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. 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)
Albumin increases osmolarity of blood; increases osmotic pressure
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
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
'Increased absorptive area is useful because digested nutrients (including sugars and amino acids) pass into the villi through diffusion - which is effective only at short distances. In other words - **increased surface area (in contact with the flui

2. Ovum development is halted At what stage until fertilization...
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
At metaphase II of meiosis II (halted during reductional division); if fertilized - process continues toward haploid gamete
- 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
***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

3. chylomicron concentration in blood after meal
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
Peak at 1-2hr after meal; chylomicrons themselves have half - life of about 1hr after formation in enterocytes
Membrane - bound - endocytosed bodies
90-140 mg/dl

4. Important of villi (='shaggy hair') More fluid makes contact with the epithelial tissue: thus nutrients in solution have less distance to travel to diffuse into villi.

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

5. In other words...
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
Ammonia; must be converted to urea by liver and excreted in urine by kidney
Paracrine (local) - endocrine (longer distance)
An ether phospholipid; hi conc in myelin; thus - hi conc in heart tiss - nervous tiss

6. 80% of end product of carbohydrate metabolism is...
Reconstituted into TAGs at smooth ER; first stop for most digested fat is liver
Interneurons working to integrate signals received from the peripheral nervous system (sense organs)
Nervous - muscle - epithelial (defines inner/outer) - connective (extensive matrices)
Glucose

7. How do nutrients move?
Below hypothalamus
AAs can be burned for energy or converted to fat for storage
Organs
From lumenal (apical) to enterocyte to basolateral side of epithelial tissue

8. what else is located in the inner ear (not directly related to auditory)
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
Two perpendicular semicircular canals involved in balance - equilibrium
Prophase I: crossing over occurs; nuclear envelope is absorbed into ER; chromosomes condense)
Dehydration reaction; broken apart with enzyme - catalyzed hydrolysis

9. STOMACH: no absorption
Protein digestion begins in stomach; low pH denatures proteins - kills bacteria; mixes - stores food and destroys it to chyme (BOLUS-->CHYME)
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)
Gonadotropin releasing hormone - GnRH
Peak at 1-2hr after meal; chylomicrons themselves have half - life of about 1hr after formation in enterocytes

10. How does blood sugar move into tissues?
- 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
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
Facilitated diffusion from hi to lo conc
Inactive: rhodopsin is activated by photons; activated rhodopsin hyperpolarizes rod cells - causes photobleaching

11. Three stages of the menstrual cycle
Ectoderm: outer coverings - nervous system Mesoderm: between covering ie musc - bone - etc - endoderm: digestive tract - viscera
Can be saturated; conc of a solute is called the transport maximum --->excess goes into urine
Follicular (proliferative)= 8d - Luteal (post - ovulation; corpus luteum secretions)= 13d - Menstruation (shed uterine lining if no implantation)= 5
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)

12. spermatogonia arise from
Epithelial tissue near semniferous tubules
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
Ectoderm: outer coverings - nervous system Mesoderm: between covering ie musc - bone - etc - endoderm: digestive tract - viscera
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

13. mitosis creates somatic cells
Meiosis creates germ cells
Processes: axons - dendrites
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
Reconstituted into TAGs at smooth ER; first stop for most digested fat is liver

14. What is the net effect of the loop of Henle
Result: stress reaction; increase glycogenolysis - gluconeogenesis; fat/prot breakdown; increase blood glucose
Apoproteins attach to outside of globules; these move to Golgi and are released into interstitial fluid via exocytosis as chylomicrons --->most go to lacteal system
Ups bicarbonate secretion by pancreas; raises pH to 6.0
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)

15. bile + fat forms
Micelles; micelles transport lipase products to enterocytes for absorption at brush border
Below hypothalamus
Organs
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. Bile salts and lipase
The renal corpuscle
Prod of steroid hormones in testes - ovaries
Beta cells
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

17. Mucus - digestive enzymes released thru
Secondary follicle: Theca cells differentiate from interstitial tissue - surround follicle - secrete testosterone when stimd by LH (compare to Leydig cells)
The wall of the body or of a body cavity or hollow structure
Glands w/ducts: Exocrine glands
Drugs - toxins - bile pigments (color the urine) - uric acid - antibiotics

18. energy source of neurons
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
Glucose and ketone bodies (not from glycogen stores)
'Increased absorptive area is useful because digested nutrients (including sugars and amino acids) pass into the villi through diffusion - which is effective only at short distances. In other words - **increased surface area (in contact with the flui
All carbs absorbed at enterocytes are carried to liver by portal vein

19. signal transduction occurs only in
Eukaryotes
sucrose (gluc+fruc) - lactose (gluc+galactose) - starch (gluc+gluc)
Ventrally (picture skeletal vertebrae)
Alpha cells; stims gluconeogenesis in liver; acts via cAMP second messenger

20. What is the function of the loop of Henle
Nuclear envelope reassembled in daughter cells; cytokinesis occurs; nucleoli reappear (site of rRNA synthesis)
Lots of water - minerals (electrolyte balance) - vitamins (aided by gut bacteria)
Increases solute conc and osmotic pressure of the ***medulla
Tight regulation of parietal cells needed b/c gastric acid secretion is E- intensive; parietal cells are hi in mitochons

21. What are phagosomes
Membrane - bound - endocytosed bodies
Contain capillary network - lymph vessels (lacteals)
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
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

22. Meiosis II: EQUATIONAL DIVISION
Testosterone and estradiol
Posterior pituitary hormone; acts on uterus - mammary glands; causes uterine contractions - milk ejection
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
Fat is insoluble in blood and requires a carrier like lipoproteins (vLDL...HDL) or albumins; ...vLDL has hi triglycerides - hi cholesterol

23. from thoracic duct - chylomicrons stick to capillary walls...
Where lipoprotein lipase hydrolyzes TAGs; products diffuse into target tiss (mostly liver - adipose tissue)
Moves thru lymph sys; emptied into large veins (thus into bloodstream) of the neck at Thoracic duct
Interstitial fluid (eg prostaglandins - cytokines)
Sensory (afferent - dorsal) - motor (efferent - ventral)

24. Anterior eye
**NO*** lipase digests fat; no bonds broken by bile; only opens up more SA for lipase
cornea (1.4 refractory index; bends light) - pupil (size of pupil is determined by contraction state of the iris) - aqueous humor
On to the distal tubule where sodium - calcium are reabsorbed - protons - bicarbonate - potassium are secreted via membrane transport proteins
Trypsin(- ogen; activates other panc enzymes after it is activated by enterokinase of sm intest); chymotrypsin - amylase - lipase

25. What else do parietals do?
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
On to the distal tubule where sodium - calcium are reabsorbed - protons - bicarbonate - potassium are secreted via membrane transport proteins
Sensory neurons are affector; motor neurons are effector // dorsal afferent (dorsal - Back- side of spinal cord carries sensory signals to brain; ventral effector
Secrete intrinsic factor; important for absorbing vitamin B12 in sm intest

26. FLAT PG: TSH aka thyrotropin
Chyme (by combined activity of exocrine glands)
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
Duodenum (wraps around pancreas; most digestion occurs here) - jejunum (pH 7-9; 2m) - ileum
75% water/ 25% solid mass: of that solid mass: 10-20% fat = phospholipid bilayer of bacteria - slough - off enterocytes ie stomach lining (must be constantly rebuilt) 10-20% inorganic material 30% roughage = fiber = cellulose (indigestible) 2-3% prot

27. FLAT PG: ACTH
Secreted by implanted egg; HCG prevents degeneration of the corpus luteum; HCG in blood/urine is first sign of pregnancy
Development of placenta begins with implantation; eventually - by end of first trimester - placenta will replace corpus luteum and its estrogen/progest secretions
Needs time for bile - lipase - micelle migration - enterocyte uptake
Adrenocorticotropin; stims adrenal cortex release of glucocorticoids (eg cortisol - a steroid) stress hormones via second messenger system using cAMP

28. The bolus (chewing) is digested to what in the stomach
Estradiol
Below hypothalamus
Chyme (by combined activity of exocrine glands)
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

29. trypsin is secreted by
Pancreas; active at sm intestinal pH; hydrolyzes peptide bonds of (pepsin - digested) peptides
AAs can be burned for energy or converted to fat for storage
Secondary spermatocyte (stim'd by FSH from Sertoli cells -->EQUATIONAL DIVISION-->spermatid - which matures further into spermatozoa; released into semeniferous tubule; transported to epididymis
Only musc and esp ** liver can store large amounts

30. Where does the bolus go after mouth chews food
Moves down thru esophageal sphincter
Ammonia; must be converted to urea by liver and excreted in urine by kidney
Neurons may perform one of three functions....
Low because AAs are immediately used in translation

31. exocrine types
Sudiferous (sweat) - sebaceous - digestive (bile - pancreatic enzs) - mucosal
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
Zygotes are diploid
(haploid organism) many fungi and protozoa; individuals are typically haploid; fertilization may occur with immediate meiosis back to haploid state

32. Four tissues
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
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
Facilitated diffusion: no symport w/ secondary transport
Nervous - muscle - epithelial (defines inner/outer) - connective (extensive matrices)

33. How does reabsorption force nutrients across apical membrane of proximal tubule
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
Drugs - toxins - bile pigments (color the urine) - uric acid - antibiotics
AAs can be burned for energy or converted to fat for storage
Via secondary active transport proteins (COSTS E TO FILTER BLOOD - ESTABLISH FLUID/ION BALANCE)

34. What does peroxisome do
Micelles; micelles transport lipase products to enterocytes for absorption at brush border
Oxidizes macromolecules; breaks down very long - chain FAs by beta - oxidation; products (acetyl - CoA) are shuttled to mitochondrion for citric acid cycle
Maintains hi estrogen levels; body does not recognize luteal surge - ovulation does not occur; hi progesterone can lessen shedding by thickening the uterine lining
Increase surface area of sm intestine; this improves digestion (enzymes adsorbed to villi) and absorption

35. 90% digestion - absorption occurs in...
PNS- Somatic - afferent (dorsal root ganglion) + efferent (ventral horns) PNS- ANS- afferent (sensors on viscera) + SYMP - PARA pre - post - ganglionic neurons
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
Pancreatic duct (made of acinar cells?)
Contain capillary network - lymph vessels (lacteals)

36. hypothalamus - AP - ACTH - cortisol release from adrenal cortex
'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
Result: stress reaction; increase glycogenolysis - gluconeogenesis; fat/prot breakdown; increase blood glucose
Visceral layer= parietal layer; serous membrane is the container of the coelom/peritoneal cavity
vitreous humor - retina - fovea

37. inhibin secreted by
Testes>Semeniferous tubules>Sertoli cells; feedback on AP FSH production
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... ...
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**
Estrogen: steroid; stims LH in luteal surge; causes growth of female sex organs progesterone: prepares/maintains uterus for pregnancy

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

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

39. What if large intestine isn't working well
Mostly reabsorbed to liver
**NO*** lipase digests fat; no bonds broken by bile; only opens up more SA for lipase
Which is why lactase - maltase - dextrinase - sucrase are on brush border
Diarrhea: excess water loss in feces; poor absorption of vitamins - minerals

40. small intestine=
The wall of the body or of a body cavity or hollow structure
Transfer signals from neuron - neuron; 90% of neurons are interneurons
Duodenum (wraps around pancreas; most digestion occurs here) - jejunum (pH 7-9; 2m) - ileum
Going up - water - impermeable: salt is actively pumped out - filtrate osmolarity goes down as salt leaves

41. almost all cells can store Some glycogen - but...
Fat synthesis; carbs stored as free fatty acids - esterified to TAGs (requires small amount of E)
Secreted by implanted egg; HCG prevents degeneration of the corpus luteum; HCG in blood/urine is first sign of pregnancy
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)
Only musc and esp ** liver can store large amounts

42. Different tissues working together
(diploid and haploid individuals = ALTERNATION of GENERATIONS) a fusion of gametic and zygotic life cycles
Homologous chromosomes separate - migrate towards opposite poles/centrioles
From lumenal (apical) to enterocyte to basolateral side of epithelial tissue
Organs

43. 'Cell bodies of somatic motor neurons are located in....'
Synthesizes lipids (including steroids); detoxifies drugs; is continuous with lumen
Spinal cord ventral horns; somatic motor neurons use acetylcholine for NTs (voluntary)
Albumin increases osmolarity of blood; increases osmotic pressure
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

44. 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
Albumin increases osmolarity of blood; increases osmotic pressure
'Increased absorptive area is useful because digested nutrients (including sugars and amino acids) pass into the villi through diffusion - which is effective only at short distances. In other words - **increased surface area (in contact with the flui
Peak at 1-2hr after meal; chylomicrons themselves have half - life of about 1hr after formation in enterocytes

45. keep in mind that enterocyte is like a regular euk cell
Going up - water - impermeable: salt is actively pumped out - filtrate osmolarity goes down as salt leaves
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
Via secondary active transport proteins (COSTS E TO FILTER BLOOD - ESTABLISH FLUID/ION BALANCE)
Has memb - bound organelles - etc...

46. cAMP - cGMP - calmodulin...
Moves thru lymph sys; emptied into large veins (thus into bloodstream) of the neck at Thoracic duct
Mediate complex cell processes thru eg phosphorylation via secondary messenger (G protein) systems = signal transduction pathway - GPCR (G protein coupled receptor)
Parathyroid hormone (peptide; increases blood Ca); thus - might increase osteoclast/decrease osteoblast activity
Testes>Semeniferous tubules>Sertoli cells; feedback on AP FSH production

47. medium for paracrine hormones
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
Ups bicarbonate secretion by pancreas; raises pH to 6.0
Facilitated diffusion from hi to lo conc
Interstitial fluid (eg prostaglandins - cytokines)

48. main point of fat transport...
Zygote (fertilization in fallopian tubes); morula (up to 8 cells - undifferentiated ie totipotent); blastocyst (4+ days - implants into uterus; HCG secretion stims corpus luteum; gradually placenta replaces HCG as estrogen/progest source; cells not t
Salivary amylase; both hydrolyze glycosidic linkages
Fat is insoluble in blood and requires a carrier like lipoproteins (vLDL...HDL) or albumins; ...vLDL has hi triglycerides - hi cholesterol
ER

49. What surrounds the hydrophilic heads of the new TAGs
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
Oxidizes macromolecules; breaks down very long - chain FAs by beta - oxidation; products (acetyl - CoA) are shuttled to mitochondrion for citric acid cycle
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
Apoproteins attach to outside of globules; these move to Golgi and are released into interstitial fluid via exocytosis as chylomicrons --->most go to lacteal system

50. portal vein physiology...

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