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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. what happens to bile secretions
Mostly reabsorbed to liver
Prophase I: crossing over occurs; nuclear envelope is absorbed into ER; chromosomes condense)
Posterior pituitary hormone; acts on uterus - mammary glands; causes uterine contractions - milk ejection
pericardial cavity - pleural cavity (contains lungs) - peritoneal cavity (abdominal)

2. What is the net effect of the distal tubule
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
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
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
Four 23 N daughter cells are formed from one 46 2N mother (germ - line) cell; four haploid gametes

3. The apical side of the villi...
(diploid organism) humans are part of gametic life cycle ie produce gametes; diploid germ - line stem cells undergo meiosis to form haploid gametes
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
Faces the lumen
Secreted by delta cells of Islets of langerhans; inhibits insulin and glucagon; slows digestion

4. What is the adventitia?
Alpha cells; stims gluconeogenesis in liver; acts via cAMP second messenger
Outermost layer of blood vessel
Parathyroid hormone (peptide; increases blood Ca); thus - might increase osteoclast/decrease osteoblast activity
Meiosis creates germ cells

5. Aldosterone (sodium uptake - potassium secretion)
Four 23 N daughter cells are formed from one 46 2N mother (germ - line) cell; four haploid gametes
Sensory (afferent - dorsal) - motor (efferent - ventral)
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)
Know that 90% digestion - absorption occurs in sm intestine --> fine breakdown of carbs - fat - prots

6. cAMP - cGMP - calmodulin...
Mediate complex cell processes thru eg phosphorylation via secondary messenger (G protein) systems = signal transduction pathway - GPCR (G protein coupled receptor)
Interstitial fluid (eg prostaglandins - cytokines)
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
Secrete intrinsic factor; important for absorbing vitamin B12 in sm intest

7. parathyroid hormone
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
Increases blood Calcium
Direction of differentiation
pericardial cavity - pleural cavity (contains lungs) - peritoneal cavity (abdominal)

8. Seen in lysosomal storage diseases
Buildup of macromolecules in lysosome due to deficient lysosome enzymes
Night vision
(haploid organism) many fungi and protozoa; individuals are typically haploid; fertilization may occur with immediate meiosis back to haploid state
Oxidizes macromolecules; breaks down very long - chain FAs by beta - oxidation; products (acetyl - CoA) are shuttled to mitochondrion for citric acid cycle

9. Epithelium of the sm intestine: enterocytes lined w/brush border (digestion/absorption); goblet cells (mucous); crypts of Lieberkuhn exocrine glands (lysozyme)
Increases blood Calcium
90-140 mg/dl
Know that 90% digestion - absorption occurs in sm intestine --> fine breakdown of carbs - fat - prots
cornea (1.4 refractory index; bends light) - pupil (size of pupil is determined by contraction state of the iris) - aqueous humor

10. extracellular matrix formed mainly of...
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... ...
Polysaccharides w/proteoglycans attached = glycosaminoglycans; often give pliability
Glucose and ketone bodies (not from glycogen stores)
Secondary spermatocyte (stim'd by FSH from Sertoli cells -->EQUATIONAL DIVISION-->spermatid - which matures further into spermatozoa; released into semeniferous tubule; transported to epididymis

11. During ejaculation - sperm...

12. albumin has What affect on blood osmotic pressure
Nervous - muscle - epithelial (defines inner/outer) - connective (extensive matrices)
An endogenous morphine
Albumin increases osmolarity of blood; increases osmotic pressure
Facilitated diffusion: no symport w/ secondary transport

13. The path from blood plasma to urine

14. pancreatic enzymes are zymogens
Trypsinogen is activated by enterokinase in the brush border; in turn - it activates other enzymes
Alpha 1-4 and 1-6 (branching) glycosidic linkages
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... ...
Normally contracted

15. Between meals most fats appear in blood as
Beta cells
Development of placenta begins with implantation; eventually - by end of first trimester - placenta will replace corpus luteum and its estrogen/progest secretions
'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
Lipoproteins; albumin carries free fatty acids when fat is mobilized from adipose tissue - etc

16. Different organs working together
Glucose and ketone bodies (not from glycogen stores)
ER
Regulated by gastrointestinal horms
Systems (eg digestive system consists of many organs)

17. Creating gradients requires what?
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
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
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
An endogenous morphine

18. lining of abdominal cavity=
Has memb - bound organelles - etc...
***nicotinic is ionotropic; muscarinic is GPCR
Contain capillary network - lymph vessels (lacteals)
Serous membrane (slick - reducing friction) that forms lining of the coelom --> secretes lubricating fluid

19. Meiosis I Telophase I
Spike in estrogen - LH levels; secondary follicle bursts - releases into body cavity - swept along by fimbriae
Nuclear envelope reassembled in daughter cells; cytokinesis occurs; nucleoli reappear (site of rRNA synthesis)
On the chyme exiting the stomach and entering duodenum thru the pyloric sphincter
Gastric inhibitory pep; increase of pancreatic - enz activating enzymes (which cleaves zymogens like trypsinogen); increased gall bladder contraction; decreases stomach mobility

20. What do the glomerulus and Bowman's capsule add up to...
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
Bacterial flagellin: hollow filament (not microtub); euk: 9+2 microtubule w/dynein bridges
The renal corpuscle
'tones the bone'; decreases free Calcium conc; acts opposite to parathyroid hormone; thyroid polypeptide

21. sensory (afferent)/interneurons/motor (efferent)
Neurons may perform one of three functions....
Outermost layer of blood vessel
Somatic sensory = dorsal root ganglia (outside spinal cord); somatic effector = ventral horns of spinal cord
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

22. serous membranes have a viscera - facing layer and a body wall - facing layer
(diploid and haploid individuals = ALTERNATION of GENERATIONS) a fusion of gametic and zygotic life cycles
Visceral layer= parietal layer; serous membrane is the container of the coelom/peritoneal cavity
Can be saturated; conc of a solute is called the transport maximum --->excess goes into urine
Paracrine (local) - endocrine (longer distance)

23. FLAT PG: LH
Salivary amylase (weak); sm intest amylase (breaks down large polysaccharides)
Trypsinogen is activated by enterokinase in the brush border; in turn - it activates other enzymes
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
Drugs - toxins - bile pigments (color the urine) - uric acid - antibiotics

24. Interaction of corpus luteum/placenta
CARB- Digesting: dextrinase (polysachs produced by hydrolysis of starch) - maltase (glucose - glucose) - sucrase (glucose - fructose) - lactase (galactose - glucose) - Protein- Digesting: peptidases - NUCLEOTIDE- Digesting: nucleosidases
Development of placenta begins with implantation; eventually - by end of first trimester - placenta will replace corpus luteum and its estrogen/progest secretions
Two perpendicular semicircular canals involved in balance - equilibrium
Form barrier to extracellular fluid

25. duodenum must have receptors for fat content - protein because
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
Liver is the control center for blood glucose; is fed by portal vein from sm intest
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
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

26. keep in mind that enterocyte is like a regular euk cell
Zygotes are diploid
Below hypothalamus
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
Has memb - bound organelles - etc...

27. Liver Functions
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
CARB- Digesting: dextrinase (polysachs produced by hydrolysis of starch) - maltase (glucose - glucose) - sucrase (glucose - fructose) - lactase (galactose - glucose) - Protein- Digesting: peptidases - NUCLEOTIDE- Digesting: nucleosidases
Ganglion
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

28. Adrenal cortex hormones (STEROIDS)
Glucocorticoid (cortisol); mineralocorticoid (aldosterone)
Note: enteric= small intestine - double layer of peritoneum that suspends jejunum/ileum from posterior abdominal wall = connective tissue
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
Adrenocorticotropin; stims adrenal cortex release of glucocorticoids (eg cortisol - a steroid) stress hormones via second messenger system using cAMP

29. large intestine E. coli aid absorption of...
After morula - with blastocyst (+8 cell count)--->totipotent to embryonic stem cell and so on
About 7.2
Vitamin K - b12 - thiamin - riboflavin
Abdominal cavity - which is coated in serous fluid

30. Alpha - amylase found where
Glucose and ketone bodies (not from glycogen stores)
Reconstituted into TAGs at smooth ER; first stop for most digested fat is liver
In mouth - breakdown of starch into polysaccharides
Below hypothalamus

31. Path of urine

32. axon hillock physiology
Injury that does not sever SC (causes deep lesion from back - front) might cause loss of feeling without full loss of motion
(haploid organism) many fungi and protozoa; individuals are typically haploid; fertilization may occur with immediate meiosis back to haploid state
Note: enteric= small intestine - double layer of peritoneum that suspends jejunum/ileum from posterior abdominal wall = connective tissue
Conjunction of cell body w/axon

33. Embryology
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
Secondary follicle: Theca cells differentiate from interstitial tissue - surround follicle - secrete testosterone when stimd by LH (compare to Leydig cells)
Digestion
Result: stress reaction; increase glycogenolysis - gluconeogenesis; fat/prot breakdown; increase blood glucose

34. So - following blastocyst implantation (4d) - at approx 2 weeks past fertilization
Interstitial fluid (eg prostaglandins - cytokines)
Gastrulation occurs: formation of three primary germ layers = differentiation
Arrested at primary oocyte; hypothalamus GnRH->FSH released at puberty stims granulosa cell development; granulosa secrete zona pellucida = primary follicle
Meiosis creates germ cells

35. Most important nutrients absorbed by large intestine
At the first capillary bed of the nephron called the glomerulus which is encased by ***Bowman's capsule
Lots of water - minerals (electrolyte balance) - vitamins (aided by gut bacteria)
Contains hydrolytic enzymes; thus - digests endocytosed substances; derived from golgi
Oxytocin and ADH (aka vasopressin)

36. in the presence of ADH what happens to movement of water across nephron membr
Arrested at primary oocyte; hypothalamus GnRH->FSH released at puberty stims granulosa cell development; granulosa secrete zona pellucida = primary follicle
Homologous chromosomes separate - migrate towards opposite poles/centrioles
FAT=9 cal per gram Carbs=4.5 cal per gram - Prot=4 cal per gram - these seem to be for anhydrous forms
Water flows from the tubule - concentrating the filtrate - raising BP

37. In effect LH - FSH stimulate
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
Prod of steroid hormones in testes - ovaries
Maintains hi estrogen levels; body does not recognize luteal surge - ovulation does not occur; hi progesterone can lessen shedding by thickening the uterine lining
Regulated by gastrointestinal horms

38. FLAT PG: TSH aka thyrotropin
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
'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.'
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
Di - tri - peptides; inside enterocytes are hydrolyzed to amino acids

39. thyroid hormones: Not All One Kind of HORM
Inner lining of blood vessels
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)
Calcitonin (peptide; lowers blood Ca); T3/T4 (tyrosine - derived; increase basal metabolic rate); T4= thyroxine
Alpha 1-4 and 1-6 (branching) glycosidic linkages

40. 80% of end product of carbohydrate metabolism is...
Sensory neurons are affector; motor neurons are effector // dorsal afferent (dorsal - Back- side of spinal cord carries sensory signals to brain; ventral effector
Faces the lumen
Glucose
Salivary amylase (weak); sm intest amylase (breaks down large polysaccharides)

41. FSH - LH - HCG - inhibin are...
Gastrulation occurs: formation of three primary germ layers = differentiation
Peptides
- 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
To the organelle w/ lumen: smooth ER; they are resynthesized into TAGs

42. 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.

43. A group of cell bodies in CNS is nucleus - outside CNS is...
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
Uncontracted: parasymp (eg opoid use)
Ganglion
Sudiferous (sweat) - sebaceous - digestive (bile - pancreatic enzs) - mucosal

44. Thus - central nervous sys is...
Interneurons working to integrate signals received from the peripheral nervous system (sense organs)
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
Reconstituted into TAGs at smooth ER; first stop for most digested fat is liver
Spike in estrogen - LH levels; secondary follicle bursts - releases into body cavity - swept along by fimbriae

45. almost all exocytosed proteins pass through this
Smooth ER
It is the animal counterpart of starch; it is more highly- branched - thus releases more glucose monomers upon repeated hydrolysis than starch
Alpha cells; stims gluconeogenesis in liver; acts via cAMP second messenger
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

46. What does peptic refer to in general
Arrested at primary oocyte; hypothalamus GnRH->FSH released at puberty stims granulosa cell development; granulosa secrete zona pellucida = primary follicle
Digestion
HCl; secreted by parietal cells under stim by gastrin
Fovea (highest amount of cones)

47. euk cell has two principal sides
Lipoproteins; albumin carries free fatty acids when fat is mobilized from adipose tissue - etc
FAT=9 cal per gram Carbs=4.5 cal per gram - Prot=4 cal per gram - these seem to be for anhydrous forms
On to the distal tubule where sodium - calcium are reabsorbed - protons - bicarbonate - potassium are secreted via membrane transport proteins
Lumen (ie continuous w/body cavity) and cytosol

48. Chewing does what?
Posterior pituitary hormone; acts on uterus - mammary glands; causes uterine contractions - milk ejection
Increases surface area of food ball (bolus)
Most absorption occurs in sm intestine
Chylomicrons are much bigger

49. Important aspect of crypt of Lieberkuhn - secreted intestinal juice
Peptide; prolactin promotes milk production; prolactin release is stimulated by act of suckling - which in turn inhibits menstrual cycle
Salivary amylase; both hydrolyze glycosidic linkages
Estradiol
Contains lysozyme - which regulates bacteria within intestine; breaks down peptidoglycans (**bact wall); innate immunity

50. Induction affects...
Has memb - bound organelles - etc...
Inactive: rhodopsin is activated by photons; activated rhodopsin hyperpolarizes rod cells - causes photobleaching
- 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
Direction of differentiation