Diseases - Immune System Flashcards
Defence system, inflammatory response, phagocytosis, antigen, antibody, types of immune response, B-lymphocyres (hormonal response), T-lymphocytes (cell-mediated response)
Defense system
What’s the top layer of skin composed of?
Dead cells containing the indigestible protein keratin
Defense system
What is the purpose of sebum?
Sebum is produced by the skin to lower the pH, inhibiting the growth of pathogens
Defense system
What is the purpose of extracellular lysozymes?
Lysozymes are anti-bacterial enzymes found in saliva, sweat, tears and breast milk
Defense system
What is the primary defense against ingested bacteria?
Many ingested bacteria are destroyed in the stomach by acid (HCl)
Defense system
What is the primary defense against pathogens inhaled?
A sticky substance in the respiratory tract, mucus, traps pathogens, before being wafted towards the throat by cilia
Defense system
How are pathogens and foreign substances dealt with after the body’s “first line of defense”
Foreign materials and pathogens are targeted by the immune system
Inflammatory response
What is the role of white blood cells in the process of inflammation?
White blood cells release histamine into the wound
Inflammatory response
what are the effects of histamine?
histamine increases vasodilation and vascular permeability
Inflammatory response
what are the effects of increased vasodilation?
vasodilation increases local blood flow causing the to the area become red and warm
Inflammatory response
what are the effects of increased vascular permeability?
increased vascular permeability allows the release of tissue fluid into the affected tissues, this may cause local swelling
Inflammatory response
what makes tissue fluid a good defense against pathogens?
tissue fluid contains plasma proteins (anti bodys)
Phagocytosis
what allows the phagocytes to break down pathogens?
phagocytes contain digestive enzymes within lysosomes
Phagocytosis
what is the primary purpose of neutrophils?
neutrophils primarily engulph bacteria
Phagocytosis
what is the primary purpose of macrophages?
macrophages primarily engulf larger partials; including old, damaged or infected erythrocytes (red blood cells)
Phagocytosis
where are phagocytes naturally found in the body?
phagocytes are found in the blood, lymph systems, and (in lower concentrations) in the tissues
Phagocytosis
how do phagocytes enter the tissues from the blood?
phagocytes squeeze through the walls in the venules to reach enter the tissue
Phagocytosis
why do phagocytes travel through the bloodstream?
phagocytes travel through the bloodstream because it allows them to move faster to tissues infected with pathogens
Phagocytosis
how are phagocytes attracted to pathogens/infected tissues?
phagocytes are attracted by chemotaxis
Phagocytosis
how does the opsonization of bacteria by antibodies improve the process of phagocytosis?
binding between the opsonized bacteria (bacteria coated in antigens) and the phagocyte is improved
Phagocytosis
when a particle is first engulfed by a phagocyte, what two structures are formed around it?
the phagocyte forms a (1) phagocytic vesical (phagosome) within a protrusion of the cytoskeleton known as a (2) pseudopod around the particle
Phagocytosis
once ingested, how does the phagocyte digest the pathogen?
lysosomes fuse with the phagosome, releasing digestive enzymes, digesting the pathogen into harmless, component nutrients (and sometimes pieces of the cell wall)
Phagocytosis
if no extensive vasculature is present at the site of infection, what is formed?
puss, a mixture of immune cells (mostly dead) and digested pathogens/foreign particles, is formed.
Antigens
what process is stimulated by antigens stimulate?
an immune response is stimulated by antigens
Antigens
what are antigens made of?
usually proteins, although they can also be polysaccharides, nucleic acids or lipids
