The brain LO1-2

Question 1

Composed of

Answer 1

Interneurons & neuroglia
organised into areas of gray matter & white matter
gray matter contains:
- cell bodies of interneurons
organised into nuclei
white matter primarily contains:
- myelinated axons of interneurons organised into tracts

Question 2

Cerebrum

Answer 2

• Largest part of the brain
• Divided into two cerebral hemispheres by the longitudinal fissure (fissure = deep groove)
• Separated from the cerebellum by the transverse fissure

Question 3

Surface area of brain

Answer 3

• gyrus/gyri (ridge)
• sulcus/sulci (shallow groove)
  cover entire surface –> increases the surface area
  of the cerebrum = more neurons

Question 4

Externally, each cerebral hemisphere is divided into

Answer 4

frontal, parietal, temporal, occipital, insula lobes
(central sulcus between frontal lobe and parietal lobe)

Question 5

Internally, each cerebral hemisphere is divided into
three regions:

Answer 5

-Cerebral cortex: outer region of gray matter - contains nuclei
- Cerebral white matter: inner region of white matter, contains tracts
- Basal nuclee: islands of gray matter deep within the white matte

Question 6

Cerebral Cortex (outer gray matter)

Answer 6

Contains nuclei that:
- receive, localise and interpret sensory input
- control voluntary skeletal muscle movements
- perform intellectual and language functions
- store memories
- control our emotions, behaviours and
determine personality

Question 7

Cerebral cortex areas

Answer 7

motor areas
- control voluntary skeletal muscle movements
sensory areas
- receive and localise sensory input
- allow us to consciously perceive sensations
association areas
- interpret sensory input to make sense of the information
- plan and coordinate motor responses
- perform intellectual functions, store memories & determine behaviours and personality

Question 8

Left and right cerebral cortex

Answer 8

receives sensory
information from, and
controls skeletal muscles
on, the RHS/LHS of body
Left controls right
Right controls left

Question 9

Primary Motor Cortex (PMC)

Answer 9

• Located in the precentral gyrus of each frontal lobe
• Generates the somatic motor output that stimulates
  voluntary skeletal muscle movements
• the amount of primary motor cortex devoted to controlling a body part is proportional to the complex nature of its movements
  Damage = = paralysis
  (loss of voluntary movements_

Question 10

Motor Association Areas

Answer 10

Plan & coordinate voluntary
motor activities
Act via the primary motor cortex
frontal eye field:
Broca’s area
premotor cortex

Question 11

frontal eye field

Answer 11

controls voluntary eye movements

Question 12

Broca’s area

Answer 12

controls the muscles involved in speech
production
- usually located in the left hemisphere (left frontal lobe) only
- damage = Broca’s aphasia

Question 13

premotor cortex

Answer 13

Controls learned, skilled motor activities of
a complex nature, e.g., typing, tying a bow
- damage = loss of complex motor skills

Question 14

Sensory Areas of the Cerebral Cortex

Answer 14

Allow us to become consciously aware of (perceive) sensations originating from:
- general sensory receptors for pain, temperature, touch,
vibration, pressure, proprioception
- special sensory receptors for vision, smell, taste, hearing, balance

Question 15

Primary Somatosensory Cortex (PSC)

Answer 15

• Located in the postcentral gyrus of each parietal lobe
• Receives general sensory information
• Perceives sensations of touch, pain, vibration, pressure, temperature & proprioception

Question 16

Somatosensory Association Area

Answer 16

• Receives general sensory input from the primary
  somatosensory cortex
• Interprets general sensory input and compares it to stored memories of past sensory experiences so that you can recognise an object by touch alone
• Damage = failure to
  identify objects by
  touch alone

Question 17

Special Sensory Areas

Answer 17

Visual cortex
- receives visual input detected by photoreceptors
- damage = blindness
Visual association area
- interprets visual input à allows us to recognise what we see
- stores memories of past
visual images
- damage = failure to
recognise objects

Question 18

Olfactory cortex

Answer 18

Temporal lobe
Perceives different
odours

Question 18

Auditory areas

Answer 18

Auditory cortex
- receives sound input detected by the hair cells in the ear to produce & locate sounds
- damage = deafness
Auditory association area
- interprets auditory input –> allows us to recognise sounds
- stores memories of past sounds
- damage = failure to recognise what is heard

Question 19

Visceral cortex

Answer 19

Insula
Perceives visceral
sensations

Question 20

Gustatory cortex

Answer 20

Insula
Perceives taste
sensations

Question 21

Vestibular (equilibrium)
cortex

Answer 21

Insula
Awareness of balance

Question 22

Wernicke’s Area

Answer 22

• Usually located in left temporal lobe (left hemisphere) only
• Comprehends written and spoken language
• Damage = Wernicke’s aphasia

Question 23

Prefrontal Cortex (a.k.a. anterior association area)

Answer 23

• Located in each frontal lobe
• Is responsible for our intellect, complex learning abilities (cognition), personality and behaviour
• Damage = personality changes (moody, impulsive, reckless etc)