Week 2 - Structure of the brain Flashcards
1
Q
Negative feedback loops in which part/s of the brain ensure that cortisol levels do not rise indefinitely?
A
- Hypothalamus
- Pituitary gland
2
Q
What is the enteric nervous system?
A
An internal network of neurons within the gut which can work independently and in concert with the brain
3
Q
What is the ‘gut-brain axis’?
A
Bidirectional communication between the brain and the GI tract involving the immune system, neurons and the endocrine system
4
Q
How is the enteric nervous system different from the other parts of the peripheral nervous system?
A
There are some reflexes that operate entirely in the gut without any input from the CNS
5
Q
At the simplest level, what are the three main parts of the brain?
A
- Cerebrum
- Cerebellum
- Brain stem
6
Q
What regions are in the cerebrum?
A
- Cerebral cortex
- Subcortical regions
7
Q
How big is the cerebrum?
A
It is the largest part of the brain
8
Q
Where is the cerebellum located?
A
In the back of, and below, the cerebrum
9
Q
What is the cerebellum associated with?
A
- Control of balance
- Movement
10
Q
Under what is the brain stem located?
A
Below the cerebrum
11
Q
What is the brain stem responsible for?
A
Control of involuntary processes such as heart rate and breathing
12
Q
What is the structure that covers the cerebrum?
A
The cerebral cortex
13
Q
What are the four lobes of the cerebrum?
A
- Frontal lobe
- Occipital lobe
- Parietal lobe
- Temportal lobe
14
Q
What is the role of the frontal lobe?
A
- Controlling movement and language
- Higher cognitive skills such as reasoning and planning
15
Q
What is the role of the parietal lobe?
A
- Processing information about touch
- Spatial awareness
16
Q
What is the role of the temporal lobe?
A
- Processing auditory information
- Speech
- Memory
17
Q
What is the role of the occipital lobe?
A
- Processing visual information
18
Q
What is the name of the ridges found in the outer layer of the brain?
A
Gyri
19
Q
What is the name of the grooves found in the outer layer of the brain?
A
Sulci
20
Q
What is the prefrontal cortex?
A
A subdivision of the frontal lobe
21
Q
What is the prefrontal cortex responsible for?
A
- Executive function
- Planning complex behaviour
- Decision-making
- Moderating behaviour
22
Q
What is the orbitofrontal cortex?
A
A subregion of the prefrontal cortex
23
Q
What is the purpose of the orbitofrontal cortex?
A
It is involved in reward and emotions
24
Q
What does the pituitary gland do?
A
- Releases certain hormones into the blood
- Responds to signals from the brain
25
How (directionally) is the top of the brain described?
In the dorsal, or superior, direction
26
How (directionally) is the lower part of the brain described?
The ventral, or inferior, direction
27
Where is the cerebellum located?
Towards the posterior of the brain, at the lowest point, spanning both hemispheres
28
In which region of the brain would you find the brain stem?
The ventral region
29
Where in the brain would you find the parietal lobe?
At the top and back, spanning both hemispheres
30
Where in the brain would you find the occipital lobe?
At the back, roughly mid-height, spanning both hemispheres
31
Where in the brain would you find the ooccipital lobe?
Low on the side on each hemisphere
32
Where in the brain is the prefrontal cortex?
The anterior region of the frontal lobe - the very front/topmost, spanning both hemispheres
33
Where would you find the motor cortex?
Just behind the prefrontal cortex, on both hemispheres
34
Where is the primary somatosensory cortex?
It is part of the occipital lobe, spanning both hemispheres at the back of the brain
35
What is the type of cut which divides the two hemispheres of the brain?
A sagittal cut
36
What is the singulate cortex responsible for?
- Emotions
- Resolving conflicts
- Deciding a course of action
37
What is the corpus callosum?
A large bundle of myelinated neurons which connects the two hemispheres
38
How many ventricles does the brain have?
4r
39
What is the hippocampus responsible for?
- Organisation/retrieval of memories
- Spatial learning tasks
- Navigation
40
What is the amygdala involved with?
- Behaviour
- Emotions
- Retrieval of unpleasant memories
41
What is the hypothalamus responsible for?
- Control of emotional reactions
- Eating
- Drinking
- Connects with pituitary gland to trigger hormonal secretions to emotions
42
The brain stem consists of which areas?
- Midbrain
- Pons
- Medulla
43
What is the ventral tegmental area?
An area within the midbrain involved in addictions and rewards
44
What is the ventral tegmental area responsible for:
- Addiction
- Rewards
45
What do the pons play roles in?
- Control of arousal
- Waking
- Sleep
46
What subconscious processes does the medulla control?
- Breathing
- Digestion
- Control of heart rate
- Blood vessel function
47
What is cerebrospinal fluid (CSF)?
Fluid which surrounds the brain and spinal cord.
It provides cushioning and buoyancy, protects against trauma, removes waste products
48
What is the function of the nucleus accumbens?
It is an area which receives input from dopaminergic neurons in the ventral tegmental area
49
What is the nucleus accumbens important for?
- Motivation
- Addictions
50
What are the types of cells which form the blood-brain barrier?
- Astrocytes
- Pericytes
- Endothelial cells
51
What class of cells do astrocytes belong to?
Glial cells
52
What is the main function of astrocytes?
To support the environment of the brain
53
What is the function of pericytes within the blood-brain barrier?
- Control brain blood flow
- Maintain blood-brain barrier
54
What types of substances may move across the blood-brain barrier?
- Fat-soluble molecules such as oxygen and CO2
- Glucose
- Amino acids
55
What types of substances are not able to pass across the blood-brain barrier?
- Pathogens
- Some drugs
56
Which feature of the blood-brain barrier ensures that bacteria and viruses are unable to cross from blood vessels to the brain tissue?
The tight junctions between endothelial cells in the blood vessels
57
What is the neurovascular unit?
The cells of the brain that help regulate the brain’s blood supply
58
Which are the types of cells that make up the neurovascular unit?
- Neurons
- Astrocytes
- Pericytes
- Microglial cells
- Endothelial cells
59
What is one of the key functions of astrocytes?
To detect activity in neurons and alter dilation of local blood vessels accordingly
60
What are the four ventricles of the brain?
- Two lateral ventricles
- Third ventricle
- Fourth ventricle
61
What is the choroid plexus?
A region of the ventricles that produces CSF via filtration of the blood
62
How is CSF described?
As an ultra-filtrate of blood plasma
63
What electrolytes does CSF contain?
- Sodium ions
- Chloride ions
- Bicarbonate ions
64
What is the lymbic system?
A group of structures which are involved with memory, emotion and arousal
65
What are the structures of the lymbic system?
- Hypothalamus
- Hippocampus
- Amygdala
66
How does an MRI work?
A patient is exposed to a strong magnetic field and then to a radio-frequency wave, which affect the behaviour of nuclei atoms in water molecules
67
What is the substantia nigra involved in?
- Movement
- Reward
- Addiction
68
What does an fMRI do?
Registers blood flow to functioning areas of tissue. It highlights brain areas that are active in a specific cognitive task
69
How does a PET scan work?
Radiolabelled compounds are ingested and can be detected in brain regions where activity is high
70
What does the ‘PET’ in PET scan stand for?
Positron emission topography
71
What is spatial resolution?
A measure of the accuracy with which structures or activities can be localised within the brain and distinguished from one another
72
What is temporal resolution?
A measure of the accuracy of recording changes over time
73
What is a ‘default mode network’ (DMN)?
A collection of brain regions that are thought to be activated when an individual in in a ‘resting’ state
74
Which regions are thought to be involved with the DMN (default mode network)?
- Medial prefrontal cortex
- Parietal cortex
- Posterior cingulate cortex
75
What is the salience network thought to be involved with?
Choosing which aspects of the external environment require the most focus at any given time
76
What is the central executive network involved with?
Complex, cognitively demanding tasks
77
What is a correlation coefficient?
A parameter that indicates the strength of a relationship between two variables
78
How is a correlation coefficient expressed?
- As a number between 1.0 and -1.0
- Denoted by the symbol r (italicised)
79
What are ‘fibre tracts’?
Bundles of axons that connect one brain region to another
80
What is white matter?
Parts of the neuronal fibres which are coated in a myelinated sheath
81
What are the names of the two classifications of fibre tracts within the brain?
- Association fibres
- Commissural fibres
82
What function do association fibres perform within the brain?
They connect brain regions within the same hemisphere
(e.g. parts of the limbic system to the frontal lobe)
83
What function do commissural fibres perform within the brain?
They connect regions across the he)
84
What is the corpus callosum?
A large bundle of fibres which connects the two hemispheres of the brain
85
What is ‘brain lateralisation’?
The tendency for one side of the brain to be dominant for a particular task
86
For most people, which side of the brain is dominant for naming objects?
The left side
87
Which side of the brain is mainly responsible for speech?
The left hemisphere
88
What is DWI (diffusion weighted magnetic resonance imaging)?
A type of MRI which tracks the direction of movement of water molecules
89
What can DWI (diffusion weighted MRI) be used for?
Mapping the pathways of fibre tracts
90
What is a ‘connectome’?
A map of all the the various connections of fibre tracts within the brain
