Test your basic knowledge |

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. Kidney
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
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
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
Estrogen: steroid; stims LH in luteal surge; causes growth of female sex organs progesterone: prepares/maintains uterus for pregnancy

2. portal vein physiology...

Warning: Invalid argument supplied for foreach() in /var/www/html/basicversity.com/show_quiz.php on line 183

3. Embryology
Ganglion
Testosterone and estradiol
Zygote - morula (first four days) - blastocyst (4 day+; implants in uterine lining) - gastrula (2 week) - neurula (3 week)...
Epithelial tissue near semniferous tubules

4. Local vs long - distance mediators
Peptide; prolactin promotes milk production; prolactin release is stimulated by act of suckling - which in turn inhibits menstrual cycle
Has memb - bound organelles - etc...
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
Paracrine (local) - endocrine (longer distance)

5. inhibin secreted by
Testes>Semeniferous tubules>Sertoli cells; feedback on AP FSH production
90-140 mg/dl
Paracrine (local) - endocrine (longer distance)
Outermost layer of blood vessel

6. Meiosis II: EQUATIONAL DIVISION
Peptides
Sensory neurons are affector; motor neurons are effector // dorsal afferent (dorsal - Back- side of spinal cord carries sensory signals to brain; ventral effector
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
Determination is a pre - programmed fate - differentiation is the actual materialization of that fate

7. from the loop of henle...
Alpha cells; stims gluconeogenesis in liver; acts via cAMP second messenger
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
Development of placenta begins with implantation; eventually - by end of first trimester - placenta will replace corpus luteum and its estrogen/progest secretions
On to the distal tubule where sodium - calcium are reabsorbed - protons - bicarbonate - potassium are secreted via membrane transport proteins

8. sporic life cycle
On to the distal tubule where sodium - calcium are reabsorbed - protons - bicarbonate - potassium are secreted via membrane transport proteins
Pancreatic duct (made of acinar cells?)
(diploid and haploid individuals = ALTERNATION of GENERATIONS) a fusion of gametic and zygotic life cycles
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

9. glucagon secreted by
Alpha cells; stims gluconeogenesis in liver; acts via cAMP second messenger
Only musc and esp ** liver can store large amounts
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
Hypothalamus --->AP--->target tissues eg TSH - thyroid - T3/T4 release - increase basal metabolic rate

10. Chewing does what?
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
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
Increases surface area of food ball (bolus)
The wall of the body or of a body cavity or hollow structure

11. A pinpoint iris is contracted or uncontracted
Result: stress reaction; increase glycogenolysis - gluconeogenesis; fat/prot breakdown; increase blood glucose
Ectoderm: outer coverings - nervous system Mesoderm: between covering ie musc - bone - etc - endoderm: digestive tract - viscera
Creates one ovum (23 N) and three polar bodies
Uncontracted: parasymp (eg opoid use)

12. 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)
Determination is a pre - programmed fate - differentiation is the actual materialization of that fate
Organs
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
Beta cells

13. FLAT PG: LH
'tones the bone'; decreases free Calcium conc; acts opposite to parathyroid hormone; thyroid polypeptide
Lens will be rounded; contraction of the lens (ie focusing) is done by ciliary muscle
Glycosaminoglycans - prots - AAs - lipids
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

14. cytosol pH
Protein digestion begins in stomach; low pH denatures proteins - kills bacteria; mixes - stores food and destroys it to chyme (BOLUS-->CHYME)
Glands w/ducts: Exocrine glands
About 7.2
On the chyme exiting the stomach and entering duodenum thru the pyloric sphincter

15. Posterior eye
Lower blood pH
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
vitreous humor - retina - fovea
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

16. large intestine E. coli aid absorption of...
Changes: volume of filtrate does not change: osmolarity of filtrate --->reabsorbed ions like sodium carry water across membrane
Vitamin K - b12 - thiamin - riboflavin
In gastric pits; secretions combine into gastric juice
Low because AAs are immediately used in translation

17. week three: neurulation; mesoderm induces ectoderm; thus - NEURULATION INVOLVES SC Development - at week three
Secreted by implanted egg; HCG prevents degeneration of the corpus luteum; HCG in blood/urine is first sign of pregnancy
Has memb - bound organelles - etc...
Direction of differentiation
Notochord (mesoderm) induces ectoderm to thicken into neural plate --->neural tube --->spinal cord

18. at lo blood sugar...
Liver breaks down glycogen (glycogenolysis); at hi blood sugar it builds up glycogen (glycogenesis)
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
Fovea (highest amount of cones)
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

19. What is gastric acid?
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
Smooth ER
HCl; secreted by parietal cells under stim by gastrin
'visceral organs develop adjacent to a cavity and invaginate into the bag - like coelom'

20. Meiosis I: REDUCTIONAL DIVISION Interphase: G1 (growth; enzymes - structural proteins needed for gametic production are synthesized); S (DNA of homologous chromosomes is duplicated; mother cell goes from 46 2N to 46 2N with sister chromosomes connect
CARB- Digesting: dextrinase (polysachs produced by hydrolysis of starch) - maltase (glucose - glucose) - sucrase (glucose - fructose) - lactase (galactose - glucose) - Protein- Digesting: peptidases - NUCLEOTIDE- Digesting: nucleosidases
Prophase I: crossing over occurs; nuclear envelope is absorbed into ER; chromosomes condense)
Organs
Gonadotropin releasing hormone - GnRH

21. Luteal surge
Low because AAs are immediately used in translation
Oxidizes macromolecules; breaks down very long - chain FAs by beta - oxidation; products (acetyl - CoA) are shuttled to mitochondrion for citric acid cycle
Spike in estrogen - LH levels; secondary follicle bursts - releases into body cavity - swept along by fimbriae
Fovea (highest amount of cones)

22. What is main difference is signal transmission in nicotinic vs muscarinic?
ER
Systems (eg digestive system consists of many organs)
***nicotinic is ionotropic; muscarinic is GPCR
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)

23. The path from blood plasma to urine

Warning: Invalid argument supplied for foreach() in /var/www/html/basicversity.com/show_quiz.php on line 183

24. Stomach has no lacteals
Transfer signals from neuron - neuron; 90% of neurons are interneurons
RBCs - large proteins; What does enter is called the filtrate
Most absorption occurs in sm intestine
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

25. examples of different cavities... (compartments for viscera)
Determined by whether in front of or behind the lens
Direction of differentiation
Liver breaks down glycogen (glycogenolysis); at hi blood sugar it builds up glycogen (glycogenesis)
pericardial cavity - pleural cavity (contains lungs) - peritoneal cavity (abdominal)

26. Sensory - motor neurons are part of which nervous system
To the organelle w/ lumen: smooth ER; they are resynthesized into TAGs
Peripheral nervous sys
Posterior pituitary hormone; acts on uterus - mammary glands; causes uterine contractions - milk ejection
On to the distal tubule where sodium - calcium are reabsorbed - protons - bicarbonate - potassium are secreted via membrane transport proteins

27. How do monoglycerides and ffas get to brush border?
Receive signals from receptor cell w/ ability to interact with its environment; 99% sensory input is discarded
Micelles; micelles (made of bile) go back and forth between brush border and chyme
Diarrhea: excess water loss in feces; poor absorption of vitamins - minerals
Know that 90% digestion - absorption occurs in sm intestine --> fine breakdown of carbs - fat - prots

28. PNS review: SAME DAVE
Lysosome
Sensory neurons are affector; motor neurons are effector // dorsal afferent (dorsal - Back- side of spinal cord carries sensory signals to brain; ventral effector
All carbs absorbed at enterocytes are carried to liver by portal vein
Increase surface area of sm intestine; this improves digestion (enzymes adsorbed to villi) and absorption

29. What do the glomerulus and Bowman's capsule add up to...
Estradiol (estrogen - steroid horm); prepares uterine wall for pregnancy; just before ovulation - release of estradiol stims LH in pos feedback
The renal corpuscle
Somatic nervous sys - autonomic nervous sys
Most absorption occurs in sm intestine

30. What does lipase attack exactly
Alpha cells; stims gluconeogenesis in liver; acts via cAMP second messenger
= catecholamines; fight/flight; vasoconstrictors of internal organs - skin; vasodilators of skel musc; also considered stress hormones; epinephrine - norepinephrine
The crypts of Lieberkuhn: sm intestine pH is not right; brush border enzs won't work right
TAGS--->FFAs; remember that FFAs are broken down for energy in mito matrix by beta - oxidation

31. What is the function of the loop of Henle
Increases solute conc and osmotic pressure of the ***medulla
Corpus luteum; secretes estradiol - progesterone throughout pregnancy OR if no pregnancy - for about 2 weeks (till menstruation = shedding of uterine lining)
HCl; secreted by parietal cells under stim by gastrin
Number of centromeres - Not number of chromatids eg - two sister chromatids connected by one centromere = one chromosome

32. position of AP...
Nuclear envelope reassembled in daughter cells; cytokinesis occurs; nucleoli reappear (site of rRNA synthesis)
Below hypothalamus
Form barrier to extracellular fluid
Lipoproteins; albumin carries free fatty acids when fat is mobilized from adipose tissue - etc

33. Three stages of the menstrual cycle
Peptide; prolactin promotes milk production; prolactin release is stimulated by act of suckling - which in turn inhibits menstrual cycle
Nitrogen
Adrenocorticotropin; stims adrenal cortex release of glucocorticoids (eg cortisol - a steroid) stress hormones via second messenger system using cAMP
Follicular (proliferative)= 8d - Luteal (post - ovulation; corpus luteum secretions)= 13d - Menstruation (shed uterine lining if no implantation)= 5

34. On what surface of the retina is the eye most sensitive
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
Fovea (highest amount of cones)
Pancreas; active at sm intestinal pH; hydrolyzes peptide bonds of (pepsin - digested) peptides
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

35. After meiosis II - Male

Warning: Invalid argument supplied for foreach() in /var/www/html/basicversity.com/show_quiz.php on line 183

36. How long are peptides when absorbed at brush border
Sorts - modifies - concentrates proteins from the ER
Organs
Corpus luteum degrades into corpus albicans
Di - tri - peptides; inside enterocytes are hydrolyzed to amino acids

37. Epithelium of the sm intestine: enterocytes lined w/brush border (digestion/absorption); goblet cells (mucous); crypts of Lieberkuhn exocrine glands (lysozyme)
Know that 90% digestion - absorption occurs in sm intestine --> fine breakdown of carbs - fat - prots
Estradiol
Parathyroid hormone (peptide; increases blood Ca); thus - might increase osteoclast/decrease osteoblast activity
Sympathetic: dilates pupil (for night hunting)

38. trypsin is secreted by
Gastric inhibitory pep; increase of pancreatic - enz activating enzymes (which cleaves zymogens like trypsinogen); increased gall bladder contraction; decreases stomach mobility
Increase surface area of sm intestine; this improves digestion (enzymes adsorbed to villi) and absorption
Secreted by implanted egg; HCG prevents degeneration of the corpus luteum; HCG in blood/urine is first sign of pregnancy
Pancreas; active at sm intestinal pH; hydrolyzes peptide bonds of (pepsin - digested) peptides

39. exocrine types
Sudiferous (sweat) - sebaceous - digestive (bile - pancreatic enzs) - mucosal
Spike in estrogen - LH levels; secondary follicle bursts - releases into body cavity - swept along by fimbriae
Abdominal cavity - which is coated in serous fluid
Lower blood pH

40. What is the net effect of the loop of Henle
Vitamin K - b12 - thiamin - riboflavin
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)
Ectoderm: outer coverings - nervous system Mesoderm: between covering ie musc - bone - etc - endoderm: digestive tract - viscera
Secreted by implanted egg; HCG prevents degeneration of the corpus luteum; HCG in blood/urine is first sign of pregnancy

41. Posterior pituitary hormones (Small Peptides)
Oxytocin and ADH (aka vasopressin)
Two perpendicular semicircular canals involved in balance - equilibrium
Break down TAGs to monoglycerides and free fatty acids
- 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

42. from thoracic duct - chylomicrons stick to capillary walls...
Where lipoprotein lipase hydrolyzes TAGs; products diffuse into target tiss (mostly liver - adipose tissue)
Renal pyramids --->renal calyx-->renal pelvis -->ureter -->urethra
Many modern drugs are ligands for GPCRs
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)

43. chylomicron concentration in blood after meal
All carbs absorbed at enterocytes are carried to liver by portal vein
Peak at 1-2hr after meal; chylomicrons themselves have half - life of about 1hr after formation in enterocytes
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.
Sympathetic: dilates pupil (for night hunting)

44. signal transduction occurs only in
Glucose and ketone bodies (not from glycogen stores)
Eukaryotes
Most absorption occurs in sm intestine
Nervous - muscle - epithelial (defines inner/outer) - connective (extensive matrices)

45. What is somatostatin
Liver is the control center for blood glucose; is fed by portal vein from sm intest
Secreted by delta cells of Islets of langerhans; inhibits insulin and glucagon; slows digestion
Trypsin(- ogen; activates other panc enzymes after it is activated by enterokinase of sm intest); chymotrypsin - amylase - lipase
Result: stress reaction; increase glycogenolysis - gluconeogenesis; fat/prot breakdown; increase blood glucose

46. PNS nerve signal
All carbs absorbed at enterocytes are carried to liver by portal vein
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
Zygote - morula (first four days) - blastocyst (4 day+; implants in uterine lining) - gastrula (2 week) - neurula (3 week)...
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

47. medium for paracrine hormones
Pancreatic duct (made of acinar cells?)
Interstitial fluid (eg prostaglandins - cytokines)
Creates one ovum (23 N) and three polar bodies
Prod of steroid hormones in testes - ovaries

48. What if large intestine isn't working well
Sensory (afferent - dorsal) - motor (efferent - ventral)
vitreous humor - retina - fovea
Faces the lumen
Diarrhea: excess water loss in feces; poor absorption of vitamins - minerals

49. calcitonin

Warning: Invalid argument supplied for foreach() in /var/www/html/basicversity.com/show_quiz.php on line 183

50. What Changes - Doesn't Change as a result of movement of molecules across membranes in the proximal tubule
Ammonia; must be converted to urea by liver and excreted in urine by kidney
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
Peptides
Changes: volume of filtrate does not change: osmolarity of filtrate --->reabsorbed ions like sodium carry water across membrane