EXSC 224: Final Exam
90 Cards in this Set
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immune system
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collection of mechanisms within organism that protects against infection, disease, or biological invasion
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immunity
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state of having sufficient biological defenses to avoid infection, disease, or other unwanted biological invasions
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adaptive defenses
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composed of highly specialized, systemic cells and processes that eliminate pathogenic challenges in a HIGHLY SPECIFIC manner
--triggered by vaccines
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pathogens
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biological agent that causes disease or illness to host
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antigen
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molecule that sometimes stimulates an immune response
(proteins or polysaccharides)
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antibody
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proteins that are found in blood; used by immune system to identify and neutralize foreign objects
--made/secreted by immune system
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2 types of innate defenses
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surface barriers;
skin, mucous membranes-- pH proteins provide protection
internal barriers;
phagocytes, fever, NK cells, antimicrobial proteins, inflammation
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2 types of adaptive defenses
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humoral immunity;
B cells- produce antibodies, released into blood
cellular immunity;
T cells- ''assassin'', can kill directly; regulates adaptive immune system
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innate internal defenses: macrophage
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mature monocyte, found in blood but can travel to intracellular space
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resident macrophage
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sit in specific area until something occurs to stimulate innate immune response
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neutrophil
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polymorphonuclear cells (PMNCs)
-able to phagocytize; not as strong as macrophage
-FIRST IMMUNE CELLS TO ARRIVE to site of injury
-don't want at site of injury to long, can cause excess damage
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Natural Killer Cells
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-assoc. with attacking cells when they become cancerous
--pierce membrane of cell with ''pore''
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defensins
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used to penetrate cell membrane
-secreted by NEUTROPHILS
-puts hole in membrane, disrupts cell's ability to maintain membrane potential
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nitric oxide
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free radical; unstable because of unpaired electron
-secreted by MACROPHAGES
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interferon
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-secreted by cell infected by virus
-cell realizes something is wrong and warns other healthy cells
-stimulates healthy cells to design defense against virus
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complement system pathways
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classical and alternative
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complement system: classical pathway
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-produce pore inserted into target cell
---pore= proteins = membrane attack complex
-antigen-antibody complex>> antibody coats protein or cell and makes it a macrophage target (opsonization)
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complement system: alternative pathway
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-spontaneous activation and stabilizing factors
-NO inhibitors on pathogen surface
-system becomes active b/c no way to stop it
-stimulates histamine release.. increase blood vessel permeability
-attract phagocytes by chemotaxis
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Fever
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-good for you at low grade
-liver stimulated to take up minerals from bloodstream
-cytokines secreted by immune system= small signaling molecules
-----cytokines go to hypothalamus; tell it to raise body temp.
-inc. temp. = inc. enzymatic activity
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sequence of events of innate system response
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1) leukocytosis = chemoattractants secreted >> enter circulatory system and cause neutrophil attraction
2) margination = neutrophil interacts with receptors, slows, and stops
3) diapedesis = neutrophil squeezes btwn cells of capillary and leaves cardiovascular system; capillary permeab…
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Adaptive Defense System
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-has MEMORY
-initiated by vaccination; allows more rapid immune response in future
-SPECIFIC to each cell; each cell remembers one antigen
-systemic= occurs throughout body
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Adaptive Humeral Defense
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-uses complete antigens, incomplete antigens, antigenic determinants, and self-antigens
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complete antigen
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small molecule, usually a protein
-specific seq. recognized by body
-reactivity and immunogenicity
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incomplete antigen
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has reactivity but NOT immunogenicity
-nucleic acid difficult for immune system to recognize>> needs to combine with antigen for body to recognize as "self"
-assoc. with allergies
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antigenic determinants
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each protein has unique sequence identified by cell as self (in an antigen)
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self-antigens
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MHC= major histocompatibility complex
-puts piece of "you" on outside of cell
-can communicate to cells when one cell is sick
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immunogenicity
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immunogenicity
cells stimulated to multiply
--antigen's ability to activate naive immune cell
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reactivity
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cells can recognize and bind to antigen for elimination
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Class 1 MHC
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on ALL cells EXCEPT RBCs
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Class 2 MHC
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found ONLY on APCs (B cells and macrophages)
-different variation of MHC; immune-specific
-ANTIGEN-PRESENTING
-alerts rest of immune system if finds something irregular
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Adaptive Cellular Defense
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-B cells and T cells
-immunocompetence (can identify antigen) and self-tolerance (doesn't attack "you")
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B cells
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-mature in Thymus
-PRODUCE ANTIBODIES -- proteins that target antigens for elimination
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how naive B cells propogate
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-anitbody sticks out of cell surface; recognizes one antigen
-antigen binds to receptor and B cell >>initiates cloning
-Memory B cell- responds to antigen and aids rapid and large immune response in future
-Plasma cell- (effector B cells) create antibodies at HIGH rate
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antibody titer
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adaptive humoral defense
-rapid antibody production at 2nd exposure to antigen
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T cells
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-mature in BONE MARROW
-can be assassins or regulators
-95% produced die
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Positive Selection of T cells
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-occurs in Thymus
-FAILURE to RECOGNIZE SELF-MHC > apoptosis
-SUCCESSFUL RECOGNITION >> antigen-presenting thymic cell secretes substance >> T cell lives
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Negative Selection of T cells
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-occurs in Thymus
-reacts STRONGLY TO SELF > T cell dies
-reacts TINY BIT TO SELF >> T cell lives and enters circulatory system as naive cell
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what differentiates T cells?
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cell differentiation markers
CD4 or CD8
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CD8
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- T cell receptor interacts with Class 1 MHC
-once activated, proliferates to create MEMORY cells and CYTOTOXIC T cells
-ASSASIN
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CD4
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-T cell receptor works with Class 2 MHC
-DO NOT KILL; ONLY REGULATE rest of immune system
-produce HELPER T cells and REGULATORY cells
-ENFORCER
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Helper T cells
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can stimulate cytotoxic T cells, B cells
-controls adaptive immune system
-if not made >> immune system severely compromised (ex. AIDS)
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types of acquired B cell immunity
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naturally acquired and artificially acquired
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naturally acquired immunity
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active= injection; contact with pathogen
passive= antibodies pass from mother to fetus via placenta or mother to baby via breast milk (only temporary!)
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artificially acquired immunity
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active= vaccines; dead or attenuated pathogens
passive= injection of immune serum (ex. snake bite anti-venom)
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antibody structure
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-stem region
-light and heavy chains
-varied antigen binding sites
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antigen antibody complex is inactivated by (3):
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-neutralization- mask dangerous parts of bacteria and viruses
-agglutination- ex. cells forced to lyse if given wrong blood transfusion
-precipitation
**all lead to phagocytosis
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antigen antibody complex activated by
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complement- leads to cell lysis and enhances inflammation and phagocytosis
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T cell Activation (2 step):
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1) antigen presentation and recogniton
-T cell binds/recognizes cell via MHC2 complex >> produces non-self protein recognized by T cell
-T cell is not activated
2)co-stimulatory molecule
-CD4 protein activates > APC stimulated to secrete B7 = costimulatory molecule > stimulates T cell…
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limited immune response without ________ but large immune response with it
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helper T cells
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Cytotoxic T cells
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-can be stimulated via cytokines from Helper T cell
-activated by 3 cell combination (APC + MHC1 + MHC2)
-allows vesicles to dock on target cell membrane and release perforin proteins and granzymes into cell to digest contents
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special situations of immune response (4):
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1- transplants
2- immunodeficiencies
3- autoimmune
4- hypersensitivities
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transplants (4);
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-autograph- take part of you and graph somewhere else; body already recognizes "you"
-isograft- occur w/ identical twins; have same cell markers
-allograft- graft from non-identical person; need to match as many similarities as poss.; requires anti-rejection drugs
-xenograft- graft fro…
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immunodeficiencies (3);
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-SIDS- adaptive system doesn't function (genetic); can get marrow transplant
-Acquired Immnodeficiency- Hodgekins Dz - cancer of B cells; B cells proliferate but are inactive
-AIDS- low T cell count, low immune response; assoc. with HIV positive
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autoimmune (4):
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autoimmune Dz= when body attacks self
-multiple sclerosis- immune system attacks myelin-sheath making Schwann cells
-Grave's Dz
-Type 1 diabetes
-rheumatoid arthritis
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hypersensitivity (allergies): immediate
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-can be localized or spread throughout via circulatory system >> can lead to anaphylactic shock = hapten combines with protein in cell and is viewed as foreign>> antibodies attack
-histamine produced by mast cells > cause inflammation
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hypersensitivity: subacute
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-slower and longer
-cytotoxic rxns -- mismatched blood transfusion
-immune-complex -- farmer's lung
-antibody-related, T cells
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hypersensitivity: delayed
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-contact dermatitis, TB test
-test for exposure to TB
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6 activities of digestion
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1- ingestion
2-propulsion
3-mechanical digestion
4-chemical digestion
5-absorption
6-defecation
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2-propulsion
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move food through alimentary canal, down esophagus into intestines
--only uses smooth muscle
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3- mechanical digestion
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mastication with teeth; tongue helps mix food; occurs in stomach and small intestine
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4- chemical digestion
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related to enzymes usually secreted from pancreas; occurs in small intestine
-salivary glands secrete amylase
-tongue also secretes
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5- absorption
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occurs in small intestine
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6- defecation
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assoc. with rectum and anus
-anus' skeletal muscle allows voluntary control
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MOUTH
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-stratified squamous epithelium (non-keratinized)
-buccal glands keep mouth moist
-defensins secreted
---hard palate and soft palate (skeletal muscle) force food down into esophagus
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TONGUE
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-two mucles: one lengthens and one moves
-vallate papilla- lingual lipase= small secretion of lipase to breakdown fatty acids
-fungiform papilla-
-filliform papilla- creates FRICTION to pick up food
**all three assoc. with tastebuds
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SALIVARY GLANDS
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-parotid gland- towards jaw
-sublingual gland- all around front of mouth
-submandibular gland- base of tongue
**all three extrinsic and empty into mouth
all three secrete amylase and water; only parotid does not have mucous cells
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Salivation control
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-parasympathetic control by ANS (cranial nerves III and IX)
-chemo and pressoreceptors signal pons and medulla
---chemoreceptors activated by acidic substances
---pressoreceptors activated by mechanical signals from mouth
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TEETH
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-made of same material as bone but at higher density than collagen
incisors- cut/nip off food
canines- tear/pierce food
permolars/bicsupids and molars- grind/crush food
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Tooth regions (3)
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Crown: visible portion of tooth
-enamel just below gum line
-dentin= hardened conn. tissue; maintained by adontoblasts
-pulp cavity extends into crown; provides nutrients and sensation
Neck: area covered by skin, small enamel and dentin sections
Root: embedded into jaw bone
-sur…
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ESOPHAGUS
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-circular and longitudinal muscles contract alternately
-gastroesophogeal spincter prevents stomach acid from entering esophagus
-ONLY TRANSPORTS FOOD
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Esophagus layers (4)
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1-mucosa- lots of friction; stratified squamous epithelium
2-submucosa- allows expansion/contraction peristalis; areolar conn. tissue
3-muscularis externa- muscle layers; circular and longitudinal
4-adventitia- holds everything together
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STOMACH
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-hollow, muscular organ
-chyme= mix of food and acid in stomach
-joined to esophagus (gastroesophogeal sphincter) and small intestine (pyloric sphincter)
-lined by mucous-producing cells
3 parts:
fundus, body, pyloric region (antrum and canal)
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Stomach muscles
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longitudinal, circular, and oblique
work together to mix food and HCl in stomach
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stomach control and nerves
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sympathetic control- splanchric nerve inhibits parasympathetic control
parasympathetic control- vagus nerve increases stomach motility and contractility and helps empty stomach
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Stomach wall layers (2)
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1) modified muscularis layer
-allows mixing, churning of food
2)modified mucosa layer
-connected via tight junctions to prevent acid between cells; cells constantly renewed
-gastric pits and glandular region
----mucous neck cells- produce mucous in upper regions
----parietal cells…
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SMALL INTESTINE
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-body's major digestive and absorptive organ
-pyloric sphincter to ileocecal valve
-arterial and venous blood supply
-3 regions: duodenum, jejunum, ileum
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duodenum
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1 ft long
-bile and pancreatic juices released
-bile acts as emulsifier, aids absorption of fats and fat-soluble vitamins
-pancreas secretes tripsinogen and fatty lipases into lumen
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jejunum
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8 ft long
lots of absorption
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ileum
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12 ft long
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Small Intestine control
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Autonomic NS control:
-sympathetic- splanchnic nerve thru celiac and mesenteric plexus
-parasympathetic- vagus nerve, increases intestinal motility
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mucosa adaptations in Small Intestine
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-increase SA for greater nutrient absorption
1) plicae circulares- form spiral within wall
2) villi- located on plicae; crypts of lieberkuhn in between
3) microvilli- smallest; located on indiv. cells of villi; lots of mitochondria for active absorption
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Crypts of Lieberkuhn
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between villi mucosa; small pits
-decreased density along length of small intestine
-secretes intestinal juice-- slightly basic to combat stomach acid's pH
-stimulated by distention of intestinal mucosa
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LARGE INTESTINE
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--major job is to absorb water from indigestible food and eliminate them from the body
3 unique features:
-teniae coli- 3 bands of smooth muscle
-haustra- pocket-like sacs
-epiploic appendages- fat-filled pouches that hang from surface
Alimentary Canal:
-cecum, appendix, colon, …
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Cecum
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receives contents from small intestine via ileocecal valve
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Appendix
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has many immune cells
-appendicitis= inflammation of blocked cells
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Colon
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ascending, transverse, descending, sigmoid sections
where feces resides before reaches certain amount and goes to rectum
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Rectum
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joined at sigmoid colon
-receives feces and recognizes need to "go" = stretch response
-rectal valve= 3 transverse valves allow gas to pas but not solids
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Anal Canal
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feces passes from rectal canal to anal canal when you really need to "go"
2 sphincters:
internal is smooth muscle - NO control
external is skeletal muscle - have control
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gastrocolic reflex
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when stomach stretches, SI and LI signaled to stretch
-all 3 organs affected and enhances movement of food down system
-only for food intake, not defecation
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Irritable Bowel Syndrome
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very sensitive to gastrocolic reflex
--Chrone's Dz- extreme inflammation of valve
--Celiac's Dz- sensitivity to gluten
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EXSC 224: Test 2