Week 3 - topic 2

Question 1

Main structures of the CNS

Answer 1

*look up image

Question 2

The forebrain

Answer 2

The forebrain is located rostrally (towards the nose) and has two main divisions:

• Telencephalon
• Diencephalon

Question 3

Telencephalon

Answer 3

Cerebrum = Left and Right Cerebral Hemisphere

Cerebral hemispheres =
Cerebral cortex
Limbic system
Basal ganglia

Question 4

Cerebral cortex

Answer 4

The cerebral cortex surrounds the two cerebral hemispheres
Folded/Convoluted:
- sulci (small grooves)
- fissures (large grooves)
- gyri (bulges in between grooves)

Question 5

Lobes of the central cortex

Answer 5

Frontal
Parietal
Temporal
Occipital

There are two of each lobe in the brain (one in each hemisphere)

Question 6

Cerebral cortex - sensory cortex

Answer 6

Sensory Cortex: Three areas of the cerebral cortex receive information from sensory organs

Primary visual cortex
Primary auditory cortex
Primary somatosensory cortex

Question 7

Cerebral cortex - contralateral connections

Answer 7

Contralateral Connections
For all senses except taste and smell:
- Sensory information from the left goes to the right cerebral hemisphere
- Sensory information from the right goes to the left cerebral hemisphere

Question 8

Cerebral cortex - primary motor cortex

Answer 8

• The primary motor cortex is the region of the cerebral cortex most directly involved in the control of movement
• Contralateral connections

Question 9

Cerebral cortex - association cortex

Answer 9

Association Cortex

• Sensory Association Cortex
• Motor Association Cortex

Question 10

Sensory association cortex

Answer 10

• Each primary sensory area of the cerebral cortex sends information toadjacent regions for further processing
• Regions further away receive information from more than one sensorysystem – allows us to connect information across senses

Question 11

Brain diagram

Answer 11

*look up images 1 and 2

Question 12

Basal ganglia

Answer 12

• Collection of nuclei below the cerebral cortex
  nuclei = an identifiable group of cell bodies in the CNS
• Involved in motor control

Question 13

Limbic system

Answer 13

• Widespread group of brain nuclei that innervate each other to form a network
• Involved in learning, memory, and emotions
• look up image

Question 14

Limbic cortex and singular gyrus

Answer 14

• located around medial edge of cerebral hemisphere

- a form of cerebral cortex

Question 15

Hippocampus

Answer 15

• learning and memory
• medial temporal lobe structure
• part of limbic system

Question 16

Amygdala

Answer 16

• important for processing emotions
• interior of rostral temporal lobe
• forms part of limbic system
• processing feelings and expressions of emotions, emotion memories and recognising signs of emotions in others

Question 17

Fornix and mammillary bodies

Answer 17

• fibre bundle connecting the hippocampus to other parts of the brain, including the mammillary bodies of the hypothalamus
• part of limbic system

Question 18

Lateralization in the cerebral cortex - left side processing

Answer 18

• The left hemisphere is related to analysis of information (extracting elements that make up an experience)
• This makes the left hemisphere well suited for processing serial events (things that happen one after the other), and controlling behaviour sequences
• As you can imagine, this means that the left hemisphere is important for language processing

Question 19

Lateralization in the cerebral cortex - right side processing

Answer 19

• The right hemisphere is related to synthesis of information
• This makes the right hemisphere good at combining things for holistic processing
• This type of functionality is important for drawing and reading maps

Question 20

Corpus callosum

Answer 20

• The corpus callosum is a large bundle of axons that interconnects corresponding regions of association cortex on each side of the brain. The left and right frontal lobes are connected, as are the left and right temporal, parietal, and occipital lobes.
• The corpus callosum allows the two sides to talk to one another, and because of this, each part of the association cortex has an idea about what is happening in the corresponding region on the opposite side

Question 21

Thalamus

Answer 21

• The largest portion of the diencephalon
• Located above the hypothalamus
• Main function = a relay station

Question 22

Thalamus nuclei (groups of neural cell bodies)

Answer 22

• Lateral geniculate nucleus (LGN) = visual relay
• Medial geniculate nucleus = auditory relay
• Ventrolateral nucleus = motor relay
• Other nuclei receive and send information to and from the cerebral cortex

Question 23

Hypothalamus

Answer 23

• Located underneath the thalamus
• Controls the autonomic nervous system (regulates bodily functions)
• Controls the endocrine system (hormones)
• Small, but complex structure with many nuclei
• part of diencephalon

Question 24

Mesencephalon

Answer 24

The mesencephalon is the midbrain and it has two major components:

• Tectum
• Tegmentum

Question 25

Tectum

Answer 25

Dorsal portion of mesencephalon
Two main structures:
-> Superior colliculi = visual system/visual reflexes
-> Inferior colliculi = auditory system

*look up image

Question 26

Brain diagram - brain stem

Answer 26

*look up image

Question 27

Tegmentum

Answer 27

Located beneath the Tectum
Structures:
- Part of the Reticular Formation 
- The Periaqueductal Gray Matter
- Red Nucleus and the Substantia Nigra
- Nuclei related to controlling eye movements

Question 28

The hindbrain

Answer 28

The hindbrain surrounds the fourth ventricle and has two major parts:

• Metencephalon - (Pons and Cerebellum)
• Myelencephalon - (Medulla)

Question 29

Cerebellum

Answer 29

• Cerebellar cortex + cerebellar nuclei
• Cerebellar peduncles (little feet) attach the cerebellum to the pons
• Motor control and smooth, coordinated movement

Question 30

Pons

Answer 30

• Looks like a big lump on the brain stem
• It contains part of the reticular formation
• Relays information from cerebral cortex to cerebellum

Question 31

Medulla oblongata

Answer 31

• The main structure in the myelencephalon is the medulla oblongata
• Contains part of the reticular formation: specifically nuclei that control vital functions such as regulation of the cardiovascular system, respiration, and skeletal muscle tone

Question 32

The spinal cord

Answer 32

• The Spinal Cord is a long, tubelike structure of nervous tissue that extends caudally (away from the front of the face) from the medulla oblongata in the hindbrain.
• The main function of the spinal cord is that it distributes motor fibers to the effector organs of the body (glands and muscles) and collects somatosensory information (e.g. pressure, touch) to pass onto the brain

Question 33

Vertebral column

Answer 33

• The spinal cord is protected by the vertebral column.
• The column is composed of 24 vertebrae (interlocking bones) across three main regions; cervical (neck), thoracic (chest); lumbar (lower back), as well as fused vertebrae that make up the sacral and coccygeal sections.
• The spinal cord passes through a hole in each of the vertebrae which is called the spinal formamen

Question 34

Spinal roots

Answer 34

• The spinal cord isn’t as long as the vertebral column - the rest is filled by spinal roots.
• A spinal root is a bundle of axons surrounded by connective tissue.
• Spinal roots occur in pairs which fuse and form a spinal nerve

Question 35

Dorsal and ventral spinal roots

Answer 35

Dorsal Root: The spinal root that contains incoming sensory fibres
Ventral Root: The spinal root that contains outgoing motor fibres