1. Briefly describe the process of inflammation in an area that has been traumatized.
The body employs inflammation as a defense mechanism in reaction to certain forms of tissue damage. The inflammatory response occurs in three stages:
a. Vasodilation causes an increase in blood flow to the damaged area. Substances such as histamine, kinin, and other chemicals cause not only vasodilation, but also the capillaries to become leaky, and to permit the entry of WBCs to the area. This is explained by vascular permeability which enables the entry of antibodies and clotting factors to the site of injury.
b.As the blood accumulates, phagocytes emigrate from the blood, going to the interstitial fluid. Phagocytic cells, like neutrophils and monocytes, die few days after a reaction. As a result, platelets, thromboplastin, and fibrinogen, and pus are formed.
c. After all of this, it is time for the tissue to begin repair and regeneration.
2. Choose one type of Immunity (Innate and Humoral) and explain how its mechanism protects our body.
INNATE (NONSPECIFIC) BODY DEFENSES are mechanical barriers to harmful and disease-causing microorganisms and pathogens. It is divided into two lines of defenses:
a. 1st Line: Surface membrane barriers including the skin and mucous membranes for prohibiting the invasion of microorganisms. This line of defense includes the:
Skin (epidermis) as the mechanical barrier:
- Acid mantle inhibits bacterial growth
- Sebum contains bacteria-killing chemicals.
- Keratin also provides resistance against acids and alkalis.
- Mucus traps microorganisms.
- Nasal hairs filtering and trapping particles and cilia for propelling mucus away from lower respiratory tract.
- Gastric juices, being acidic and concentrated by protein-digesting enzymes, destroy pathogens in stomach
- Lacrimal secretions(tears) and saliva don't only lubricate and cleanse eyes and oral cavity, but both of them also contain lysozymes that destroys microorganisms
b. 2nd Line: Cells and Chemicals are internal defenses. This line of defense includes specialized human cells and chemicals produced by the body. Examples are:
- Phagocytes that engulf and destroy pathogens
- Natural Killer (NK) cells, which promote cell lysis and release perforin and granzymes to degrade cell contents.
- Inflammatory responses, whenever body tissues are injured.
- Antimicrobial chemicals(proteins) like complement and interferons. Complement is a group of plasma proteins that lyses microorganisms. Meanwhile, Interferons interfere with the ability of the viruses to multiply
- Fever, characterized by increase in body temperature, is also considered as a systemic response to invasion of microorganisms and is trigered by pyrogens.
REFERENCES:
- Marieb, E. N., & Keller, S. M. (2021). Chapter 12: The Lymphatic System and Body Defenses. In Essentials of human anatomy & physiology (13th ed., pp. 420–427). essay, Pearson Education Limited.
- Tortora, G. J., & Derrickson, B. (2017). Chapter 22.6 Innate Immunity. In Principles of anatomy and physiology (15th ed., pp. 822–824). essay, Wiley Custom Learning Solutions.