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MCAT Prep - 2

Subjects : mcat, science

Instructions:

Answer 50 questions in 15 minutes.
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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. calcitonin

2. What (typically - ie not pre - ovulation) feeds back to decrease LH - FSH production?
Testosterone and estradiol
- 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
Focuses light thru the vitreous humor onto retina; acts as a converging lens (image is real - inverted)
Synthesizes lipids (including steroids); detoxifies drugs; is continuous with lumen

3. Embryology
Somatic nervous sys - autonomic nervous sys
Testes>Semeniferous tubules>Sertoli cells; feedback on AP FSH production
Mediate complex cell processes thru eg phosphorylation via secondary messenger (G protein) systems = signal transduction pathway - GPCR (G protein coupled receptor)
Zygote - morula (first four days) - blastocyst (4 day+; implants in uterine lining) - gastrula (2 week) - neurula (3 week)...

4. Between meals most fats appear in blood as
Focuses light thru the vitreous humor onto retina; acts as a converging lens (image is real - inverted)
***starting with adipose tiss: FFAs are transported in the blood by albumin (major component of blood plasma); one albumin typically carries three fatty acid molecules but can hold up to 30 FAs
Lipoproteins; albumin carries free fatty acids when fat is mobilized from adipose tissue - etc
Di - tri - peptides; inside enterocytes are hydrolyzed to amino acids

5. The bolus (chewing) is digested to what in the stomach
Chyme (by combined activity of exocrine glands)
Corpus luteum degrades into corpus albicans
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
Only musc and esp ** liver can store large amounts

6. What is a normal blood glucose range
Adrenocorticotropin; stims adrenal cortex release of glucocorticoids (eg cortisol - a steroid) stress hormones via second messenger system using cAMP
Diarrhea: excess water loss in feces; poor absorption of vitamins - minerals
visual (rhodopsin is receptor - derived from Vit A; conformation change occurs with photon to hyperpolarize rod cells; cone cells use photopsin for receptor) - olfactory - mood (NTs targeted by antidepressants - antipsychotics - etc; GABA is inhibit
90-140 mg/dl

7. Where are these exocrine glands located
Glands w/ducts: Exocrine glands
Contain capillary network - lymph vessels (lacteals)
In gastric pits; secretions combine into gastric juice
Formed in kidney (nephron) - sent thru renal pelvis - down ureter to bladder - drained by urethra'

8. examples of different cavities... (compartments for viscera)
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
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
***nicotinic is ionotropic; muscarinic is GPCR
pericardial cavity - pleural cavity (contains lungs) - peritoneal cavity (abdominal)

9. duodenum must have receptors for fat content - protein because
Below hypothalamus
In liver (RBC recycling of heme); stored in gall bladder; released via cystic duct to common bile duct (shared w/liver); common bile duct joins up with panc duct...everything feeds into the sm intest at the ampulla of vater**
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
5

10. what cannot cross the fenestrations of the renal corpuscle
Photon (hv)- rhodopsin - conformation change - GPCR- Na less permeable - hyperpolarized rod cells - generates AP= photobleaching at visible light wavelengths (390-700nm)
Abdominal cavity - which is coated in serous fluid
Carbohydrates are highly hydrated: one water mol per carbon mol - fats are anhydrous: contain more reduced carbons per unit mass - altogether fats contain 6X energy per unit mass
RBCs - large proteins; What does enter is called the filtrate

11. trypsin is secreted by
Pancreas; active at sm intestinal pH; hydrolyzes peptide bonds of (pepsin - digested) peptides
Pancreatic duct (made of acinar cells?)
Increase surface area of sm intestine; this improves digestion (enzymes adsorbed to villi) and absorption
Abdominal cavity - which is coated in serous fluid

12. How do monoglycerides and ffas get to brush border?
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
Micelles; micelles (made of bile) go back and forth between brush border and chyme
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)
AAs enter bloodstream for uptake by all cells (esp liver). If intracellular prot conc is at max AAs can be converted to fats or glucose via gluconeogenesis. Byproduct of gluconeo is ammonia --->urea.

13. signal transduction occurs only in
Neurons may perform one of three functions....
Somatic nervous sys - autonomic nervous sys
Eukaryotes
Night vision

14. almost all cells can store Some glycogen - but...
Formed in kidney (nephron) - sent thru renal pelvis - down ureter to bladder - drained by urethra'
Fructose is a structural isomer of glucose
Only musc and esp ** liver can store large amounts
Low because AAs are immediately used in translation

15. spermatogonia arise from
The renal corpuscle
5
Epithelial tissue near semniferous tubules
Salivary amylase (weak); sm intest amylase (breaks down large polysaccharides)

16. What hormones affect the stomach?
sucrose (gluc+fruc) - lactose (gluc+galactose) - starch (gluc+gluc)
Hormones --->stimulate exocrine glands - acetylcholine (increases all secretion of gastric pits) - gastrin (from G cells) - histamine (increases HCl secretion of parietals) ...Ach increases all secretions; gastrin increases gastric acid (parietal cel
Membrane - bound - endocytosed bodies
Where lipoprotein lipase hydrolyzes TAGs; products diffuse into target tiss (mostly liver - adipose tissue)

17. micelles vs liposomes
Photon (hv)- rhodopsin - conformation change - GPCR- Na less permeable - hyperpolarized rod cells - generates AP= photobleaching at visible light wavelengths (390-700nm)
Prod of steroid hormones in testes - ovaries
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
Liposome has phospholipid bilayer

18. What is the endothelium?
Sudiferous (sweat) - sebaceous - digestive (bile - pancreatic enzs) - mucosal
Inner lining of circulatory system
Prophase I: crossing over occurs; nuclear envelope is absorbed into ER; chromosomes condense)
- 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

19. How is glucose absorbed in sm intest
Secondary spermatocyte (stim'd by FSH from Sertoli cells -->EQUATIONAL DIVISION-->spermatid - which matures further into spermatozoa; released into semeniferous tubule; transported to epididymis
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
Excretes waste products: urea - uric acid - ammonia - phosphate - maintains homeostasis: including body fluid volume (water reabsorption) and solute composition (mineral balance - nutrient reabsorption) - controls *plasma* pH: antiport of Na/K and pr
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

20. Stomach has no lacteals
Most absorption occurs in sm intestine
On to the distal tubule where sodium - calcium are reabsorbed - protons - bicarbonate - potassium are secreted via membrane transport proteins
Salivary amylase (weak); sm intest amylase (breaks down large polysaccharides)
(haploid organism) many fungi and protozoa; individuals are typically haploid; fertilization may occur with immediate meiosis back to haploid state

21. In effect LH - FSH stimulate
Vitamin K - b12 - thiamin - riboflavin
Prod of steroid hormones in testes - ovaries
Pancreatic duct (made of acinar cells?)
Via secondary active transport proteins (COSTS E TO FILTER BLOOD - ESTABLISH FLUID/ION BALANCE)

22. Most important nutrients absorbed by large intestine
Testosterone and estradiol
Lots of water - minerals (electrolyte balance) - vitamins (aided by gut bacteria)
Smaller - more water soluble short - chain FAs go directly to bloodstream at villi capillaries
Liver breaks down glycogen (glycogenolysis); at hi blood sugar it builds up glycogen (glycogenesis)

23. Meiosis I Telophase I
Nervous - muscle - epithelial (defines inner/outer) - connective (extensive matrices)
Homologous chromosomes separate - migrate towards opposite poles/centrioles
Zygote (morula) composed of eight or more cells; All cells at this stage are TOTipOTENT STEM Cells: do not grow - form by cleavage
Nuclear envelope reassembled in daughter cells; cytokinesis occurs; nucleoli reappear (site of rRNA synthesis)

24. Liver Functions
Sensory neurons are affector; motor neurons are effector // dorsal afferent (dorsal - Back- side of spinal cord carries sensory signals to brain; ventral effector
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
Determined by whether in front of or behind the lens
Night vision

25. AP- peptides (FSH - LH - ACTH - TSH - prolactin - hGH); PP- peptides (ADH - oxytocin); thyroid - peptide *and* tyr - derived (T3/T4 - calcitonin); parathyroid - peptide (PTH; raise blood Ca via pathway involving vitamin D)
Water flows from the tubule - concentrating the filtrate - raising BP
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
Adrenal gland -- AC: steroids (cortisol - aldosterone); AM: catecholamines (epi - norepi); Islets of langerhans: peptides (insulin/glucagon) ANTAGONISTS: calcitonin (thyroid - peptide lowers Ca in blood); parathyroid hormone - peptide - vitamin D pat
Liposome has phospholipid bilayer

26. from the loop of henle...
Facilitated diffusion: no symport w/ secondary transport
Know that 90% digestion - absorption occurs in sm intestine --> fine breakdown of carbs - fat - prots
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)
On to the distal tubule where sodium - calcium are reabsorbed - protons - bicarbonate - potassium are secreted via membrane transport proteins

27. PNS nerve signal
Fructose is a structural isomer of glucose
Chyme (by combined activity of exocrine glands)
Processes: axons - dendrites
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

28. Sensory - motor neurons are part of which nervous system
Photon (hv)- rhodopsin - conformation change - GPCR- Na less permeable - hyperpolarized rod cells - generates AP= photobleaching at visible light wavelengths (390-700nm)
Testosterone and estradiol
Peripheral nervous sys
Oxidizes macromolecules; breaks down very long - chain FAs by beta - oxidation; products (acetyl - CoA) are shuttled to mitochondrion for citric acid cycle

29. light detection via GPCRs
RBCs - large proteins; What does enter is called the filtrate
Oxytocin and ADH (aka vasopressin)
In gastric pits; secretions combine into gastric juice
Photon (hv)- rhodopsin - conformation change - GPCR- Na less permeable - hyperpolarized rod cells - generates AP= photobleaching at visible light wavelengths (390-700nm)

30. Beta - oxidation in liver produces...
Increase surface area of sm intestine; this improves digestion (enzymes adsorbed to villi) and absorption
Gall bladder - pancreatic secretions increase - arrive via ampulla of vater (duct glands); insulin secretion increases (fed state; ductless glands)
Ketone bodies; thus excessive reliance on fat for energy (eg low carb diets) results in ketosis; blood acidity increases
Increases blood Calcium

31. 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
Pancreatic duct (made of acinar cells?)
Four 23 N daughter cells are formed from one 46 2N mother (germ - line) cell; four haploid gametes
After 4 day+ - morula cells have formed fluid - filled ball (blastocyst); this implants in uterus at day 5-7; blastocyst is made up of EMBRYONIC STEM Cells; once implanted w/blastocyst - female is pregnant

32. After meiosis II...
(diploid organism) humans are part of gametic life cycle ie produce gametes; diploid germ - line stem cells undergo meiosis to form haploid gametes
Four 23 N daughter cells are formed from one 46 2N mother (germ - line) cell; four haploid gametes
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
Collection of cell bodies; cell processes project out from both ends of ganglion; synapses with interneuron in spinal cord on one end and sensory receptor on other

33. Determination is different than differentiation
sucrose (gluc+fruc) - lactose (gluc+galactose) - starch (gluc+gluc)
Determination is a pre - programmed fate - differentiation is the actual materialization of that fate
Going up - water - impermeable: salt is actively pumped out - filtrate osmolarity goes down as salt leaves
Notochord (mesoderm) induces ectoderm to thicken into neural plate --->neural tube --->spinal cord

34. Both divisions (somatic - autonomic) of PNS consist of...
Protein digestion begins in stomach; low pH denatures proteins - kills bacteria; mixes - stores food and destroys it to chyme (BOLUS-->CHYME)
Called a tract in the CNS; bundling together of axons/dendrites thru which many diff signals pass; many many neurons are bundled together into a single nerve
Result is proton secreted into lumen - bicarbonate into interstitial fluid (diffuses into blood); result is also increased blood pH and decreased pH stomach
Sensory (afferent - dorsal) - motor (efferent - ventral)

35. Where else does ADH act
Travels vas deferens - urethra; mixes with prostate fluids - seminal vesicles - couper's gland - etc
Interstitial fluid (eg prostaglandins - cytokines)
Increases surface area of food ball (bolus)
At the collecting duct: becomes more permeable to water which passively diffuses *into the medulla* concentrating the urine

36. Where is bile produced
Chylomicrons are much bigger
Testosterone and estradiol
In liver (RBC recycling of heme); stored in gall bladder; released via cystic duct to common bile duct (shared w/liver); common bile duct joins up with panc duct...everything feeds into the sm intest at the ampulla of vater**
Only musc and esp ** liver can store large amounts

37. zygotic life cycle
(haploid organism) many fungi and protozoa; individuals are typically haploid; fertilization may occur with immediate meiosis back to haploid state
Nervous - muscle - epithelial (defines inner/outer) - connective (extensive matrices)
Number of centromeres - Not number of chromatids eg - two sister chromatids connected by one centromere = one chromosome
Liver breaks down glycogen (glycogenolysis); at hi blood sugar it builds up glycogen (glycogenesis)

38. gradual increase in FSH typical of primary follicle development;
Dehydration reaction; broken apart with enzyme - catalyzed hydrolysis
5
HCl; secreted by parietal cells under stim by gastrin
Secondary follicle: Theca cells differentiate from interstitial tissue - surround follicle - secrete testosterone when stimd by LH (compare to Leydig cells)

39. What is the pH at the entrance to the duodenum
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
PH 6.0; this accomplished by pancreatic secretion of bicarbonate which ups pH
Hydrostatic pressure forces some plasma thru *fenestrations of the glomerular endothelium* and into Bowman's capsule; B.C. is continuous with lumen of nephron
Increase surface area of sm intestine; this improves digestion (enzymes adsorbed to villi) and absorption

40. Glucose is a .... sugar; fructose is a .... sugar
Lowers osmolarity of the filtrate (IONS - Water Are Taken Back Up By The Kidney)--->at the end of the distal tubule (the collecting tubule) is where aldosterone acts - along with the JGA
Focuses light thru the vitreous humor onto retina; acts as a converging lens (image is real - inverted)
Glucose = aldose fructose = ketose
visual (rhodopsin is receptor - derived from Vit A; conformation change occurs with photon to hyperpolarize rod cells; cone cells use photopsin for receptor) - olfactory - mood (NTs targeted by antidepressants - antipsychotics - etc; GABA is inhibit

41. small intestine=
Which is why lactase - maltase - dextrinase - sucrase are on brush border
Duodenum (wraps around pancreas; most digestion occurs here) - jejunum (pH 7-9; 2m) - ileum
Somatic sensory = dorsal root ganglia (outside spinal cord); somatic effector = ventral horns of spinal cord
Size of fist; two kidneys; have cortex (steroid hormones) and medulla (catecholamines) - receives about 20% of cardiac output - blood travels down arteries - up veins -'urine is created by the kidney and emptied into the renal pelvis - which is empti

42. What is the path of a sound wave that enters the ear?
Mostly reabsorbed to liver
Sensory (afferent - dorsal) - motor (efferent - ventral)
Inner lining of blood vessels
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

43. Glycogenolysis/gluconeogenesis
Spike in estrogen - LH levels; secondary follicle bursts - releases into body cavity - swept along by fimbriae
Low because AAs are immediately used in translation
Break down TAGs to monoglycerides and free fatty acids
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

44. axon hillock physiology
Peptide; stims growth of nearly all cell of body; all other anterior pituitary horms have specific targets; upregulates anabolic pathways; use of fat for energy goes up (fat - burning); increases AA transport across cell membrane (nutrient uptake)
Normally contracted
Conjunction of cell body w/axon
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

45. important pancreatic enzymes
Cancer; apop can be programmed cell death; mitochon can play important role in apop
Trypsin(- ogen; activates other panc enzymes after it is activated by enterokinase of sm intest); chymotrypsin - amylase - lipase
Prod of steroid hormones in testes - ovaries
Mouth - esophagus - stomach - duodenum - jejunum - ileum - ascending colon - transverse colon - descending colon - sigmoid colon - rectum - anus

46. What is secreted into filtrate by cells of the proximal tubule?
Drugs - toxins - bile pigments (color the urine) - uric acid - antibiotics
The crypts of Lieberkuhn: sm intestine pH is not right; brush border enzs won't work right
Regulated by gastrointestinal horms
'tones the bone'; decreases free Calcium conc; acts opposite to parathyroid hormone; thyroid polypeptide

47. How does the body mobilize fat stores
Result: stress reaction; increase glycogenolysis - gluconeogenesis; fat/prot breakdown; increase blood glucose
***starting with adipose tiss: FFAs are transported in the blood by albumin (major component of blood plasma); one albumin typically carries three fatty acid molecules but can hold up to 30 FAs
Serous membrane (slick - reducing friction) that forms lining of the coelom --> secretes lubricating fluid
Via secondary active transport proteins (COSTS E TO FILTER BLOOD - ESTABLISH FLUID/ION BALANCE)

48. inhibin secreted by
Development of placenta begins with implantation; eventually - by end of first trimester - placenta will replace corpus luteum and its estrogen/progest secretions
Testes>Semeniferous tubules>Sertoli cells; feedback on AP FSH production
Fovea (highest amount of cones)
In liver (RBC recycling of heme); stored in gall bladder; released via cystic duct to common bile duct (shared w/liver); common bile duct joins up with panc duct...everything feeds into the sm intest at the ampulla of vater**

49. parathyroid hormone
Increases blood Calcium
Growth 1 (G1) phase: STRUCTURAL ProteinS - ENZYMES; This is a very active period - where the cell synthesizes its vast array of proteins - including the enzymes and structural proteins it will need for growth. In G1 stage each of the chromosomes cons
Systems (eg digestive system consists of many organs)
cornea (1.4 refractory index; bends light) - pupil (size of pupil is determined by contraction state of the iris) - aqueous humor

50. Local vs long - distance mediators
To the organelle w/ lumen: smooth ER; they are resynthesized into TAGs
Paracrine (local) - endocrine (longer distance)
Lens will be rounded; contraction of the lens (ie focusing) is done by ciliary muscle
sucrose (gluc+fruc) - lactose (gluc+galactose) - starch (gluc+gluc)