Systems level architecture

Question 1

Evolution: pain. How does the body react?

Answer 1

Spinal cord-withdrawal reflex. Requires sensory receptors.

Question 2

Evolution: loom. How does the body react?

Answer 2

Need an avoidance mechanism. Need sensory mechanism to see threat/hear. Sensorimotor midbrain tackles this.

Question 3

Evolution: learned threat. How does the body react?

Answer 3

Avoidance mechanism. Uses cortex and limbic system. Need a high level of processing (Memory)

Question 4

Response suppression. What is it?

Answer 4

High level of response and cognitive control

Question 5

Spinal cord?

Answer 5

Part of the CNS within the vertebral column

Question 6

What is the vertebral column comprised of?

Answer 6

The cervical/thoracic/lumbar and sacral region

Question 7

Spinal cord roots

Answer 7

Have the dorsal and ventral roots

Question 8

Dorsal root?

Answer 8

Afferent. Is sensory receptors. Affected by the world

Question 9

Ventral root

Answer 9

Efference. Has an effect on the world (is an output). Motor.

Question 10

Ventral root

Answer 10

Efferent. Has an effect on the world (is an output). Motor.

Question 11

Subdivisions of the brain

Answer 11

Forebrain(telencephalon and diencephalon)/Midbrain (mesencephalon)/Hindbrain (metencephalon and myelencephalon)

Question 12

Hindbrain: medulla

Answer 12

• Base of brain: medulla
• Basic controls such as respiration. Low level control
• Excretory reflexes
• Motor control: balance
• Can be damaged by intracranial pressure

Question 13

Hindbrain: pons

Answer 13

• Relay from cortex and midbrain to cerebellum
• Contains millions of neuronal fibres
• Pontine reticular formation (generates patterns such as walking)

Question 14

Hindbrain: cerebellum

Answer 14

• Motor structure
• Smaller than brain but contains many neurons as the rest of the CNS
• For ‘motor errors’ adjusts weights to eliminate error
• Thought exclusive for motor coordination but recently implicated in cognitive and affective/emotional function

Question 15

Midbrain: tectum (called colliculi)

Answer 15

• Visual/spatial and auditory frequency range
• Has two parts: superior colliculus and inferior colliculus
• Superior: sensitive to sensory change: defensive movements. Not quite conscious. Can detect an object that is getting bigger
• Inferior: similar but for auditory signals.

Question 16

Midbrain: tegmentum

Answer 16

Has three structures
1.) The periaqueductal gray: for pain modulation and receiving pain signals. Has a role in pain (ascending and descending pain signals). Has roles in reproduction and defensive behaviour
2.) Red nucleus: target of cortex and cerebellum projects to spinal cord. Has a role in pre-cortical motor control (esp arms and legs)
3.) Substanitia nigra: part of the basal ganglia. Substantia nigra pars compacta: basal ganglia input
Substantia nigra pars reticulata: basal ganglia output

Question 17

Forebrain: what are the two main parts

Answer 17

The Diencephalon. Has two main parts:

1. ) Thalamus
2. ) Hypothalmus

Question 18

Forebrain: thalamus (relay structure)

Answer 18

• Has specific nuclei: relay signals to cortex/limbic system for all sensations
• Non specific nuclei: role in regulating state of sleep/wakefulness/levels of arousal
• Important relays from basal ganglia + cerebellum back to cortex

Question 19

Diencephalon: Hypothalamus

Answer 19

• Regulates the pituitary gland which regulates hormonal secretion: interface between brains + hormones
• Role in hormonal control of motivated behaviours: hunger/thirst/pain/temperature/pleasure/sex

Question 20

Forebrain: cerebral cortex

Answer 20

Subcortical (under cortex) portions: basal ganglia and limbic system

Question 21

Basal ganglia

Answer 21

• Parkinsons is a disease of the B.G
• Is a group of structures
• Loop organisation
• Involved in motor function
• Role in action selection and reinforcement learning

Question 22

Limbic system

Answer 22

• Group of structures
  -involved in emotion and memory
  Influences the formation of memory by integrating emotional states with stored memories of physical sensations
• Amygdala: important. E.g. have a bad experience with a carrot so you have a bad emotional reaction to a memory of a carrot

Question 23

What are the 6 structures of the limbic system?

Answer 23

1. ) Amygdala
2. ) Hippocampus
3. ) Fornix
4. ) Cingulate gyrus
5. ) Septum
6. ) Mammilary body

Question 24

Cerebral cortex: cortical lobes

Answer 24

1.)

Question 25

Cortical lobes

Answer 25

• Gray matter (6 layers): made of cell bodies

- White batter: made of fibres/axons

Question 26

Frontal lobe

Answer 26

• For planning/response inhibition

Question 27

Parietal lobe

Answer 27

• Has the postcentral gyrus
  Contains the primary somatosensory cortex
• Permits complex spatio-temporal predictions e.g. catching something when you’re moving

Question 28

Temporal lobe

Answer 28

• Contains primary auditory cortex

- Inferotemporal cortex: recognition of faces and objects

Question 29

Occipital lobe

Answer 29

• Has a dorsal stream and a ventral stream
  Dorsal: vision for movement. Where is it in relation to us?
  Ventral: vision for identification. What does it mean to us?

Question 30

Cerebral cortex: cortical lobes

Answer 30

1. ) Frontal lobe
2. ) Parietal lobe
3. ) Temporal lobe
4. ) Occipital lobe