Biochem/Physiology Flashcards
Sugars that contain aldehyde groups that are \_\_\_ to carboxylic acids are classified as \_\_\_\_ sugars. • oxidized, non-reducing • oxidized, reducing • reduced, non-reducing • reducing, oxidizing copyright Cl 20 13-2014 Dental Decks BIOCHEMISTRY /PHYSIOLOGY
aldehydes oxidized to acids;
reducing
lactose, maltose, glucose, fructose
contain free anomeric carbon (C1, carbonyl group, available for redox, can be oxidized)
it’s the one on the rightmost of the ring, usually involved in bond formation
if that oxygen is not attached to anything else, it is a reducing sugar
carbonyl - reducing properties
sucrose is NOT reducing - reducing groups of glucose and fructose involved in glycosidic bond (no free anomeric carbon)
reducing sugars:
lactose, glucose, maltose (2x glu), fructose, galactose
reducing carbon
anomeric C1 carbonyl
aldehyde group that can be oxidized to carboxyl
Which of the following glycosaminoglycans can be found functioning in synovial fluid? • heparin • keratan sulfate • hyaluronate • dermatan sulfate • chondroitin sulfate • heparan sulfate
hyaluronate
glycoproteins - no repeat units, covalent bond bw sugars and protein
proteoglycans - w/ carbohydrate chains (GAGs) linked covalently to protein core
disaccharide repeat units: hexosamine + uronic acid
only hyaluronate is NOT sulfated and not covalently attached to protein
GAGs - lubricants, support elements in CT
hyaluronate - synovial fluid, eye humor, loose CT ECM - large polymer, shock absorbing
CS - ctlg, bone, heart valves - most abundant GAG
Heparan sulfate - BM, cell surfaces - more acetylated than heparin
heparin - granules of maast cells - anticoagulant, more sulfated than heparan sulfate
dermatan sulfate - skin, blood vessels, heart valves
keratan sulfate - cornea, bone, ctlg; aggregated w CS
GAG in basement membrane
heparan sulfate
less sulfated than heparin
more acetylated than heparin
mast cells GAG
heparin
more sulfated than heparan, less acetylated than heparan
most abundant GAG
CS
synovial fluid GAG
hyaluronate
not covalently bound to protein, not sulfated
large polymer, absorbs shock
non-sulfated GAG and where
hyaluronate, humor of eye, synovial
large, absorbs shock
Which intestinal enzyme breaks down the O-glycosidic bond between glucose and fructose? • maltase • lactase • sucrase • none of the above copyright Cl 20 13-2014 Dental Decks BIOCHEMISTRY /PHYSIOLOGY
SAADDES
sucrase
maltose = 2 glucoses lactose = glu + gala sucrose = glu + fru
Glucose, fructose, and galactose are classified as: • monosaccharides • disaccharides • oligosaccharides • polysaccharides copyright Cl 20 13-2014 Dental Decks
SAADDES
monosaccharides
Which of the following polysaccharides is hydrolyzed by glucan transferase? • starch • glycogen • cellulose • glycosaminoglycans copyright Cl 20 13-2014 Dental Decks BIOCHEMISTRY /PHYSIOLOGY SAADDES
glycogen
starch and glycogen - storage
structural - cellulose
GAGs are heteropolysacch
starch modes: alpha 1-6 amylose - unbranched amylopectin - v branched both hydrolyzed by amylase (parotid and pancreas)
glycogen - branched
alpha 1-4
especialy abundant in liver
cleaved by glucan transferase
modes, link and cleavage of starch
amylose (unbranched) and amylopectin (branched)
alpha 1-6
amylase from parotid and pancreas
link and cleavage of glycogen
branched, alpha 1-4
glucan transferase
The ground substance ofthe extracellular matrix is made up of: • type II collagen • type Ill collagen • proteoglycan molecules • fibri lli n
PGs = core protein with GAG side chains
major fx - lubricants, ecm, sieve
glycoproteins: NO serial repeat, covalent bond between carbs (NOT GAGs) protein; shorter and branched
enzymes, hormones, ABs, components of cll membrane
glycolipids - cell membrane receptors, all derived from ceramide
The most abundant glycosaminoglycan in the body is: • keratan sulfate • dermatan sulfate • chondroit in sulfate • heparan sulfate
CS
For each letter, choose the most appropriate answer to fill in the blank.
Dextrans are (A) __ of (B) __ produced extracellularly by bacteria and
yeast. The enzyme used to produce dextrans is (C) __, and the substrate
is (D) __ . A side product of dextran production is (E) __ , which is
formed into (F) __ and stored intracellularly as reserve nutrients.
• (A) monosacchari des I polysaccharides I oligosacchari des
• (B) glucose I fructose I galactose
• (C) dextran synthase I glucosyl transferase I fructosyl t ransferase
• (D) maltose I sucrose I lactose
• (E) glucose I fructose I galactose
• (F) starch I glycogen I !evans
Dextrans are polysaccharides of glucose produced extracellularly by bacteria and
yeast. The enzyme used to produce dextrans is glucosyl transferase (dextran sucrase), and the substrate
is sucrose . A side product of dextran production is fructose , which is
formed into fructans (levans) and stored intracellularly as reserve nutrients.
strep mutans produces dextran from sucrose
dextran - sticky polymer of glucose
enzyme splits sucrose into glucse and fructose and links glucoses into dextran
dextran deposited as thick glycocalyx
All of the following statements are true EXCEPT one. Which one is the EXCEPTION?
• rods contain rhodopsin -a photopigment
• cones are responsible for color vision
• rods are used for dark adaptation
• rods and cones are located in the retina
• cones are more abundant than rods
• cones are more abundant than rods
retina - innermost nervous tissue of eye
photopigments: opsin + retinal
rods - rhodopsin; no color; light intensity, night vision, vit A; periphery; MORE abundant, higher sensitivity, lower acuity
cones - color, central retina(fovea); red green blue
rods vs cones: sensitivity, acuity, type
rods higher sensitivity, more at periphery and more in general, lower acuity, night vision, vit A
cones central (fovea)
photopigment
opsin + retinal
which one’s night vision
rods
Which of the following structures of the eye functions like a shutter in the
camera analogy, allowing more or less light into the eye?
·lens
• retina
• cornea
• iris
iris
A sound wave will strike the first. • membrane of the oval window • membrane of the round window • tectorial membrane • tympanic membrane special sense organs 11 copyright Cl 20 13-2014 Dental Decks BIOCHEMISTRY /PHYSIOLOGY
tympanic membrane
tympanic –> membrane of oval –> move perilymph in bony labirynth of cohclea and endolymph in membranous labirynth
endolymph –> basiar membranes vibrate –> stimulate hairs of Corti –> transmit
inner ear = membranous and bony labyrinth
vestibule (utricle and saccule) - balance
semicircular canals - equilibrium
cochlea - vestibular and basilar meambranes
balance in inner ear
utricle and saccule, vestibule
endolymph vs perilymph
membranous vs bony labyrinth
also endolymph transmits further: vibrates basilar membrane –> hairs of Corti
Your patient just returned from an ophthalmology appointment where
she received tropicamide to induce mydriasis. What significance does
this have on her dental appointment?
• the patient can’t distinguish colors when choosing denture teeth
• the patient will be extra sensitive to the overhead dental light
• the patient will have trouble seeing without bright light
• the patient will experience blurry vision
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BIOCHEMISTRY /PHYSIOLOGY
• the patient will be extra sensitive to the overhead dental light
miosis - constriction
mydriasis - dilation
myopia - eye too long, far objects focus in front of retina
hyperopia - focus is behind retina
astigmatism - curvature not uniform
presbyopia - loss of elasticity of lens
The normal range for hemoglobin is different between the sexes and is
approximately ___ for men and ___ for women.
• 5-8 grams per deciliter, 2-3 grams per deciliter
• 9-11 grams per decili ter, 7-9 grams per deciliter
• 13-18 grams per decili ter, 12-16 grams per deciliter
• 20-22 grams per decili ter, 18-21 grams per deciliter
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13-18, 12-16
each Hb - 4 Fe
leaving lung - 98% saturated
returning is 75% saturated
only 30% of CO2 binds to Hb, rest is dissolved
CO2 binds to protein portion
oxygen - to Fe (coordination bonds, loose)
congestive heart failure and COPD - high Hb
anemia, cirrhosis and HYPERthyroidism - low Hb
Bohr effect in Hb bnding
acid in tissues assists unloading
high Hb
polycythemia, COPD, congestive HF
low Hb
anemia, hyperthyroidism, cirrhosis
Although albumin accounts for only 60% of the total plasma protein, it provides
80% of the colloid osmotic pressure of the plasma.
The colloid osmotic pressure is necessary to prevent edema.
• both statements are true
• both statements are fa lse
• the first statement is true, the second is fa lse
• the first statement is fa lse, the second is true
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both true
80% of colloid pressure in plasma is albumin
loss of albumin –> hyper Bb emia and jaundice
The principal hormone for serum calcium regulation is: • calcitonin • parathyroid hormone • thyroid hormone • vasopressin/antidiuretic hormone
PTH via kidneys and bones
calcitonin is complementary
increased Ca - hyperD, hyperPTH
decreased Ca - diarrhea, hypo
PTH increases serum Ca and decreases P
vit D increases both P and Ca
Which of the following blood equations is correct? • serum = plasma- fibrinogen • plasma = serum -fibrinogen • serum = hematocrit + plasma • hematocrit = fibrinogen - plasma blood
• serum = plasma - fibrinogen
serum - no fibrin and other coagulation products
plasma = blood - formed elements; 55% of blood
45% of blood - formed elements
The general term for reactions that prevent or minimize loss of blood
from the vessels if they are injured or ruptured is:
• erythropoiesis
• syneresis
• homeostasis
• hemostasis
hemostasis
guarding against blood loss: cnstriction, plt aggregation, coagulation
prothrombin activator = X+V
thrombin coverts fibrinogen to fibrin
liver synthesizes factors II, VII, IX and X
clotting factors from liver
2, 7, 9, 10
prothrombin activator
5+10
draw out clotting pathways
NOW
tissue factor and 7a contact in injury
Iron, the most important mineral in the formation of hemoglobin, is absorbed
mainly in the ___ and is only absorbed as ___ .
• ascending colon, Fe3•
• sigmoid colon, Fe2•
• duodenum, Fe2+
• jejunum, Fe2+
duodenum, Fe2+
ferritin and hemosiderin for intracellular iron storage
75% in hemoglobin ad myoglobin
in duodenum –> binds to apotransferrin –> transferrin in plasma for transport
excess - in liver
vit C promotes Fe uptake (antioxidant)
Bb - product of heme degradation
transferrin vs ferritin
trans is transport
ferritin and hemosiderin - storage
effects of vit D on Ca and P
both increase
which vitamin promotes Fe absorption
C! reduces to Fe2+
absorbed in duodenum
0 blood type is referred to as: • universal donor • universal recipient • neither of t he above blood
universal donor
don’t produce AB antigens
AB - no AB antibodies, universal recipients
O blood type - no antibodies or no antigens?
no antigens
AB type is vv
The most important feature of the hemoglobin molecule is its ability to
combine loosely and reversibly with oxygen.
Oxygen does not combine with the two positive bonds of the iron in the
hemoglobin molecule. Instead it binds loosely with one of the so-called
coordination bonds of the iron atom.
• both statements are true
• both statements are fa lse
• the first statement is true, the second is fa lse
• the first statement is fa lse, the second is true
both true
oxyHb dissociation curve to right
to right means harder to saturate, affinity decreased, dissociation enhanced
low PO2, increased acid, increased temperature, increased BPG, increased CO2
p50 - half-saturated Hb
27 mmHg
dissociation curve to left
means higher affinity, harder to dissociate
higher PO2, higher PH, lower BPG
what is Hb curve
binding vs pressure
All of the following are common subunit hemoglobin chains EXCEPT one. Which one is the EXCEPTION? • alpha • beta • gamma • delta • epsilon
epsilon
normal Hb - 2 alpha and 2 beta, fetal is 2 alpha nad 2 gamma
Fe is Fe2+
combination with CO2 is at protein portion
CO has higher affinity
metHb has Fe3+ and can’t bind oxygen
The most common form of hemoglobin in the adult human being i s: • hemoglobin H • hemoglobin S • hemoglobin M • hemoglobin A • hemoglobin C
A; 2 alpha and 2 beta
H is 4 beta chains (defect in alpha, thalassemia)
S - val instead of glu, sickle cell; decreased solubility of deoxyHb
M - metHb (Fe3+, can’t bind)
C - lysine instead of glu, reduced RBC plasticity
HbH
alpha-thalassemia, 4 beta chains
HbM
metHb, Fe3+, can’t bind
HbS
sickle, val instead of glu, reduced solubility of deoxy
HbC
reduced plasticity, lys instead of glu
In the normal person, about 90% of all erythropoietin is formed in the
—‘·the remainder is formed mainly in the __ _
• kidneys, liver
•liver, kidneys
· bone marrow, kidneys
· kidneys, bone marrow
kidney; liver
erythrocytes contain Hb and carbonic anhydrase
in adults made in marrow of membranous bones (vertebrae, sternum, ribs, ilia)
Which ofthe following will shift the oxygen-hemoglobin dissociation curve to the right? Select all that apply. • increased carbon dioxide concentration • increased blood temperature • increase in pH • increased 2,3-biphosphoglycerate (BPG)
increased CO2, increased t, decreased pH, increased BPG
dissociation curve to right mena slower affinity, easier to unload
BPG forms in hypoxia
BPG?
forms in hypoxia, shifts curve to right
The substance intrinsic factor, essential for absorption of vitamin B12 in the ileum, is secreted by the: • chief cell s • parietal cell s • gastrin cells • mucous cells
parietal
oxyntic gland = mucous, chief and parietal
vagus - strongest stimulant of all secretion
All of the following slow gastric emptying EXCEPT one. Which one is the
EXCEPTION?
• gastri c inhibitory peptide
• activation of the sympathetic nervous system
• secretin
• activation of the enteric nervous system
• cholecystokinin
• activation of the parasympathetic nervous system
parasymps
CKK, secretin and gastric inhibitory peptide inhibit emptying
feedback from small intestine inhibits emptying
gastrin and presence of food in stomach enhance emptying
sympathetic inhibits GI motility
but parasymp and ACh stimulate digestive activities
contractions in GI: peristalsis and mixing/segmentation
Three of the following signaling molecules are important in causing
pancreatic secretion. Which of the following is NOT one of them?
• cholecystokinin
• secretin
• acetylcholine
• epinephrine
Epi
ACh - from vagus
CKK - secr by duodenum and upper jejunum
secretin - same
ACh and CKK stimulate pancreatic enzymes
secretin stimulates water and bicarbonate in pancreatic ducts
CKK and secretin secreted in
duodenum and jejunum
ACh and CKK effect on pancreas
enzymes from acinar
secretin effect on pancreas
water and bicarb from ducts
Your patient comes in and says that his physician has diagnosed him with pernicious
anemia. As you know, this is caused by the malabsorption of vitamin
812.
1. What protein is crucial in the absorption of vitamin B12?
• gastrin
• intrinsic factor
• pepsin
2. What cell is responsible for the faulty glycoprotein implicated in pernicious anemia?
• chief cell s
• parietal cell s
• mucous neck cell s
•gcells
3. What type of glands within the stomach contain these cells?
• pyloric glands
• gastric glands
• cardiac glands
• none of the above
1 - IF
2 - parietal
3 - gastric
oxyntic = gastric
pyloric - mucus + gastrin
oxyntic - parietal + peptic + mucous neck
HCl secretion increased by ACh, gastrin and histamine
what increases HCl secretion
histamine, gastrin, ACh
Distension of the intestine by chyme and parasympathetic neural activity
___ the contractile force, while sympathetic neural activity ____ it.
• decrease, increases
• increase, decreases
• have no effect on, increases
• none of the above
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increase, decrease
Which of the following pairings regarding the absorption in the small intestine is INCORRECT? • fructose -- facilitated diffusion • free fatty acids -- simple diffusion • dipeptides -- primary active transport • glucose -- secondary active transport 30
• dipeptides – primary active transport
they are actually SECONDARY active transport
free FAs diffuse simply after being emulsified by bile salts and pancreatic lipase
dipeptides and AAs: Na-dependent transporter (AA) or H-dependent contransport
sugars - secondary active transporters driven by Na gradient
absorption of free FAs
simple diffusion when emulsified by bile salts and pancreatic lipase
absorption of monosaccharides
secondary active transport, driven by Na
absorption of peptides
AA: secondary active w/ Na
dipeptides: H-driven secondary active
Place the following phases of gastric secretion in their proper order: • intestinal phase • gastric phase • cephalic phase 31
cephalic gastric intestinal
intestinal phase (CKK, secretin, gastric inhibitory peptide) inhibit stomach activity
presence of food and gastrin enhances
gastrin on stomach activity
enhances
As an action potential reaches a skeletal muscle cell, what is the order of
activation by which the signal is transmitted internally through the muscle
cell so that contraction results?
• acetylcholine, calcium, t roponin, tropomyosin, myosin heads
• calcium, acetylcholine, t roponin, tropomyosin, myosin heads
• acetylcholine, calcium, tropomyosin, t roponin, myosin heads
• calcium, acetylcholine, t ropomyosin, t roponin, myosin heads
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ACh, Ca, troponin, tropomyosin, myosin heads
dissociation of actin-myosin when ATP binds to myosin
The immediate source of energy for muscle contraction is ATP binding to
myosin. The ATP pool, however, is extremely small and has three sources
of replenishment. Which of the following is NOT a source?
• creatine phosphate
• lactic acid
• glycogen
• cellular respiration
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lactic acid
creatine phosphate + ADP creatine + ATP
glycogen - 2 ATPs
As you complete the seating of a crown, you ask your patient to tap lightly on
the articulating paper. Which of the following statements correctly describes
the physiology responsible for a patient’s light tapping on the articulating
paper?
• the “all or nothing” phenomenon occurs; all fibers in the masseter and medial
pterygoid are partially stimulated, causing a light contraction
• fractionation occurs; each muscle fiber involved is stimulated only by a fraction of
the alpha-motor neurons innervating the fiber, and so the fibers contract lightly
• fractionation occurs; only a few small alpha-motor units are recruited, and the masseter
and medial pterygoid muscles contract lightly
• the”all or nothing” phenomenon occurs; the muscles that close the mouth are stimulated
ful ly but are countered by stimulation of the muscles that open the mouth,
causing a slight closing of the mouth
fractionation; few small motor units recruited
small tension required - small units recruited
greater force needed - larger motor units recruited
neuromuscular jxn - ACh nicotinic
All of the following statements comparing fast and slow-twitch muscle fibers
are true EXCEPT one. Which one is the EXCEPTION?
• fast-twitch fibers are about twice as large in diameter than slow-twitch muscle fibers
• slow-twitch fibers have a greater resistance to fatigue than fast-twitch muscle fibers
• the enzymes of oxidative phosphorylation are considerably more active in slowtwitch
fibers than in fast-twitch fibers
• fast-twitch fibers contain more mitochondria and myoglobin than slow-twitch
muscle fibers
• fast-twitch fibers can deliver extreme amounts of power for a few seconds to a
minute versus slow-twitch fibers
fast-twitch fibers contain more mitochondria and myoglobin than slow-twitch
muscle fibers
this is false
fast mm - rapid powerful actions low oxidative capacity, low resistance to fatigue very anaerobic, not a lot of m/ch extensive SR low myoglobin, high glycogen
slow mm - prolonged
all vv
oxidative capacity related to number of capillaries, myoglobin content and number of m/ch
which mm type is a lot of myoglobin
slow
also very oxidative
fast is anaerobic and glycogen instead
which mm type is glycogen
fast
also very anaerobic and not many m/ch
in which mm more SR
fast
All of the following statements concerning muscle spindles are true
EXCEPT one. Which one is the EXCEPTION?
• they are found within the belly of muscles
• they consist of small, encapsulated intrafusal f ibers and run in parallel with the
main muscle f ibers (extrafusal f ibers)
• the finer the movement required, the smaller the number of muscle spindles in a
muscle
• they detect both static and dynamic changes in muscle length
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• the finer the movement required, the smaller the number
of muscle spindles in a muscle
***This is false; the finer the movement required, the greater the number of muscle
spindles in a muscle.
sensory organs (proprioception) in mm - 1 - muscle spindles (measure length): specialized intrafusal fibers, sensory terminals, motor terminals (gamma); when stretched, activate alpha motor neurons
alpha for skel mm, gamma for spindle
runs parallel with main fibers
2 - Golgi tendon organs - measure mm tension (=contraction); inhibit alpha motor
opposite of spindle
mm spindle senses what
measures length, recruits more alphas by its gamma motor
intrafusal, parallel to main
finer movement - more spindles
When a muscle is ___, the ___ reflex reacts. This reflex is considered
__ , and the result is __ _
• contracted/golgi tendon/monosynaptic/contraction
• stretched/golgi tendon/ disynaptic/ relaxation
• stretched/ stretch/monosynaptic/contraction
• contracted/ stretch/disynaptic/relaxation
• stretched/ stretch/monosynaptic/ relaxation
when mm stretched, stretch reflex
monosynaptic, results in contracion
detected by spindles
like knee jerk
golgi tendon reflex is reverse; disynaptic, results in relaxation
flexor withdrawal reflex (like touching hot stove) - polysynaptic
spindle reflex =
when stretched –> contraction (like knee jerk)
monosynaptic
activates alpha units
tendon reflex =
Golgi tendon organs
when contracted –> relaxation
disynaptic
inhibits alpha units
flexor reflex =
like hot stove
polysynaptic in response to pain
Most reflex arcs have: • three basic elements • four basic elements • f ive basic elements • six basic elements muscles
six
receptor, sensory (afferent), integration center, interneuron, motor (efferent) and effector
spinal reflexes - stretch and tendon reflex
In a single muscle, there are both intrafusal and extrafusal fibers. All of the
following statements are true in the description of intrafusal fibers EXCEPT
one. Which one is the EXCEPTION?
• contain nucl ear bag f ibers that detect fast, dynamic changes
• innervated by gamma-motor neurons
• contain nuclear linking f ibers that transmit afferent signals
• encapsulated in sheaths to form muscle spindles
• contain nuclear chain fibers that detect static changes
• contain nuclear linking fibers that transmit afferent signals
extrafusal fibers - bulk of mm, innerv by efferent alpha neurons
intrafusal - encapsulated, form spindles, innerv by efferent gamma
types: nuclear bag (fast, dynamic changes; fast ia afferents) and nuclear chain (static changes, slow II afferents and Ia too)
no such thing as nuclear linking?
efferents and afferents of intrafusal
intrafusals form spindles, encapsulated
gamma efferents
bag: fast dynamic, Ia afferents
chain: slow, II and Ia afferents
Within the spinal cord, the H-shaped mass of gray matter is divided into
horns, which consist mainly of neuron cell bodies. Cell bodies in the
posterior (dorsal) horn relay:
• voluntary motor impulses
• reflex motor impulses
• sensory impulses
• all of the above
sensory
anterior is motor
Which of the following structures plays a role by associating with the
corticospinal system to control complex patterns of motor activity?
• hypothalamus
• hippocampus
• basal ganglia
• thalamus
basal ganglia
= striatum (caudate + putamen) globus pallidus, substantia nigra and subthalamic nucleus
lateral and around thalamus
dmg - Parkinsons and Huntington’s
thalamus relays sensory
hypothalamus - 4Fs
hippocampis - memory and learning
sensory relay
thalamus
memory and learning
hippocampus
homeostasis and 4Fs
hypothalamus
corticospinal and motor contrrol
basal ganglia
The main structures of the hindbrain include which of the following? Select all that apply. • medulla oblongata • pons • cerebral hemispheres • cerebellum
medulla, pons and cerebellum
medulla - reflexes
pons - respiratory/urinary centers; facial sensation/motor, control of eye mvmt
cerebellum - equiibrium
limbic is in temporal lobe
where is limbic
temporal lobe
pons
respiratory/urinary
eye mvmt
sensory and motor of face
diencephalon =
thalamus and hypothalamus
temporal fxx
hearing, language comprehension, memory storage and recall
memory storage and recall lobe
temporal
frontal fxx
motor, judgment, reasoning, language expression, social behavior
language expression lobe
frontal
social behavior lobe
frontal
judgment lobe
frontal
awareness of body shape lobe
parietal
sensation lobe
parietal
parietal fxx
somatosensory + body image and awareness
For the following questions, use the same answer choices.
1. Which of the following has the thickest layer of muscle?
2. Which of the following is the major regulator of blood flow?
3. Which of the following contain valves?
4. Which of the following are large vessels that contain deoxygenated
blood? Is there an EXCEPTION to this rule?
5. Which has higher compliance, veins or arteries?
• veins
• arteries
• capillaries
• arterioles
• venules
arteries - thickest mm
arterioles - regulator of blood flow
veins - valves, large compliance, carry deoxygenated (except pulmonary)
Which structures are the site of highest resistance in the cardiovascular system? • veins • arteries • arterioles • venules When these structures are acted on by nitric oxide or adenosine, they will: • constrict • dil ate • stay the same This will affect total peripheral resistance in what way? • increase • decrease • stay the same
arterioles
dilate
decrease
a1 adrenergic receptors - arterioles
b2 adrenergic - skel arterioles
b1 - heart mm and kidney
b blockers - antuHTN
b1 adrenergic receptors
heart and kidney
beta bockers are antiHTN
For the following questions, use the same answer choices.
1. Which circuit supplies the alveoli of the lungs?
2. Which circuit supplies the connective tissue of the lungs?
3. Which has a lower blood pressure?
4. Which has a greater volume of blood flow per minute?
5. Which circuit involves the thick-walled left ventricle?
• pulmonary circuit
• systemic circuit
• both
• neither
alveoli supplied by pulmonary connective of lungs by systemic lower pressure in pulmonary circuit greater volume of blood flow per minute in neither LV is from systemic
pulmonary circuit supplies ONLY alveoli
Your patient tells you that he just had a heart bypass operation. He says that
they used a vein from his leg and re-routed blood that previously flowed
through his left anterior descending coronary artery (often referred to as the
widow maker). Which of the following explanations is correct in answering
how a vein can adequately replace an artery?
• although veins have higher compliance normally, when under high pressure, compliance
decreases and so the vein acts very similar to an artery when put in these conditions
• although veins have lower compliance normally, when under the high pressure, compliance
increases and so the vein acts very similar to an artery when put in these conditions
• although veins have higher resistance normally, when under the high pressure, resistance
decreases and so the vein act s very similar to an artery when put in these conditions
• although veins have lower resistance normally, when under high pressure, resistance increases
and so the vein acts very similar to an artery when put in these conditions
although veins have higher compliance normally, when under high
pressure, compliance decreases and so the vein acts very similar to
an artery when put in these conditions
at rest most blood is in systemic veins
compliance can decrease under high pressure, so veins can accomodate
Your patient presents with stage 1 hypertension. His blood pressure is
15O mmHg/99 mmHg, confirming his diagnosis.
l. ls his pulse pressure normal, high, or low?
2. To bring his blood pressure down to normal, he could attempt to do what to the total
peripheral resistance?
• increase it
• decrease it
3. Normally, the mean pressure in the aorta is about 100 mmHg. Eventually, the blood will
return via the vena cava at a pressure of 4 mmHg. Where did the blood pressure decrease
the most as blood traveled through the body?
• large veins
• large arteries
• arterioles
• venules
• capillaries
high
decrease
arterioles
pulse pressure = systolic - diastolic
aorta 100mmHg, arterioles 30mmHg, vena cava 4 mmHg
There are two general causes of extracellular fluid edema:
(1) abnormal leakage of fluid from the plasma to the interstitial spaces
across the capillaries, and (2) failure of the lymphatics to return fluid from
the interstitium back into the blood.
The most common clinical cause of interstitial fluid accumulation is
excessive capillary fluid filtration.
• both statements are true
• both statements are fa lse
• the first statement is true, the second is fa lse
• the first statement is fa lse, the second is true
both true
capillary filtration: increased hydrostatic pressure, decreased plasma colloid
positive net –> filtration; negative net –> absorption back into capillaries
hydrostatic favors filtration, colloid osmotic favors reabsorption
Your patient has just finished her 2-hour appointment and is eager to get
out of the office. She stands up from the chair very fast, and quickly becomes
dizzy and nearly faints. This is termed orthostatic hypotension.
1. Which of the following receptors a re most important in the short-term regul ation of her
blood pressure and returning it to normal?
• stretch receptors in the carotid sinus
• chemoreceptors in the aortic bodies
• chemoreceptors in the carotid bodies
• stretch receptors in the pulmonary circul ation
2. This drop in blood pressure will cause what to happen?
• sympathetic impulses to increase
• parasympathetic impulses to increase
• both to increase
• neither to increase
3. The effect on the heart will be:
• increased heart rate, decreased stroke volume
• increased heart rate, increased stroke volume
• decreased heart rate, decreased stroke volume
• decreased heart rate, increased stroke volume
stretch in carotid (IX)
symp increase
increased HR and SV
It’s 4 o’clock on a Friday afternoon, and you are about to do a quick preparation and
restoration. When you give the injection, the patient complains of severe discomfort. You
realize you forgot to aspirate the needle first, and you have just injected into an artery.
1. Your needle passed through the artery layers in which order?
• tunica adventitia, tunica media, tunica intima
• tunica media, tunica intima, tunica adventitia
• tunica intima, tunica media, tunica adventitia
• tunica adventitia, tunica intima, tunica media
2. Judging by their relative thicknesses, which is the toughest vessel to puncture?
• artery
• vein
• capillary
3. Which layer is thicker: tunica media or tunica adventitia?
4. Which layer is innervated by the autonomic nervous system?
• tunica intima
• tunica media
• tunica adventitia
5. By puncturing this artery, you have hit the vessel with the greatest:
• resistance
• pressure
• cross-sectional area
• blood volume
adventitia-media-intima artery media media pressure
arteries - largest pressure
arterioles - largest resistance
capillaries - largest X-section
veins - largest volume
largest pressure
arteries
largest X-section
capillaries
arteries largest what
pressure
In your practice, you see quite a few HIV/AIDS patients. These patients have a
virus that has the unique ability to:
• produce(+) ssRNA from a(- ) ssRNA molecule
• produce(- ) ssRNA f rom a(+) ssRNA molecule
• produce DNA f rom an mRNA molecule
• produce dsRNA from an ssRNA molecule
DNA from mRNA
reverse transccriptase
retroviruses
AZT - competitive inhibitor of HIV reverse transcriptase
AZT - against what and mechanism of action
inhibitor of HIV reverse transcriptase
Ribosomes are surrounded by a membrane and form a separate cellular compartment.
In bacteria, they are either free-floating in the cytoplasm or attached to the
plasma membrane, and in eukaryotes they are either free floating in the cytoplasm
or bound to the membrane of the endoplasmic reticulum.
• both statements are true
• both statements are fa lse
• the first statement is true, the second is fa lse
• the first statement is fa lse, the second is true
first false, second true
can be attached to plasma membrane in bacteria
Genetic recombination experiments depend heavily upon the action of which enzymes? Select all that apply. • dna l igases • alkaline phosphatase • creatine kinase • restriction endonuclease
ligases and endonucleases
southern blot - for DNA
All of the following statements are true EXCEPT one. Which one is the
EXCEPTION?
• the replication of DNA involves some RNA intermediates
• the replication of DNA involves DNA ligase linking DNA molecules together
• the replication of DNA requires unzipping of the DNA molecule
• the replication of DNA involves the building of the new ssDNA strand f rom 3’ to 5’
• the replication of DNA involves the building of the new ssDNA strand from 3’ to 5’
(5 to 3 is direction of polymerase)
RNA intermediates - primers for polymerase
topoismerases unwind, gyrases coil
RNA polymerase does NOT require a primer
which requires a primer
DNA poly
RNA poly
both
DNA poly requires RNA primer
Okazaki
lagging strand, 5-3 in short pieces, then stritched by ligase
Which of the following enzymes is NOT involved in unwinding, unzipping
and rezipping the DNA molecule during replication?
• topoisomerases
• helicases
• gyrases
• polymerases
polymerases
replication itself
helicases unwind
topoisomerases unwind
gyrases rewind
Which of the following is contained in a nucleoside? Select all that apply. • nitrogen base • phosphate • ribose/deoxyribose sugar • serine • nitrate
N base + sugar
nucleoTide also has phosphate
backbone of nucleic acid - alternating phosphates and pentoses
which has phosphate:
nucleoSide or nucleoTide
Tide
does nucleoside have phosphate
no
does nucleotide have phosphate
yes
Which of the following are the same in RNA and DNA molecules? • the purines • the pyrimidines • both the purines and pyrimidines • neither the purines and pyrimidines
purines
pyrimidine: T in DNA, U in RNA
Which of the following RNA mutations is least likely to have a significant
effect on the product protein?
• the elimination of the third nucleotide of a codon
• the elimination of the first nucleotide of a codon
• a substitution of the third nucleotide of a codon
• a substitution of the first nucleotide of a codon
third substitution (wobble)
initiation: AUG
termination: UAA, UGA, UAG
anticodon - complementary on tRNA; antiparallel!
A sequence of DNA reads “A-T-T-G-C-A:’How many hydrogen bonds would you
expect to see holding this sequence to its complementary strand?
·12
·14
·16
·18
14
A sequence of DNA is "T-A-G-T-A-T-C-A-T". What would the complementary RNA sequence be? • A-T-C-A-T-A-G-T-A • A-U-C-A-U-A-G-U-A • U-T-C-U-T-U-G-T-U • A-G-C-A-U-A-G-T-U
• A-U-C-A-U-A-G-U-A
opposite directions
A+G = T+C
All of the following statements concerning the backbone of DNA are true
EXCEPT one. Which one is the EXCEPTION?
• it is constant throughout the molecule
• it consists of deoxyriboses linked by “phosphodiester bri dges” or “phosphodiester
bonds”
• it is hydrophobic
• it is highly polar
not hydrophobic! - it is hydrophilic
phopshodiester linkages between riboses
Which type of RNA is the least abundant in the cell?
• messenger RNA
• t ransfer RNA
• ribosomal RNA
mRNA
most abundant - rRNA
The activity level of which enzyme controls the rate of glycolysis? • aldolase • phosphoglucose isomerase • phosphofructokinase • triose phosphate isomerase
• phosphofructokinase
irreversible transfer of phosphate from ATP to fructose-6-phosphate
rate limiting
aldolase cleaves 6-C into two 3-Cs
glycolysis: net gain of 2, needs 2 to begin, 4 produced in substance phosphorylation
then either fermentation(anaerobic) or aerobic in m/ch
fluoride inhibits pyruvate synthesis and bacterial acid production
lactate dehydrogenase converts pyruvate to lactate under anaerobic
All of the following are the most useful enzymes for the diagnosis of acute
myocardial infarction EXCEPT one. Which one is the EXCEPTION?
• creatine kinase (CK)
• lactate dehydrogenase (LDH)
• alanine t ransaminase (ALT)
• aspartate t ransaminase (AST)
ALT
ALT+AST - liver CK + LDH + AST - heart lipase and amylase - pancreas CK - mm diseases LDH - pulmonary infarction GGT - biliary
elevated LDH
pulmonary infarction
mm diseases marker
CK
heart markers
LDH, CK, AST
liver markers
ALT and AST
biliary marker
GGT
GGT
biliary marker
LDH
heart and lung
CK
mm and heart
AST
liver and heart
ALT
very liver
All oft he following statements concerning transamination reactions are true
EXCEPT one. Which one is the EXCEPTION?
• these reactions involve the transfer of an amino group from one amino acid to an
a-keto acid
• the enzymes that catalyze these reactions are known as t ransaminases or
aminotransferases
• glutamate and a-ketoglutarate are often involved in these reactions, serving as one
of the amino acid/a-keto acid pairs
• pyridoxal phosphate (PLP), which is derived from vitamin B6 serves as the cofactor
for these reactions
• all amino acids participate in these reactions at some point in their catabolism
• all amino acids participate in these reactions at some point in their catabolism
this is false; serine and threonine never do
transamination involves AA and alpha-keto acid
require pyridoxal phosphate (B6) - can accept/donate amino acid
coenzyme of transamination
pyridoxal phosphate B5 PLP
players in transamination
alphaKG and AA w/ PLP and transaminase
which AAs don’t transaminate
serine and threonine
All of the following are true of oxidative deamination reactions EXCEPT one. Which one is the EXCEPTION? • provide a-ketoacids fo r energy • provide ammonia fo r urea synthesis • occur mainly in the liver and kidney • provide a detoxification mechanism
• provide a detoxification mechanism
deamination (in contrast to transaminases) liberat amino group as free ammonia
eventually goes to urea cycle
especially in liver and kidneys
AA converted to keto acid
Carbonic anhydrases are ___ -containing enzymes that catalyze the
reversible reaction between carbon dioxide hydration and bicarbonate
dehydration.
• manganese
• selenium
• zinc
• mercury
Zinc!
great concentration in erythrocytes
water + CO2 H+ + HCO3-
Which of the following components of the electron transport chain accepts only electrons? • FMN (flavin mononucleotide) • coenzyme Q (ubiquinone) • cytochrome b • oxygen
cytochrome b
cytochromes accept only electrons
other things also accept hydrogen
components of electron transport chain:
FMN (electrons from NADH –> to CoQ;; derived from riboflavin; NAD+ derived from niacin)
coenzyme Q - receives electrons from FMN and FADH2
cytochromes receive from CoQ
oxygen - ultimate acceptor – reduced to water
ultimate electron acceptor in respiratory chain
oxygen –> reduced to water
Which ofthe following is NOT an enzyme classification? • oxidoreductase ·ligase • t ransferase • oxygenase • hydrolase • isomerase
oxygenase - not a class
oxidoreductases transferases hydrolases lyases (break C-O, C-C, C-N) isomerases ligases
Which of the following enzymes is responsible for dissolving blood clots? • prothrombin • thrombin • fibrinogen • plasmin
plasmin aka fibrinolysin - from plasminogen
cleave peptide bond in fibrin
A zymogen is converted to its active enzyme form by which of the following mechanisms? • removal of a peptide fragment • addit ion of a peptide fragment • addit ion of an amino group • removal of an amino group
• removal of a peptide fragment
zymogens - inactive precursors of proteolytic enzymes
Starch molecules are broken down by enzymes known as: • oxygenases • isomerases • peroxidases • amylases
amylases
alpha 1-4?
Your patient’s medical history says that she has von Gierke’s disease. She is
missing the enzyme which converts ____ _
• glucose-6-phosphatase, glucose-6-phosphate to glucose
• glucose-6-phosphatase, glucose-6-phosphate to fructose-6-phosphate
• pyruvate carboxylase, pyruvate to phosphoenolpyruvate
• pyruvate carboxylase, pyruvate to 2-phosphoglycerate
B
• glucose-6-phosphatase, glucose-6-phosphate to glucose
gluconeogenesis rxns: pyruvate –> oxaloacetate –> phosphoenolpyruvate
fructose 1,6 biP –> fru 6 P
glu 6 P –> glucose (no high energy bond)
in glycolysis, glucose –> pyruvate
in gluconeogenesis, pyruvate –> glucose
Km is the substrate concentration at which the enzyme is half-saturated with
its substrate.
Km is also the substrate concentration at which the reaction is half maximal.
• both statements are true
• both statements are fa lse
• the first statement is t rue, the second is fa lse
• the first statement is fa lse, the second is true
both true
Km increases with competitive inhibitor
Vmax is reduced with noncompetitive inhibitor
competitive inhibitor effect
increases Km
noncompetitive inhibitor effect
reduces Vmax
All of the following statements concerning allosteric enzymes are true
EXCEPT one. Which one is the EXCEPTION?
• they frequently catalyze a committed step early in a metabolic pathway
• they often have two or more subunits, each with substrate binding sites that exhibit
cooperativity
• allosteric activators cause the enzyme to bind substrate more readily
• allosteric inhibitors cause the enzyme to bind substrate less readily
• they follow the Michael is-Menton kinetics
• they follow the Michaelis-Menton kinetics
this is false
two active sites with complex cooperativity
site for substrate and site for effector
covalent modifications - most commonly phosphorylation
What is the substrate for glycogen synthesis? • UDP-glucose • TDP-glucose • ADP-glucose • CTP-glucose • GTP-glucose
UDP
glycogen synthase make alpha 1-4 bonds
glucose enters cell
phosphorylated by hexokinase (most tissues) or glucokinase (in liver)
glu 6 P coverted to glu 1 P then to UDP glu (by pyrophosphorylate)
glucokinase
phosphorylates glucose in liver
in most tissues it’s hexokinase
Which of the following best describes an “uncompetitive inhibitor”?
• essentially a noncompetitive inhibitor that can bind only when the substrate is
attached
• essentially a competitive inhibitor that can bind only when the substrate is attached
• a noncompetitive inhibitor that can be overcome by increasing substrate concentration
• an irreversible inhibitor (the two are synonyms)
• essentially a noncompetitive inhibitor that can bind only when
the substrate is attached
has to bind to ES complex, not free enzyme
compare to noncompetitive - do not compete, do not overlap, cannot be overcome by more substrate = allosteric; binds to either free enzyme or ES complex
irreversible - destro something essential; eg COX
A competitive inhibitor of an enzyme: • increases Km without affecting V max • decreases Km without affecting Vmax • increases V max without affecting Km • decreases both Vmax and Km
increases Km without affecting Vmax
at Vmax active sites are saturated
Trypsinogen is activated either by trypsin or by the duodenal enzyme: • endopeptidase • alanine aminotransferase • enteropeptidase • pancreatic lipase
• enteropeptidase
presence of AAs in duodenum stimulates CKK –> causes release of pancreatic zymogens and delivery of bile
trypsinogen activated by trypsin or by enteropeptidase
trypsin activates everything else
Which enzyme is derived from osteoblasts and its serum level rises in bone
conditions with increased osteoblastic activity?
• lactate dehydrogenase
• alanine t ransaminase
• alkaline phosphatase
• acid phosphatase
alkaline phosphatase
acid phosphatase is tumor marker of prostate
Which of the following equations is correct? • haloenzyme +cofactor = cohaloenzyme • apoenzyme+ cofactor = haloenzyme • coenzyme + cofactor = enzyme • coenzyme+ apoenzyme = coapoenzyme
apoenzyme + cofactor = haloenzyme
Fe is cofactor for
cytochrome oxidase, catalase, peroxidase, ferredoxin
Cu is cofactor for
cytochrome oxidase, pyruvate phosphokinase
Zn is cofactor for
carbonic anhydrase, alcohol dehydrogenase
Mg is cofactor for
hexokinase, glu6phosphatase, pyruvate kinase
pyruvate phosphokinase cofactor
Cu
pyruvate kinase cofactor
Mg
Which ofthe following functions as a coenzyme vital to tissue respiration? • pyridoxal phosphate • biocytin • thiamine pyrophosphate • tetrahydrofolate
thiamine (B1) - cofactor for pyruvate dehydrogenase
All of the major anterior pituitary hormones, EXCEPT for growth hormone
exert their principal effects by stimulating target glands such as the
thyroid gland, adrenal cortex, ovaries, testicles and mammary glands.
Growth hormone, in contrast to other hormones, does not function
through a target gland but exerts its effects directly on all or almost all
tissues of the body.
• both statements are true
• both statements are fa lse
• the first statement is t rue, the second is fa lse
• the first statement is fa lse, the second is true
both true
major target is liver
excessive gh –> gigantism (before puberty) or acromegaly (after)
gh raises blood glucose, anabolic and lipolytic
stimulate gh: low blood sugar, low free FA, starvation, stress, exercise, testosteron/estrogen, deep sleep, GHRH
what sugar levels stimulate GH
low
Testosterone and pituitary FSH are required for normal sperm production.
Many cells express the androgen receptor and the FSH receptor.
• both statements are true
• both statements are fa lse
• the fi rst statement is t rue, the second is fa lse
• the fi rst statement is fa lse, the second is t rue
first is true, second is false
only sertoli express androgen and FSH receptor
All of the following hormones use the adenylyl cyclase-cAMP second messenger
system EXCEPT one. Which one is the EXCEPTION?
• adrenocorticotropic hormone (ACTH)
• calcitonin
• glucagon
• somatostatin
• thyroid-releasing hormone
TRH
cAMP hormones: ACTH, Angiotensin II (epithelial), Calcitonin, catecholamines (beta), FSH, glucagon, LH, PTH, TSH, secretin, somatostatin
IP3/Ca hormones: Angiotensin II (vascular smooth mm), catecholamines (alpha), GRH, GHRH, oxytocin, TRH, vasopressin
cAMP hormones
ACTH, angiotensis II (epith), catecholamines (beta), TSH, LH, FSH, glucagon
calcitonin, PTH
secretin, somatostatin
IP3 hormones
angiotensin II (vascular smooth mm), catecholamines (alpha), TRH, GHRH, GRH, oxytocin, vasopressin
Which of the following is the best-known stimuli for increasing the rate of
thyroid-stimulating hormone (TSH) secretion by the anterior pituitary
gland?
• exposure to heat
• exposure to cold
• exposure to stress
• exposure to relaxation
cold
TSH (cAMP) is stimulated by TRH (IP3)
Releasing hormones are synthesized in the: • posterior pituitary • hypothalamus • anterior pituitary • ovary
hypothalamus
ADH is formed primarily in the paraventricular nuclei and oxytocin is formed
primarily in the supraoptic nuclei of the hypothalamus.
ADH and oxytocin are secreted by the posterior pituitary.
• both statements are true
• both statements are fa lse
• the first statement is t rue, the second is fa lse
• the first statement is fa lse, the second is true
first false, second true
ADH primarily supraoptic, oxytocin primarily paraventricular
where is ADH made
supraoptic
where is oxytocin made
paraventricular
All of the following are factors and conditions that decrease insulin secretion EXCEPT one. Which one is the EXCEPTION? • decreased blood glucose • fasting • somatostatin • increased blood f ree fatty acids • alpha-adrenergic activity
• increased blood free fatty acids
stimulate insulin secretion
GLUT4 transporter on cell membrane
Glucagon, a hormone secreted by the alpha cells of the islets of Langerhans
when blood glucose concentration falls, has several functions that are
diametrically opposed to those of insulin.
The most important function of glucagon is to increase the blood glucose
concentration, an effect that is exactly the opposite that of insulin.
• both statements are true
• both statements are fa lse
• the first statement is true, the second is fa lse
• the first statement is fa lse, the second is true
both true
As the acidic stomach contents pass into the small intestine, the low pH
triggers secretion of the hormone ___ into the blood.
• cholecystokinin
• gastric inhibitory peptide
• gastrin
• secretin
secretin
in duodenum in response to acidic contents from stomach
stimulates water and bicarb from pancreatic ducts
CKK in response to fats and AAs, stimulates bile and enzymes
The enterogastric reflex. which is initiated when the duodenum fills with
___ , inhibits the “pyloric pump:’ thereby inhibiting gastric motility and
emptying.
• bicarbonate
• acid chyme
• enkephalins
• water
acid chyme
enterogastrones - small intestine in response to acidity, presence of AAs and presence of free FAs in chyme
inhibit gastric emptying
All of the following statements concerning aldosterone are true EXCEPT one. Which one is the EXCEPTION? • causes Na• retention • causes K• excretion • renin controls it • acts at the distal tubule • is produced in the kidney
• is produced in the kidney
this is false
produced in adrenal cortex (glom zone)
increases resorption of Na and water, increases excretion of K
decreased Na stimulates juxtaglom to secrete renin –> angiotensins –> aldosterone
atrial natriuretic - opposite to aldosterone
Addison’s dz - adrenocortical insufficiency; hypotension, hyperpigmentation, mm weakness, anorexia, hypoglycemia, hyperK acidosis
Oral contraceptives work by:
• inhibiting foll icle formation by eliminating the LH surge
• inhibiting ovulation by eliminating the LH surge
• inhibiting foll icle fo rmation by eliminating the FSH surge
• inhibiting ovulation by eliminating the FSH surge
• inhibiting ovulation by eliminating the LH surge
ovulation - result of estrogen-induced LH surge
About 93% of the metabolically active hormones secreted by the thyroid
gland is thyroxine (T 4), and 7% triiodothyronine (T 3).
T 4 is deiodinated and then T 3 typically binds to the TH receptor.
• both statements are true
• both statements are fa lse
• the first statement is t rue, the second is fa lse
• the first statement is fa lse, the second is true
both true
93% is T4 (thyroxine), but most converted to T3 (more potent, less stable)
increase O consumption and heat production
Catecholamines are synthesized from: • alanine • tyrosine • proline • arginine
tyrosine
pheochromocytoma - excessive CCh
release of epi and NE from medulla stimulated by pregnaglionic ACh from symps
All of the following are affected by epinephrine and/or norepinephrine EXCEPT one. Which one is the EXCEPTION? • blood glucose • total peripheral resistance • heart rate • kidney function
kidney fx
medulla is NC derived
chromaffin cells: 80% epi, 20% NE
Parathyroid hormone causes which of the following to occur? • removal of calcium via the kidney • removal of calcium from bone • removal of calcium via the Gl system • none of the above
removal of Ca from bone
on kidneys: decreases Ca excretion, increases P excretion
in GI: increases Ca absorption –> kidney makes Vit D
no Ca in diet –> increase of PTH and bone resorption
Which of the following hormones' secretion is stimulated by stomach distention? • gastrin • cholecystokinin (CCK) • secretin • gastric inhibitory peptide (GIP) • all of the above
gastrin
stimulates acid secretion and growth of mucosa
hypergastrinemia –> ZES
Which of the following gastrointestinal hormones seems to be the most
potent in causing a moderate increase in insulin secretion?
• gastrin
• gastric inhibitory peptide (GIP)
• cholecystokinin (CCK)
• secretin
GIP
secreted by mucosa of upper small intestine in resonse to FAs and AAs
slows gastric emptying
anticipatory increase of insulin
A tumor of the adrenal gland is causing your patient to conserve sodium in
the renal tubules causing increased blood volume, pressure and edema.
Where is the location of this adenoma?
• zona glomerulosa of the adrenal cortex
• zona fasciculata of the adrenal cortex
• zona reticu laris of the adrenal cortex
• adrenal medulla
zona glomerulosa
Cortisol is the primary glucocorticoid produced by the adrenal cortex gland.
Cortisol’s principal physiological actions include all of the following EXCEPT
one. Which one is the EXCEPTION?
• increase hepatic gluconeogenesis
• increase hepatic glycogenolysis
• increase protein catabolism
• stimulation of fat deposit ion and inhibit ion of lipolysis
• inhibit ACTH secretion (negative feedback mechanism)
• maintenance of blood pressure by sensit izing arteri oles to the action of noradrenaline
• renal excretion
stimulation of fat deposition and inhibition of lipolysis is wrong
Cushing - hypercortisol: centripetal fat, mm wasting and weakness, moon facies
Which of the following is classified as a "stress hormone"? • growth hormone (GH) • thyroid-stimulating hormone (TSH) • adrenocorticotropic hormone (ACTH) • follicle-stimulating hormone (FSH) This hormone stimulates the excretion of: • cortisol • adrenal in • aldosterone • two of the above
ACTH
cortisol
CRH in stress from HT –> ACTH –> cortisol
aldosterone is NOT stimulated by ACTH!
Cortisol (hydrocortisone) has a direct inhibitory effect on which structures? Select all that apply. • adrenal cortex • hypothalamus • anterior pituitary gland • posterior pituitary gland
HT and anterior pituitary
btw also potentiates glucagon and epinephrine
inhibits insulin
The placenta secretes five hormones that are essential to pregnancy. Which of the following is NOT one of them? • oxytocin • progesterone • relaxin • estrogen • human chori onic gonadotropin (hCG) • human placental lactogen (hPL)
oxytocin
chorionic maintains corpus luteum
Somatostatin acts by both endocrine and paracrine pathways to affect its target
cells. A majority of the circulating somatostatin appears to come from the ____
and ___ .
• gallbladder, large intestine
• pancreas, gastrointestinal tract
• stomach, adrenal medulla
• bladder, small intestine
pancreas and GI
inhibits locally in pancreas
inhibits GH
inhibits GI hormones
Prolactin is said to be under “predominant inhibitory control:’ Which ofthe
following explains why?
• In normal conditions, prolactin is constantly synthesized in the anterior pituitary.
Only when prolactin is not needed does the inhibitory mechanism kick in.
• In normal conditions, prolactin inhibitory facto r is produced by the hypothalamus.
Only when prolactin is needed does the hypothalamus stop synthesis and secretion.
• In normal conditions, prolactin is synthesized by the hypothalamus. However, prolactin
inhibitory hormone prevents the secretion unless prolactin is needed.
• In normal conditions, prolactin inhibitory factor is produced by the anterior pituitary.
Only when prolactin is needed does this stop and the ovaries are able to produce
prolactin
In normal conditions, prolactin inhibitory factor is produced by the hypothalamus.
Only when prolactin is needed does the hypothalamus stop synthesis and secretion.
prolactin is lactotrope
dopamine inhibits prolactin
normally large amts of dopamine from HT so prolactin is inhibited
in pregnancy and lactation dopamine is suppressed
what inhibits prolactine and from where
dopamine from HT
Steroid hormones are synthesized by a series of enzymatic modifications of: • triiodothyronine • thyroxine • cholesterol • 5-dihydrotestosterone
cholesterol
androgens: adrenal cortex and gonads
estrogens: adrenal cortex and gonads
progestins: ovaries and placenta
steroids are nonpolar, readily cross membranes to act on intracellular receptors
Calcitonin, a peptide hormone secreted by the thyroid gland, tends to
decrease plasma calcium concentration.
In general, calcitonin has effects opposite to those of parathyroid hormone.
• both statements are true
• both statements are fa lse
• the first statement is t rue, the second is fa lse
• the first statement is fa lse, the second is true
both true
calcitriol stimulated by hypoCa and hypoP
The amount ofT 4 produced and released by the thyroid gland is controlled by which of the following? • hypothalamus • medulla oblongata • parathyroid gland • pituitary gland
pituitary
T hormones and C/ch are derivatives of tyrosine
On his 21st birthday, John celebrates with his first few beers. He notices
(along with other symptoms of inebriation) that he has an increased need to
urinate. This is physiologically caused by a decrease in production of:
• oxytocin
• antidiuretic hormone (ADH)
• parathyroid hormone (PTH)
• aldosterone
ADH
ethanol and caffeine decrease ADH
nicotine increases ADH
sweating increases ADH, drinking a lot decreases ADH
hypoADH or hypoactivity of posterior pituitary - diabetes insipidus (polyuria, polydipsia, polyphagia)
diabetes insipidus
hypoADH
polyuria, polyphagia, polydipsia
Polypeptide and protein hormones are stored in secretory vesicles until needed.
Steroid hormones are usually synthesized from cholesterol and are not stored.
• both statements are true
• both statements are fa lse
• the first statement is t rue, the second is fa lse
• the first statement is fa lse, the second is true
both true
All cells have a resting potential.
During the upstroke of the action potential, the cell repolarizes, or becomes
Jess positive.
• both statements are true
• both statements are fa lse
• the first statement is t rue, the second is fa lse
• the first statement is fa lse, the second is true
first is true, second is false
resting potential about -70
depol - opens Na, threshold about -50, then depol up to +55
all or none
typical resting potential
-70
All of the following statements are true EXCEPT one. Which one is the
EXCEPTION?
• peripheral nerve f ibers can sometimes regenerate if the soma (cell body) is not
damaged and some of the neurilemma remains intact
• the neurilemma forms a regeneration tube through which the growing axon
reestablishes its original connection
• if the nerve originally led to a skeletal muscl e, the muscle atrophies in the absence
of innervation but regrows when the connection is re-established
• nerve fibers of the CNS (brain and spinal cord) possess the thickest neurilemma
115
nerve fibers of the CNS (brain and spinal cord)
possess the thickest neurilemma
this is false
no neurilemma in CNS –> that’s why no regenration
neurilemma is sheath of Schwann
lesions of spinal cord: ipsi los of motor, contra loss of pain and temperature
lesions of spinal cord: ipsi vs contra
ipsi motor, contra pain and temperature
what is neurilemma
Schwann
enables regenration in PNS
The primary action of local anesthetics in producing a conduction
block is to decrease the permeability of the ion channels to:
• calcium ions
• chloride ions
• potassium ions
• sodium ions
116
Na
small myelinated fibers of pain and temperature are anesthesized first; then touch, proprioception and mm tone
lateral spinothalamic
contralateral pain and temperature
spinocerebellar
unconscious kinesthesia
fasciculi gracilis and cuneatus
= middle lemniscus
discriminating touch and pressure
anterior spinothalamic
crude touch and pressure
crude touch and pressure
anterior spinothalamic
contralateral pain and temperature
lateral spinothalamic
unconscious kinesthesia
anterior and posterior spinocerebellar
discriminating touch and pressure
middle lemniscus - fasciculi gracilis and cuneatus –> to medulla –> via thalamus to somatosensory in parietal
Spatial summation occurs when:
• two inhibitory inputs arrive at a postsynaptic neuron within 1 minute of each other
• two excitatory inputs arrive at a postsynaptic neuron simultaneously
• two inhibitory inputs arrive at a postsynaptic neuron 10 seconds apart
• two excitatory inputs arrive at a postsynaptic neuron in rapid succession
• two excitatory inputs arrive at a postsynaptic neuron simultaneously
temporal - when rapid succession
Saltatory conduction happens in myelinated neurons only. Which of the following are effects of saltatory conduction compared to conventional conduction? Select all that apply. • conduction is faster • conduction is slower • conduction is at the same rate • conduction consumes more energy • conduction consumes less energy • conduction consumes the same energy
conduction is faster and consumes less energy
nodes of Ranvier, less energy to reestablish resting gradients
larger diameter - faster conduction
In most instances, acetylcholine has an inhibitory effect.
GABA is believed always to cause inhibition.
• both statements are t rue
• both statements are fa lse
• the first statement is true, the second is fa lse
• the first statement is false, the second is true
first is false, second is true
glycine also always inhibitory
A patient of yours presents with symptoms similar to Parkinson’s disease. He
claims that the physicians have not diagnosed him with Parkinson’s because
it was due to trauma. The trauma affected which part of his brain?
• pons
• pari etal lobe
• basal ganglia
• thalamus
basal ganglia
dopamine
motor control
basal ganglia are extrapyramidal
The two classes of acetylcholine receptors in autonomic ganglia are: • nicotinic and alpha • alpha and beta • nicotinic and muscari nic • muscarinic and beta
muscarinic and nicotinic
nicotinic - neuromuscular jxns and medulla
also all synapses between pre and postganglionic
fast EPSP
blocked by hexamethonium and curare
muscarinic -
postganglionic - all parasymp, some symp
slow EPSP, blocked by atropine
parasymp flow
pregangl to gangl is nicotinic ACh, target is musc ACh
symp flow
pregangl to gangl is nicotinic ACh, target mostly NE except sweats and medulla which are musc ACh
Motor signals are transmitted directly from the cortex to the spinal cord
through the corticospinal tract and indirectly through multiple accessory
pathways that involve the basal ganglia, cerebellum and various nuclei of
the brain stem.
The most important output pathway from the motor cortex is the corticospinal
tract, also called the pyramidal tract.
• both statements are t rue
• both statements are fa lse
• the first statement is true, the second is fa lse
• the first statement is false, the second is true
both true
desc pathways:
lateral (for limbs) = lateral corticospinal + corticobulbar; contralateral
and medial:
ventral corticospinal, lateral and medial vestibulospinal, reticulospinal and tectospinal (head and posture)
all mostly posture
The effectors of the autonomic nervous system include all of the following EXCEPT one. Which one is the EXCEPTION? • smooth muscle • cardiac muscle • glands • skeletal muscle
skel mm
The action potential is generated by the rapid opening and subsequent
voltage inactivation of voltage-dependent __ channels and the delayed
opening and closing of voltage-dependent __ channels.
Na, K
A patient of yours lists a selective 13-blocker in her medication list. You know
that this is for her hypertension. What is the mechanism of this drug?
• blocks 131-adrenergic receptors in the heart, causing a decrease in heart rate and
force of contraction
• blocks 132-cholinergic receptors in the heart, causing a decrease in heart rate and
force of contraction
• blocks 131-cholinergic receptors in the heart, causing a decrease in heart rate and
force of contraction
• blocks 132-adrenergic receptors in the heart, causing a decrease in heart rate and
force of contraction
blocks b1-adrenergic receptors in the heart, causing a decrease in heart rate and
force of contraction
b2 - smooth mm and liver
a1 - postsynaptic symps vascular constriction
a2 - presynaptic symps, inhibit NE
NE mostly alpha
epi both
NE effects
mostly alpha
1 - postsynaptic vessel constriction
2 - presynaptic NE inhibition
Epi effects
both alpha and beta
a1 - postsynaptic smooth mm vessel constriction
a2 - presynaptic NE inhibits
b1 - heart
b2 - smooth mm and liver
All cells, including neurons, have a resting membrane potential that is
typically around (-)70mV.
An action potential is propagated with the same shape and size along the
entire length ofthe axon.
• both statements are t rue
• both statements are fa lse
• the first statement is true, the second is fa lse
• the first statement is false, the second is true
127
both true
Exteroreceptors signal internal events.
Sensory receptors can be classified in terms of the types of energy that they
transduce or according to the sources of the input.
• both statements are true
• both statements are false
• the first statement is true, the second statement is false
• the first statement is fa lse, the second statement is true
first false, second true
When scaling and root planing, you are using a firm finger rest for minutes at
a time.
1. Which of the following are the receptors that are used in sensing this
continuous pressure?
2. Which of the following are the receptors used when you are manipulating
an instrument in your fingers?
• pacinian corpuscles
• meissner’s corpuscles
• ruffini’s corpuscles
• krause’s corpuscles
Ruffini
Pacinian
Meissner: epidermis; light pressure, low vibration
Krause: mucosa; touch, low vibration, cold
Ruffini: dermis; crude touch, heat
Pacinian: deep pressure, high vibration, stretch
crude touch receptor and where
Ruffini in dermis
pressure and high vibration and what else
Pacinian in dermis + stretch
touch and cold and where and what else
Krause mucosa, low vibrations
discriminating touch and where and what else
Meissner, epidermis, low vibrations
meissner
discriminating touch, low vibr
krause
mucosa cold, low vibr
ruffini
heat, crude touch
pacinian
deep pressure, high vibr, stretch
The primary functional unit of the sympathetic and parasympathetic nervous systems is the: • one-neuron motor pathway • two-neuron motor pathway • three-neuron motor pathway • four-neuron motor pathway I
two
All preganglionic neurons are \_\_\_ in both the sympathetic and the parasympathetic nervous systems. • dopaminergic • serotonergic • cholinergic • adrenergic
cholinergic, nicotine
Nerves connect with muscles at the ____. There, the ends of nerve
fibers connect to special sites on the muscle’s membrane called ____ _
These plates contain receptors that enable the muscle to respond to _______
• gap junction, motor end plates, norepinephrine
• mucocutaneous junction, visceral end plates, epinephrine
• neuromuscular junction, motor end plates, acetylcholine
• neuromuscular junction, sensory end plates, norepinephrine
neuromuscular jxn
motor end plates
ACh
end plate potential at junction generates current in adjacent mm
The entry of which of the following into the presynaptic terminal
triggers the release of neurotransmitter?
• sodium
• potassium
• chloride
• calcium
Ca
Strictly speaking, the all-or-none principle refers to the: • strength of muscle contraction • resting potential • action potential • excitatory postsynaptic potential
action potential
Tracts descending to the spinal cord are concerned with voluntary motor
function, muscle tone, reflexes, equilibrium, visceral innervation and
modulation of ascending sensory signals. The largest and most important
of these tracts that controls skilled voluntary movement is the:
• rubrospinal tract
• vestibulospinal t ract
• reticulospinal tract
• corticospinal tract
corticospinal
There are two major groups of descending tracts from the brain: the corticospinal,
or pyramidal tracts, and the extrapyramidal tracts.
The pyramidal tracts descend directly without synaptic interruption, from the
cerebral cortex to the spinal cord.
• both statements are true
• both statements are false
• the first statement is t rue, the second is false
• the f irst statement is false, t he second is t rue
both true
Which of the following characteristics is shared by simple and facilitated
diffusion of glucose?
• it is saturable
• requires metabolic energy
• occurs down an electrochemical gradient
• require a Na• gradient
occurs down the gradient
transporters: Glut1: glucose into RBCs Glut2: glu to liver and pancreas Glut3: neurons Glut4: mm and adipose, regulated by insulin Glut5: fructose in intestine and testes
glut1
rbcs
glut2
liver and pancreas
glut3
neurons
glut4
mm and ADIPOSE, regulated by insulin
glut5
fru in GI and testes
RBCs glucose
glut1
mm and adipose glucose
glut4, insulin control
fructose and where
glut 5, GI and testes
liver and pancreas
glut2
neurons
glut3
Which of the following patients has the least chance of edema formation?
• a patient with inflammation
• a patient who is standing
• a patient with venous constriction
• a patient with arteri olar constriction
arteriolar constriction
isotonic solution
no osmosis
0.9% NaCl or 5%glucose
hypotonic solution
osmosis into cell
swell and lyse
hypertonic solution
osmosis out of cell
shrink
Which of the following is NOT an oncogene? • HER-2/neu • ras •myc • src ·CAAT
CAAT - binding for RNA transcription factors
HER2/neu - growth factor receptor - breast cancers
ras - signal transduction
myc - transcription factor, Burkitt’s lymphoma
src - tyrosine kinase
HER2/neu
growth factor receptor, breast cancer
ras
signal transduction
myc
transcription factor
Burkitt
src
tyrosine kinase
The organic part of bone matrix is mainly composed of type Ill collagen.
The collagen fibers provide bone with great tensile strength, while the
inorganic salts allow bone to withstand compression.
• both statements are true
• both statements are false
• the f irst statement is t rue, the second is false
• the f irst statement is fa lse, the second is t rue
141
first is wrong
second true?
organic ECM mostly type I
All of the following bonds are considered to be weak bonds EXCEPT one. Which one is the EXCEPTION? • hydrogen bonds • ionic bonds • covalent bonds • van der Waal s forces Weak bonds are involved in all of the following EXCEPT one. Which one is the EXCEPTION? • secondary structure of proteins • cell membrane • dsDNA structure • amino acid linkage
covalent is not weak
AA linkage
The pitch of a sound is related mainly to which of the following characteristics of a sound wave? • amplitude of the sound wave • frequency of the sound wave • superimposed wave • secondary waves •length of the sound wave 143
frequency (Hz)
loudness - amplitude (dB)
timbre - superimpositions
The major intracellular cation is: • sodium • potassium • magnesium • chromium
K
ICF - K
ECF - Na
60-40-20 rule:
60% of body wt is water
40% is ICF
20% is ECF
The temperature of the body is regulated by neural feedback mechanisms
that operate primarily through the hypothalamus.
Shivering is the most potent mechanism for increasing heat production.
• both statements are true
• both statements are false
• the f irst statement is t rue, the second is false
• the f irst statement is fa lse, the second is t rue
both true
Which of the following solutions has an osmotic pressure different from the
other two solutions?
• 1M glucose
• 1M sodium chloride
• 1M potassium chloride
• they all have the same osmotic pressure
glucose
osmotic pressure depends on number of solute particles present
tonicity depends on impermeable parts
Which of the following statements concerning the two principal laws of
thermodynamics is FALSE?
Select all that apply.
• they apply only to closed systems, that is, entities within which there can be no
loss of energy or of mass
• the f irst law says that the total quantity of energy in the universe remains
constant (this is the principle of the conservation of energy)
• the second law states that the quality of this energy is degraded irreversibly
(this is the principle of the degradation of energy)
• the second law, known as Carnot’s principle, is controlled by the concept of
entropy
• the two laws describe the concept that Delta G is positive in an exergonic
reaction
• the two laws describe the concept that Delta G is
positive in an exergonic reaction
first law - conservation in closed system
second law - heat dissipartion and entropyy
exergonic rxns - delta G is negative, heat lost
Isotopes of an element:
• have different chemical properties but t he same weights
• have the same chemical properties but different weights
• have different chemical properties and weights
• have the same chemical properties and weights
miscellaneous
same properties but different weights
same atomic number
isotopes - # of neutrons
mass = protons + neutrons
number = protons
Growth and preparation of the chromosomes for replication occurs in
which phase of the cell cycle?
G1
G1 - growth and preparation for replication
S - synthesis of DNA and centromeres
G2 - preparation for mitosis
M - mitosis
Which class of antibody is the first antibody to appear in the circulation after antigen stimulation? •lgA •lgD •lgE •lgG •lgM
IgM
filtered and fully reabsorbed
glucose
filtered and secreted and released in first pass
PAH
freely filtered, not secreted and not reabsorbed
inulin, for GFR testing
The thick ascending limb of the loop of Henle is called the “diluting
segment” because:
• sodium chloride (NaCI) is reabsorbed with a proport ional amount of water
• water is reabsorbed f rom the tubular lumen
• water is secreted into the tubular lumen
• sodium chloride (NaCI) is reabsorbed without water
• sodium chloride (NaCI) is reabsorbed and water is secreted
I
• sodium chloride (NaCI) is reabsorbed without water
proximal tubule: fluid reabsorbed
loop of Henle: desc is permeable to water but not salts; asc is impermeable to water but permeblae to salts - salts reabs, water stays
distal: ion exchange
most reabsorption in kidney
proximal tubule
