Lecture 2: Basic Structural and Functional Brain Anatomy Flashcards
What is the nervous system made up of?
Central nervous system and peripheral nervous system
What is the central nervous system made up of?
Brain and Spinal chord
What is the brain made up of?
Brain stem and Cerebral Hemispheres
What are the three cerebral hemispheres?
- Cortex
- Sub-cortical structures
- White-matter tracts
What is the peripheral nervous system made of?
Somatic nervous system and autonomic nervous system
What is the autonomic nervous system made up of?
Sympathetic nervous system and parasympathetic nervous system
What are the functions of the neurons in the the brain stem, thalamus, and hypothalamus?
respiration, digestion, glucose metabolism, arousal, regulation of body temperature, blood pressure, swallowing, coughing, sneezing, vomiting, circadian rhythms, etc.
What is the name of a specific group of neurons in the brain stem, thalamus, and hypothalamus?
The Reticular Formation
The reticular formation, a complex network of cells in the core of the brainstem is involved in the control of arousal and sleep.
What is the Thalamus?
The Thalamus acts as a relay station in the brain, transmitting sensory and motor signals
What are the two nucleus’ in the hypothalamus?
The superchiasmatic nucleus and ventromedial nuclues
What is the function of the superchiasmatic nucleus?
controls the circadian (24 hr) biological rhythms
What is the function of the ventromedial nucleus?
Controls the conversion of blood glucose into body fat
What is the corpus callosum?
White matter tracts connective the two hemispheres
What is intercallosal transfer?
Electrical impulses that travel from neurons in one hemispheres and reach neurons in the other hemisphere via the corpus callosum
What is grey matter?
On the outer part of the brain: cerebral cortex. At the level of micro-structure, the cortex is made of bodies of nerve cells - neurons
What is white matter?
Situated under the grey matter. Is made of the long elongated part of the nerve cells - axon.
What is grey matter partly formed by?
Body and dendrites
What is the axon of a neuron?
Part of white matter. They are covered in a protective layer of myelin. The white appearance comes from the light colour of myelin
What is gyrus?
Plateau on cortical surface
What are gyrus?
Fold/ ditch in cortical surface; major sulci are offered referred to as fissures
How are the hemispheres made up?
Each Cerebral Hemisphere is divided into four lobes, separated by three major sulci: the central, lateral and parietal-occipital sulci
What is the top of the brain called when looking at one hemisphere?
Superior (dorsal)
What is the top of the brain called when looking at one hemisphere?
Inferior (ventral)
What is the front of the brain called when looking at one hemisphere?
Anterior (rostral)
What is the back of the brain called when looking at one hemisphere?
Posterior (caudal)
What is the top of the brain called when looking at both hemispheres, down the centre of the brain?
Medial superior
What is the bottom of the brain called when looking at both hemispheres, down the centre of the brain?
Medial inferior
What is the left of the brain called when looking at both hemispheres, down the centre of the brain from the front?
Lateral (right)
What is the right of the brain called when looking at both hemispheres, down the centre of the brain from the front?
Lateral (left)
What are the names of the three slices?
- Axial
- Coronal
- Sagittal
What is an axial slice?
From top down in horizontal slices
What is a coronal slice?
From front to back in vertical slices
What is a sagittal slice?
From hemisphere to hemisphere in vertical slices
What is cytoarchitecture?
Brodmann found that cortical regions cary in the detailed cellular structure
What is phrenology?
School of thought that attempted to localise mental processes anatomically
What is equipotentiality?
- Flourens was one of the earliest proponents of the idea that cognitive functions (such a memory) are not localised but diffusely distributed in the brain
- Following experiments on animals, he concluded that basic physiological regulation and motor functions (breathing, circulation) are localised (e.g. breathing regulation in the brain stem and control of balance in the cerebellum)
- However he could not localise cognitive functions and concluded that different parts of the brain are equally involved in these functions (equipotential)
What does the primary motor cortex control?
The body, head, and limb movement
What is the somatosensory cortex responsible for?
the sensation of touch, sensation from the skin as well as sensation from muscles and some internal organs
What is the primary visual cortex responsible for?
Basic vision
What is the primary auditory cortex responsible for?
Basic hearing
What are the olfactory and gustatory cortices responsible for?
Smell and taste, respectively
What is the hierarchical organisation in senses?
Primary sensory area - the cortical area where sensory information arrives
Secondary sensory area - where the perceptual information gets passed to for more sophisticated processing to take place
Association areas - Where information from different modalities of difference types is integrates
What is the Primary Visual Cortex?
- The primary visual cortex is the first place of a series of places where vision is “created”
- Different regions of the visual field (real world) are perceived in different regions in the primary visual cortex
- There is a correspondence (a mapping) between the spatial structure of the primary visual cortex and the spatial structure of the real world
- Visual processing is then split into a pathway specialised in the analysis of the stimulus features (colour, shape)- the ‘what’ pathway.
- And a pathway specialised in rapid detection of stimulus location and motion- the ‘where’ pathway
What are Fusiform Gyrus?
- Cells in the inferior temporal lobe (the Fusiform gyrus) seem to respond to highly complex visual stimuli
- There is an area in the Fusiform that seems to specialise in face recognition (Fusiform Face Area, FFA)
- Neuroimaging studies of face processing consistently find FFA activation
- Damage to FFA or cell loss in FFA due to degeneration often result in impaired face recognition- prosopagnosia
What is the hierarchical organisation of motor control?
The primary motor cortex exerts direct control over movement However, other areas (premotor and supplementary motor) are involved in the planning of movement and integration of motor behaviour with other behaviour
What are the challenges in functional localisation?
- The dorso-lateral prefrontal cortex (dlPFC) is the region of the brain which expanded more than any other in the course evolution of primates…
- Yet patients with lesions to this region rarely show selective/specific deficits
What is the function of the dorsal lateral prefrontal cortex?
- Supports diverse cognitive tasks
- Its function might be to enables rapid focus shifts, task separation, and structured problem-solving and it seems central to intelligent thought and action.
What is the function of Broca’s area?
Speech production
What did Fedorenco et al (2012) find about Broca’s area?
Fedorenco et al. (2012) found using fMRI that Broca’s area contains two distinct types of subregions: one specialized for language processing and another more general-purpose region engaged in a wide range of cognitive tasks. These subregions lie side by side, reflecting both specialization and broad engagement across different cognitive domains.
What does Localisation of Function tell a psychologist?
- Can the anatomical region tell us anything about the psychological process that resides there, or the relationship between that process and behaviour?
- It might – consider the following kind of inference often made in neuroimaging, the reverse inference
- Say you are a psychologist interested in Post-Traumatic Stress Disorder, particularly in the “flashbacks” experienced by individuals with PTSD
- You want to know if the flashbacks are predominantly visual or whether they involve auditory, tactile, olfactory imagery
- Then scanning someone’s brain while they experience flashbacks may provide you with the answer by comparing the activation of the areas associated with different kinds of imagery
