L30 Introduction to Immunology and the Immune System

Flashcards covering key vocabulary and concepts from the Introduction to Immunology and the Immune System lecture.

Immunology

The study of an organism’s immune system in health and disease.

Immune System

An organised system of organs, cells and molecules that interact together to defend the body against disease (pathogens)

Disease examples

Infectious= HIV, influenza, malraia. Inflammatory= Alergy, lupus, diabetes. Cancer.

Microbes

Viruses, Bacteria, Fungi, Protozoa. Some are pathogens.

Primary and secondary lymphoid organs

Primary: production of white blood cells (lymphocytes); Secondary: sites where immune responses are initiated

Primary lymphoid organs

Thymus, bone marrow.

Thymus

‘School’ for white blood cells called T cells; developing T cells learn not to react to self. As we age this disapears because autoimmune system.

Bone marrow

Source of stem cells that develop into cells of the innate and adaptive immune responses

Secondary lymphoid organs

Spleen, lymph nodes.

Lymph nodes

Located along lymphatic vessels; Lymph fluid from blood and tissue is filtered; Site of initiation of immune responses

Spleen

Site of initiation for immune responses against blood-borne pathogens (filters blood).

3 layers of defense

chemical and physical barriers, innate, and adaptive.

Epidermis

Dead cells, keratin and phagocytic immune cells (thin outer layer).

Dermis

Thick layer of connective tissue, collagen and blood vessels and phagocytic immune cells

Antimicrobial peptides (AMPs) or skins defensins

Forms pores in microbial cell membranes. Lysozyme (breaks down bacterial cell walls= cell death). Sebum (low pH), Salt (hypertonic). Making a hostile environment for pathogen.

Mucosal membranes

Line inside of body exposed to outside, 1-2 layers.

The mucociliary escelator

Cilia line epithelium, and move in tandem to move mucus containing microbe before it does harm. Thats why we cough up mucus.

Epithelium

Tightly packed live cells, constantly renewed, mucus-producing goblet cells

Chemical defensins of mucosal surfaces

Stomach- low pH, gall bladder- bile, intestine- digestive enzymes (break down microbes), mucus (contains defensins and lysozymes), (tears, urine) flush out.

Skin vs mucous membranes

Innate immunity

Already in place, Rapid (hours), Fixed, Limited specificities, Has no specific memory

Adaptive immunity

Improves during the response, Slow (days to weeks), Variable, Highly specific, Has long-term specific memory