understand that they function differently. Autoimmune immunity is much longer than passive immunity, but it takes a certain amount of time from injection to the production of antibodies, just like vaccination. Passive immunity, on the other hand, is mainly used for ** or emergency prevention because it is not produced by the human body itself, just like injecting snake venom.
p17, the enzyme that catalyzes the hydrolysis of lipase.
Lipase"It is an enzyme, and the enzyme is a protein, so it is natural to use protease. >>>More
In fact, you don't have to be so nervous, you may just put too much pressure on yourself, relax, and the workbook or something wrong is a good thing, learn more lessons, don't miss it again, and the review before the exam is very important, I usually look at the notes, and then see that I am not very familiar with the will be memorized, and then 5.3 wrong questions to see more, but there is no need to do 5.3 in the second year of high school, you can try my method, maybe it will get better.