The Brain and Cerebral Cortex

Question 1

Why is the brain referred to as the master organ?

Answer 1

It is responsible for virtually all our thoughts, feelings and behaviours.

Question 2

Average weight of the adult brain?

Answer 2

1.5kg

Question 3

How many neurons, and how many connections between them?

Answer 3

Billions; trillions

Question 4

Explain how the brain is protected.

Answer 4

Encased in the skull; space between the brain and the skull containing fluid to protect it against knocks.

Question 5

Describe the consistency of the brain.

Answer 5

Jelly like; covered by a strong plastic-like membrane.

Question 6

Define: cerebral cortex

Answer 6

The convoluted (folded) outer layer of the two cerebral hemispheres, involved in cognitive processes such as learning, language, memory, attention, problem solving and perception (LLAMPP), and both planning and controlling voluntary bodily movements.

Question 7

How thick is the cerebral cortex and what is its surface area?

Answer 7

2-4mm; 0.25m2.

Question 8

The size of the cerebral cortex may be linked to an organism’s intellectual ability. Explain. (3 marks)

Answer 8

Larger cerebral cortex = more capable of higher order mental processes.
Birds -> cats -> primates -> humans
Humans have the largest cerebral cortex and the greatest number of mental abilities.

Question 9

Do more “complex” mammals have greater or less amounts of association cortex area than simple mammals?

Answer 9

Greater man

Question 10

What are the 3 categories for the areas of cerebral cortex?

Answer 10

Sensory cortex areas
Motor cortex areas
Association cortex areas

Question 11

Define: sensory cortex areas

Answer 11

Receive and process information from our different senses, through sensory receptors.

Question 12

Make a flow chart of the way sensory information reaches the brain.

Answer 12

Sensory info -> sensory receptors -> spinal cord -> thalamus -> primary cortex -> to be processed!

Question 13

What are the sensory areas of the brain?

Answer 13

Primary somatosensory cortex
Primary visual cortex
Primary auditory cortex

Question 14

Define: motor cortex area

Answer 14

Receives and processes information about voluntary bodily movements; and sends information about bodily movements to skeletal muscles.

Question 15

Define: association cortex area

Answer 15

receive and integrate information between sensory and motor areas as well as from other lobes to enable higher-order mental processes.

Question 16

Define: higher order mental processes

Answer 16

decision-making, memory, perception, planning and learning (dmppl – dumpling)

Question 17

What sensory/motor phrase refers to the areas of the cerebral cortex collectively, and which refer to the areas within the individual lobes?

Answer 17

Lobes: sensory areas
Collective: sensory cortex areas

Question 18

What areas make up the primary cortex area?

Answer 18

Sensory and motor areas

Question 19

What percentage of the cerebral cortex is made up of association areas and primary cortex areas?

Answer 19

75% association areas

25% primary cortex areas

Question 20

Where are association areas located?

Answer 20

Typically next to the primary cortex which is specialised in interpreting its info; if located further away, it might be involved in integrating information from several senses and memories.

Question 21

Define: central fissure

Answer 21

a very deep groove which runs from the top down the sides of each hemisphere between the motor and somatosensory cortex, separating the front (anterior) of the cortex from the rear (posterior) section.

Question 22

Define: cortical lobe

Answer 22

Areas of the brain associated with different structures and functions.

Question 23

What are the lobes named after?

Answer 23

The plate of the skull protecting it.