Neuroanatomy - CNS & Cerebral Cortex

Question 1

What are the subdivisions (structural organization) of the brain?

Answer 1

Cerebral hemispheres
Diencephalon (thalamus, hypothalamus, epithalamus)
Brain stem (midbrain, pons, medulla)
Cerebellum

Question 2

Explain the Gray matter and where is it found?

Answer 2

Gray matter represents the short and non myelinated neurons and neuron cell bodies.

GM can be organized into nuclei (looking like spots), which can be found on the cerebrum, cerebellum, and brain stem.
Some is at the outer layer of the cerebrum, known as the corticoid areas.
Butterfly region of spinal cord

Question 3

Explain the White matter.

Answer 3

White matter represents the long, and mostly white myelinated (insulated) neurons.

Question 4

What fills up the ventricles of the brain?

Answer 4

Cerebral Spinal Fluid, lined by ependymal cells

Question 5

Explain how the ventricles connect to each other.

Answer 5

The pair lateral ventricles are separated by the septum pellucidum.

The lateral ventricles communicate with the 3rd ventricle via the interventricular foramen.

The 3rd ventricle connects to 4th ventricle via the cerebral aqueduct and the 4th is continuous with central canal.

Question 6

What are the 3 apertures and what are they for?

Answer 6

The 4th ventricles has paired lateral apertures and a median aperture. The 3 connect the ventricles to the subarachnoid space.

Question 7

Explain the shapes and sections of the hemispheres.
What are the two main fissures?

Answer 7

Sulci (plur.) are the “hills”, separated by the gyri “valleys”.

We have the central gyrus in between the precentral gyrus (motor) and the postcentral gyrus (sensory).
Lateral sulcus & parieto-occipital sulcus…

We have the longitudinal fissure and the transvers cerebral fissure separating the cerebrum from the cerebellum.

Lobes: F, T, P O, and insular

Question 8

What is the function of the cerebral cortex GM?

Answer 8

Conscious behaviour

Question 9

What are the areas of landmarks called on the cerebral cortex?

Answer 9

Brodmann areas

Question 10

What are the 4 generalizations of the cerebral cortex?

Answer 10

1. Motor, sensory, association areas
2. Contralateral: each hemisphere handles the opposite side of body
3. Lateralization: symmetrical but not the same in function
4. No functional areas of cortex acts alone - all conscious behaviour involves the entire cortex.

Question 11

Where is the primary motor cortex situated?

Answer 11

Precentral gyrus of frontal lobe

Question 12

What cells allow for the control of skeletal muscles?

Answer 12

Pyramidal cells: large neurons in which the axons project to the spinal cord, following the corticospinal tract –> voluntary motor functions

Question 13

Mapping of the body in CNS

Answer 13

Somatotopy
(Face, hands, tongue represented the largest)

Question 14

Explain what happens during a stroke

Answer 14

Contralateral: damage on R hemisphere paralyzes the L side of body.

ONLY voluntary movement lost while reflex still possible.

Question 15

Which part of the motor area helps to plan movement and allow to do complex tasks, and depends on sensory feedbacks?

(Sometimes referred to as muscle memories)

Answer 15

Premotor cortex.

Question 16

Explain an example of a damage to premotor cortex.

Answer 16

Keyboard typing:
Damage to premotor cortex would mean that you can still move your fingers but no memory to know where to place your fingers before typing a word.
(No memories of series of motor response used before)

Question 17

Motor speech area (language production) and planning on the L hemisphere

Answer 17

Broca’s area

Question 18

What are the 4 motor areas?

Answer 18

1. Primary motor cortex
2. Premotor cortex
3. Broca’s area
4. Frontal eye field

Question 19

Where is the primary somatosensory cortex situated?

Answer 19

Postcentral gyrus

Question 20

How does the primary somatosensory cortex receives info?

Answer 20

From receptors of the skin & proprioceptors (muscles & joints) - spatial discrimination

Question 21

Somatosensory association cortex

Answer 21

Integrate/analyze somatic input and uses prior experiences and knowledge for interpretation

Question 22

Name the two visual areas and their role.

Answer 22

Primary visual cortex - map of visual space on retina (damage = loose vision)

Visual association area - interprets visual image
(damage = can see BUT not recognize)

Question 23

What is the inability to recognize something that you see?

Answer 23

Visual Agnosia

Question 24

What does the olfactory cortex covers on the medial aspect of temporal lobe?

Answer 24

Uncus (–> limbic system)

Question 25

What are the 8 sensory areas?

Answer 25

1. Primary somatosensory cortex
2. Somatosensory association cortex
3. Visual area (PVC & VAA)
4. Auditory cortex (2)
5. Vestibular cortex
6. Olfactory cortex - uncus
7. Gustatory cortex - insula
8. Visceral sensory area

Question 26

What are the steps to reach the multimodal association cortex?

Answer 26

1. Sensory receptors
2. Primary sensory cortex
3. Sensory association cortex
4. Multimodal association cortex

Question 27

Which part of the multimodal association cortex that is responsible for the working memory, judgement, reasoning, planning, conscience?

Matures slowly and linked with limbic system?
Linked with developments of personalities

Answer 27

Anterior association area (prefrontal cortex)

Question 28

Which part of the multimodal association cortex is for the storage of complex memories & link sensory inputs?

Answer 28

Posterior association area

Question 29

Which area is responsible for the understanding of language?

Answer 29

Wernicke’s area

Question 30

What is contralateral neglect

Answer 30

Cannot see or localize - don’t see one side of body as a part of them

Question 31

What is cerebral dominance?

Answer 31

Hemisphere dominant for language - LEFT

Question 32

Right cerebral dominance are L-handed or…

Answer 32

Ambidextrous

Question 33

Which fibers (WM) are responsible to connect areas of the two hemispheres?

Answer 33

Commissural fibers (ex. corpus callosum)

Question 34

Which fibers (WM) are responsible for connections within a hemisphere? (connect gyri, lobes)

Answer 34

Association fibers

Question 35

Which fibers (WM) are responsible to connect cortex to the rest of NS? (vertical)

Answer 35

Projection fibers

Question 36

What are the 3 parts of the basal nuclei?

Answer 36

Caudate nucleus (ring), Putamen (lateral), Globus pallidus (medial)

Question 37

The basal nuclei is responsible for what?

Answer 37

No direct to motor pathways
Roles overlap with cerebellum: start/stop
Filtering
Associated with cognition and emotion

Question 38

Which disease is associated the degeneration of caudate nucleus, in which the patient is unable to control feelings, thoughts or movement?

Answer 38

Huntington’s disease (huntingtin protein accumulates)

Question 39

Which disease is associated the degeneration of dopamine-releasing neuron of substantia nigra?

Answer 39

Parkinson’s disease

Question 40

Lists the parts of the diencephalon and which ventricle does it enclose? What are the key roles?

Answer 40

= thalamus, hypothalamus, epithalamus
- enclose the 3rd ventricle
- key roles: mediating, motor activities, cortical arousal, learning, memory

Question 41

What connects the two masses of the thalamus GM

Answer 41

Interthalamic adhesion

Question 42

Where is the epithalamus and what does it contain?

Answer 42

Dorsal of diencephalon, roof of 3rd ventricle
- Pineal gland for melatonin
- Choroid plexus for production of CSF

Question 43

What does the hypothalamus regulate? (7)

Answer 43

• ANS
• Emotional response and behavioural
• Body temp regulation
• Sleep and wake regulation
• Water balance and thirst regulation
• Control endocrine system
• Regulation of food intake

Question 44

What release melatonin (sleep-awake cycle)?

Answer 44

Suprachiasmatic nucleus

Question 45

What releases ADH and oxytocin?

Answer 45

Supraoptic & paraventricular nuclei