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MCAT Prep - 2

Subjects : mcat, science

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. duodenum must have receptors for fat content - protein because
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
Inner lining of blood vessels
It targets liver conc of prothrombin - fibrinogen etc
Note: enteric= small intestine - double layer of peritoneum that suspends jejunum/ileum from posterior abdominal wall = connective tissue

2. SYMP neurons originate in= PARA neurons originate in=
sucrose (gluc+fruc) - lactose (gluc+galactose) - starch (gluc+gluc)
Injury that does not sever SC (causes deep lesion from back - front) might cause loss of feeling without full loss of motion
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
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

3. Spinal cord horns (thick knobs) point
AAs can be burned for energy or converted to fat for storage
***nicotinic is ionotropic; muscarinic is GPCR
Ventrally (picture skeletal vertebrae)
Lower blood pH

4. What is the endothelium?
Paracrine (local) - endocrine (longer distance)
Nuclear envelope reassembled in daughter cells; cytokinesis occurs; nucleoli reappear (site of rRNA synthesis)
Visceral layer= parietal layer; serous membrane is the container of the coelom/peritoneal cavity
Inner lining of circulatory system

5. Meiosis I Metaphase I
Secondary oocyte (stim'd by LH stimulation of theca cells causing release of testosterone - converted to estradiol; eventually brings about luteal surge -->EQUATIONAL DIVISION-->ovum released during ovulation into fallopian tube; burst follicle becom
Follicular phase: primary - secondary - ovulation (1 week) luteal phase: ovulation - thickening of uterine lining w/corpus luteum secretion - corpus luteum degrades (2 weeks) flow: shedding of uterine lining (4 days)
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
Estradiol

6. Bile salts and lipase
Glucose and ketone bodies (not from glycogen stores)
Result: stress reaction; increase glycogenolysis - gluconeogenesis; fat/prot breakdown; increase blood glucose
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
Inner lining of blood vessels

7. Different tissues working together
Organs
Stomach - sm intest - spleen - pancreas from the hepatic portal vein...all blood that passes thru liver go thru flattened spaces called the ***hepatic sinusoids -->hepatic vein --->vena cava
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
Increases blood Calcium

8. insulin secreted by
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
Beta cells
Organs
Glucose = aldose fructose = ketose

9. 3 phases of menstrual cycle
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
Sensory neurons are affector; motor neurons are effector // dorsal afferent (dorsal - Back- side of spinal cord carries sensory signals to brain; ventral effector
Sorts - modifies - concentrates proteins from the ER
Follicular phase: primary - secondary - ovulation (1 week) luteal phase: ovulation - thickening of uterine lining w/corpus luteum secretion - corpus luteum degrades (2 weeks) flow: shedding of uterine lining (4 days)

10. little by little chyme is squirted out thru pyloric sphincter
Regulated by gastrointestinal horms
Salivary amylase (weak); sm intest amylase (breaks down large polysaccharides)
Paracrine (local) - endocrine (longer distance)
Sympathetic: dilates pupil (for night hunting)

11. Three stages of the menstrual cycle
Follicular (proliferative)= 8d - Luteal (post - ovulation; corpus luteum secretions)= 13d - Menstruation (shed uterine lining if no implantation)= 5
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)
pericardial cavity - pleural cavity (contains lungs) - peritoneal cavity (abdominal)
Liver is the control center for blood glucose; is fed by portal vein from sm intest

12. Luteal surge
Receive signals from receptor cell w/ ability to interact with its environment; 99% sensory input is discarded
Monitors filtrate pressure in the distal tubule; has specialized cells (granular cells) that secrete an enzyme (**renin); renin initiates regulatory cascade that produces angiotensin I - II - III that stim adrenal cortex to secrete aldosterone... ...
Spike in estrogen - LH levels; secondary follicle bursts - releases into body cavity - swept along by fimbriae
Vitamin K - b12 - thiamin - riboflavin

13. Exocrine GlandS: stomach
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
- 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
Small amounts of hydrolyzed phospholipids and cholesterol: like other fat mols these can diffuse thru enterocyte membrane
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

14. ADH
Fat synthesis; carbs stored as free fatty acids - esterified to TAGs (requires small amount of E)
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
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
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

15. What Changes - Doesn't Change as a result of movement of molecules across membranes in the proximal tubule
Conjunction of cell body w/axon
Chyme (by combined activity of exocrine glands)
Follicular (proliferative)= 8d - Luteal (post - ovulation; corpus luteum secretions)= 13d - Menstruation (shed uterine lining if no implantation)= 5
Changes: volume of filtrate does not change: osmolarity of filtrate --->reabsorbed ions like sodium carry water across membrane

16. trypsin is secreted by
Hydrostatic pressure forces some plasma thru *fenestrations of the glomerular endothelium* and into Bowman's capsule; B.C. is continuous with lumen of nephron
Direction of differentiation
Visceral layer= parietal layer; serous membrane is the container of the coelom/peritoneal cavity
Pancreas; active at sm intestinal pH; hydrolyzes peptide bonds of (pepsin - digested) peptides

17. Human chorionic gonadotropin...
Secreted by implanted egg; HCG prevents degeneration of the corpus luteum; HCG in blood/urine is first sign of pregnancy
Chyme (by combined activity of exocrine glands)
Zygote - morula (first four days) - blastocyst (4 day+; implants in uterine lining) - gastrula (2 week) - neurula (3 week)...
23 N; 23 chromosomes and haploid (no homologous chromosomes); each chromosome has two sister chromatids Male: primary spermatocyte -->REDUCTIONAL DIVISION (first stim'd at puberty by GnRH - LH-->secondary spermatocyte Female: primary oocyte (arreste

18. The EYE
After morula - with blastocyst (+8 cell count)--->totipotent to embryonic stem cell and so on
Injury that does not sever SC (causes deep lesion from back - front) might cause loss of feeling without full loss of motion
Where lipoprotein lipase hydrolyzes TAGs; products diffuse into target tiss (mostly liver - adipose tissue)
Focuses light thru the vitreous humor onto retina; acts as a converging lens (image is real - inverted)

19. Path of urine

20. overall - fatty - prot - rich food in duod causes
Which is why lactase - maltase - dextrinase - sucrase are on brush border
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
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
Gastric inhibitory pep; increase of pancreatic - enz activating enzymes (which cleaves zymogens like trypsinogen); increased gall bladder contraction; decreases stomach mobility

21. pancreatic amylase is much stronger than
Increases solute conc and osmotic pressure of the ***medulla
Contains hydrolytic enzymes; thus - digests endocytosed substances; derived from golgi
Cancer; apop can be programmed cell death; mitochon can play important role in apop
Salivary amylase; both hydrolyze glycosidic linkages

22. Different organs working together
An ether phospholipid; hi conc in myelin; thus - hi conc in heart tiss - nervous tiss
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
Systems (eg digestive system consists of many organs)
Contains hydrolytic enzymes; thus - digests endocytosed substances; derived from golgi

23. Adrenal medulla hormones (TYR- DERIVED)
Below hypothalamus
= catecholamines; fight/flight; vasoconstrictors of internal organs - skin; vasodilators of skel musc; also considered stress hormones; epinephrine - norepinephrine
Going up - water - impermeable: salt is actively pumped out - filtrate osmolarity goes down as salt leaves
Gastrulation occurs: formation of three primary germ layers = differentiation

24. What else do parietals do?
Follicular (proliferative)= 8d - Luteal (post - ovulation; corpus luteum secretions)= 13d - Menstruation (shed uterine lining if no implantation)= 5
Stomach - sm intest - spleen - pancreas from the hepatic portal vein...all blood that passes thru liver go thru flattened spaces called the ***hepatic sinusoids -->hepatic vein --->vena cava
Secrete intrinsic factor; important for absorbing vitamin B12 in sm intest
Night vision

25. 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
Ketone bodies; thus excessive reliance on fat for energy (eg low carb diets) results in ketosis; blood acidity increases
Neurons may perform one of three functions....
Smaller - more water soluble short - chain FAs go directly to bloodstream at villi capillaries
- 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

26. spermatogonia arise from
Glycosaminoglycans - prots - AAs - lipids
Can be saturated; conc of a solute is called the transport maximum --->excess goes into urine
Paracrine (local) - endocrine (longer distance)
Epithelial tissue near semniferous tubules

27. Energy from fat - prot - gluc
In gastric pits; secretions combine into gastric juice
Smooth ER
Notochord (mesoderm) induces ectoderm to thicken into neural plate --->neural tube --->spinal cord
FAT=9 cal per gram Carbs=4.5 cal per gram - Prot=4 cal per gram - these seem to be for anhydrous forms

28. What is somatostatin
Tight regulation of parietal cells needed b/c gastric acid secretion is E- intensive; parietal cells are hi in mitochons
Secreted by implanted egg; HCG prevents degeneration of the corpus luteum; HCG in blood/urine is first sign of pregnancy
Secreted by delta cells of Islets of langerhans; inhibits insulin and glucagon; slows digestion
HCl; secreted by parietal cells under stim by gastrin

29. small intestine=
Fallopian tubes
Duodenum (wraps around pancreas; most digestion occurs here) - jejunum (pH 7-9; 2m) - ileum
Increases surface area of food ball (bolus)
Corpus luteum; secretes estradiol - progesterone throughout pregnancy OR if no pregnancy - for about 2 weeks (till menstruation = shedding of uterine lining)

30. PNS review: SAME DAVE
'Microvilli function as the **primary surface of nutrient absorption in the gastrointestinal tract**. Because of this vital function - the microvillar membrane is packed with enzymes that aid in the breakdown of complex nutrients into simpler compoun
Sensory neurons are affector; motor neurons are effector // dorsal afferent (dorsal - Back- side of spinal cord carries sensory signals to brain; ventral effector
Gastrulation occurs: formation of three primary germ layers = differentiation
Abdominal cavity - which is coated in serous fluid

31. size of chylomicrons (fat + apoproteins) vs lipoproteins ('cholesterol')
Pancreatic duct (made of acinar cells?)
Chylomicrons are much bigger
Secreted by implanted egg; HCG prevents degeneration of the corpus luteum; HCG in blood/urine is first sign of pregnancy
Testosterone and estradiol

32. What does lipase attack exactly
Fallopian tubes
TAGS--->FFAs; remember that FFAs are broken down for energy in mito matrix by beta - oxidation
Has memb - bound organelles - etc...
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

33. After meiosis II - Female

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

35. amylase acts where on carbs
Smooth ER
Dehydration reaction; broken apart with enzyme - catalyzed hydrolysis
Ectoderm: outer coverings - nervous system Mesoderm: between covering ie musc - bone - etc - endoderm: digestive tract - viscera
Salivary amylase (weak); sm intest amylase (breaks down large polysaccharides)

36. What is main difference is signal transmission in nicotinic vs muscarinic?
Fovea (highest amount of cones)
Development of placenta begins with implantation; eventually - by end of first trimester - placenta will replace corpus luteum and its estrogen/progest secretions
Increase surface area of sm intestine; this improves digestion (enzymes adsorbed to villi) and absorption
***nicotinic is ionotropic; muscarinic is GPCR

37. almost all exocytosed proteins pass through this
Secondary spermatocyte (stim'd by FSH from Sertoli cells -->EQUATIONAL DIVISION-->spermatid - which matures further into spermatozoa; released into semeniferous tubule; transported to epididymis
Sensory neurons are affector; motor neurons are effector // dorsal afferent (dorsal - Back- side of spinal cord carries sensory signals to brain; ventral effector
Smooth ER
Two perpendicular semicircular canals involved in balance - equilibrium

38. What does peptic refer to in general
'Microvilli function as the **primary surface of nutrient absorption in the gastrointestinal tract**. Because of this vital function - the microvillar membrane is packed with enzymes that aid in the breakdown of complex nutrients into simpler compoun
Low because AAs are immediately used in translation
Liposome has phospholipid bilayer
Digestion

39. Thus - central nervous sys is...
Mostly reabsorbed to liver
Spike in estrogen - LH levels; secondary follicle bursts - releases into body cavity - swept along by fimbriae
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
Interneurons working to integrate signals received from the peripheral nervous system (sense organs)

40. Between meals most fats appear in blood as
Lipoproteins; albumin carries free fatty acids when fat is mobilized from adipose tissue - etc
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
Beta cells
Follicular (proliferative)= 8d - Luteal (post - ovulation; corpus luteum secretions)= 13d - Menstruation (shed uterine lining if no implantation)= 5

41. gametic life cycle
Gall bladder - pancreatic secretions increase - arrive via ampulla of vater (duct glands); insulin secretion increases (fed state; ductless glands)
(diploid organism) humans are part of gametic life cycle ie produce gametes; diploid germ - line stem cells undergo meiosis to form haploid gametes
Testes>Semeniferous tubules>Sertoli cells; feedback on AP FSH production
Conjunction of cell body w/axon

42. Most important nutrients absorbed by large intestine
Nitrogen
Corpus luteum; secretes estradiol - progesterone throughout pregnancy OR if no pregnancy - for about 2 weeks (till menstruation = shedding of uterine lining)
sucrose (gluc+fruc) - lactose (gluc+galactose) - starch (gluc+gluc)
Lots of water - minerals (electrolyte balance) - vitamins (aided by gut bacteria)

43. golgi body
Sorts - modifies - concentrates proteins from the ER
Moves down thru esophageal sphincter
Processes: axons - dendrites
Sensory (afferent - dorsal) - motor (efferent - ventral)

44. what else is located in the inner ear (not directly related to auditory)
***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
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)
- enterocytes w/ *microvilli brush border*: membrane - bound digestive enzymes for carbs - fats - nucleic acids - goblet cells: secrete mucous - Deep between villi are the intestinal exocrine glands - the crypts of Lieberkuhn - which secrete pH 7.6 i
Two perpendicular semicircular canals involved in balance - equilibrium

45. What determines number of chromosomes?
Moves down thru esophageal sphincter
Number of centromeres - Not number of chromatids eg - two sister chromatids connected by one centromere = one chromosome
Reconstituted into TAGs at smooth ER; first stop for most digested fat is liver
Fovea (highest amount of cones)

46. euk cell has two principal sides
Estradiol (estrogen - steroid horm); prepares uterine wall for pregnancy; just before ovulation - release of estradiol stims LH in pos feedback
Two perpendicular semicircular canals involved in balance - equilibrium
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
Lumen (ie continuous w/body cavity) and cytosol

47. Meiosis I Telophase I
Dehydration reaction; broken apart with enzyme - catalyzed hydrolysis
**NO*** lipase digests fat; no bonds broken by bile; only opens up more SA for lipase
Uncontracted: parasymp (eg opoid use)
Nuclear envelope reassembled in daughter cells; cytokinesis occurs; nucleoli reappear (site of rRNA synthesis)

48. How does blood sugar move into tissues?
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
Fallopian tubes
Corpus luteum; secretes estradiol - progesterone throughout pregnancy OR if no pregnancy - for about 2 weeks (till menstruation = shedding of uterine lining)
Facilitated diffusion from hi to lo conc

49. What is endothelium?
Inner lining of blood vessels
Hypothalamus --->AP--->target tissues eg TSH - thyroid - T3/T4 release - increase basal metabolic rate
Going up - water - impermeable: salt is actively pumped out - filtrate osmolarity goes down as salt leaves
Ketone bodies; thus excessive reliance on fat for energy (eg low carb diets) results in ketosis; blood acidity increases

50. Think of spinal cord injury
Di - tri - peptides; inside enterocytes are hydrolyzed to amino acids
Which is why lactase - maltase - dextrinase - sucrase are on brush border
Injury that does not sever SC (causes deep lesion from back - front) might cause loss of feeling without full loss of motion
Mouth - esophagus - stomach - duodenum - jejunum - ileum - ascending colon - transverse colon - descending colon - sigmoid colon - rectum - anus