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69 Cards in this Set
- Front
- Back
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The reason that our cells have a membrane potential is:
a. the sodium/potassium pump creates it b. proteins are primarily present in intracellular fluid c. calcium permeability for the cell membrane is low d. the absence of electrogenic pumps in the cell membrane e. the osmotic imbalance between intra- and extracellular fluids |
B
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Which has the lowest intracellular concentration?
a. K b. Na c. Ca d. Cl e. PO4 |
C
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Na/K ATPase is an example of:
a. An ATP-dependent pump b. An electrogenic pump c. Antiport d. All of above e. A and B, but not C |
D
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Bone receives about 5% of cardiac output.
This is less extensive than for cartilage. Are these T or F? |
True
False |
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Which of the following cells does NOT depend on bone marrow for production of that cell type?
a. Osteoblasts b. Osteoclasts c. Erythrocytes d. Lymphocytes e. Platelets |
A
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Peak body bone mass occurs around age
a. 13 b. 18 c. 25 d. 40 e. 50 |
C
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The Gemini study linked ________ to demineralization of bone.
a. flight b. increased age c. low gravity d. low activity (exercise) e. osteocyte antagonists (inhibitors) |
D
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Bone "remodeling"
a. occurs throughout our life b. is the balance between bone synthesis and resorption c. is greatest in cancellous bone d. is greater in children than in adults e. all of the above |
E
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A plasma calcium concentration of 4 mM
a. is referred to as hypocalcemia b. would tend to promote bone resorption c. is most likely to be seen just before eating a meal d. would likely result in calcium phosphate precipitation e. is used in the treatment of stroke |
D
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Most dietary calcium ends up in
a. the feces b. the urine c. extracellular fluid d. muscle e. bone |
A
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Most of the phosphate in our body is found in
a. mitochondria b. sarcoplasmic reticulum c. bone d. extracellular fluid e. ATP |
C
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Collagen is present in bone to provide
a. compressive strength b. tensile strength c. elastic strength d. a permanent matrix for calcification e. cytoskeletal structure for osteoblasts |
B
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Which of the following hormones promotes bone growth by inhibiting resorption?
a. growth hormone b. thyroid hormone c. cortisol d. estrogen e. insulin |
D
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Which of the following is implicated as a local signal in producing bone loss with periodontal disease?
a. prostaglandin E b. interleukin 1 c. TNF alpha d. integrin e. fibroblast growth factor 2 |
A
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The covalent crosslinks between collagen fibrils are fromed by the enzyme
a. prolyl hydroxylase b. lysyl oxidase c. collagenase d. carbonic anhydrase e. thrombin |
B
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Which of the following agents would NOT cause spastic paralysis?
a. carbachol b. curare c. physostigmine d. nerve gas e. methacholine |
B
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Increasing the load prior to an isotonic twitch
a. decreases delay, decreases distance moved, and increases velocity of shortening b. increases delay, decreases distance moved, and increases velocity of shortening c. decreases delay, increases distance moved, and decreases velocity of shortening d. increases delay, decreases distance moved, and decreases velocity of shortening e. increases delay, increases distance moved, and decreases velocity of shortening |
D
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Which of the following would you NOT expect to be characteristic of muscle fibers in antigravity muscles?
a. many mitochondria b. myoglobin c. high glycogen d. slow myosin ATPase e. all of the above would be expected |
C
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Muscle fatigue and rigor mortis share what characteristics?
a. lack of stimulation b. low ATP levels c. low intracellular free calcium d. inhibition of crossbridge formation e. all of the above |
B
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Summation of muscle twitch tension is possible even though muscle action potentials cannot summate because
a. calcium remains elevated longer than the duration of the muscle action potential b. the series elastic element maintains tension longer than the muscle AP c. myosin ATPase activity remains activated when calcium is gone d. as sarcomeres shorten, their strength of contraction becomes greater e. recruitment, using asynchronous activation, occurs in the muscle fiber |
A
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Which is NOT a difference between skeletal and smooth muscle?
a. breadth of length-tension relationship b. maximal tension that can be developed c. presence of troponin d. inhibition of contraction by NE e. presence of slow waves |
B
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Activation of mysoin light-chain kinase
a. participates in skeletal muscle regulation of contraction b. results in inhibition of myosin ATPase c. would tend to increase the strenght of contraction of smooth muscle d. is inhibited by calcium unbinding from calmodulin e. occurs when troponin binds to calcium |
D
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Which is NOT a component of thin filaments?
a. G-actin b. tropomyosin c. troponin C d. ADP e. all of the above are found in thin filaments |
E
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Which of the following occurs immediately following the "Power Stroke"?
a. ATP binds to myosin b. ADP binds to myosin c. ADP unbinds from actin d. ATP is hydrolyzed by myosin e. ATP is hydrolyzed by actin |
A
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Transmission at the neuromuscular junction is primarily terminated by
a. washout b. high-affinity reuptake of ACh c. high-affinity reuptake of choline d. catabolism by ACh esterase e. catabolism by choline acetyl transferase |
D
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Crossbridging occurs within the
a. Z disc b. I band c. H zone d. A band e. M line |
D
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In skeletal muscle, calcium binds to
a. tropomyosin b. myosin phosphorylase c. calmodulin d. troponin C e. troponin I |
D
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In comparison to adults, calcium turnover in children's bones
a. is greater b. is less c. occurs primarily in the ends of long bones d. occurs primarily in cortical bone e. does not involve phosphate |
A
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Increased activity during childhood would tend to
a. increase bone length b. increase bone thickness c. increase bone calcium d. all of the above e. A & B, but not C |
D
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The majority of daily dietary calcium
a. is incorporated into bone b. is lost in the feces c. is lost in the urine d. is trapped in the rapidly exchangeable pool e. remains in exracellular fluid |
B
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Osteoblasts decrease the chance of exceeding solubility product inside the cell by
a. forming phosphate esters b. pumping calcium into the osteoid c. activating alkaline phosphatase d. all of the above e. A & B, but not C |
E
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A protein found in both osteoblasts and osteoclasts is
a. alkaline phosphatase b. acid phosphatase c. carbonic anhydrase d. collagenase e. all of the above are found in both |
C
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Which of the following is FALSE?
a. the H zone decreases during contraction b. the I band decreases during contraction c. the A band decreases during contraction d. thin filament length remains constant during contraction e. thick filament length stays constant during contraction |
C
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Which of the following would NOT be found in thin filaments?
a. F-actin b. tropomyosin c. troponin C d. light chain myosin e. ADP |
D
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In the sliding filament theory, ATP is used to
a. break existing crossbridges b. 'cock' the myosin heads c. act as a binding site on thin filaments d. all of the above e. A and B, but not C |
E
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A motor unit is
a. a single muscle cell and the neurons which innervate it b. a single neuron and the muscle cells that it innervates c. the area of the skeletal muscle cell membrane at the synapse d. the group of muscle cells contracting during a muscle twitch e. the cortical neurons responsible for coordinating a movement |
B
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Which of the following is most likely to result if calsequestrin is destroyed in a muscle cell?
a. increased muscle tone b. decreased contractile strength c. increased frequency of muscle action potentials d. destruction of t-tubules e. flaccid paralysis |
A
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Twitch tension exists after active contraction because of the presence of
a. ATP b. the series elastic element c. action potential reverberation d. slow resequestration of calcium by the sarcoplasmic reticulum e. muscle being maintained at optimal length |
B
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Which type of muscle is characterized by large fiber size, no pacemaker potentials and fatigues easily?
a. fast twitch skeletal b. slow twitch skeletal c. single unit smooth d. multi-unit smooth e. cardiac |
A
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Smooth muscle contraction is regulated by
a. calcium binding to troponin b. release of calcium from the sarcoplasmic reticulum c. phosphorylation of myosin by myosin light chain kinase d. calmodulin activation of myosin phosphatase e. all of the above are parts of one mechanism |
C
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Which of the following is NOT seen to stimulate smooth muscle contraction?
a. ACh b. NE c. stretch d. depolarization of slow wave potentials e. all of the above can stimulate smooth muscle contraction |
E
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Which muscle type is maintained below the peak of the length-tension curve?
a. fast twitch skeletal b. multi-unit smooth c. cardiac d. single-unit smooth e. all of the above are maintained at Lo |
C
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All of the following are true of ALL surface epithelia EXCEPT
a. they are avascular b. they rest on a basement membrane c. they consist of multiple layers d. they consist of closely packed cells with little intercellular material e. their cells are held together mainly by desmosomes |
C
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Scar formation is carried out by
a. fibroblasts b. mast cells c. basement membranes d. foreign body giant cells e. macrophages |
A
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Which of the following are implicated in scar contraction?
a. monocytes b. myofibroblasts c. monocytes d. foreign body giant cells e. neutrophils |
B
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Viewed in the electron microscope, a transverse section through a skeletal muscle fiber that shows a mixture of thick and thin filaments must pass through the
a. Z-line b. A-band c. I-band d. H-band e. M-line |
B
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Skeletal muscle fibers
a. originate in embryos by fusion of myofibroblasts b. shorten by twisting c. are joined to adjacent fibers by intercalated disks d. have peripheral nuclei e. contract when they are activated by neurotransmitters diffusing through the sarcolemma |
D
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A lack of Vitamin D would
a. cause bones to become thicker b. cause bones to store more calcium c. decrease the weight-bearing ability of long bones d. increase the length of bones in the extremities e. have no effect on bone |
C
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Which of the following are multinucleated?
1. purkinje cell 2. osteoblast 3. cardiac muscle cell 4. osteoclast 5. skeletal muscle fiber |
4 and 5
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Twisted nuclei are a diagnostic feature of
a. contracted cardiac muscle b. contracted smooth muscle c. contracted skeletal muscle d. osteoclasts e. motor neurons |
B
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During contraction of a skeletal muscle fiber, all of the following occur EXCEPT:
a. the sarcomeres become narrower b. the A-bands become narrower c. the I-bands become narrower d. the H-bands disappear e. bridges are formed between thick and thin filaments |
B
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All of the following cell types utilize lysosomes to carry out their specialized function EXCEPT
a. osteoclasts b. kupffer cells c. paneth cells d. chief cells e. microglia |
A
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All of the following are present in relation to cardiac muscle fibers EXCEPT
a. central nuclei b. intercalated disks c. branching fibers d. sarcomeres e. satellite cells |
E
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Action potentials in skeletal muscle fibers reach deeply situated myofibrils via
a. Z-disks b. T-tubules c. intercalated disks d. sarcoplasmic reticulum e. M-lines |
B
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Which acts as an ATPase during contraction of a muscle?
a. actin b. heavy meromyosin c. light meromyosin d. tropomyosin e. calcium ions |
B
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Endochondral bone formation begins with the formation of
a. a fibrous connective tissue model b. a membranous model c. a cartilaginous model d. a calcified model e. no model at all, just the presence of osteoblasts |
C
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How would increasing the proportion of organic molecules to inorganic components in the bony matrix affect the physical characteristics of bone?
a. the bone would contain more reticular fibers b. the bones would be stronger c. the bones would be more brittle d. the bones would have greater weight-bearing capacity e. the bones would be more flexible |
C
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The sarcoplasmic reticulum stores
a. oxygen b. glycogen c. ATP d. calcium ions e. glucose |
D
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Regeneration of skeletal muscle is accomplished by
a. differentiation of satellite cells b. division of muscle fibers c. hypertrophy of myofibrils d. increase in size of endomysium e. insertion of additional intercalated disks |
A
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Heavy meromyosin is located only in
a. I band b. A band c. Z disk d. intercalated disk e. H band |
B
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In an electron microscope, a transverse section through a skeletal muscle fiber that shows only thin filaments must be through the
a. I band b. A band c. H band d. M line e. Z disk |
A
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A wave of depolarization (action potential) is conveyed to myofibrils in the interior of cardiac muscle fibers by means of
a. gap junctions b. elements of sarcoplasmic reticulum c. T-tubules d. Z disks e. mitochondria |
C
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In almost all cases, skin is designated as thin when it
a. has a relatively thin stratum corneum b. includes hair follicles c. has associated eccrine sweat glands d. lacks melanocytes e. lacks hemidesmosomes |
A or B
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Which of the following cells perform an immunological function in the epidermis?
a. keratinocytes b. Langerhans cells c. melanocytes d. monocytes e. lymphocytes |
B
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All of the following are present in BOTH thick and thin skin EXCEPT
a. keratin b. melanosomes c. capillaries d. stratum corneum e. desmosomes |
B
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Tetany is the result of
a. infection with Clostridium tetani b. a defect in the pars nervosa c. a lack of calcitonin d. a deficiency of parathyroid hormone e. a deficiency of glucocorticoids |
C
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When the arrector pili muscles contract
a. goose bumps are formed b. hairs are shed c. sweat is released from sweat glands d. shivering occurs e. the skin changes color |
A
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An albino person lacks
a. keratin b. carotene c. melanocytes d. tyrosinase e. MSH |
D
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Thyrocalcitonin
a. counteracts the effects of thyroid hormone b. counteracts the effects of parathyroid hormone c. is formed by iodination of colloid d. affects osteoclasts e. maintains the epiphyseal plate in long bones |
B
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