MCAT Prep - 2

Instructions:

• Answer 50 questions in 15 minutes.
• If you are not ready to take this test, you can study here.
• Match each statement with the correct term.
• Don't refresh. All questions and answers are randomly picked and ordered every time you load a test.

This is a study tool. The 3 wrong answers for each question are randomly chosen from answers to other questions. So, you might find at times the answers obvious, but you will see it re-enforces your understanding as you take the test each time.

1. What does peptic refer to in general
Gonadotropin releasing hormone - GnRH
Secrete intrinsic factor; important for absorbing vitamin B12 in sm intest
Digestion
Micelles; micelles (made of bile) go back and forth between brush border and chyme


2. from thoracic duct - chylomicrons stick to capillary walls...
It is the animal counterpart of starch; it is more highly- branched - thus releases more glucose monomers upon repeated hydrolysis than starch
Form barrier to extracellular fluid
Where lipoprotein lipase hydrolyzes TAGs; products diffuse into target tiss (mostly liver - adipose tissue)
Neurons may perform one of three functions....


3. Creating gradients requires what?
Lots of energy; eg neurons have hi glucose need for 3Na out 2K in ATPase; stomach epithel tiss needs E for parietal cells to pump protons into lumen and bicarbonate into blood
Combined via conjunction of pancreatic duct and common bile duct; common bile duct originates at **cystic duct where gall bladder and liver secretions combine ..cystic duct+common bile duct+pancreatic duct --->into duodenum
In gastric pits; secretions combine into gastric juice
Contains lysozyme - which regulates bacteria within intestine; breaks down peptidoglycans (**bact wall); innate immunity


4. 90% digestion - absorption occurs in...
Small intestine; duodenum is smallest and does most DIGESTION; jejunum is medium and does most ABSORPTION; ileum is biggest and does most absorption along with jejunum
Peptide; responsible for luteal surge (driven in part by LH-->testosterone -->estradiol -->LH positive feedback); results in ovulation (follicle bursting) - releasing egg into fallopian tube/oviduct
Comes into play in the large intestine - where vitamin b12 is absorbed w/help of E. coli; thus; must travel thru bloodstream to large intestine
RBCs - large proteins; What does enter is called the filtrate


5. Contrast PNS- Somatic with PNS- Autonomic
Smaller - more water soluble short - chain FAs go directly to bloodstream at villi capillaries
Oxytocin and ADH (aka vasopressin)
Moves down thru esophageal sphincter
PNS- Somatic - afferent (dorsal root ganglion) + efferent (ventral horns) PNS- ANS- afferent (sensors on viscera) + SYMP - PARA pre - post - ganglionic neurons


6. During ejaculation - sperm...

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7. FLAT PG: ACTH
Adrenocorticotropin; stims adrenal cortex release of glucocorticoids (eg cortisol - a steroid) stress hormones via second messenger system using cAMP
Neurons may perform one of three functions....
About 7.2
Hypothalamus --->AP--->target tissues eg TSH - thyroid - T3/T4 release - increase basal metabolic rate


8. SYMP neurons originate in= PARA neurons originate in=
Changes: volume of filtrate does not change: osmolarity of filtrate --->reabsorbed ions like sodium carry water across membrane
SYMP: spinal cord --->paravetebral ganglion PARA: spinal cord - brain; cell processes --->ganglion near effector organ (preganglionic neurons) extend outside of spinal cord to synapse at ganglia - go on along postganglionic neurons
- filtration occurs at the fenestrations of the renal corpuscle - most reabsorption and secretion occur in the proximal tubule - medulla is concentrated in the loop of henle - sodium and calcium are reabsorbed in the distal tubule -->collecting tubul
Work together to emulsify fats: bile works as a detergent to increase SA of the fat; increased SA gives more substrate to lipase for digestion


9. Aldosterone (sodium uptake - potassium secretion)
Steroid; target tissue is distal convoluted tubule of nephron and collecting duct; increases blood mineral concentration; potassium - protons secreted (blood pH increases); sodium - chloride reabsorbed (BP increases)
Faces the lumen
Within the paravertebral ganglion - running parallel to spinal cord
Glucose


10. Mucus - digestive enzymes released thru
Via secondary active transport proteins (COSTS E TO FILTER BLOOD - ESTABLISH FLUID/ION BALANCE)
Glands w/ducts: Exocrine glands
Bacterial flagellin: hollow filament (not microtub); euk: 9+2 microtubule w/dynein bridges
5


11. What do the glomerulus and Bowman's capsule add up to...
Presence of fat - prot in duodenum causes release of **gastric inhibitory peptide**; result is slower stomach contraction; slower emptying into duod thru pyloric sphincter (slower chyme secretion); more time to properly digest - absorb nutrients
Urine enters kidneys via artery - to arteriole - capillary bed - glomerulus - Bowman's capsule - proximal tubule - loop of henle (concentrates medulla) - distal tubule - collecting tubule - collecting duct (renal pyramids) - renal calyx - renal pelvi
Eukaryotes
The renal corpuscle


12. Gastrulation: ectoderm/mesoderm/endoderm
Ectoderm: outer coverings - nervous system Mesoderm: between covering ie musc - bone - etc - endoderm: digestive tract - viscera
Digestion
Photon (hv)- rhodopsin - conformation change - GPCR- Na less permeable - hyperpolarized rod cells - generates AP= photobleaching at visible light wavelengths (390-700nm)
Secondary spermatocyte (stim'd by FSH from Sertoli cells -->EQUATIONAL DIVISION-->spermatid - which matures further into spermatozoa; released into semeniferous tubule; transported to epididymis


13. spermatogonia arise from
Water flows from the tubule - concentrating the filtrate - raising BP
Glucose and ketone bodies (not from glycogen stores)
Nitrogen
Epithelial tissue near semniferous tubules


14. How is glucose absorbed in sm intest
via symport - secondary transport (ie by pre - established - ATP- intensive) with Na gradient into enterocyte......with no Na gradient (ie without ATP) carbohydrate monomers could not be transported in
To the organelle w/ lumen: smooth ER; they are resynthesized into TAGs
Needs time for bile - lipase - micelle migration - enterocyte uptake
Bacterial flagellin: hollow filament (not microtub); euk: 9+2 microtubule w/dynein bridges


15. cholinergic receptors: NICTONIC and MUSCARINIC Nicotinic: neuromuscular effectors (ionotropic) Muscarinic: PARA effectors (GPCRs) Adrenergic: SYMP effectors (GPCRs)
**only para effectors have muscarinic receptors; symp effectors are adrenergic (epi - norepi); **neuromuscular junction uses nicotinic receptors
To the organelle w/ lumen: smooth ER; they are resynthesized into TAGs
Secondary follicle: Theca cells differentiate from interstitial tissue - surround follicle - secrete testosterone when stimd by LH (compare to Leydig cells)
vitreous humor - retina - fovea


16. testosterone can be aromatized to...
Liposome has phospholipid bilayer
All carbs absorbed at enterocytes are carried to liver by portal vein
Prophase II: no crossing over b/c there are no homologous chromosomes; nuclear envelope dissolves Metaphase II: chromosomes line up at metaphase plate Anaphase II: sister chromatids separate - migrate to opp poles Telophase II: nuclear envelope reap
Estradiol


17. keep in mind that enterocyte is like a regular euk cell
Salivary amylase; both hydrolyze glycosidic linkages
Nitrogen
REABSORPTION: draws off water and ions - increases osmolarity of the medulla while slightly lowering osmolarity of the filtrate -->medulla must have hi osmolarity in order to concentrate urine at collecting duct (final step in nephron)
Has memb - bound organelles - etc...


18. Seen in lysosomal storage diseases
**only para effectors have muscarinic receptors; symp effectors are adrenergic (epi - norepi); **neuromuscular junction uses nicotinic receptors
Spike in estrogen - LH levels; secondary follicle bursts - releases into body cavity - swept along by fimbriae
Buildup of macromolecules in lysosome due to deficient lysosome enzymes
Maintains hi estrogen levels; body does not recognize luteal surge - ovulation does not occur; hi progesterone can lessen shedding by thickening the uterine lining


19. Kidney physiology...

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20. Posterior eye
vitreous humor - retina - fovea
Where lipoprotein lipase hydrolyzes TAGs; products diffuse into target tiss (mostly liver - adipose tissue)
Corpus luteum degrades into corpus albicans
Mediate complex cell processes thru eg phosphorylation via secondary messenger (G protein) systems = signal transduction pathway - GPCR (G protein coupled receptor)


21. What is the endothelium?
Glucose
Increase surface area of sm intestine; this improves digestion (enzymes adsorbed to villi) and absorption
Inner lining of circulatory system
Salivary amylase; both hydrolyze glycosidic linkages


22. motor (efferent) neurons --> VENTRAL
Ganglion
Secondary spermatocyte (stim'd by FSH from Sertoli cells -->EQUATIONAL DIVISION-->spermatid - which matures further into spermatozoa; released into semeniferous tubule; transported to epididymis
Normally contracted
Carry signals to musc OR Gland


23. parathyroid hormone
Transfer signals from neuron - neuron; 90% of neurons are interneurons
Signal picked up by sensory cell - goes thru dorsal root ganglion to SC - may continue to interneurons in brain or simple reflex arc in SC - brain integrates info and decides (voluntary) response - travels back down SC to appropriate ventral root gan
Increases blood Calcium
Glucose = aldose fructose = ketose


24. protein absorption at enterocyte
Somatic nervous sys - autonomic nervous sys
Fallopian tubes
Amino acid monomers - di - tri absorbed by symport at enterocyte; each AA has slightly diff mechanism; from entero - AAs enter bloodstream where they are taken up by all cells of the body - esp the liver by active or facilitated transport (NEVER PASS
Note: enteric= small intestine - double layer of peritoneum that suspends jejunum/ileum from posterior abdominal wall = connective tissue


25. light detection via GPCRs
Neurons may perform one of three functions....
Needs time for bile - lipase - micelle migration - enterocyte uptake
Photon (hv)- rhodopsin - conformation change - GPCR- Na less permeable - hyperpolarized rod cells - generates AP= photobleaching at visible light wavelengths (390-700nm)
Alpha 1-4 and 1-6 (branching) glycosidic linkages


26. portal vein physiology...

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27. euk cell has two principal sides
Lumen (ie continuous w/body cavity) and cytosol
SYMP: spinal cord --->paravetebral ganglion PARA: spinal cord - brain; cell processes --->ganglion near effector organ (preganglionic neurons) extend outside of spinal cord to synapse at ganglia - go on along postganglionic neurons
Within the paravertebral ganglion - running parallel to spinal cord
At metaphase II of meiosis II (halted during reductional division); if fertilized - process continues toward haploid gamete


28. week three: neurulation; mesoderm induces ectoderm; thus - NEURULATION INVOLVES SC Development - at week three
The crypts of Lieberkuhn: sm intestine pH is not right; brush border enzs won't work right
Outer ear= pinna (auricle)- external auditory canal - eardrum (tympanic membrane) inner ear= malleus - incus - stapes - ...oval window - cochlea - where sound is transduced into neural signal...enters cochlea at scala vestibuli - where pressure chang
Notochord (mesoderm) induces ectoderm to thicken into neural plate --->neural tube --->spinal cord
Raises BP; causes collecting ducts at end of nephron (kidney) to become permeable to water - which concentrates urine; coffee - beer block ADH and increase urine volume


29. How does blood sugar move into tissues?
Facilitated diffusion from hi to lo conc
Contains lysozyme - which regulates bacteria within intestine; breaks down peptidoglycans (**bact wall); innate immunity
PH 6.0; this accomplished by pancreatic secretion of bicarbonate which ups pH
PNS- Somatic - afferent (dorsal root ganglion) + efferent (ventral horns) PNS- ANS- afferent (sensors on viscera) + SYMP - PARA pre - post - ganglionic neurons


30. micelles also pick up
Small amounts of hydrolyzed phospholipids and cholesterol: like other fat mols these can diffuse thru enterocyte membrane
Sudiferous (sweat) - sebaceous - digestive (bile - pancreatic enzs) - mucosal
Stims release of tyrosine - derived horms T3/T4 (increase basal metabolic rate); TSH increases thyroid cell size - number - rate of T3/T4 synth -----> thus - iodine deficiency causes swollen thyroid due to lack of neg feedback onto TSH in anterior pi
Tight regulation of parietal cells needed b/c gastric acid secretion is E- intensive; parietal cells are hi in mitochons


31. lining of abdominal cavity=
Serous membrane (slick - reducing friction) that forms lining of the coelom --> secretes lubricating fluid
90-140 mg/dl
Secrete intrinsic factor; important for absorbing vitamin B12 in sm intest
Result: stress reaction; increase glycogenolysis - gluconeogenesis; fat/prot breakdown; increase blood glucose


32. mucus cells line the stomach...
Needs time for bile - lipase - micelle migration - enterocyte uptake
Contain rough ER and Golgi to make mucous; mucous is full of **glycoprots (sticky) and electrolytes*; protects epithelial tiss of stomach from low pH and lubricates stomach
Follicular (proliferative)= 8d - Luteal (post - ovulation; corpus luteum secretions)= 13d - Menstruation (shed uterine lining if no implantation)= 5
Glands w/ducts: Exocrine glands


33. mitosis creates somatic cells
sucrose (gluc+fruc) - lactose (gluc+galactose) - starch (gluc+gluc)
Notochord (mesoderm) induces ectoderm to thicken into neural plate --->neural tube --->spinal cord
Meiosis creates germ cells
Abdominal cavity - which is coated in serous fluid


34. what else is located in the inner ear (not directly related to auditory)
Stom= G cells (gastrin) - parietal (oxyntic); chief (peptic); mucous cells (hi ER - Golgi to make sticky glycoprots) - sm intest= enterocytes (w/brush border of maltase - sucrase - lactase - dextrinase; peptidase; lipase; nucleases); goblet cells (mu
Nuclear envelope reassembled in daughter cells; cytokinesis occurs; nucleoli reappear (site of rRNA synthesis)
Two perpendicular semicircular canals involved in balance - equilibrium
Gonadotropin releasing hormone - GnRH


35. pancreatic enzymes are zymogens
PNS- Somatic - afferent (dorsal root ganglion) + efferent (ventral horns) PNS- ANS- afferent (sensors on viscera) + SYMP - PARA pre - post - ganglionic neurons
Trypsinogen is activated by enterokinase in the brush border; in turn - it activates other enzymes
Alpha cells; stims gluconeogenesis in liver; acts via cAMP second messenger
Conjunction of cell body w/axon


36. 80% of end product of carbohydrate metabolism is...
Break down TAGs to monoglycerides and free fatty acids
Pepsin - secreted by chief cells in the stomach epithelial lining and active at low pH - breaks down proteins to polypeptides. Protein hydrolysis is aided by the highly acidic environment (hi gastric acid from parietal cells). Polypeptides are squirt
Two perpendicular semicircular canals involved in balance - equilibrium
Glucose


37. Where does blood to be filtered by kidney enter the nephron?

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38. Inside the kidney: ...JGA (w/granular cells sensitive to hydrostatic pressure able to secrete renin - activate aldosterone - increase BP) is adjacent to distal tubule - monitors filtrate pressure
- filtration occurs at the fenestrations of the renal corpuscle - most reabsorption and secretion occur in the proximal tubule - medulla is concentrated in the loop of henle - sodium and calcium are reabsorbed in the distal tubule -->collecting tubul
Oxytocin and ADH (aka vasopressin)
Bacterial flagellin: hollow filament (not microtub); euk: 9+2 microtubule w/dynein bridges
Travels vas deferens - urethra; mixes with prostate fluids - seminal vesicles - couper's gland - etc


39. Think of spinal cord injury
Increase surface area of sm intestine; this improves digestion (enzymes adsorbed to villi) and absorption
Injury that does not sever SC (causes deep lesion from back - front) might cause loss of feeling without full loss of motion
Determined by whether in front of or behind the lens
Number of centromeres - Not number of chromatids eg - two sister chromatids connected by one centromere = one chromosome


40. What is the adventitia?
Glucose
Membrane - bound - endocytosed bodies
Most absorption occurs in sm intestine
Outermost layer of blood vessel


41. After meiosis I - daughter cells are...

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42. In other words...
An endogenous morphine
Food is digested from mouth to stomach (denaturation by gastric acid - digested by pepsin) to duodenum (more digestion); then absorption occurs in jejunum and ileum
Glucose and ketone bodies (not from glycogen stores)
Di - tri - peptides; inside enterocytes are hydrolyzed to amino acids


43. trypsin is secreted by
Micelles; micelles (made of bile) go back and forth between brush border and chyme
1) by integral ion channels 2) transmitted by second messenger system
Pancreas; active at sm intestinal pH; hydrolyzes peptide bonds of (pepsin - digested) peptides
After morula - with blastocyst (+8 cell count)--->totipotent to embryonic stem cell and so on


44. Meiosis I Telophase I
Within the paravertebral ganglion - running parallel to spinal cord
Thru tight junctions by favorable osmotic gradient
Testes>Semeniferous tubules>Sertoli cells; feedback on AP FSH production
Nuclear envelope reassembled in daughter cells; cytokinesis occurs; nucleoli reappear (site of rRNA synthesis)


45. How does glycogen compare to starch
It is the animal counterpart of starch; it is more highly- branched - thus releases more glucose monomers upon repeated hydrolysis than starch
Note: enteric= small intestine - double layer of peritoneum that suspends jejunum/ileum from posterior abdominal wall = connective tissue
Zygotes are diploid
(diploid organism) humans are part of gametic life cycle ie produce gametes; diploid germ - line stem cells undergo meiosis to form haploid gametes


46. almost all cells can store Some glycogen - but...
Only musc and esp ** liver can store large amounts
Outermost layer of blood vessel
Stores blood: when expanded liver serves as blood reservoir for body - filters blood: Kupfer cells phagocytize bacteria picked up from intestines - destroys bad RBCs: also done by Kupfer cells - detoxifies blood: detoxified chemicals are excreted eit
Posterior pituitary hormone; acts on uterus - mammary glands; causes uterine contractions - milk ejection


47. fat digestion is time - intensive
Needs time for bile - lipase - micelle migration - enterocyte uptake
Spinal cord ventral horns; somatic motor neurons use acetylcholine for NTs (voluntary)
Liver Functions pt. 2 - Carb metabolism: blood is sent straight to liver from sm intest thru portal vein; liver is control center for blood glucose; _______________ - fat metabolism: oxidizes fat for energy by beta - oxidation - forms most lipoprotei
Fat is insoluble in blood and requires a carrier like lipoproteins (vLDL...HDL) or albumins; ...vLDL has hi triglycerides - hi cholesterol


48. micelles vs liposomes
Paracrine (local) - endocrine (longer distance)
Bacterial flagellin: hollow filament (not microtub); euk: 9+2 microtubule w/dynein bridges
Liposome has phospholipid bilayer
Form barrier to extracellular fluid


49. What are the memb - bound enzymes of the brush border?
(diploid organism) humans are part of gametic life cycle ie produce gametes; diploid germ - line stem cells undergo meiosis to form haploid gametes
- parietal cells (**oxyntic= hi oxygen consumption - hi E??): have hi conc mito; need lots of energy to create proton gradient; thus - responsible for extremely harsh pH conditions in stom; denaturing conditions - chief cells (peptic): synthesize pep
CARB- Digesting: dextrinase (polysachs produced by hydrolysis of starch) - maltase (glucose - glucose) - sucrase (glucose - fructose) - lactase (galactose - glucose) - Protein- Digesting: peptidases - NUCLEOTIDE- Digesting: nucleosidases
Small amounts of hydrolyzed phospholipids and cholesterol: like other fat mols these can diffuse thru enterocyte membrane


50. Meiosis I Metaphase I
Mediate complex cell processes thru eg phosphorylation via secondary messenger (G protein) systems = signal transduction pathway - GPCR (G protein coupled receptor)
Homologous chromosomes line up w/ attachment of spindle fibers/microtubule polymers to centromeres via kinetochores; identical in appearance under light microscope to metaphase of mitosis
Testes>Semeniferous tubules>Sertoli cells; feedback on AP FSH production
PH 6.0; this accomplished by pancreatic secretion of bicarbonate which ups pH