Neuroanatomy: Cerebral Cortex and Vision

Question 1

what does it mean to perseverate?

Answer 1

when asked to do a series of tasks, the patient will repeat a single action over and over without moving on to the next

Question 2

what is extinction?

Answer 2

when the patient is confronted with the same stimulus bilaterally and simultaneously he/she will only perceive the stimulus on the normal side

Question 3

what is apraxia?

Answer 3

inability to perform a certain task, not due to primary motor or sensory deficits, but rather due to higher order planning or conceptualization of the task

Question 4

which are more numerous: rods or cones?

Answer 4

rods, by a ratio of 20:1

Question 5

how many neurons does the brain have?

Answer 5

100 billion

Question 6

what function do rods serve?

Answer 6

night vision: they have poor sensitivity in lighted environments, but are more sensitive than cones in darkness

Question 7

what functions do cones serve?

Answer 7

visual acuity, color detection, spatial and temporal resolution

Question 8

If a patient presents with unilateral ptosis, a laterally deviated eye on that same side, and intact pupil constriction in that eye, what is your suspicion?

Answer 8

third nerve palsy due to diabetes (diabetes affects the microvasculature which supplies the center of the nerve, which consists of EOM nerves while pupillary nerves are on the outside)