Muscle Physiology Quiz

Which is NOT a property of single-unit smooth muscles?

• Varicosities

• Contract as a unit

• Connected by gap junctions

• Controlled by hormones

Smooth muscle cells do not have which protein(s)?

• Actin

• Myosin

• Troponin

• Tropomyosin

Which is false about Golgi tendon organs (GTO)?

• They respond primarily to muscle tension

• They are found at the junction of tendons and muscle fibers

• They respond primarily to muscle length

• They send sensory information to the CNS

The motor neurons that innervate the normal contractile fibers of the muscle are the ________.

• Gamma motor neurons

• Beta motor neurons

• Delta motor neurons

• Alpha motor neurons

The _________ monitors the position of skeletal muscles and joints.

• Mechanoreceptors

• Chemoreceptors

• Proprioceptors

• Baroreceptors

After stretching an intrafusal fiber, the next event is

• Decreased action potential frequency

• Increased frequency of action potentials along the associated sensory neuron

• Inhibition of the stretch reflex

• Relaxation of extrafusal fibers

The action potentials of myocardial autorhythmic cells are due to a combination of increasing Na+ and Ca2+ ________ and decreasing K+ ________.

• Efflux, influx

• Influx, efflux

• Reflux, efflux

• Efflux, reflux

Missing waves at what point in an ECG might indicate the absence of repolarization of the ventricles?

• P wave

• QRS complex

• T wave

• R wave

The Frank-Starling law of the heart states that stroke volume is proportional to __________.

• Heart rate

• End-diastolic volume

• Blood pressure

• Cardiac output

The ________ signify the ventricular repolarization and relaxation.

• P wave

• QRS complex

• T waves

• R waves