BIOL 2160 Exam 4

A genetic mutation that destroys SERCA pumps in skeletal muscle cells might have which of the following consequences?

Inability to activate troponin

Inability to relax skeletal muscle

Inability to produce an end plate potential

Reduced acetylcholine release

Inability to relax skeletal muscle

At the neuromuscular junction, the end plate potential occurs:

On the sarcoplasmic reticulum

On the skeletal muscle cell membrane

On the motor axon terminal

On troponin

None of the above

On the skeletal muscle cell membrane

Blood leaving the legs and traveling to the heart will be carried by:

The Superior Vena Cava

The Inferior Vena Cava

The inferior Vena Cava

Compared to cardiac muscle, action potentials in skeletal muscle are:

Longer in duration

Shorter in duration

Shorter in duration

During inspiration, alveolar pressure is ________________ atmospheric pressure.

Less than

The same as

Greater than

None of the above

Less than

During isovolumetric contraction:

Ventricular pressure > Atrial pressure > Aortic pressure

Atrial pressure > Ventricular pressure > Aortic pressure

Atrial pressure > Aortic pressure > Ventricular pressure

Aortic pressure > Ventricular pressure > Atrial pressure

Aortic pressure > Ventricular pressure > Atrial pressure

During ventricular filling, you would expect the mitral valve to be:

Closed

Open

Open

During ventricular ejection:

AV valves are open

Ventricular pressure > Aortic pressure

Aortic pressure > Ventricular pressure

None of these

Ventricular pressure > Aortic pressure

Low intensity exercise will most likely result in an increase in ____________ fibers.

Glycolytic

Oxidative

Oxidative

If phosphatases stopped being produced, the duration of smooth muscle contraction would be much:

Shorter

Longer

Longer

If the tricuspid valve failed to open:

Blood would flow from the right atrium to the left atrium

Blood could not flow from the right atrium to the right ventricle

Blood could not flow from the left atrium to the left ventricle

Blood would flow from the ventricle to the pulmonary artery

Blood could not flow from the right atrium to the right ventricle

In smooth muscle cells, what does Ca2+ bind directly to?

Myosin light chain

Crossbridges

Calmodulin

Myosin light chain kinase

Calmodulin

Myosin has the highest affinity for actin when the myosin head is bound to:

Calcium

Troponin

ADP + Pi

ATP

ADP + Pi

Patent Ductus Arteriosus (PDA) is the result of which two blood vessels remaining connected after birth?

Vena Cava and Pulmonary Artery

Aorta and Pulmonary Artery

Pulmonary Artery and Pulmonary Vein

Aorta and Vena Cava

Aorta and Pulmonary Artery

Pulmonary ventilation occurs:

In the blood

In the lungs

In the lungs

Smooth muscle forms crossbridges.

True

False

True

The blood that undergoes systemic circulation is pumped by:

the right side of the heart

the left side of the heart

the left side of the heart

The nicotinic acetylcholine receptor is:

Equally permeable to Na+ and K+

More permeable to K+ than it is to Na+

More permeable to Na+ than it is to K+

None of the above

Equally permeable to Na+ and K+

The partial pressure for oxygen in the alveoli is _________ than the partial pressure for oxygen in pulmonary capillaries.

greater

less

greater

The partial pressure for carbon dioxide is tissues is ________ than the partial pressure for carbon dioxide in systemic capillaries.

greater

less

greater

The partial pressure of CO2 is higher in systemic arteries than it is in systemic veins.

false

true

false

The purpose of DHP receptors in skeletal is to:

Reposition troponin over cross bridges

Pump Ca2+ back into the SR

Detect action potentials along t-tubules

Propagate action potentials along the sarcolemma

Detect action potentials along t-tubules

The purpose of pulmonary ventilation is to:

Move air into tissue cells

Create pressure gradients between the air in the lungs and the blood in the capillaries

Create pressure gradients between alveolar air and atmospheric air

None of the above

Create pressure gradients between alveolar air and atmospheric air

The force of the heartbeat is due to the activity of:

Contractile cells

Pacemaker cells

Contractile cells

The t-tubule is part of the:

Muscle cell membrane

Sarcoplasmic reticulum

Motor neuron

Motor end plate

Muscle cell membrane

The three factors that determine air flow are: atmospheric pressure, alveolar pressure, and resistance. Which of these changes most often?

Atmospheric pressure

Alveolar pressure

Resistance

None of the above

Alveolar pressure

The bicuspid valve:

Controls blood flow into the aorta

Controls blood flow into the pulmonary artery

Controls blood flow into the left ventricle

Controls blood flow into the right ventricle

Controls blood flow into the left ventricle

The valve separating the pulmonary vein from the left atrium is which type of valve?

Bicuspid valve

Semilunar valve

Tricuspid valve

There is no valve separating the pulmonary vein from the left atrium

AV valve

There is no valve separating the pulmonary vein from the left atrium

The Vena Cava:

Carries deoxygenated blood to the heart

Carries oxygenated blood from the lungs to the heart

Carries deoxygenated blood to the lungs

Carries deoxygenated blood to the heart

Voltage-gated Na+ channels inactivate during the cardiac pacemaker cells action potential.

False

True

True

What determines whether a fiber is fast or slow twitch?

How quickly the myosin head can hydrolyze ATP

How many mitochondria it contains

How many glycolytic enzymes it contains

How quickly its troponin molecules bind to Ca2+

How quickly the myosin head can hydrolyze ATP

What is accomplished with the removal of the inorganic phosphate (Pi) during skeletal muscle contraction?

Addition of an organic phosphate

Cocking of the myosin head

It begins the power stroke

It begins the power stroke

What is the main structural difference between the conducting zone and the respiratory zone?

The respiratory zone has thinner walls

The respiratory zone has thicker walls

The respiratory zone has thinner walls

What is the purpose of L-type Ca2+ channels in contractile cells?

To allow these cells to reach threshold

To ensure a long refractory period for the contractile cells

To shorten the duration of action potentials

To allow summation and tetanus in heart muscle

None of the above

To ensure a long refractory period for the contractile cells

What would be the consequence of the aortic semilunar valve not closing properly?

Oxygenated blood would not flow from the right ventricle to the pulmonary artery

Deoxygenated blood would flow from the pulmonary artery to the right ventricle

Deoxygenated blood would not flow from the right ventricle to the pulmonary artery

Oxygenated blood would flow from the aorta to the left ventricle

Oxygenated blood would flow from the aorta to the left ventricle

What would happen if the atmospheric pressure were to suddenly drop?

Oxygen would flow out of your lungs very quickly

CO2 would no longer flow out of your lungs

Oxygen would flow into your lungs more quickly

Oxygen would flow out of your lungs very quickly

When the diaphragm contacts:

Pressure in the lungs decreases

Pressure in the lungs increases

None of these

Pressure in the lungs decreases

When would you expect the bicuspid valve to be closed?

When the pressure in the right ventricle is higher than pressure in the right atrium

When the pressure in the right atrium is higher than pressure in the right ventricle

When the pressure in the left ventricle is higher than pressure in the left atrium

None of the above

When the pressure in the left ventricle is higher than pressure in the left atrium

Where does conduction of action potentials slow?

AV node

the Bundle of His

the SA node

Pukinje fibers

AV node

Where does the majority of Ca2+ needed for smooth muscle contraction come from?

Rough ER

Smooth ER

Mitochondria

Outside the cell

Outside the cell

Where is the motor end plate found?

On tropomyosin

On the motor neuron

ON the sarcoplasmic reticulum

On the muscle cell

On the muscle cell

Where would you expect pressure to typically be the highest?

Arteries

Veins

Venules

Capillaries

Arteries

Which channel is responsible for the stimulus that opens HCN channels in cardiac pacemaker cells?

T-type voltage-gated Ca2+ channels

Voltage-gated Na+ channels

Voltage-gated K+ channels

L-type voltage-gated Ca2+ channels

Voltage-gated K+ channels

Which channel type allows the membrane potential of cardiac pacemaker cells to reach threshold?

T-type Ca2+ channels

L-type Ca2+ channels

Voltage-gated Na+ channels

Funny Channels

T-type Ca2+ channels

Which channel type is NOT opened before threshold?

They are all open before threshold

Funny channels

T-type Voltage-gated Ca2+ channels

L-type Voltage-gated Ca2+ channels

L-type Voltage-gated Ca2+ channels

Which event directly cocks the myosin head?

Removal of ADP

ATP hydrolysis

Binding of myosin to actin

Removal of the inorganic phosphate (Pi)

ATP hydrolysis

Which of these is a condition in which breathing does not meet the demands of the tissues?

Hypoventilation

Hypernea

Hyperventilation

None of these

Hypoventilation

Which of these is Calcium-sensitive?

Tropomyosin

Troponin

Actin

Myosin

Troponin

Which of these is the thin, fiber-like protein that physically covers up the myosin-binding site on actin when Ca2+ levels are low?

Tropomyosin

Troponin

Tropomyosin

Which type of muscle fibers will be darker in color?

Glycolytic

Oxidative

Oxidative