Unit II Flashcards
Infection
definition
presence and multiplication of pathogens
Pathogen
definition
disease causing agent
what primarily defends the body from infection
spleen and lymph nodes
mechanisms of defense
innate (nonspecific) defense
adaptive (specific) defense
Innate (nonspecific) defense
“inborn” protection against many types of pathogens
^^don’t develop as a result
Adaptive (specific) defense
2 forms of immunity?
“learned” protection against specific pathogens provided by T and B cells
-cell mediated immunity
-antibody mediated immunity
Cell-mediated immunity
T cell function
cells attack pathogens and attack through phagocytosis or release of chemical toxins
Antibody-mediated immunity
B cell function
secrete antibodies, work indirectly, attack by circulating antibodies
Innate (nonspecific) defenses
what kinds of natural things help defend?
physical barriers such as skin, mucus membranes
phagocytes
immune surveillance such as natural killer cells (lymphocytes) = find abnormal cells and cause destruction
interferons (chemicals released to protect you)
complement system
inflammation
fever (low grade fever beneficial for combatting infection)
Natural Killer cell process
-NK cell releases perforins, which stick to each other and form a hole in enemy cell membrane
-granzymes from NK cell enter perforin hole and degrade enemy cell enzymes
-enemy cell dies
-macrophage engulfs and digests dying cell
Inflammation
signs and reasons why
goal of inflammation
would causes come from?
-Redness and heat (due to increased blood flow to site)
-swelling (due to increased capillary permeability)
-Pain (due to tissue fluid pressure and inflammatory chemicals stimulating pain receptors)
-goal: get WBC to area to fight bad cells
-come from blood, mast cells, WBC, damaged tissues
Complement system
what is it
end result
what does it promote
-involves large number of plasma proteins
-end result: formation of a membrane attack complex that forms holes in pathogen cell membranes
-promotes phagocytosis, inflammation, chemotaxis
Inflammation Chart Diagram
Tissue damage occurs –> bacteria enters tissue –> chemical mediators are released (WBC, damaged cells) –> chemotaxis, increased vascular permeability (capillaries leaky), increased blood flow –> increased numbers of white blood cells and chemical mediators at site –> bacteria are contained, destroyed, and phagocytized –> either bacteria gone = tissue repair OR bacteria remain = additional chemical mediators activated
Adaptive (Specific) Immunity
terms
Adaptive immunity
antigen
activation
proliferation
differentiation
Adaptive immunity
resistance to a specific pathogen
Antigen
-any molecule capable of binding to a T cell or B receptor
-usually part of a pathogen (ex. bacterial or viral protein)
Activation
change in behavior of lymphocyte at the onset of immune response
Proliferation
production of a large number of identical lymphocytes (Clone)
Differentiation
production of cells with different functions from a single line
T Cell characteristics
-produced in red bone marrow
-mature in thymus
70-80% of circulating lymphocytes - most common
-many reside in lymph nodes and spleen
-millions of different T cell receptors that bind to antigens
-another cell has to show to T cell
Antigen Presenting Cell info
-typically a macrophage, B cell, or infected cell
-the antigen is presented to T cell in combination with a major histocompatibility complex
-antigen “selects” the T cell that will be activated and proliferate to form a clone (clonal selection)
Major histocompatibility complex
what are the classes?
Class I - on nucleated body cells and platelets
Class II - on antigen presenting cells
Main Types of T cells
helper t cells
cytotoxic t cells
memory t cells
Helper T cells info
Activation requires APC
secrete cytokines that target other WBCs
activate B cells to produce antibodies
activate cytotoxic t cells
Stimulate macrophages and attract other WBC
cytotoxic t cells info
-activation requires - exposure to antigen and cytokines from helper t cell
-proliferation produces a clone of cells that bind to cancerous or virally infected cells and secrete perforin
-differentiation produces memory t cells
memory t cells info
-respond to subsequent exposure to pathogen
-activation and proliferation results in the production of a new clone of cytotoxic t cells
cell mediated immunity - summary
-pathogen enters body -> phagocytized by APC
-APC presents antigen to helper T will with a receptor that fits antigen -> this helper cell secretes cytokines
-cytokines activate cytotoxic t cells and then produce clone
-splits into memory cells -> take part next time, effector cells =take part now
B cells info
-activation requires
—–exposure to antigen
——cytokines from a helper T cell
-proliferation produces clone
-differentiation produces plasma cells (secrete antibodies) and memory cells (respond to next infection)
Antibodies info
-gamma globulin plasma proteins
-four polypeptides (or 2x or 5x)
—two heavy chains, two light chains
-polypeptide regions
—-constant (same for each antibody of a class)
—-variable (different for each antibody)
-two antigen binding sites
-classes of immunoglobulins (IgG most important 80-85%)
IgG info
most important 80-85%
activates complement, promotes phagocytosis, can cross placenta and provide immune protection
Actions of antibodies
-inflammation - prevent spread of antigens
-chemotaxis - attracts WBC to area
-agglutination - antigens clump
-precipitation - antigens become insoluble
-neutralization - antibodies coat and prevent infection
where do all blood cells originate from
red bone marrow
how are T and B cells transported to the lymphatic organs
through the blood
what are antigens presented by Class I MHC proteins triggered by
-what does the infection result in
-end result
viral or bacterial infection of body cell
-results in abnormal peptides in cytoplasm
-end result: abnormal peptides are displayed by Class I MCH proteins on plasma membrane
process of b cells
antigen recognition, b cell activation, clone formation, differentiation (most become plasma cells), action (plasma cells release antibodies that can bind)
antibody mediated summary
-b cell binds to and engulfs antigen
-b cell displays antigen in combination with MHC to helper t cell with TCR
-activated helper T cell secrete cytokines to activate b cell
-proliferation
-differentiation produces plasma cells (secrete antibodies) and memory cells
Immune responses
what are their names
Primary immune response
Secondary immune response
Primary immune response
-Occurs first time pathogen is encountered
-antibodies detected in 5-10 days
Secondary immune response
-occurs after first time pathogen is encountered (3,4,5th…)
-antibodies detected in 1-2 days
Immunity classification - acquired adaptive
what are the names of each
-active immunity –> breaks down into neutral and artificial
-passive immunity –> breaks down into neutral and artificial
Active immunity definition
immunity provided by individual’s own immune system
-self immune system learns
Passive immunity definition
immunity is transferred from another person or animal
-immune system doesn’t learn
Active immunity (natural)
antigens are introduced through natural exposure
-immunity you develop getting sick
Active immunity (artificial)
antigens are deliberately introduced in vaccine
-vaccine giving you antigen to make antibodies
Passive immunity (natural)
antibodies from mother are transferred to child across placenta or in breastmilk
-baby never gets infect, just gets immunity from mom
Passive immunity (artificial)
antibodies produced by another person or animal are injected
-antibodies premade from other source
Nutrients
substances in food where we get energy and building materials (like cell parts, tissues)
2 main categories of digestive system
Digestive tract (9m)
Accessory structures
what does the digestive tract include (6)
mouth
pharynx
esophagus
stomach
small intestine (longest part)
large intestine
what does the accessory structures of the digestive tract include(6)
teeth
tongue
salivary glands
pancreas
liver
gallbladder
Digestive tract wall names (deep to superficial)
Mucosa
Submucosa
Muscularis Externa
Serosa
Mucosa
structure
function
structure: simple columnar epithelium, lamina propria (areolar tissue), muscularis mucosae (smooth muscle)
function: absorption, secretion, protection
Submucosa
what is it made up of
dense irregular connective tissue with glands, blood vessels, nerves, etc.
Muscularis externa
structure
function
structure: inner circular smooth muscle layer, outer longitudinal smooth muscle layer
function: mixing movements occur in stomach, propelling movements (peristalsis - esophagus, stomach, small and large intestine) — (segmentation - small intestine)
Serosa
what is it made up of
simple squamous epithelium and areolar tissue
Functions of digestive tract (7)
ingestion
mechanical processing (chewing, moving food)
digestion
secretion (release into lumen)
absorption (of nutrients from digestive)
compaction (forming feces)
defecation (elimination of feces from body)
Mouth (Oral Cavity)
function and lining
-functions in ingestion and mechanical processing
-Lining - both keratinizing and nonkeratinizing stratified squamous epithelium
mouth (oral cavity)
palate info
teeth info
tongue info
palate: hard, soft with uvula, palatine tonsils provide immune surveillance
teeth: deciduous (baby teeth) - incisors, cuspids, molars
adult: incisors, cuspids, premolars (molars in deciduous teeth), molars
tongue: papillae with taste buds, lingual frenulum (tissue above top teeth), lingual tonsils
average number of teeth in deciduous and adult teeth
deciduous 20
adult 32
Salivary Glands
how many major glands
names
6 (occur in pairs)
parotid
submandibular
sublingual
Salivary Glands
Secretions and functions of those
Serous (runny) secretion
–cleanses mouth, dissolves food
–salivary amylase begins carbohydrate digestion
Mucous (sticky) secretion
–buffers pH
–binds food into bolus (mass of food to swallow)
–provides lubrication
Salivary Amylase
source
location of action
substrates
products
serous cells
mouth
starch and glycogen
maltose
Pepsin
source
location of action
substrates
products
extra notes
gastric glands
stomach
proteins
peptides
secreted as pepsinogen, activated by HCl
Pharynx
where is it
names of regions
vertical tube behind nose and mouth
nasopharynx, oropharynx, laryngopharynx
Nasopharynx
location
passageway for
structures
behind nasal cavity
air
pharyngeal tonsils, opening to auditory tubes
Oropharynx
location
passageway for
posterior to oral cavity
air and food
Laryngopharynx
location
passagway for
structures
inferior to oropharynx
air and food
glottis
During swallowing..
what does tongue do
what does uvula do
what does epiglottis do
-pushes bolus into oropharynx
-blocks opening to nasopharynx
-blocks opening to larynx
Esophagus
what does it do
where does movement occur
lined by
where does it pass through
how does it appear
-transports bolus from pharynx to stomach
-via peristalsis
-nonkeratinizing stratified squamous epithelium
-passes through esophageal hiatus of diaphragm
-normally collapsed
What do the two esophageal sphincters do?
-upper esophageal sphincter at superior end prevents air from entering esophagus
-lower sphincter at inferior end prevents stomach contents from entering esophagus
Stomach
functions
-mixes food with gastric juice forming chyme
-chemical digestion of proteins begins
-limited absorption (water, salts, etc)
-distention and storage
Stomach
structures
-rugae (stripes, lines)
-most inner muscle layer = oblique of muscularis externa
-greater and lesser curvatures
-regions (cardia, fundus, body, pylorus)
-gastric glands secrete gastric juice through gastric pits
Gastric juice components
what kinds of cells
what do they secrete
Chief cells
-secrete pepsinogen, an inactive precursor of the protein digesting enzyme protein
Parietal cells
-secrete HCl which converts pepsinogen to pepsin
-secrete instrinsic factor for b12 absorption in small intesting (needed for making RBC)
G-cells
-secrete gastric hormone gastrin
Mechanisms of regulation of gastric juice secretion
Neural: ANS (system) - parasympathetic impulses promote gastric secretion, sympathetic impulses inhibit gastric secretion
Hormonal: CCK, gastirc inhibitory peptide, and secretin from duodenum inhibit gastric secretion - gastrin from stomach and small intestine promotes gastric secretion
phases of regulation of gastric juice secretion
-Cephalic phase (right before eating) - parasympathetic impulses stimulate gastric secretion
-Gastric phase (food is in stomach) - stretching of stomach simulates gastric juice and gastrin secretion, gastrin stimulates gastric juice secretion
-Intestinal phase (chyme entering small intestine) - intestinal gastrin briefly stimulates gastric secretion, sympathetic impulses inhibit gastric secretion while deuodenum produces chyme
Small intestine structure
functions
how long
regions
info
-functions in chemical digestion and absorption of all four types
-6 m long
-name refers to diameter
-regions (duodenum is c shaped, 25cm —– jejunum is 2+ m —– ileum is 3+ m)
-circular folds, villi, and microvilli increase surface area for absorption
-villus contains capillaries and lacteal
-digestive enzymes (brush border) are bound to microvilli
Small intestine
function
chemical digestion of carbs, proteins, lipids
-absorption (monosaccharides and amino acids cross mucosa and are transported to liver by hepatic portal vein)
-secretion
–water fluid to dissolve chemicals
–mucus for protection
–digestive hormones
Large Intestine
functions
how name is referred
-compaction and defacation
-mucus secretion (protect tissue, neutralize pH, bind feces)
-absorption (water by osmosis, electrolytes by active transport)
-name refers to diameter, not length
Large intestine
parts
wall structure
-cecum with appendix (ileocecal valve)
-colon (ascending, transverse, descending, sigmoid)
-rectum
-anal canal
-mucosa contains SCE
-no villi
-bands of longitudinal muscle = teniae coli
-pouches = haustra
Liver
structure
-four lobes (right, left, quadrate, caudate) that are divided into lobules
-lobule structures
–hepatocytes (liver cells)
–branches from hepatic artery (O2 input)
–branches from hepatic portal vein (nutrient input)
–liver sinusoids
–central vein (output leading to hepatic vein)
–bile canaliculi –> bile ductules –> bile ducts
Sucrase
source
location of action
substrates
products
extra notes
small intestine
small intestine
digests sucrose
glucose, fructose
brush border enzyme
Maltose
source
location of action
substrates
products
extra notes
small intestine
small intestine
digests maltose
glucose, glucose
brush border enzyme
Lactase
source
location of action
substrates
products
extra notes
small intestine
small intestine
digests lactose
glucose, galactose
brush border enzyme
Peptidases
source
location of action
substrates
products
extra notes
small intestine
small intestine
peptides
amino acids
brush border enzyme
Intestinal Lipase
source
location of action
substrates
products
extra notes
small intestine
small intestine
triglycerides
fatty acid and monoglyceride
brush border enzyme
Digestive/Metabolic Functions of Liver (5)
-synthesizing plasma proteins/clotting factors
-phagocytizing damaged red blood cells
-storing cells
-inactivating toxins
-storing iron, fat-soluble vitamins, glycogen, lipids
Primary Liver Digestive Functions
BGL
-Maintenance of blood glucose level (controlled by insulin and glucagon)
—glycogenesis (glucose to glycogen)
—glycogenolysis (glycogen to glucose)
—gluconeogenesis (make glucose from lipids/amino acids)
Primary Liver Digestive Functions
Protein
-Protein metabolism
—deamination of amino acids and production of urea
—amino acid conversion (nonessential)
—plasma protein synthesis
Primary Liver Digestive Functions
Lipid
-Lipid metabolism
—synthesis of phospholipids and cholesterol
—conversion of carbs and proteins into triglycerides for energy storage
—fatty acids used for energy
Primary Liver Digestive Functions
Bile
-Bile secretion
—functions as emulsifier
—forms micelles
—lipase works to digest lipids
Gallbladder
function
associated ducts
others
-stores and concentrates bile from liver
-associated ducts:
—cystic: attached to gallbladder
—hepatic: come from liver lobes
—common hepatic: hepatic ducts merge
—common bile: cystic and common hepatic ducts meet
—hepatopancretic ampulla/sphincter: near wall of small intestine
-fills with bile backflow
-gallstones form when cholesterol precipitates
-bile release stimulated by CCK
Pancreas
functions
Digestive system (exocrine) function = secretion of pancreatic juice into small intestine
Endocrine system function = secretion of insulin and glucagon into blood
Pancreas
duct work
pancreatic duct -> hepatopancreatic ampulla/sphincter -> lumen of duodenum
Pancreatic juice components
-pancreatic amylase
-pancreatic lipase
-nucleases (2)
-proteolytic enzymes
–trypsin
–chymotrypsin
–carboxypeptidase
-bicarbonate iones (neutralize pH of chyme and inactive pepsin)
Hormonal Regulation of Pancreatic Secretion
secretions
Acidic chyme in the duodenum causes the duodenum to secrete…
-cholesystokinin = stimulates pancreas to secrete digestive enzymes
-secretin = stimulates pancreas to secrete bicarbonate ions
Intestinal lipase
source
location of action
substrates
products
notes
small intestine
small intestine
triglycerides
fatty acid and monoglyceride
brush border enzyme
Pancreatic amylase
source
location of action
substrates
products
pancreas
small intestine
starch, glycogen
maltose
Nucleases
source
location of action
substrates
products
pancreas
small intestine
nucleic acids
nucleotides
Trypsin
source
location of action
substrates
products
notes
pancreas
small intestine
proteins
peptides
secreted as trypsinogen, activated by enteropeptidase
Chymotrypsin
source
location of action
substrates
products
notes
pancreas
small intestine
proteins
peptides
secreted as chymotripsinogen, activated by trypsin
Carboxypeptidase
source
location of action
substrates
products
notes
pancreas
small intestine
peptides
amino acids
secreted as procarboxypeptidase, activated by trypsin