Question

what are the 7 major categories of innate defenses of immunity? how do innate defenses contribute to the immunity response in our body?

Answer 1

Type Mechanism

Anatomic Barriers

Skin - mechanical barriers retards entry of microbes.Acidic environment retards growth of microbes.

Mucous membranes - normal flora competes with microbes for attachment sites and nutrients.Mucus entraps foreign microorganisms.cilia propel microorganisms out of body.

Physiological barrier

Temperature - normal body temperature inhibits growth of some pathogens.Fever response inhibits growth of some pathogens.

Low pH - Acidity of stomach contents kills most ingested microorganisms.

Chemical mediators- lysozyme cleaves bacterial cell wall.Interferon induces antiviral state of uninfected cells.Complement lyses microorganisms or facilitate phagocytosis.Toll like receptor recognise microbial molecules,signal cell to secrete immunostimulatory cytokines.Collectins disrupt cell wall of pathogen.

Phagocytic and endocytic barriers - various cell internalize and break down foreign molecules.Specialised cells internalize,kill, digest whole microorganisms.

Inflammatory barriers- tissue damage and infection induces leakage of vascular fluid , containing serum proteins with antibacterial activity and influx of phagocytic cells into the affected area.

Hope it Helps , Best Wishes.