virus vs. bacteria	virus dead have to infect a host cell to produce their effects submicroscopic viral infections are systemic ex. flu, covid-19, hivm epstein barr virus bacteria living can live anywhere (plant, body, soil, water etc.) large localized ex. pneumonia, tb, tetanus, food poisoning
capsid shapes of virus	capsid - houses the genetic material for a virus the covering for a virus’ DNA or RNA capsomere - subunits of a protein that makes up a capsid single stranded DNA or RNA double stranded DNA or RNA
4 types of viruses	helical - helix the viral nucleic acid coils into a helical shape and the capsid proteins wind around the inside or outside of the nucleic acid this forms a long-tube or rod-shaped structure ex. tobacco mosaic virus polyhedral - pentagon contain nucleic acid in a polyhedral (many-sided) shell or capsid ex. adenovirus spherical/isometric/icosahedral spherical viruses influenza complex incorporate a larger variety of components into their capsids than simple viruses ex. bacteriophage
4 phases of how a virus genetically infects a host cell	step 1: attachment receptors on the surface of the host cell bind to virus capsid proteins or virus envelope glycoproteins viruses can attach only to cells that have the right receptor molecules viruses can be very specific about what species or cell type they can infect step 2: entry bacteriophage DNA enters the host cell “naked” viruses may enter eukaryotic cells by endocytosis or if enveloped, by fusion with the cell’s membrane step 3: replication and assembly DNA transcribe mRNA → make viral proteins duplicate DNA to make viral genomes RNA make complementary RNA if necessary transcribe mRNA → make viral proteins copy RNA to make new viral genomes RNA retrovirus reverse transcribe RNA to make DNA, using reverse transcriptase DNA incorporated into host genome DNA directs synthesis and assembly of new viruses the viral genes then direct the assembly of the new proteins and genomes to make new viruses step 4: egress (release) may involve lysis and death of the host cell may involve budding, which does not directly kill the host cell
viral envelope	an extra layer of protection around the capsid, but they’re only produced when a virus comes into contact with a host cell
host range	each particular virus can infect cells of only a limited number of host species this is known as the host range of the virus viruses identify host cells by a “handshake” fit between viral surface proteins and specific receptor molecules on the outside of cells some viruses have broad host ranges whereas other are very specific measles only affect humans we are closer to pigs than we are monkeys in this case
the pathway of how a virus infects a host cell	how DNA is duplicated and how capsid proteins are formed from DNA
lytic vs. lysogenic cycles	lytic cycles a phage replicative cycle that culminates in the death of the host cell phage 𝜆 attaches to and injects its DNA into the host cell (bacterial cell) new phage DNA is made and incorporated into new phages the phages will cause the host cell to lyse/burst so the phages can infect other bacterial cells lysogenic cycles host cells are not lysed, but here, phages coexist with them in a state called lysogeny phage 𝜆 attaches to and injects its DNA into the host cell (bacterial cell) the fake DNA is added/incorporated into the bacterial chromosome the bacterial cell (with the phage DNA in it), reproduces to produce new daughter cells which infect other host cells sometimes, the phage DNA can be removed from the bacterial chromosome and then it can proceed into the lytic cycle (ultimately killing the host cell in this case) this phage is now called a temperate/prophage as it undergoes both the lytic and lysogenic cycles
temperate phage	phages that are capable of using both modes of replicating within bacterium prophage - form when phage DNA integrates into the bacterial chromosome
retrovirus	an enzyme that transcribes an RNA template into DNA providing an RNA DNA information flow that is the opposite of the usual direction
the role of HIV	replicative cycle of HIV HIV binds to receptors on the host cell via glycoproteins on its viral envelope host cell - white blood cells: basophil, neutrophils, eosinophils, lymphocytes, and monocytes which mature into macrophages the wbc (host cell) takes in the virus via endocytosis HIV disassembles, exposing the viral RNA and reverse transcriptase enzymes reverse transcriptase catalyzes DNA from RNA forming a DNA RNA hybrid a second strand of DNA is made/replicated, resulting in double stranded DNA the two strands of DNA are inserted into the DNA/genome of the wbc forming a provirus the provirus is used to make new RNA to act as the genome for future HIV viruses mRNA is also transcribed from the provirus to make new capsid proteins, glycoproteins, and reverse transcriptase enzymes new glycoproteins are transported in vesicles to later form the viral envelope of new HIV viruses capsid proteins and reverse transcriptase enzymes are assembled with the new viral RNA HIV is exported from the cell via exocytosis provirus - they form when viral DNA is inserted into a host cells’ DNA
the cycle of enveloped viruses infecting a host cell	an RNA virus binds to receptors on the host cell via glycoproteins that are on the viruses’ viral envelope this causes the host cell to take in the virus via endocytosis host cell enzymes rapidly degrade the capsid isolating the viral RNA that the virus came in with viral RNA serves as a template to make complementary RNA from it RNA polymerase accomplishes this step some complementary RNA is used to make additional complementary RNA any remaining complementary RNA is used to translate both glycoproteins and capsid proteins (capsomeres) glycoproteins - translates in the ER and golgi apparatus/complex capsid proteins - translated in the cytosol the glycoproteins are packaged into a vesicle which will later become part of the viral envelope of the virus capsid proteins are assembled around the viral RNA glycoproteins, capsid proteins, and viral RNA are assembled and the new virus is exported from the cell via exocytosis
the two ways a plant cell infects other cells	horizontal transmission virus typically enters by way of damaged plant tissue may come from pollen, another plant, or vectors such as insect bites vertical transmission virus is transmitted from the parent plant
plant viruses	hypoplasia - decreased growth and vigor necrosis of the plant or plant tissue
viroids	small circles of RNA only know to infect plants can replicate within cells do not manufacture any proteins can cause crop failures
components of a vaccine	trigger immune protection prepared using… attenuated “live” virus “killed” virus molecular subunits very small risk of infection
prions	proteinaceous infectious particles very small contain no nucleic acid not destroying by cooking found in nervous tissue associated with animal infections

8 blood types	the ABO blood group features 2 antigens - A antigen & B antigen type A: only the A antigen is present type B: only the B antigen is present type AB: both the A & B antigens are present type O: neither A nor B antigens are present
the Rh blood group	features the Rh antigen also known as the D-antigen have the Rh antigen = Rh positive (+) without the Rh antigen = Rh positive (-)
antigens & antibodies	antigens protein on the cell that can cause the immune system to respond if a blood type is anti-B, then it contains the A antigen if a blood type is anti-A, then it contains the B antigen if a blood type has no antibodies present, then it contains both A & B antigens if a blood type is anti-A & B, then it doesn’t contain any antigens antibodies the plasma proteins of the immune system produced by cells derived from activated B-lymphocytes and bind to foreign antigens cause bound antigens to clump together - agglutination antibodies are referred to as agglutins agglutination destroys RBCs - hemolysis
donor vs. recipient chart
red blood cells	erythrocytes
white blood cells	leukocytes - used to reach areas of inflammation, injury and pathogen myosin don’t function in the blood, but they use blood as a transport vehicle to reach tissues when they reach their destination, they adhere (margination) to the walls of the capillaries or venules they then exit the blood via endothelial cells of the vessels agranulocytes - lack visible cytoplasmic granules monocytes lymphocytes t-cells b-cells granulocytes neutrophils eosinophils basophils
granulocytes (the Phils)	contain cytoplasmic granules that the cells release when activated have a single nucleus with multiple lobes that are connected by thin bands of nuclear material contain general lysosomal granules neutrophils the most common type of leukocyte make up 60-70% of total leukocytes in the blood contain 3-6 shaped lobes polymorphonucleocytes (PMNs/Polys) active phagocytes that ingest and destroy bacterial cells they are attracted to injured cells by chemicals released by the damaged cells through chemotaxis eosinophils account for <4% of all leukocytes nucleus is bilobed involved in the body’s response to infection to parasitic worms and in allergic reactions granules contain substances specific to enzymes and toxins that are specific to parasites as well as mediating inflammation they are phagocytes and ingest foreign molecules that have been bound by proteins of the immune system basophils the rarest leukocyte, <1% of all leukocytes in the blood all you can see are the granules release chemicals from their granules that mediate inflammation
agranulocytes (the Cytes)	lack visible granules but contain lysosomes lymphocytes the 2nd most numerous type of leukocyte the blob cells make up 20-25% of total leukocytes in the blood contain large, spherical nuclei and thin rim of light blue cytoplasm that is visible when stained 2 lymphocytes that are activated by cellular markers (antigens) B-lymphocytes/B-cells: mature in bone marrow T-lymphocytes/T-cells: mature in the thymus monocytes account for 3-8% of the total WBC population the bean cell the largest leukocyte remain in the blood for a few days before exiting the capillaries and entering the tissues becomes macrophages when they exit the bloodstream via diapedesis macrophage (active phagocyte) - ingest dead and dying cells activate parts of the immune system by displaying phagocytosed antigens to other leukocytes
chemotaxis	occurs with any type of cellular injury kill bacterial cells enhance inflammation attract more neutrophils and leukocytes
platelets	thrombocytes
t-cells vs. b-cells	t-cells mature in the thymus do not produce antibodies they are receptors for individual antigens once bound, they can activate components of the immune system and destroy abnormal body cells b-cells mature in bone marrow produce proteins called antibodies that bind to antigens and remove them from tissues secrete antibodies with a specific structure that allows them to bind only to 1 unique antigen
components of the lymphatic system	spleen thymus lymphatic vessels - contain lymph 1. pick up excess fluid in the extracellular space 2. transport it through the body 3. deliver it back to the cardiovascular system lymph nodes lymph - the color of lymph comes from fats in forms of triglyceride small intestine
3 broad functions of the lymphatic system	function 1: regulation of interstitial fluid volume cytosol the amount of fluid that is lost from plasma measures 2-4L/day this fluid must be returned to circulation blood volume (amount of water in blood) and BP (force of blood against your arteries) will drop too low to maintain homeostasis function 2: absorption of dietary fats the breakdown of products of fats in the diet cannot pass through the spaces of endothelial cells of blood capillaries they can enter the lymphatic vessels in the small intestine they will travel through these vessels to be delivered to the blood with lymph function 3: immune functions lymphoid organs filter pathogens from lymph and blood they house leukocytes and play a role in their maturation
vessels	lymphatic collecting vessels collect lymph - they merge to form larger vessels known as lymph trunks lumbar trunks - receive lymph from lower limbs and pelvic area intestinal trunk - receives fat-containing lymph from the small lymphatic vessels in the small intestine jugular trunk - receive lymph from the head and neck bronchomediastinal trunk - receive lymph from the thoracic cavity subclavian trunk - receive lymph from the upper limbs
thoracic vs. right lymphatic ducts	thoracic ducts cisterna chyli and trunks from the left side of the body drain into these ducts the largest lymphatic ducts drains into the internal jugular and left subclavian veins drains all of the lower body and the left side of the upper body right lymphatic ducts remaining trunks from the upper right side of the body drain into these ducts drains into the junction of the right internal jugular and right subclavian veins
lymphatic valves	lymphatic vessels have lymphatic valves prevent lymph from flowing backward often found lodged between muscles contracting muscles massage lymph up towards the heart lymph flow through the vessels and is driven by contractions of smooth muscle you can find this type of muscle in the walls of lymph-collecting vessels
lacteal	specialized lymphatic capillaries collect fat in the large intestine
blood vs. lymphatic capillaries	blood capillaries connect arterioles to venules form a two-way system tightly packed and formed of endothelial cells lymphatic capillaries blind-ended a one-way system that only moves lymph away from tissues endothelial cells are not tightly joined; they can flap open and closed
lymphatic capillaries	an increase in pressure in the interstitial fluid is caused when fluid leaks from blood capillaries this forces the lymphatic endothelial cells apart large volumes of fluid now enter the lymphatic capillaries when the pressure in the interstitial fluid decreases… the endothelial cells flap shut this turn allows for this system to control the amount of fluid between our cells macrophages and other immune cells also enter the lymph - this makes these vessels leaky
permeability affecting lymph nodes	lymphatic capillaries are extremely permeable pathogens (bacteria or cancer cells) in the interstitial fluid can enter much easier than blood capillaries meaning they can spread all around the lymphatic system there is a stop sign - clusters of lymph nodes are found along the pathway of lymphatic vessels they limit the spread of pathogens acting as filters trapping them = preventing them from traveling elsewhere
primary tissue of the lymphatic system	reticular connective tissue is the predominant tissue also known as lymphoid tissue reticular fibers - form “nets” that help to trap disease causing pathogens catch pathogens and cellular debris in the reticular connective tissue
dendritic cells	immune system cells with spiny processes some are derived from bone marrow others are derived from connective tissue
reticular cells	produce reticular fibers abundant in the spleen and lymph nodes
MALT	specialized MALT consists of spherical clusters called lymphoid follicles/nodules exposure to pathogens not exposed - consists primarily of B-cells exposed - contain germinal centers which consist of; dividing B-cells, specialized dendritic cells, and macrophages they are found… the tonsils around oral and nasal cavities peyer's patches appendix come into contact with stool and fecal matter
germinal center	if you have germinal centers that are found in the small intestine, they are going to only be found in the ileum of the small intestine
peyer’s patches	a form of specialized MALT found in the ileum also referred to as aggregated lymphoid nodules
3 tonsils	pharynx = throat nasopharynx oropharynx laryngopharynx lingual frenulum: band of tissue that holds the tongue to the floor of the mouth (oral cavity) tonsillar crypt: traps debris and bacteria more likely to come exposed to pathogens so it becomes inflamed tonsillitis
appendix	the appendix defends against bacteria in the large intestine it is very easy for bacteria and fecal matter to become trapped in the appendix resulting in appendicitis bacteria ends up spilling into the abdominopelvic cavity leads to internal bleeding could be fatal if not treated
lymph nodes	small bean shaped clusters of lymphatic tissue found along lymphatic vessels throughout the body axillary lymph - armpit cervical - neck inguinal - groin mesenteric - abdominal organs/visceral organs (internal/in the body)
lymph being filtered in a lymph node	lymph (containing pathogens/debris) will enter the lymph node via an afferent lymphatic vessel afferent - lymph is flowing towards the lymph node any pathogens/debris that's found in lymph becomes trapped in the reticular fibers of reticular connective tissue of the lymph node cleansed lymph now leaves a lymph node through an efferent lymphatic vessel efferent - exit
innate vs. adaptive immunity	innate immunity quicker type of immune response norovirus (stomach flu), rhinovirus (common cold), & strep can all trigger this response adaptive immunity slower type of immune response antigens: glycoprotein markers
specific vs. nonspecific immunity	specific specific: responds to unique/specific antigens that are found on particular pathogens (including viruses and bacteria) nonspecific nonspecific: responds to any pathogen or class of pathogens
surface barrier	mucous membrane GI tract - digestive tract or alimentary canal goblet cells: cells that produce mucus pseudostratified columnar epithelium houses the goblet cells cilia: the organelles that propel/move mucus normal/gut flora: healthy bacteria the skin also called cutaneous membrane 2 layers - the epidermis and the dermis hypodermis is not a layer of your skin because it consists primarily of adipose/fat tissue keratin is found in the skin, hair and nails acidic pH - skin's acid mantle epidermis: consists of 4 or 5 skin layers
layers of thick and thin skin	the epidermis is found in the palmer (hands) or plantar (feet) 5 layers - thick skin & 4 layers - thin skin stratum corneum stratum lucidum - only found in thick skin stratum granulosum stratum spinosum stratum basale/germinativum dermal layers: papillary & reticular dermis
complement system	a group of proteins that function in innate immunity consists of 20+ plasma proteins that are produced by the liver complement proteins are designated with the “C” followed by a number complements proteins circulate primarily in their active forms they must be activated by a cascade of events mediated by enzymes these proteins can be activated via the classical or alternative pathway classical pathway begins when inactive complement proteins bind to antibodies bound to antigen alternative pathway begins at the cleavage of an inactive complement protein (C3) into its active form C3b both pathways converge when C3b is activated this cleaves the inactive protein C5 into its active component of C5b
effects of activated complement proteins	effect 1: cell lysis some complement proteins lyse the plasma membranes of pathogens - destructions mediated by C5b C5b binds to the surface of a pathogen provides a docking site for several other activated complement proteins all these complement proteins form a structure - membrane attack complex (MAC) MAC inserts itself into the plasma membrane of the target cell this creates a pore that causes it to lyse effect 2: enhanced inflammation the inflammatory response is a nonspecific response to cellular injury several complement proteins enhance this response basophils are triggered and mast cells release chemicals that mediate inflammation effect 3: neutralizes viruses C3b and components of the MAC binds to certain viruses this can neutralize them this can block them from infecting host cells effect 4: enhanced phagocytosis C3b acts as an opsonin binding both pathogens and phagocytes opsonization: makes phagocytes bind more strongly to the pathogen and enhances phagocytosis effect 5: clearance of immune complexes C3b binds to immune complexes - clusters of antigens bound to antibodies triggering their phagocytosis this clears these complexes from circulation preventing them from lodging in different tissues around the body
cytokines	secreted by cells of both innate and adaptive immunity regulate the development and activity of immune cells proteins produced by several types of immune cells that enhance the immune response tumor necrosis factor (TNF) secreted primarily by activated macrophages in response to certain bacteria and pathogens effects of TNF induce flu-like symptoms attracts phagocytes to the area of infection increasing activity of phagocytes stimulates phagocytes to release additional cytokines severe infections = TNF secretion increases dramatically septic shock - drop in BP, organ failure, blood clotting, severe in blood (glucose) interferons (INF) produced by macrophages, dendritic cells, NK cells, and cells of adaptive immunity produced in response to infection with intracellular agents interfere with the ability of pathogens to infect other cells inhibit viral replication inside host cells activate components of innate and adaptive immunity partially response for symptoms of the flu interleukins constitute a class of 29 cytokines produced mainly by different types of leukocytes effects: stimulate production of neutrophils by the bone marrow stimulate NK cells triggering the production of certain types of INFs activating T-cells
inflammatory response	occurs in reaction to any cellular injury damaged cells release inflammatory mediators causing local changes in the damaged tissue phagocytes arrive at the area and clean up damaged tissue you step on a splinter - a form of tissue damage the sternum corneum would be the first skin layer that is damaged any damages cells and nearby mast cells are known the release the components of their granules granules - inflammatory mediators chemotaxis: recruit white blood cells to the are produce the 4 cardinal signs of inflammation 3.1. redness histamine and bradykinin are on the smooth muscle on the wall of an arteriole causing the muscle tissue to relax causing vasodilation vasodilation - wider this leads to an an increased amount of blood flow through the arteriole - hyperemia hyperemia leads to an increase in heat and redness (erythema) 3.2. swelling inflammatory mediators make capillaries “leaky” causing them to leak out fluid into a tissue space leaking causes localized edema or swelling the fluid is very rich in clotting and complement proteins if clotting proteins are required, the dermis would have had to be impacted 3.3. pain inflammatory mediators (bradykinin & prostaglandins) act on local sensory neurons to carry sensory/afferent related information to the CNS information - pain CNS - the brain and the spinal cord the inflammatory mediators also help to increase the speed of an action potential so pain related info can travel to the brain faster 3.4. complement proteins which leak out into tissue spaces stimulus chemotaxis to recruit white blood cells to an are of injury 4. local macrophages start to engulf/ingest pathogens via phagocytosis 5. 1 hr later… neutrophils arrive to the are of damage and under margination & diapedesis to then phagocytic any pathogens acute rise in neutrophils - leukocytosis 6. 3-4 hrs later… monocytes arrive and later mature into macrophages in the tissues spaces to engulf pathogens via phagocytosis
pus being beneficial
roles of…	helper t-cells: CD4 t-cells cytotoxic t-cells: CD8 t-cells

bio: ch. 21/42 - blood typing, immunology & viruses