This site is 100% ad supported. Please add an exception to adblock for this site.



undefined, object
copy deck
What region of the brain is impt for regulation of appetite and thrist
=hypothalamus 1. Appetite -regions for both satiety (ventromedial nucleus) and feeding (lateral hypothalamus) -stimulation feeding center -> eat -stimulate satiety center -> stop eating 2. Thirst -influenced by ECF volume, plasma osmolality, other factors (ex dryness of mouth)
What 2 cranial nerves trigger swallowing?
=reflex -CN IX and CN X -Components 1. initiation -voluntary via bolus of food propelled into pharynx 2. Involuntary contraction -pharyngeal muscles push bolus into esophagus 3. Automatic closure of glottis 4. peristaltic contraction of esophagus -upper esophageal sphincter and lower esophageal sphincter transiently relax to allow passage of food
True or false: the stomach is a site of major chemical digestion of food
-false -it only does a little chemical digestion -main fxns: 1. storage 2. mixing 3. controlled emptying
Name 3 substances produced by colonic bacteria (normal flora)
1. Vit K 2. complex B vitamins 3. folic acid
Hexokinase is associated w/what metabolic process?
Glycosis -phosphorylate glucose (1st step) -hexokinase is found in all cells -uses ATP to add on the phosphate group
Glucokinase is associated w/what metabolic process?
-Glycolysis -found in liver ONLY -phosphorylates glucose -uses ATP to add on the phosphate group
Phosphofructokinase is associated w/what metabolic process?
-glycolysis -uses ATP to add phosphate group -makes fructose1,6bisphosphate -rate limiting step of glycolysis -activated by AMP -inhibited by ATP, citrate
Pyruvate kinase is associated w/what metabolic process?
-glycolysis -catalyzes formation of pyruvate and ATP -Can be inhibited by: 1. phosphorylation 2. ATP, acetyl-CoA, alanine (allosteric)
Lactate dehydrogenase is associated w/what metabolic process?
-glycolysis (but ONLY under anaerobic conditions) -reduce pyruvate to lactate -regenerates NAD+ (impt so glycosis can continue)
Pyruvate dehydrogenase is associated w/what metabolic process?
-making pyruvate into acetyl CoA (so it can be broken down by the Krebs cycle); irreversible rxn -multienzyme complex (3 diff parts) -5 coenzymes required -inactivated by: 1. phosphorylation 2. allosteric inhibitors (acetylCoA, NADH) -inherited and acquired def
Pyruvate carboxylase is associated w/what metabolic process?
=gluconeogenesis -converts pyruvate -> oxaloacetate -need w/ PEPCK to overcome irreversible step of glycosis
PEPCK is associated w/what metabolic process?
=gluconeogenesis -converts oxaloacetate back into PEP -works w/pyruvate carboxylase to overcome irreversible step in glycolysis
Glucose-6-phosphatase is associated w/what metabolic process?
=gluconeogenesis -removes phosphate group from glucose -> free glucose -found ONLY in liver, kidney, intestinal epithelium -NOT in SKM -def=von Gierke disease
Glycogen phosphorylase is associated w/what metabolic process?
=glycogenolysis -breaks down glycogen (removes 1 glucose unit) by adding an inorganic phosphate
Glycogen synthase is associated w/what metabolic process?
=glycogen synthesis -takes glucose from UDP-glucose and adds it to existing glycogen chain or glycogenin (protein primer) -activated by insulin, glucose -inhibited by glucagon, epinephrine
UDP-glucose pyrophosphorylase is associated w/what metabolic process?
=glycogen synthesis -sticks glucose on a high energy carrier (UTP) -makes UDP-glucose that can then act as substrate to add glucose to glycogen
Fructose 1,6 bisphosphatase is associated w/what metabolic process?
=gluconeogenesis -hydrolysis of F1,6bisphosphate to F6P and P -opposing enzyme to PFK and regulated by same components
What is the purpose of the hexose monophosphate shunt?
1. Make NADPH for use in anabolic processes (FA biosynthesis) 2. Produce ribose-5-P for nucleotide synthesis -rxns occur in the cytoplasm -rxns do NOT produce or consume ATP -rxns do use glucose (G6P), generate CO2, and fructose6P (gets returned to glycolysis)
Transaldolase and transketolase are associated w/what metabolic process?
=hexose monophosphate shunt -help recycle the excess pentoses produced by the shunt back into fructose6P -F6P can go back to glycolysis
Glucose-6-P dehydrogenase (G6PD) is associated w/what metabolic process?
=hexose monophosphate shunt -catalyzes first step in using glucose6P from glycolysis to generate NADPH and ribose-5-P -rate limiting step -def: hemolytic anemia w/Heinz bodies in RBCs
Fructokinase is associated w/what metabolic process?
=fructose metabolism -adds phosphate group to fructose; -first step in converting fructose to intermediates that can be used in glycolysis, gluconeogenesis -def=essential fructosuria (benign condition where fructose not metabolized and found in blood and urine intact)
Aldolase B is associated w/what metabolic process?
=fructose metabolism -breaks fructose1P into 2 intermediates that can be used by gluconeogenesis and glycolysis -def=hereditary fructose intolerance -accumulate F1P -> shut down glycogenolysis and gluconeogenesis -severe hypoglycemia and vomiting -effects reversed by removing fructose and sucrose from diet
Galactokinase and galactosse-1-phosphate uridyl transferase are associated w/what metabolic process?
=galactose metabolism -convert galactose to glucose1P which can be used in other metabolic pathways -def in either enzyme ->galactosemia -def -> galactose accumulates -> converted to galactiol in nervous system (MR) and eyes (cataracts) -w/ uridyl transferase alse get hepatomegaly -tx: remove galactose and lactose from diet
What is NADPH used for?
1. Reducing biosynthetic processes (synthesizing XOL, FAs, steroid hormones) 2. Keeps glutathione in RBCs in reduced form (prevents hemolysis) 3. Used in bactericidal killing of microbes by phagocytes (oxidative burst)
What are the 2 essential fatty acids?
Essential FA=must be acquired from diet 1. Linoleic acid (18C, 2 db) -can be converted into arachadonic acid (20C) 2. Linolenic acid (18C, 3 db) -
Arachadonic acid is a: a. nucleic acid b. triacylglycerol c. fatty acid d. amino acid
=fatty acid -20C -produced from linoleic acid (essential FA acquired in diet) -impt precursor for many local hormones (PGs, thromboxanes, LTs)
Acetoacetic acid and betahydroxybutyric acid are both: a. fatty acids b. amino acids c. ketone bodies d. steroid hormone precursors
=ketone bodies -synthesized from FA and amino acids by liver during starvation, diabetic ketoacidosis -act as soluble metabolic fuel for heart, brain, SKM, kidney -excreted in urine -excess ketones=fruity breath
Dipalmitoylphosphatidylcholine is a: a. fatty acid b. triacylglycerol c. sphingolipid d. phospholipid e. glycoprotein
=phospholipid =surfactant -phospholipids are distinguished by their polar head group -in surfactant, the polar head group=choline
Cerebrosides, sphingomyelin, sulfatide, globoside and ganglioside are all examples of ________.
=sphingolipids/glycolipids -all contain ceramide (sphingosine linked to FA) -sphingolipids differentiated by X group attached to the ceramide
Compare the functions of LDL and HDL
LDL (aka bad XOL) 1. transports XOL to extrahepatic tissues HDL (aka good XOL) 1. circulating resevoir for apoproteins 2. reverse XOL transport -move XOL from extrahepatic tissues to the liver
Lipoprotein lipase is associated w/what metabolic process?
=Triglyercide (TG) transport -degrades TG circulating in chylomicrons and VLDLs -CII (apolipoprotein) is required cofactor -def -> increased amounts of chylomicrons (pancreatitis, lipemia retinalis, erruptive xanthomas)
Lecithin cholesterol acyltransferase (LCAT) is associated w/ what metabolic process?
=reverse XOL trasport -catalyzes esterification of XOL that goes into HDL and is transported from periphery -> liver
What's a myeloid stem cell?
=blood stem cell that can give rise to 3 types of blood cells 1. RBCs 2. Granulocytes (neutrophils, basophils, eosinophils) 3. plts -derived from plasma fragmentation of megakaryocytes
Granulocytes include all of the following EXCEPT: a. basophils b. eosinophils c. macrophages d. lymphocytes e. neutrophils f. 2 or more of the above
=f=macrophages and lymphocytes -mphages and lymphocytes =agranulocytes b/c they lack specific granules (vs basophils, PMNs, eosinophils that have characteristic granules)
Name 4 types of pharmacologic drugs that do NOT act through cell receptors
1. Antacids -neutralize stomach acids 2. Chelating drugs -bind metallic ions 3. Osmotically active drugs -diuretics (mannitol), cathartics (methylcellulose) 4. Volatile general anesthetics -cause reversible changes in synaptic fxn from within cell membrane -drug potency correlates with lipid solubility
Contrast efficacy and potency
Efficacy -maximum response an agonist can produce -ex. antagonists bind to R but do NOT stimulate them = NO efficacy! Potency -measure of how much drug is required to produce a given effect -less drug required -> more potent -measured by the ED50 (concentration of drug that elicits 50% response)
Define therapeutic index
=describes the safety of a drug -higher TI means drug is safer =ratio of dose of drug required to produce a toxic (TD50) effect or a lethal (LD50) effect to the dose needed for a therapeutic effect (ED50) =TD50/ED50 OR LD50/ED50
Define bioavailability of a drug
=the fraction of drug administered that reaches the systemic circulation -if bioavail=100% -> drug given IV -if bioavail <100% -> drug given other route =F
Define first pass metabolism
=Drugs absorbed from GI tract enter portal circulation and are subject to inactivation by liver before reaching systemic circulation -> decreased bioavailability
Which of the following is FALSE about orally administered drugs a. they must be lipophilic b. they have 100% bioavailability c. they can be subject to first pass metabolism d. They must be resistant to gastric acid, digestive enzymes, and GI flora
=B -NOT 100% bioavail b/c imperfect absorption +/- first pass metabolism
Where is sublingual administration impt for drugs needing rapid onset of action?
-b/c you bypass first pass metabolism and get straight into systemic venous circulation -ex. nitroglycerin
What route of drug administration is contra-indicated in pts on anticoagulants?
-intramuscular injections
Intrathecal administration of drugs refers to injecting drugs into the __________ or ______________.
-subarachnoid space or ventricular systme -bypasses blood brain barrier and blood CSF barrier
Define volume of distribution
=apparent volume into which a drug distributes =total drug in body (g) ------------------ plasma drug concentration (g/L) -the greater the Vd the slower the elimination rate
How do plasma proteins account for drug-drug interactions?
-many drugs like to bind to plasma proteins (ex albumin) and several drugs can compete for same site -if administer 2 highly protein bound drugs, one drug may displace the other drug -> higher blood concentrations of displaced drug -> side effects or toxicity
Where are most drugs metabolized?
-in the smooth ER of hepatocytes
Contrast Phase I and Phase II drug metabolism
Most drug metabolism and biotransformation occurs in the liver Phase I -Oxidation -Reduction -hydrolysis Phase II -endogenous substance added onto the drug -results in: 1. inactivation of the drug 2. drug more hydrophillic -> easier to excrete -glucuronidation -sulfation -acetylation -addition of AA -conjugated drugs secreted in bile, can be: 1. released in feces 2. reabsorbed then excreted in urine
Name 5 factors affecting liver metabolism of drugs
1. Age -very young and old have impaired met 2. Genetics 3. Hepatic insufficiency 4. Drug interactions -CYP inhibitors -> delay metabolism of a drug -CYP inducers -> speed up metabolism of a drug 5. Hepatic blood flow -decreased blood flow can impair metabolism
What's the difference between zero order and first order kinetics?
Zero order -drug decreases at a constant rate regardless of plasma concentration -ex. ethanol First order -drug eliminated in rate proportional to plasma drug concentration -rate of elimination can be described by: 1. half life (t1/2) 2. Elimination constant (ke)
Define clearance of a drug
=volume of blood that can be completely cleared of a drug per unit time =ke x Vd = (0.7/t1/2)
How long does it take drugs to be eliminated from the body?
-depends on half life -takes 4-5 times the half life to reach accumulation steady state in body -likewise, it takes 4-5 half lives of drug to be almost completely eliminated (approx 94%) -half life is used to determine dosing interval needed to get desired level of drug -if long half life, give large loading dose and smaller maintainence doses
Name 4 ways to prolong the action of a drug
1. Frequent doses 2. Time released tablets 3. slow excretion of the drug 4. inhibit metabolism (ex block CYP)
What is the significance of the hepatoduodenal ligament?
=part of the lesser omentum (an abdominal mesentery--double layered serous membrane) -Impt b/c contains the portal triad: 1. hepatic artery 2. hepatic vein 3. common bile duct
Name the structures of the foregut
1. Esophagus (distal to respiratory diverticulum) 2. stomach 3. liver 4. gallbladder 5. pancreas 6. duodenum (to entry of common bile duct) -all share common: 1. Blood supply arterial= celiac trunk 2. lymphatics -drain to celiac nodes (on celiac artery) 3. innervation -preganglion parasympthathetic: vagus -preganglionic sympathetic: thoracic splanchic nerves via celiac plexus
Name 3 unpaired branches off aorta that constitute major blood supply to abdomen.
1. Celiac trunk -foregut structures + spleen 2. Superior mesenteric artery -midgut structures 3. Hindgut structures -inferior mesenteric artery
Name the structures of the midgut
1. Duodenum after entry of common bile duct 2. Jejunum & ileum 3. cecum 4. appendix 5. ascending colon 6. 2/3 of transverse colon -All share a common: 1. Blood supply -Arterial: superior mesenteric artery 2. Innervation -preganglionic parasympathetic: vagus -preganglionic sympathetic: thoracic splanchnic via superior mesenteric plexus
Name the structures of the hindgut
1. distal 1/3 of transverse colon 2. descending colon 3. sigmoid colon 4. upper 1/3 of rectum -All share a common: 1. Blood supply Arterial: inferior mesenteric artery 2. Innervation Preganglionic parasympathetic: sacral SC 2,3,4 via pelvic splanchnic -preganglionic sympathetic:lumbar sympathic trunk via hypogastric and inferior mesenteric plexuses
What is the significance of the esophageal branch of left gastric vein?
-acts as a portal caval anastomoses -connects up with superior mesenteric vein -impt alternate route to return blood in event of liver problems (ex cirrhosis) -but can get clogged up, varicose, and even rupture b/c they're not used to high volume venous blood flow through them

Deck Info