Anatomy of the Brain - Cortical Areas

Question 1

What is the cerebral cortex and what percentage of brain weight does it comprise?

Answer 1

The cerebral cortex is a continuous layer of gray matter that wraps around either hemisphere and comprises 80% of the brain’s weight.

Question 2

What is the allocortex and how is it subdivided?

Answer 2

The allocortex is the oldest cortical region further divided into the archicortex

Question 3

What is the mesocortex and where is it found?

Answer 3

The mesocortex is a transitional form between the allocortex and isocortex with 3 to 6 cell layers found in the insula

Question 4

What is the neocortex and what percentage of the human cortex does it constitute?

Answer 4

The neocortex also known as isocortex or neopallium

Question 5

How many cellular layers does the neocortex have?

Answer 5

The neocortex has 6 layers of cells or laminae.

Question 6

How do the six major layers of the cerebral cortex vary in development?

Answer 6

The six cortical layers differ in development across regions; for example pyramidal layers are more developed in motor centers

Question 7

What are Broadman areas?

Answer 7

Broadman areas are different regions of the cortex associated with specialized functions.

Question 8

What is the main role of the primary cortex?

Answer 8

Primary cortex areas are responsible for elementary functions related to motor or sensory processing with little interpretation of information meaning.

Question 9

What is the function of association cortex?

Answer 9

Association cortex integrates information receiving input from primary areas; unimodal areas process single sensory modalities

Question 10

What is the difference between unimodal and heteromodal association areas?

Answer 10

Unimodal association areas process information from a single sensory modality while heteromodal (multimodal) areas integrate information from multiple sensory modalities.

Question 11

What are examples of gain of function pathology in cortical areas?

Answer 11

Examples include epilepsy and migraine auras.

Question 12

What are examples of loss of function pathology in cortical areas?

Answer 12

Examples include stroke and trauma

Question 13

What disorders can be caused by abnormal cortical function due to structural or connectivity abnormalities?

Answer 13

Neurodevelopmental disorders such as autism and neuropsychiatric disorders such as schizophrenia.

Question 14

What are the frontal lobe syndromes related to dorsolateral damage?

Answer 14

Dorsolateral damage causes dysexecutive syndrome or pseudodepressed syndrome characterized by poor problem-solving

Question 15

What symptoms are associated with orbitofrontal (inferior/ventral frontal) damage?

Answer 15

Orbitofrontal damage leads to disinhibited or pseudopsychopathic syndrome characterized by disinhibition and emotional lability

Question 16

What syndrome results from medial frontal/cingulate gyrus damage?

Answer 16

The akinetic/apathetic syndrome presenting as akinesia

Question 17

What are the two main regions of the parietal lobe?

Answer 17

The somatosensory cortex and the posterior parietal cortex.

Question 18

What functions does the somatosensory cortex serve?

Answer 18

Localizing sensory information such as touch and temperature

Question 19

What functions does the posterior parietal cortex serve?

Answer 19

Processing sensory and spatial awareness, and sensorimotor integration

Question 20

What are the four functionally distinct areas of the temporal lobe?

Answer 20

Primary auditory cortex (superior temporal gyrus); Wernicke’s area (posterior superior temporal gyrus); Inferior occipital region of the temporal lobe (higher order visual processing); medial temporal cortex

Question 21

What is the role of the primary auditory cortex?

Answer 21

Awareness of audible stimuli.

Question 22

Where is Wernicke’s area located and what is its function?

Answer 22

Wernicke’s area is in the posterior portion of the superior temporal gyrus in the dominant hemisphere responsible for language comprehension.

Question 23

What visual function is associated with the inferior occipital region of the temporal lobe?

Answer 23

Higher order visual processing known as the “what pathway” involved in object recognition.

Question 24

How does the insula contribute to cognitive and emotional functions?

Answer 24

By regulating emotional, cognitive, and motivational signals that are critical for normal mental health and behavior.

Question 25

What functions are attributed to the medial temporal cortex?

Answer 25

Processing of olfaction, learning, memory, and emotions.

Question 26

What is the function of the primary visual cortex?

Answer 26

Awareness of visual stimuli, including perception of color, shape, and motion.

Question 27

What role does the visual association area serve?

Answer 27

Processing and interpreting visual information.

Question 28

How is the retinocortical map organized in the primary visual cortex?

Answer 28

It is organized upside down and backwards: upper halves of visual fields are processed below the calcarine fissure, lower halves above it; central vision is processed near the occipital pole, peripheral vision closer to the calcarine fissure.

Question 29

What are the three visual processing streams and their functions?

Answer 29

The “what” stream (ventral pathway) recognizes objects, the “where” stream (dorsal pathway) processes spatial location, and the “specialized movement” stream (STS pathway) analyzes biological movement.

Question 30

Where is the insular lobe located?

Answer 30

Deep within the lateral sulcus, separating the temporal lobe from the parietal and frontal lobes.

Question 31

What functions does the insular lobe regulate?

Answer 31

Regulation of emotional, cognitive, and motivational signals.

Question 32

Why is the insular lobe important in psychopathology?

Answer 32

It plays a high importance role in emotional and cognitive regulation, linking it closely to various psychopathologies.

Question 33

What are the characteristics of dysexecutive syndrome due to dorsolateral frontal damage?

Answer 33

Poor problem-solving abilities, lack of motivation (abulia), perseverative behavior, and stimulus-bound responses.

Question 34

What personality changes can result from orbitofrontal damage?

Answer 34

Disinhibition, impulsivity, emotional instability, lack of social graces, and poor smell discrimination.

Question 35

What motor and urinary symptoms are associated with medial frontal/cingulate damage?

Answer 35

Leg weakness and urinary incontinence.

Question 36

What sensory modalities are processed by the somatosensory cortex?

Answer 36

Touch, temperature, and pain sensations.

Question 37

What is the main role of the posterior parietal cortex relating to sensorimotor integration?

Answer 37

It processes sensory and spatial awareness and integrates sensorimotor information crucial for tasks like calculus.

Question 38

How is visual information from central and peripheral vision processed in the occipital lobe?

Answer 38

Central vision is processed near the occipital pole while peripheral vision is processed closer to the calcarine fissure and anterior to the occipital pole.

Question 39

What is the significance of the “what” and “where” streams in visual processing?

Answer 39

The “what” stream identifies objects (ventral pathway) and the “where” stream determines their spatial location (dorsal pathway).