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Midterm Practice

Pregunta 1 de 50

1

The rate of Ca+ diffusion across a membrane is dependent on -

Selecciona una de las siguientes respuestas posibles:

  • Permeability of the membrane on the solute

  • Concentration gradient

  • Existence of carriers and/or channels for the solute

  • All of these are true.

Explicación

Pregunta 2 de 50

1

Na+ concentration on either side of a membrane plays a role in osmolarity, even if it is not permeable to the membrane.

Selecciona uno de los siguientes:

  • VERDADERO
  • FALSO

Explicación

Pregunta 3 de 50

1

The rate of diffusion for a solute across a membrane is dependent on -

Selecciona una de las siguientes respuestas posibles:

  • Concentration gradient

  • Temperature

  • Viscosity of the fluid

  • All of these.

Explicación

Pregunta 4 de 50

1

Homeostasis in physiological systems refers to the maintenance of a static or constant conditions in the internal environment.

Selecciona uno de los siguientes:

  • VERDADERO
  • FALSO

Explicación

Pregunta 5 de 50

1

Influences on receptor-mediated channels refers to a protein

Selecciona una de las siguientes respuestas posibles:

  • Allowing other solutes to cross a membrane, after linking to a primary molecule.

  • Allowing other solutes to cross a membrane, after a voltage change to the inside of the cell.

  • Allowing other solutes to cross a membrane, after pressure changes to the inside of the cell.

  • All of these.

Explicación

Pregunta 6 de 50

1

Osmotic pressure is the pressure necessary to allow the movement of water across a membrane.

Selecciona uno de los siguientes:

  • VERDADERO
  • FALSO

Explicación

Pregunta 7 de 50

1

Secondary active co-transporter proteins in a cell membrane have which of the properties listed below?

Selecciona una de las siguientes respuestas posibles:

  • Selectiveity

  • Uses energy from solute concentration gradient (runs downhill)

  • Saturable

  • All of these.

Explicación

Pregunta 8 de 50

1

Which statement below is NOT true?

Selecciona una de las siguientes respuestas posibles:

  • Voltage is "pressure" that moves electrons or ions through a circuit.

  • Current is the number of electron or ions moving per unit of time.

  • Resistance is not associated with the lipid membrane.

  • Conductance is the reciprocal of resistance.

Explicación

Pregunta 9 de 50

1

Active transport differs from facilitated diffusion in that it uses energy to move a substance uphill against its concentration gradient.

Selecciona uno de los siguientes:

  • VERDADERO
  • FALSO

Explicación

Pregunta 10 de 50

1

The equilibrium potential for a particular ion is the voltage in which that ions movement across a lipid membrane comes to a relative stop.

Selecciona uno de los siguientes:

  • VERDADERO
  • FALSO

Explicación

Pregunta 11 de 50

1

Depolarizing the membrane of excitable cells by ~10mV will initiate -

Selecciona una de las siguientes respuestas posibles:

  • increases in Na+ conductance (ability to move across the membrane)

  • decreases Na+ in conductance (ability to move across the membrane)

  • closing of Na+ ions protein channels

  • cell death

Explicación

Pregunta 12 de 50

1

The Nernst Equation is important for:

Selecciona una de las siguientes respuestas posibles:

  • Determining the absolute membrane potential

  • Determining the electrical potential difference, for a single ion, needed to counter the concentration difference.

  • Determining the concentration difference, for multiple ion, needed to counter the concentration difference.

  • None of these

Explicación

Pregunta 13 de 50

1

When determining the "equilibrium potential" for Na+, we have to assume the membrane is permeable to Na+.

Selecciona uno de los siguientes:

  • VERDADERO
  • FALSO

Explicación

Pregunta 14 de 50

1

Which channel is most responsible for the depolarization phase of an action potential across a cell membrane?

Selecciona una de las siguientes respuestas posibles:

  • Open Na+ channels

  • Open K+ channels

  • Open Ca++ chanels

  • All of these

Explicación

Pregunta 15 de 50

1

Which process listed below is most responsible for maintaining the electrochemical gradient?

Selecciona una de las siguientes respuestas posibles:

  • Facilitated diffusion of Na+

  • Na+/K+ pump

  • Ca++ storage

  • Starbuck's Coffee and Krispy Cream.

Explicación

Pregunta 16 de 50

1

What two factors make using the Goldman Equation more appropriate for determining the "Resting Membrane Potential", instead of using the Nertz Equation?

Selecciona una de las siguientes respuestas posibles:

  • The number of voltage-gated channels located in the membrane and concentration of ions inside the cell.

  • The relative ion concentration on either side of the membrane and the relative permeability of the membrane to the ions.

  • The amount of Krispy Cream donuts and Starbuck's coffee outside the cell.

  • The inclusion of the relative permeability of the ions.

Explicación

Pregunta 17 de 50

1

Which ion is most responsible for the initial change (depolarization) in membrane potential during the action potential?

Selecciona una de las siguientes respuestas posibles:

  • Na+

  • K+

  • Ca++

  • Cl-

Explicación

Pregunta 18 de 50

1

Ligand-gated channels are important for initiating an action potential at the neuromuscular junction.

Selecciona uno de los siguientes:

  • VERDADERO
  • FALSO

Explicación

Pregunta 19 de 50

1

Slow, oxidative muscle fibers -

Selecciona una de las siguientes respuestas posibles:

  • Use mainting oxidative phosphorylation to generate ATP.

  • Have large amounts of mitochondria.

  • Have large blood supply.

  • All of these.

Explicación

Pregunta 20 de 50

1

The sarcoplasmic reticulum stores __________ when a muscle is relaxed and releases it for binding to _______ during contraction.

Selecciona una de las siguientes respuestas posibles:

  • calcium; troponin

  • calcium; tropomyosin

  • sodium; tropomyosin

  • potassium; tropinin

Explicación

Pregunta 21 de 50

1

Put in to the correct sequence the following events involved in muscle cell contraction.

1. Voltage-gated sodium channels open, allowing sodium to flow in.
2. Spreading action potential reaches T-Tubles activating a DHP molecule.
3. Acetylcholine binds to receptors on muscle cell membrane.
4. Ligand-gated receptors allow small amounts of sodium into the cell changing membrane potential 10mV(+).
5. If enough sodium moves into the muscle cell, an impulse (action potential) develops.

Selecciona una de las siguientes respuestas posibles:

  • 3,4,1,5,2

  • 2,1,3,4,5

  • 2,4,3,1,5

  • 3,4,5,1,2

Explicación

Pregunta 22 de 50

1

Which molecule listed below is responsible for "physically" inhibiting the binding of the myosin head to the active binding site on actin?

Selecciona una de las siguientes respuestas posibles:

  • Troponin

  • Tropomyosin

  • G-actin

  • all of these

Explicación

Pregunta 23 de 50

1

In order to allow discrete events to occur, calcium is rapidly removed from the cytoplasm by __________.

Selecciona una de las siguientes respuestas posibles:

  • dihydropyridime channels

  • calcium-sequestering proteins in the cytoplasm

  • calcium pumps in the sarcoplasmic reticulum

  • DHP receptor

Explicación

Pregunta 24 de 50

1

When an action potential is generated within a motor unit -

Selecciona una de las siguientes respuestas posibles:

  • the muscle cells of the motor unit will occasionally contract.

  • only select muscle cells within the motor unit are stimulated to contract.

  • every muscle cell of the motor unit is stimulated to contract.

  • the muscle cells from the neighboring motor unit will contract.

Explicación

Pregunta 25 de 50

1

The releasing of Ca++ inside the skeletal muscle cell (intracellular) is initiated by which protein receptor listed below?

Selecciona una de las siguientes respuestas posibles:

  • Actin

  • DHP

  • Myosin

  • Tropomyosin

Explicación

Pregunta 26 de 50

1

The t-tubules are an extension of the cell membrane of the skeletal muscle cell.

Selecciona uno de los siguientes:

  • VERDADERO
  • FALSO

Explicación

Pregunta 27 de 50

1

The t-tubule of cardiac muscle

Selecciona una de las siguientes respuestas posibles:

  • form the Z lines

  • stores K+

  • provides a means of rapidly transmitting action potential to the sarcoplasmic reticulum via the DHP molecule

  • are larger than those found in skeletal muscle.

Explicación

Pregunta 28 de 50

1

The fusing of synaptic vesicles with the terminal button membrane is initiated by Ca++ influx into the cell.

Selecciona uno de los siguientes:

  • VERDADERO
  • FALSO

Explicación

Pregunta 29 de 50

1

The plateau of the cardiac action potential results from opening of voltage-gated, slow _______ channels in the membrane of the cardiac cell.

Selecciona una de las siguientes respuestas posibles:

  • sodium

  • potasium

  • calcium

  • chloride

Explicación

Pregunta 30 de 50

1

Heart muscle has long refractory period due to extended K+ channel opening.

Selecciona uno de los siguientes:

  • VERDADERO
  • FALSO

Explicación

Pregunta 31 de 50

1

Increased activity within the parasympathetic nervous system will result in changes primarily within the

Selecciona una de las siguientes respuestas posibles:

  • sinoatrial node only

  • atrioventricular node only

  • ventricles only

  • sinoatrial node and atrioventricular node

  • sinoatrial node, atrioventricular node, and ventricles

Explicación

Pregunta 32 de 50

1

Which of the following is NOT involved in triggering the normal coordinated contraction of cardiac muscle cells?

Selecciona una de las siguientes respuestas posibles:

  • release of a neurotransmitter.

  • change in membrane potential within individual cardiac muscle cells

  • initiation of an action potential

  • a pacemaker potential

  • the conduction system of the heart.

Explicación

Pregunta 33 de 50

1

The long refractory period of cardiac muscle prevents tetanic contraction of the heart.

Selecciona uno de los siguientes:

  • VERDADERO
  • FALSO

Explicación

Pregunta 34 de 50

1

The sinoatrial node requires external stimulation in order to generate an action potential.

Selecciona uno de los siguientes:

  • VERDADERO
  • FALSO

Explicación

Pregunta 35 de 50

1

Which of the following EKG events represents the depolarization of the ventricle?

Selecciona una de las siguientes respuestas posibles:

  • P wave

  • QRS complex

  • PR interval

  • T wave

Explicación

Pregunta 36 de 50

1

The spontaneous action potential generated by the Sino-Atrial Node, Atrio-ventricular Node, and Purkinje Fibers is due to K+ leaking across the cardiac muscle cell membrane.

Selecciona uno de los siguientes:

  • VERDADERO
  • FALSO

Explicación

Pregunta 37 de 50

1

The depolarization of the atria (by the Sino-Atrial Node) will be communicated (sent) to the ventricles (Purkinje fibers) by the _________.

Selecciona una de las siguientes respuestas posibles:

  • Sarcoplasmic reticulum

  • DHP molecule

  • A-V bundle (bundle of His)

  • Actin and myosin filaments.

Explicación

Pregunta 38 de 50

1

Diastolic pressure generated by the right ventricle must overcome pressure in the aorta to get blood flow out to the rest of the body.

Selecciona uno de los siguientes:

  • VERDADERO
  • FALSO

Explicación

Pregunta 39 de 50

1

The Frank-Starling mechanism of heart contraction state that as more blood enters the heart, the heart will respond by contracting with greater force. Which is the statements below helps explain how this works?

Selecciona una de las siguientes respuestas posibles:

  • The pacemaker mechanism of the heart is stimulated by increased input of blood to the left ventricle.

  • Parasympathetic inhibition of contraction will allow more force to be generated.

  • Stretched cardiac muscle has better actin/myosin filament alignment.

  • All of these.

Explicación

Pregunta 40 de 50

1

Contraction of motor units is a(n) ____________ manner allows a muscle to maintain a level of force for a duration of time without fatiguing.

Selecciona una de las siguientes respuestas posibles:

  • Synchronous

  • Asymmetrical

  • Asynchronous

  • Random

Explicación

Pregunta 41 de 50

1

Skeletal muscle fibers operate at near-optimal sarcomere length in the normal individual.

Selecciona uno de los siguientes:

  • VERDADERO
  • FALSO

Explicación

Pregunta 42 de 50

1

The speed at which the action potential travels through different parts of the heart conduction system is dependent on -

Selecciona una de las siguientes respuestas posibles:

  • blood flow through the heart

  • functioning of the Atrio-ventricular valve.

  • resistance to the spread of the action potential

  • phases of the moon.

Explicación

Pregunta 43 de 50

1

The influx of calcium into the axon terminal of a chemical synapse is responsible for the ____________.

Selecciona una de las siguientes respuestas posibles:

  • initiation of the action potential

  • termination of an action potential

  • fusion of the vesicles to the membrane and their exocytosis

  • movement of calcium through gap junctions

Explicación

Pregunta 44 de 50

1

Which substance below could be used to treat 'flaccid paralysis'?

Selecciona una de las siguientes respuestas posibles:

  • Curare

  • Botulinum Toxin

  • Tetanus Toxin

  • Diisoprophyl fluorophosphate

Explicación

Pregunta 45 de 50

1

Pressure in the right atria of the heart is ~0

Selecciona uno de los siguientes:

  • VERDADERO
  • FALSO

Explicación

Pregunta 46 de 50

1

Ventricular cardiac muscle cells demonstrate a stable resting membrane potential with no evidence of the slow depolarization of the specialized cardiac pacemaker cells.

Selecciona uno de los siguientes:

  • VERDADERO
  • FALSO

Explicación

Pregunta 47 de 50

1

Which specialized muscle tissues of the heart can generate the greatest number of action potentials in a minute?

Selecciona una de las siguientes respuestas posibles:

  • Sino-Atrial Node

  • Atrio-Ventricular Node

  • Purkinje fibers

  • All of the these.

Explicación

Pregunta 48 de 50

1

An ion's overall electrochemical gradient will tend to force that ion across the membrane in a direction that will cause membrane potential to move toward that ion's equilibrium potential.

Selecciona uno de los siguientes:

  • VERDADERO
  • FALSO

Explicación

Pregunta 49 de 50

1

The electrical potential of a membrane at rest is closest to potassium's equilibrium potential because ___________.

Selecciona una de las siguientes respuestas posibles:

  • more sodium channels are open, allowing more sodium to move into the cell.

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

  • more sodium channels are closed, allowing less sodium to move in or out of the cell.

  • all of the above.

Explicación

Pregunta 50 de 50

1

As a consequence of Frank-Starling's Law of the heart, _________________________.

Selecciona una de las siguientes respuestas posibles:

  • an increase in end-systolic volume will increase stroke volume.

  • a decrease in end-diastolic volume will increase stroke volume.

  • an increase in end-diastolic volume will increase stroke volume.

  • stroke volume is unaffected by end-diastolic volume.

Explicación