Physiology Old Exams

Front 1

High surface tension and capillary action are due to which property of water?

Back 1

water molecules are cohesive and adhesive

Front 2

the smallest living units capable of carrying out their own basic life functions sometimes even outside the body are called:

Back 2

cells

Front 3

what type of gland secretes products into ducts leading to the external environment

Back 3

exocrine glands

Front 4

which of the following descriptions INCORRECTLY describes the tissue type

Back 4

connective tissue is specialized for exchange between the internal and external environments

Front 5

order of complexity for the components of the body, from least to most complex

Back 5

cells, tissues, organs, organ systems

Front 6

homeostasis is a term which describes the process whereby the body:

Back 6

maintains a constant internal environment

Front 7

extracellular fluid is composed of

Back 7

interstitial fluid and plasma

Front 8

total body water is composed of

Back 8

intracellular and extracellular fluid

Front 9

the plasma membrane typically contains

Back 9

phospholipids, ion channels, glycoproteins

Front 10

referring to a membrane as 'selectively permeable' describes its ability to

Back 10

restrict the movement of particular molecules across a membrane

Front 11

what is the primary mechanism for maintaining homeostasis

Back 11

negative feedback

Front 12

an example of negative feedback

Back 12

when a person stands up, blood pressure decreases due to blood pooling in feet and legs. the heart and blood vessels respond in such a way as to bring blood pressure back toward normal.

Front 13

thermo-receptors act as the ____ in the thermoregulatory feedback loop

Back 13

sensor

Front 14

animals whose body temperature changes with environmental temperatures, thereby not maintaining strict thermal homeostasis, are called

Back 14

poikilotherms

Front 15

when a person walks outside into a colder environment that is still within the thermoneutral zone, which mechanism helps maintain normal body temperature?

Back 15

blood flow to the face and hands decreases

Front 16

It is often said that 'the rich get richer' (and presumably, the richer get even richer). This would be an example of...

Back 16

positive feedback

Front 17

glycogen is an example of a

Back 17

polysaccharide

Front 18

____ are lipids that form the core structure of cell membranes.

Back 18

phospholipids

Front 19

the ultimate cause of the increase in body temperature associated with an infection (fever) is a...

Back 19

pyrogen-induced upward movement of the set point

Front 20

hydrogen bonding links together

Back 20

molecules of water

Front 21

cholesterol is...

Back 21

a lipid, a steroid, and a component of cell membranes

Front 22

____ is an example of a disaccharide.

Back 22

sucrose

Front 23

when an mRNA is transcribed from a single strand of DNA (3' to 5': ACAGAGTGACAGAAC) after the uncoiling of the double strands, what is the produced mRNA sequence?

Back 23

UGUCUCACUGUCUUG

Front 24

What chemical groups will be found in a phospholipid?

Back 24

fatty acid, phosphate, glycerol

Front 25

_____ are lipid molecules composed of a glycerol and three fatty acids.

Back 25

triglycerides

Front 26

A fatty acid that contains three double bonds in its carbon chain is said to be a ____ fatty acid.

Back 26

polyunsaturated

Front 27

The amphipathic property of phospholipids can be described as...

Back 27

a polar region that dissolves in water and a nonpolar region that face one another

Front 28

Alpha-helices and beta-pleated sheets are examples of ____ structure of a protein.

Back 28

secondary

Front 29

____ are molecules that are composed of one or more phophate groups, a 5-carbon sugar, and a nitrogenous base.

Back 29

nucleotides

Front 30

Examples of polymers:

Back 30

glycogen, nucleic acid, protein

Front 31

What is an INCORRECT description of a polymer?

Back 31

ATP is a polymer of phosphates

Front 32

Which substance contains the most trans fatty acids in the fatty acid parts of the fats?

Back 32

partially hydrogenated oil

Front 33

Trans fats are viewed as having a worse effect on human health than animal fats (saturated) because...

Back 33

they decrease HDL and increase LDL

Front 34

The process whereby a complementary mRNA is produced from a DNA template is called...

Back 34

transcription

Front 35

Translation:

Back 35

is the formation of proteins from mRNA

Front 36

Enzymes act as ___ to increase reaction rate.

Back 36

catalysts

Front 37

Enzymes are what class of molecule?

Back 37

proteins

Front 38

In the induced-fit model for enzyme activity, the substrate alters the ____ of the ____ site on the enzyme.

Back 38

conformation; active

Front 39

What would increase the rate of an enzyme-catalyzed reaction?

Back 39

increasing the affinity of the enzyme for its substrate,

increasing the concentrationi of the enzyme,

increasing the concentration of substrate

Front 40

Km (Michaelis-Menten constant) is defined as:

Back 40

the substrate concentration at which the reaction rate is half its maximal value

Front 41

What is true about Km?

Back 41

a high Km indicates weak binding between an enzyme and its substrate

Front 42

In the reversible inhibition of enzyme-catalyzed reaction, which of the following indicates a competitive inhibition?

Back 42

the inhibitor binds to the active site of the enzyme; it can be reversed by an increase in a substrate concentration,

the inhibitor does not change Vmax but increases Km

Front 43

An enzyme that catalyzes a particular chemical reaction decreases the...

Back 43

activation energy

Front 44

What does not directly determine the rate at which an ion will move passively across a membrane?

Back 44

amount of ATP available

Front 45

A particular type of molecule tends to move from the side of a membrane where it is at higher concentration to the side where it is at lower concentration during...

Back 45

diffusion, facilitated diffusion, osmosis

Front 46

Which pair of characteristics is more likely to make a substance diffuse through the cell membrane?

Back 46

small, nonpolar molecule

Front 47

In facilitated diffusion only, NOT in the secondary active transport...

Back 47

a molecule is moved down its concentration gradient with the assistance of a protein carrier molecule, and no energy is required.

Front 48

____ couples the movement of a substance up its concentration gradient to another ion that is moving down its electrochemical gradient which was established earlier using cellular energy (ATP).

Back 48

secondary active transport

Front 49

during hemodialysis, if the concentration of glucose in the blood is higher than the concentration of glucose in the dialyzing fluid,

Back 49

glucose concentration of the dialyzing fluid will increase

Front 50

During COTRANSPORT of Y with sodium...

Back 50

Y and sodium both move into the cell

Front 51

In addition to functioning as a transporter, proteins in primary active transport also function as ___ in order to break ATPs so as to use their energy.

Back 51

enzymes

Front 52

The concentration of an ion inside a cell is 0.3%. The concentration of this ion outside the cell is 0.1%. The cell can obtain more of this ion inside the cell by:

Back 52

active transport

Front 53

Which of the following statements about sodium is false?

Back 53

at the potassium equilibrium potential, there is an electrical force driving sodium ions out of the cell.

Front 54

A cell is placed into a solution that has the same osmolarity. However, one of the ions inside the cell is able to move across the membrane (the solution the cell was placed into does not contain this ion). After a period of time, the solution into which the cell was placed would become:

Back 54

hypertonic

Front 55

A cell is placed in a 5% NaCl solution. This solution is ___ and the cell will ___.

Back 55

hypertonic; shrink

Front 56

A membrane permeable to water separates a chamber into 2 compartments: A and B. Compartment A contains a 10mM solution of non-permeating solute, whereas compartment B contains 40mM solution of non-permeating solute. Which of the following statements is true?

Back 56

water will move from side A to B, but solute will not move

Front 57

If there is a difference in osmolarity between a cell and its environment, water will move ___ the osmotic pressure gradient.

Back 57

up

Front 58

Of cells with membrane potentials of -70, +20, -90, and +50, which would have a greater electrical driving force for potassium ions to exit the cell?

Back 58

+50 mV

Front 59

What type of ion channels in the membrane of neurons allow ions to move across the membrane at rest, and thereby contribute to resting membrane potential?

Back 59

leak channels

Front 60

Which of the following best describes the electrochemical forces acting on sodium and potassium ions at the resting membrane potential?

Back 60

the force on sodium ions is to move into the cell, and the force on potassium ions is to move out of the cell

Front 61

The presence of the ____ prevents the dissipation of the concentration gradient for Na+.

Back 61

Na+/K+ pump

Front 62

A change in a cell's resting membrane potential, such that it becomes more negative, is referred to as a _____.

Back 62

hyperpolarization

Front 63

An example of spatial summation:

Back 63

2 stimuli from 2 sources produce graded potentials on the same neuron at the same time such that the 2 potentials sum

Front 64

What ion triggers neurotransmitter release from the presynaptic neuron?

Back 64

calcium

Front 65

The opening of voltage-gated sodium channels causes a rapid ____ of sodium that ____ the neuron's membrane.

Back 65

influx; depolarizes

Front 66

For the voltage-gated sodium channel to open and allow sodium into the cell,

Back 66

the activation and inactivation gates must both be open

Front 67

Stimuli A and B are both suprathreshold stimuli that last for one second, but stimulus A is much stronger. What is true about that?

Back 67

stimulus A will cause a higher frequency of action potentials

Front 68

The repolarization phase of action potentials in neurons is due primarily to the fact that lots of ____.

Back 68

potassium flow out of the cell

Front 69

As an action potential is propagated away from the axon hillock, propagation continues in one direction only because...

Back 69

the region just behind (more toward the cell body) the action potential is in the absolute refractory period

Front 70

The term that describes the jumping of an action potential from node-to-node in myelinated nerve fibers is...

Back 70

saltatory conduction

Front 71

Which of the following axons would have the fastest conduction velocity?

Back 71

diameter=20 microns, myelinated

Front 72

As a membrane's permeability to a particular ion increases, membrane potential will move ____ that ion's ___.

Back 72

closer to; equilibrium potential

Front 73

The all-or-none principle, associated with the action potential in a nerve cell, states that:

Back 73

once membrane potential reaches threshold, an action potential will be generated and that action potential will always look the same (with the same magnitude).

Front 74

in myelinated nerve fibers, action potentials occur at the...

Back 74

nodes of Ranvier

Front 75

when an action potential reaches the presynaptic terminal, ultimately:

Back 75

neurotransmitters will be released

Front 76

What type of ion channels in the membrane of neurons open or close in response to a neurotransmitter binding to them?

Back 76

ligand-gated channels

Front 77

Given a cation with an equilibrium potential of -55mV. If the plasma membrane of the cell is permeable only to that ion, then which of the following best describes the resting membrane potential?

Back 77

-55mV

Front 78

If a cell is at rest, the electrochemical gradient for sodium across the membrane is such that if more sodium channels are open, the net flux of sodium will be ___, thereby causing the cell's membrane potential to become more ____.

Back 78

inward, positive

Front 79

The membrane potential at which there is no net flux of an ion across the membrane is called that ion's:

Back 79

equilibrium potential

Front 80

the Na+/K+ pump is called an electrogenic pump because the imbalance between:

Back 80

Na+ out to K+ in leaves the inside of the cell with a net negative charge

Front 81

The elecrical potential of a membrane at rest is closest to potassium's equilibrium potential because:

Back 81

more potassium channels are open, allowing more potassium to move out of the cell.

Front 82

the opening of an ion channel increases a cell membrane's ____, whereas ____ will decrease.

Back 82

conductance; resistance

Front 83

During which of the following states are the majority of voltage-gated sodium channels closed and incapable of opening?

Back 83

during the absolute refractory period

Front 84

concerning the length constant (lambda), choose one best correct answer:

Back 84

length constant is the distance over which an electrotonically conducted signal decays 63%.

Front 85

Choose the incorrect statement:

Back 85

a depolarizing PSP is always an EPSP

Front 86

Slow synaptic transmission involves the binding of a neurotransmitter to a receptor that is:

Back 86

coupled to G-protein which then stimulates an ion channel

Front 87

Correct sequence of events during an action potential:

Back 87

depolarization to threshold or above > increased gNa+ (Na+ conductance) > Na+ influx > increased gK+ > K+ efflux

Front 88

Correct sequence of events during synaptic transmission:

Back 88

AP arrives in presynaptic terminal > increased gCa2+ > Ca2+ influx > exocytosis of NT > NT diffuses and binds to receptor in postsynaptic cell membrane > responses in postsynaptic cell

Front 89

Examples of somatic sensations:

Back 89

proprioception, touch, pain

Front 90

decrease in the amplitude of a receptor potential in the presence of a continuing stimulus is called:

Back 90

adaptation

Front 91

the ability to detect the direction from which a sound originates is determined by:

Back 91

the time delay between that sound reaching the right and left cochlea

Front 92

in order to focus light on the retina, the lens adjusts its refractive power through a process called:

Back 92

accommodation

Front 93

____ is a condition where light, originating from a distance, is focused in front of the retina

Back 93

myopia

Front 94

the presence of cGMP in the cytosol of a photoreceptor will directly stimulate the:

Back 94

opening of sodium channels

Front 95

in the absence of light, the membrane potential of a photoreceptor is relatively ____ by the presence of open ____ channels.

Back 95

depolarized; sodium

Front 96

the closure of sodium channels in mediated by a decrease in the cytosolic concentration of ____ that is degraded by _____.

Back 96

cAMP; phosphodiesterase

Front 97

when we enter a dark room, the retinal and opsin molecules within the ____ must first ____ before low light levels can be detected

Back 97

rods; associate

Front 98

All of these are FALSE about photoreceptors in the light (relative to the dark):

Back 98

more sodium channels are open

cGMP levels are elevated

the synaptic terminal is releasing more transmitter

the photoreceptors are more depolarized

Front 99

disks of a photoreceptor cell are located in the ___ and contain ___.

Back 99

outer segment; photopigment

Front 100

which of the following is the correct order of communication of visual information in the retina?

Back 100

photoreceptor; bipolar cell; ganglion cell

Front 101

both the auditory and vestibular systems rely upon ___ to detect movement of fluid within the ear.

Back 101

hair cells

Front 102

sound waves traveling through the air initiate a vibration of the ___. The sound waves are then transmitted along the ___ to the cochlea.

Back 102

tympanic membrane; ossicles

Front 103

a true statement about endolymph and perilymph:

Back 103

endolymph is similar in composition to intracellular fluid.

Front 104

the hair cells are embedded within the endolymph, thus, when a potassium channel opens, potassium moves ____ the cell, causing it to ____.

Back 104

out of; hyperpolarize

Front 105

bending of the stereocilia on the hair cell can induce either a closure or an opening of a potassium channel based upon the:

Back 105

direction that the stereocilia move

Front 106

frequency of sound is coded for by:

Back 106

the location of the hair cell (in the basilar membrane) stimulated

Front 107

the transduction of sound waves into neural impulses occurs in the

Back 107

cochlea

Front 108

whether the hair cell in the semicircular canal is depolarized or hyperpolarized is dependent upon the:

Back 108

directioni toward which the stereocilia are bent relative to the kinocilium

Front 109

____ is NOT one of the primary tastes

Back 109

spicy

Front 110

the detection of sweet by taste receptors occurs via the binding of organic molecules to receptors on the cell membrane activating ___ that ultimately causes a ___.

Back 110

gustducin; potassium channel to close

Front 111

which taste sensation requires a G protein

Back 111

sweet

Front 112

taste receptor cells can be depolarized by decreased outward flux of potassium by all of the following primary tastes except one. Which of the following is the exception?

Back 112

salty

Front 113

The detection of odorants occurs via the binding of organic molecules to receptors on the cell membrane, activating ___ that ultimately causes the ___.

Back 113

Golf; cation channel to open

Front 114

a skeletal muscle is composed of a number of ___, each composed of many muscle fibers

Back 114

fascicles

Front 115

a ____, the fundamental repeating unit of the myofibril that gives skeletal muscle its striated appearance, is bordered by ____.

Back 115

sarcomere; Z lines

Front 116

what is the protein component of the thin filament that binds to calcium thereby initiating skeletal muscle contraction?

Back 116

troponin

Front 117

the shortening of a skeletal muscle fiber during contraction involves:

Back 117

the sarcomeres shortening

Front 118

during skeletal muscle contraction, as the muscle shortens, the thick and thin filaments:

Back 118

slide past one another

Front 119

the repeated, oscillating interaction between actin and myosin that results in the generation of force by a skeletal muscle cell is called:

Back 119

crossbridge cycling

Front 120

the release of an inorganic phosphate from the myosin molecule directly results in the :

Back 120

power stroke

Front 121

in order for crossbridge cycling to occur, the actin-myosin complex must be broken by the:

Back 121

binding of ATP to myosin

Front 122

the sequence of events that links the action potential to changes in skeletal muscle force development is called:

Back 122

excitation-contraction coupling

Front 123

conraction of skeletal muscle fibers is stimulated by:

Back 123

motor neurons

Front 124

increases in the amount of cytoplasmic calcium required to initiate a muscle contraction are mediated by the coupling between a ___ on the T-tubule and a ___ on the membrane of the sarcoplasmic reticulum.

Back 124

dihydropyridine receptor; ryanodine receptor

Front 125

the binding of calcium to the subunit of troponin will result in

Back 125

the movement of tropomyosin, thereby exposing the myosin-binding site on the actin molecule

Front 126

what is the function of the t-tubules

Back 126

they conduct action potentials from the sarcolemma to the interior or the muscle cell

Front 127

which of the following best describes the function of transverse (t) tubules and the SR in skeletal muscle contraction?

Back 127

action potentials in t tubules are detected by dihydropyridine receptors, which are coupled to ryanodine receptors in the SR that are channels for calcium

Front 128

in order to allow muscle relaxation, calcium is rapidly removed from the cytoplasm via:

Back 128

Ca2+ pumps (Ca2+ ATPases)

Front 129

Property of isometric skeletal muscle contraction:

Back 129

load < force generated by muscle

Front 130

end plate potentials:

Back 130

are suprathreshold graded potentials; are a result of acetylcholine binding to nicotinic cholinergic receptors

Front 131

in an isotonic contraction:

Back 131

the load is moved,
muscle tension exceeds force of the load,
muscle length shortens

Front 132

a muscle is stimulated at a frequency that allows the muscle to relax completely between contractions. However, the amount of tension increases with each contraction. What is this called?

Back 132

treppe

Front 133

as skeletal muscle is further stretched beyond the length where optimum force is developed,

Back 133

the thin filaments are pulled away from thick filaments, thereby reducing their ability to interact with myosin.

Front 134

the interaction between actin and myosin in smooth muscle requires:

Back 134

that the calcium-calmodulin complex activates myosin light-chain kinase, which phosphorylates myosin light chain thereby allowing myosin to bind with actin

Front 135

What causes some muscle to appear red?

Back 135

presence of myoglobin

Front 136

which of the following statements about summation and tetanus is false?

Back 136

the maximum tension developed during summation and tetanus is treppe.