week 4

For single mechanoreceptor in the skin, what is its receptive field?Select one:
A. The region of skin surrounding the receptor
B. The region of skin where stimulation excites the receptor 
C. The region of skin that contains branches of that one receptor axon only
D. The region of skin from which the strongest response can be obtained
E. The region of skin that contains only receptors that respond to the same stimulus modality

The pathway from a sensory receptor on the skin to the cerebral cortex is:Select one:
A. ventral root on the same side of the body – spinal cord – thalamus – cerebral cortex on the opposite side of the body.
B. ventral root on the same side of the body – spinal cord – hypothalamus – cerebral cortex on the opposite side of the body.
C. dorsal root on the same side of the body – spinal cord – thalamus – cerebral cortex on the opposite side of the body. 
D. ventral root on the same side of the body – spinal cord – hypothalamus – cerebral cortex on the same side of the body
E. dorsal root on the same side of the body – spinal cord – hypothalamus – cerebral cortex on the opposite side of the body.

A motor unit isSelect one:
A. a motor neuron and the muscle cells it innervates 
B. a concept of brain organization
C. a unit of force
D. a group of motor neurons innervating a single muscle
E. a burst of firing of motor neurons

Which of the following is NOT a somatosensory modality?Select one:
A. proprioception
B. temperature
C. vision 
D. touch
E. nociception

A motor unit consists ofSelect one:
A. one neuron and all the skeletal muscle fibers it controls. 
B. one skeletal muscle fiber and the neuron that controls that fiber.
C. one skeletal muscle fiber and all the neurons that control that fiber.
D. one set of synergistic muscle that share the same motor nerve
E. one axon terminal branch and the myofibrils it controls.

Most of the time, the parallel thick and thin filaments of the myofibrils are connected by ________ that span the space between myosin and actin molecules.Select one:
A. nebulin molecules
B. crossbridges
C. sarcomeres 
D. tropomyosin molecules
E. calcium ions

Balance involvesSelect one:
A. thermoreceptive neurons
B. osmoreceptive neurons 
C. chemosensitive neurons
D. photoreceptive neurons
E. mechanosensitive neurons

Which of the following would be a stimulus for a chemoreceptor?Select one:
A. vibration
B. cell stretch
C. oxygen 
D. photon of light
E. cold temperature

The larger the receptive field,Select one:
A. the more sensory receptors it includes.
B. the larger the area of the somatosensory cortex in the brain that deals with the area.
C. the larger the stimulus needed to stimulate a sensory receptor.
D. the harder it is to discriminate the exact point of stimulation. 
E. all of the above

The somatic sensory cortexSelect one:
A. Receives information from the surface of the body 
B. Is only present in humans
C. Is involved in vision
D. Sends messages directly to the muscles
E. Is not essential for feeling touch