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. interneurons
Transfer signals from neuron - neuron; 90% of neurons are interneurons
Tight regulation of parietal cells needed b/c gastric acid secretion is E- intensive; parietal cells are hi in mitochons
Below hypothalamus
Uncontracted: parasymp (eg opoid use)

2. position of AP...
Contains hydrolytic enzymes; thus - digests endocytosed substances; derived from golgi
Below hypothalamus
Ganglion
Ups bicarbonate secretion by pancreas; raises pH to 6.0

3. cAMP - cGMP - calmodulin...
Know that 90% digestion - absorption occurs in sm intestine --> fine breakdown of carbs - fat - prots
Adrenocorticotropin; stims adrenal cortex release of glucocorticoids (eg cortisol - a steroid) stress hormones via second messenger system using cAMP
Mediate complex cell processes thru eg phosphorylation via secondary messenger (G protein) systems = signal transduction pathway - GPCR (G protein coupled receptor)
Can be saturated; conc of a solute is called the transport maximum --->excess goes into urine

4. A pinpoint iris is contracted or uncontracted
Uncontracted: parasymp (eg opoid use)
On to the distal tubule where sodium - calcium are reabsorbed - protons - bicarbonate - potassium are secreted via membrane transport proteins
Diarrhea: excess water loss in feces; poor absorption of vitamins - minerals
Small amounts of hydrolyzed phospholipids and cholesterol: like other fat mols these can diffuse thru enterocyte membrane

5. How does birth control work?
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
Maintains hi estrogen levels; body does not recognize luteal surge - ovulation does not occur; hi progesterone can lessen shedding by thickening the uterine lining
Corpus luteum degrades into corpus albicans
Prod of steroid hormones in testes - ovaries

6. micelles also pick up
Small amounts of hydrolyzed phospholipids and cholesterol: like other fat mols these can diffuse thru enterocyte membrane
Salivary amylase (weak); sm intest amylase (breaks down large polysaccharides)
Corpus luteum degrades into corpus albicans
Arrested at primary oocyte; hypothalamus GnRH->FSH released at puberty stims granulosa cell development; granulosa secrete zona pellucida = primary follicle

7. sensory (afferent) neurons
On the chyme exiting the stomach and entering duodenum thru the pyloric sphincter
Receive signals from receptor cell w/ ability to interact with its environment; 99% sensory input is discarded
Testes>Semeniferous tubules>Sertoli cells; feedback on AP FSH production
Organs

8. Different tissues working together
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
Gall bladder - pancreatic secretions increase - arrive via ampulla of vater (duct glands); insulin secretion increases (fed state; ductless glands)
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
Organs

9. in the presence of ADH what happens to movement of water across nephron membr
Ganglion
pericardial cavity - pleural cavity (contains lungs) - peritoneal cavity (abdominal)
Calcitonin (peptide; lowers blood Ca); T3/T4 (tyrosine - derived; increase basal metabolic rate); T4= thyroxine
Water flows from the tubule - concentrating the filtrate - raising BP

10. Anatomy of the villi
Contain capillary network - lymph vessels (lacteals)
Can be saturated; conc of a solute is called the transport maximum --->excess goes into urine
Which is why lactase - maltase - dextrinase - sucrase are on brush border
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

11. bile + fat forms
'The hepatic portal vein is not a true vein - because it does not conduct blood directly to the heart. It is a vessel in the abdominal cavity that drains blood from the gastrointestinal tract and spleen to capillary beds in the liver.'
Processes: axons - dendrites
Normally contracted
Micelles; micelles transport lipase products to enterocytes for absorption at brush border

12. At post - two weeks ovulation
= catecholamines; fight/flight; vasoconstrictors of internal organs - skin; vasodilators of skel musc; also considered stress hormones; epinephrine - norepinephrine
1) by integral ion channels 2) transmitted by second messenger system
'tones the bone'; decreases free Calcium conc; acts opposite to parathyroid hormone; thyroid polypeptide
Corpus luteum degrades into corpus albicans

13. thyroid hormones: Not All One Kind of HORM
Calcitonin (peptide; lowers blood Ca); T3/T4 (tyrosine - derived; increase basal metabolic rate); T4= thyroxine
Pancreas; active at sm intestinal pH; hydrolyzes peptide bonds of (pepsin - digested) peptides
Albumin increases osmolarity of blood; increases osmotic pressure
CARB- Digesting: dextrinase (polysachs produced by hydrolysis of starch) - maltase (glucose - glucose) - sucrase (glucose - fructose) - lactase (galactose - glucose) - Protein- Digesting: peptidases - NUCLEOTIDE- Digesting: nucleosidases

14. week three: neurulation; mesoderm induces ectoderm; thus - NEURULATION INVOLVES SC Development - at week three
Corpus luteum degrades into corpus albicans
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**
Notochord (mesoderm) induces ectoderm to thicken into neural plate --->neural tube --->spinal cord
All carbs absorbed at enterocytes are carried to liver by portal vein

15. what happens when glycogen stores are saturated and blood sugar remains high?
Secreted by delta cells of Islets of langerhans; inhibits insulin and glucagon; slows digestion
Fat synthesis; carbs stored as free fatty acids - esterified to TAGs (requires small amount of E)
Trypsinogen is activated by enterokinase in the brush border; in turn - it activates other enzymes
Corpus luteum degrades into corpus albicans

16. Meiosis I Metaphase I
The renal corpuscle
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
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
Increases surface area of food ball (bolus)

17. Anterior eye
cornea (1.4 refractory index; bends light) - pupil (size of pupil is determined by contraction state of the iris) - aqueous humor
1) by integral ion channels 2) transmitted by second messenger system
Peripheral nervous sys
Form barrier to extracellular fluid

18. Path of urine

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

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

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

20. What is the net effect of the distal tubule
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
Mostly reabsorbed to liver
Peristalsis (esophagus) and segmentation (bi - directional=mixing)
**NO*** lipase digests fat; no bonds broken by bile; only opens up more SA for lipase

21. Thus - central nervous sys is...
Peripheral nervous sys
Diarrhea: excess water loss in feces; poor absorption of vitamins - minerals
Interneurons working to integrate signals received from the peripheral nervous system (sense organs)
Increases solute conc and osmotic pressure of the ***medulla

22. Where are these exocrine glands located
Changes: volume of filtrate does not change: osmolarity of filtrate --->reabsorbed ions like sodium carry water across membrane
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
In gastric pits; secretions combine into gastric juice
Focuses light thru the vitreous humor onto retina; acts as a converging lens (image is real - inverted)

23. ADH
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
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
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
TAGS--->FFAs; remember that FFAs are broken down for energy in mito matrix by beta - oxidation

24. 80-90% fat absorbed this way
Moves down thru esophageal sphincter
Trypsin(- ogen; activates other panc enzymes after it is activated by enterokinase of sm intest); chymotrypsin - amylase - lipase
Moves thru lymph sys; emptied into large veins (thus into bloodstream) of the neck at Thoracic duct
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

25. What does lipase attack exactly
TAGS--->FFAs; remember that FFAs are broken down for energy in mito matrix by beta - oxidation
The crypts of Lieberkuhn: sm intestine pH is not right; brush border enzs won't work right
Contain capillary network - lymph vessels (lacteals)
Polysaccharides w/proteoglycans attached = glycosaminoglycans; often give pliability

26. Examples of GPCRs in sensory systems/signal transduction: What is the ligand or messenger in each case? ...SIGHT - SMELL - MOOD - FIGHT/FLIGHT etc
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
Micelles; micelles (made of bile) go back and forth between brush border and chyme
Direction of differentiation
vitreous humor - retina - fovea

27. serous membranes have a viscera - facing layer and a body wall - facing layer
Focuses light thru the vitreous humor onto retina; acts as a converging lens (image is real - inverted)
Visceral layer= parietal layer; serous membrane is the container of the coelom/peritoneal cavity
Peak at 1-2hr after meal; chylomicrons themselves have half - life of about 1hr after formation in enterocytes
Ganglion

28. Path of food entering body...
Increase surface area of sm intestine; this improves digestion (enzymes adsorbed to villi) and absorption
Ganglion
Carry signals to musc OR Gland
Mouth - esophagus - stomach - duodenum - jejunum - ileum - ascending colon - transverse colon - descending colon - sigmoid colon - rectum - anus

29. What are the memb - bound enzymes of the brush border?
CARB- Digesting: dextrinase (polysachs produced by hydrolysis of starch) - maltase (glucose - glucose) - sucrase (glucose - fructose) - lactase (galactose - glucose) - Protein- Digesting: peptidases - NUCLEOTIDE- Digesting: nucleosidases
Increases blood Calcium
Secreted by delta cells of Islets of langerhans; inhibits insulin and glucagon; slows digestion
Prod of steroid hormones in testes - ovaries

30. signal transduction occurs by 2 paths
Nitrogen
Interstitial fluid (eg prostaglandins - cytokines)
1) by integral ion channels 2) transmitted by second messenger system
Faces the lumen

31. PNS review: SAME DAVE
Abdominal cavity - which is coated in serous fluid
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)
Micelles; micelles transport lipase products to enterocytes for absorption at brush border
Sensory neurons are affector; motor neurons are effector // dorsal afferent (dorsal - Back- side of spinal cord carries sensory signals to brain; ventral effector

32. Meiosis I Telophase 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
Needs time for bile - lipase - micelle migration - enterocyte uptake
Outermost layer of blood vessel
Nuclear envelope reassembled in daughter cells; cytokinesis occurs; nucleoli reappear (site of rRNA synthesis)

33. ligands are the messenger compounds that target secondary messenger systems on effectors
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
FAT=9 cal per gram Carbs=4.5 cal per gram - Prot=4 cal per gram - these seem to be for anhydrous forms
Estrogen: steroid; stims LH in luteal surge; causes growth of female sex organs progesterone: prepares/maintains uterus for pregnancy
Many modern drugs are ligands for GPCRs

34. 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)
Somatic nervous sys - autonomic nervous sys
Peristalsis (esophagus) and segmentation (bi - directional=mixing)
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
Travels vas deferens - urethra; mixes with prostate fluids - seminal vesicles - couper's gland - etc

35. How is the follicle developed during oogenesis
In gastric pits; secretions combine into gastric juice
AAs can be burned for energy or converted to fat for storage
Arrested at primary oocyte; hypothalamus GnRH->FSH released at puberty stims granulosa cell development; granulosa secrete zona pellucida = primary follicle
Comes into play in the large intestine - where vitamin b12 is absorbed w/help of E. coli; thus; must travel thru bloodstream to large intestine

36. from the loop of henle...
Glycosaminoglycans - prots - AAs - lipids
In mouth - breakdown of starch into polysaccharides
Neurons may perform one of three functions....
On to the distal tubule where sodium - calcium are reabsorbed - protons - bicarbonate - potassium are secreted via membrane transport proteins

37. 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
Prophase I: crossing over occurs; nuclear envelope is absorbed into ER; chromosomes condense)
CARB- Digesting: dextrinase (polysachs produced by hydrolysis of starch) - maltase (glucose - glucose) - sucrase (glucose - fructose) - lactase (galactose - glucose) - Protein- Digesting: peptidases - NUCLEOTIDE- Digesting: nucleosidases
Sorts - modifies - concentrates proteins from the ER
Development of placenta begins with implantation; eventually - by end of first trimester - placenta will replace corpus luteum and its estrogen/progest secretions

38. remaining secondary follicle becomes
Smooth ER
Corpus luteum; secretes estradiol - progesterone throughout pregnancy OR if no pregnancy - for about 2 weeks (till menstruation = shedding of uterine lining)
Low because AAs are immediately used in translation
Eukaryotes

39. 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

40. What happens when rod cell is depolarized
Night vision
Peak at 1-2hr after meal; chylomicrons themselves have half - life of about 1hr after formation in enterocytes
Facilitated diffusion: no symport w/ secondary transport
Albumin increases osmolarity of blood; increases osmotic pressure

41. Four tissues
Glycosaminoglycans - prots - AAs - lipids
Sudiferous (sweat) - sebaceous - digestive (bile - pancreatic enzs) - mucosal
Glucose = aldose fructose = ketose
Nervous - muscle - epithelial (defines inner/outer) - connective (extensive matrices)

42. Blastocyst
- 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
Ups bicarbonate secretion by pancreas; raises pH to 6.0
Increases surface area of food ball (bolus)
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

43. What is somatostatin
Ammonia; must be converted to urea by liver and excreted in urine by kidney
Break down TAGs to monoglycerides and free fatty acids
Secondary spermatocyte (stim'd by FSH from Sertoli cells -->EQUATIONAL DIVISION-->spermatid - which matures further into spermatozoa; released into semeniferous tubule; transported to epididymis
Secreted by delta cells of Islets of langerhans; inhibits insulin and glucagon; slows digestion

44. Gland: ovaries
Estrogen: steroid; stims LH in luteal surge; causes growth of female sex organs progesterone: prepares/maintains uterus for pregnancy
Glucose
Meiosis creates germ cells
Vitamin K - b12 - thiamin - riboflavin

45. almost all exocytosed proteins pass through this
Night vision
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
Increases blood Calcium
Smooth ER

46. FLAT PG: ACTH
Adrenocorticotropin; stims adrenal cortex release of glucocorticoids (eg cortisol - a steroid) stress hormones via second messenger system using cAMP
Epithelial tissue near semniferous tubules
PNS- Somatic - afferent (dorsal root ganglion) + efferent (ventral horns) PNS- ANS- afferent (sensors on viscera) + SYMP - PARA pre - post - ganglionic neurons
It targets liver conc of prothrombin - fibrinogen etc

47. What kind of cells make up epithel tiss of stom - then sm intest?
Only musc and esp ** liver can store large amounts
Calcitonin (peptide; lowers blood Ca); T3/T4 (tyrosine - derived; increase basal metabolic rate); T4= thyroxine
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
Increases solute conc and osmotic pressure of the ***medulla

48. PNS is broken down into
Reconstituted into TAGs at smooth ER; first stop for most digested fat is liver
Lens will be rounded; contraction of the lens (ie focusing) is done by ciliary muscle
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
Somatic nervous sys - autonomic nervous sys

49. What is a normal blood glucose range
90-140 mg/dl
Changes: volume of filtrate does not change: osmolarity of filtrate --->reabsorbed ions like sodium carry water across membrane
Calcitonin (peptide; lowers blood Ca); T3/T4 (tyrosine - derived; increase basal metabolic rate); T4= thyroxine
FAT=9 cal per gram Carbs=4.5 cal per gram - Prot=4 cal per gram - these seem to be for anhydrous forms

50. when cells hit their limit for prot storage...
Protein digestion begins in stomach; low pH denatures proteins - kills bacteria; mixes - stores food and destroys it to chyme (BOLUS-->CHYME)
Facilitated diffusion: no symport w/ secondary transport
AAs can be burned for energy or converted to fat for storage
Alpha 1-4 and 1-6 (branching) glycosidic linkages