(7-16) Innate Immunity Flashcards
1. Differentiate innate immunity and adaptive immune response. 2. Define: Self vs. non-self, Phagocytes, Inflammation, Fever 3. Define first-line defense. 4. Define or identify: Lysozyme, Lactoferrin, Cytokines 5. List and describe the mechanical and chemical factors that are involved in preventing the invasion of microorganisms through the skin and mucous membranes. 6. Describe the role of normal flora in innate immunity. 7. Identify and describe of the roles of the following kinds of cel
Which 3 features of innate immunity constitute the body’s first line of defense?
- Epithelial cells (barrier)
- Antimicrobial substances (on skin & mucous)
- Normal flora
What happens when the body’s barriers are breached (general)?
A non-specific system of cells and circulating proteins reacts to invading microorganisms.
Is the inside of the body sterile or contaminated?
Sterile
Explain why the dermal and epidermal layers of the skin are difficult for invaders to penetrate.
- The Dermis is composed of tough fibrous connective tissue.
- The multi-layered epidermis is composed of stratified squamous epithelium. The outer layer is keratinized, which helps with water-tightness, and when the outer layer sloughs off, microbes fall of with it.
Which 3 parts of the body are lined with mucous membranes?
- Digestive tract
- Respiratory tract
- Genitourinary tract
What is the purpose of the mucous lining body tracts, and which cellular structural feature assists with this task?
Mucous helps wash microbes from surfaces. Cilia help to propel microorganisms to areas where they can be eliminated (ex stomach, or outside body).
What 3 antimicrobial substances are found on skin and in mucous?
- Lysozyme
- Lactoferrin
- Defensins
What is lysozyme, and which 2 places is it found?
~ Enzymes that degrade peptidoglycan (PTG).
~ Found in tears, saliva
What is lactoferrin, and which 3 places is it found?
~ Substance that sequesters iron (an essential nutrient)
~ found in saliva, mucous, and milk
What are defensins, and how do they work?
~ Antimicrobial peptides found in mucous
~ make holes in microbial membrane
What is Normal Flora?
Microorganisms growing on body surfaces of healthy individuals
How does normal flora protect from disease?
Normal flora protects via competitive exclusion.
~ covers binding sites so pathogens have nowhere to bind
~ competes for nutrients with pathogens
Where do cells of the immune system come from?
Thy are all derived from hematopoietic stem cells in red bone marrow.
What do erythrocytes (RBCs) do?
They carry oxygen in the blood.
What are platelets?
They are broken pieces of megakaryocytes. They assist in blood clotting.
What are white blood cells (WBCs)?
Defensive blood cells