Chapter 15 review questions Flashcards
what do we call the specialized cells that monitor specific internal or external conditions?
sensory receptors
Is it possible for somatic motor commands to occur at the subconscious level?
yes. somatic motor commands occur at both the conscious and subconscious level.
regardless, they both travel from motor centers in the brain along SOMATIC MOTOR PATHWAYS
define adaptation
adaptation is a decrease in receptor sensitivity or a decrease in perception after constant stimulation
Receptor A has a circular receptive field with a diameter of 2.5cm
Receptor B has a circular receptive field 7.0cm in diameter.
which receptor provides more precise sensory information?
receptor A bc it has a smaller receptive field
list the 4 types of general sensory receptors, and identify the nature of the stimulus that excites each type
thermoreceptors - temp
mechanoreceptors -physical distortion
nociceptors - pain
chemoreceptors - chemical concentration
identify the 3 classes of mechanoreceptors
tactile
proprioceptors
baroceptors
what would happen if information from proprioceptors in your legs were blocked from reaching the CNS?
esp the lack of information being sent to the cerebellum would result in your movements being uncoordinated and you could likely not walk
as a result of pressure on her spinal cord, jill cannot feel fine touch or pressure on her lower limbs. which spinal tract is being compressed
fasciculus gracilis in the posterior column of the spinal cord which carries information about fine touch and pressure from the lower limbs to the brain
which spinal tract carries action potentials generated by nociceptors
lateral spinothalamic
which cerebral hemisphere receives impulsues conducted by right fasciculus gracilis
the left cerebral hemisphere (specifically the primary sensory cortex)
what is the anatomical basis for the fact that the left side of the brain controls motor function on the right side of the body?
the crossing over (decussation) of axons, so the motor fibers of the corticospinal pathway innervate lower motor neurons on the opposite side of the body
an injury involving the superior portion of the motor cortex affects which region of the body?
the ability to control muscles in the upper limb and proximal portion of the lower limb
what effect would increased stimulation of the motor neurons of the red nucleus have on muscle tone?
this would increase stimulation of skeletal muscles in the upper limbs, thereby increasing their muscle tone
the larger the receptive field……..
the harder it is to locate the exact point of stimulation
_____ are receptors that are normally inactive, but become active for a short time whenever there is a change in the condition that they monitor
phasic