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Midterm Practice

Questão 1 de 50

1

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

Selecione uma das seguintes:

  • Permeability of the membrane on the solute

  • Concentration gradient

  • Existence of carriers and/or channels for the solute

  • All of these are true.

Explicação

Questão 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.

Selecione uma das opções:

  • VERDADEIRO
  • FALSO

Explicação

Questão 3 de 50

1

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

Selecione uma das seguintes:

  • Concentration gradient

  • Temperature

  • Viscosity of the fluid

  • All of these.

Explicação

Questão 4 de 50

1

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

Selecione uma das opções:

  • VERDADEIRO
  • FALSO

Explicação

Questão 5 de 50

1

Influences on receptor-mediated channels refers to a protein

Selecione uma das seguintes:

  • 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.

Explicação

Questão 6 de 50

1

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

Selecione uma das opções:

  • VERDADEIRO
  • FALSO

Explicação

Questão 7 de 50

1

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

Selecione uma das seguintes:

  • Selectiveity

  • Uses energy from solute concentration gradient (runs downhill)

  • Saturable

  • All of these.

Explicação

Questão 8 de 50

1

Which statement below is NOT true?

Selecione uma das seguintes:

  • 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.

Explicação

Questão 9 de 50

1

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

Selecione uma das opções:

  • VERDADEIRO
  • FALSO

Explicação

Questão 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.

Selecione uma das opções:

  • VERDADEIRO
  • FALSO

Explicação

Questão 11 de 50

1

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

Selecione uma das seguintes:

  • 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

Explicação

Questão 12 de 50

1

The Nernst Equation is important for:

Selecione uma das seguintes:

  • 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

Explicação

Questão 13 de 50

1

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

Selecione uma das opções:

  • VERDADEIRO
  • FALSO

Explicação

Questão 14 de 50

1

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

Selecione uma das seguintes:

  • Open Na+ channels

  • Open K+ channels

  • Open Ca++ chanels

  • All of these

Explicação

Questão 15 de 50

1

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

Selecione uma das seguintes:

  • Facilitated diffusion of Na+

  • Na+/K+ pump

  • Ca++ storage

  • Starbuck's Coffee and Krispy Cream.

Explicação

Questão 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?

Selecione uma das seguintes:

  • 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.

Explicação

Questão 17 de 50

1

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

Selecione uma das seguintes:

  • Na+

  • K+

  • Ca++

  • Cl-

Explicação

Questão 18 de 50

1

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

Selecione uma das opções:

  • VERDADEIRO
  • FALSO

Explicação

Questão 19 de 50

1

Slow, oxidative muscle fibers -

Selecione uma das seguintes:

  • Use mainting oxidative phosphorylation to generate ATP.

  • Have large amounts of mitochondria.

  • Have large blood supply.

  • All of these.

Explicação

Questão 20 de 50

1

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

Selecione uma das seguintes:

  • calcium; troponin

  • calcium; tropomyosin

  • sodium; tropomyosin

  • potassium; tropinin

Explicação

Questão 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.

Selecione uma das seguintes:

  • 3,4,1,5,2

  • 2,1,3,4,5

  • 2,4,3,1,5

  • 3,4,5,1,2

Explicação

Questão 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?

Selecione uma das seguintes:

  • Troponin

  • Tropomyosin

  • G-actin

  • all of these

Explicação

Questão 23 de 50

1

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

Selecione uma das seguintes:

  • dihydropyridime channels

  • calcium-sequestering proteins in the cytoplasm

  • calcium pumps in the sarcoplasmic reticulum

  • DHP receptor

Explicação

Questão 24 de 50

1

When an action potential is generated within a motor unit -

Selecione uma das seguintes:

  • 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.

Explicação

Questão 25 de 50

1

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

Selecione uma das seguintes:

  • Actin

  • DHP

  • Myosin

  • Tropomyosin

Explicação

Questão 26 de 50

1

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

Selecione uma das opções:

  • VERDADEIRO
  • FALSO

Explicação

Questão 27 de 50

1

The t-tubule of cardiac muscle

Selecione uma das seguintes:

  • 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.

Explicação

Questão 28 de 50

1

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

Selecione uma das opções:

  • VERDADEIRO
  • FALSO

Explicação

Questão 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.

Selecione uma das seguintes:

  • sodium

  • potasium

  • calcium

  • chloride

Explicação

Questão 30 de 50

1

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

Selecione uma das opções:

  • VERDADEIRO
  • FALSO

Explicação

Questão 31 de 50

1

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

Selecione uma das seguintes:

  • sinoatrial node only

  • atrioventricular node only

  • ventricles only

  • sinoatrial node and atrioventricular node

  • sinoatrial node, atrioventricular node, and ventricles

Explicação

Questão 32 de 50

1

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

Selecione uma das seguintes:

  • 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.

Explicação

Questão 33 de 50

1

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

Selecione uma das opções:

  • VERDADEIRO
  • FALSO

Explicação

Questão 34 de 50

1

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

Selecione uma das opções:

  • VERDADEIRO
  • FALSO

Explicação

Questão 35 de 50

1

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

Selecione uma das seguintes:

  • P wave

  • QRS complex

  • PR interval

  • T wave

Explicação

Questão 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.

Selecione uma das opções:

  • VERDADEIRO
  • FALSO

Explicação

Questão 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 _________.

Selecione uma das seguintes:

  • Sarcoplasmic reticulum

  • DHP molecule

  • A-V bundle (bundle of His)

  • Actin and myosin filaments.

Explicação

Questão 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.

Selecione uma das opções:

  • VERDADEIRO
  • FALSO

Explicação

Questão 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?

Selecione uma das seguintes:

  • 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.

Explicação

Questão 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.

Selecione uma das seguintes:

  • Synchronous

  • Asymmetrical

  • Asynchronous

  • Random

Explicação

Questão 41 de 50

1

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

Selecione uma das opções:

  • VERDADEIRO
  • FALSO

Explicação

Questão 42 de 50

1

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

Selecione uma das seguintes:

  • blood flow through the heart

  • functioning of the Atrio-ventricular valve.

  • resistance to the spread of the action potential

  • phases of the moon.

Explicação

Questão 43 de 50

1

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

Selecione uma das seguintes:

  • 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

Explicação

Questão 44 de 50

1

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

Selecione uma das seguintes:

  • Curare

  • Botulinum Toxin

  • Tetanus Toxin

  • Diisoprophyl fluorophosphate

Explicação

Questão 45 de 50

1

Pressure in the right atria of the heart is ~0

Selecione uma das opções:

  • VERDADEIRO
  • FALSO

Explicação

Questão 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.

Selecione uma das opções:

  • VERDADEIRO
  • FALSO

Explicação

Questão 47 de 50

1

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

Selecione uma das seguintes:

  • Sino-Atrial Node

  • Atrio-Ventricular Node

  • Purkinje fibers

  • All of the these.

Explicação

Questão 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.

Selecione uma das opções:

  • VERDADEIRO
  • FALSO

Explicação

Questão 49 de 50

1

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

Selecione uma das seguintes:

  • 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.

Explicação

Questão 50 de 50

1

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

Selecione uma das seguintes:

  • 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.

Explicação