Systems Architecture Flashcards
How is the peripheral nervous system classified?
How they connect to the CNS
Direction of propagation
Motoneurone’s target effectors
How the PNS connects to the CNS
Cranial nerves
Spinal nerves
Direction of propagation can be…
Afferent
Efferent
Motorneurone’s target effectors
Somatic
Autonomic (Parasympathetic or sympathetic)
Why can we use studies of lower species to show us how the human brain operates?
Because the basic architectural organisation of the brain has been retained within the brains of all vertebrates
What advantage does having areas of the brain specified for function?
Allows us to have more sophisticated systems (e.g. the visual system) which gives us a greater chance of survival and therefore more chance of passing on our genes
What is the evidence for functional modules?
Neural correlates of musical ability, fMRI studies of music reading and language reading shared areas of the brain
What evolutionary advantage could musical ability have?
Some suggest it attracts the opposite sex which leads to the passing on of genes
Musical virtuosity demonstrates intelligence and sensitivity, traits which females regard as favourable
How do musicians brains differ from non-musicians?
In the area which controls the hand (the hook), 90% of the population have an inverted ‘Omega’ whereas musicians have a lower-case ‘Omega’
Why do musicians have different shaped hand control areas?
Neurones sprout new connections changing the shape and size of the area
They have to do this to allow signal for the complex movements involved in musical performance to move the correct muscles in the correct order
What is the ability to produce new connections between neurones in response to physical demands called?
Plasticity
Plasticity hypothesis
The application of a stimulus leads to twofold changes in the nervous system
The nerve reacts to the incoming impulse (changes due to excitability)
Permanent functional transformations arise in particular systems of neurones as a result of appropriate stimuli or combination (plastic changes)
The average neurone forms about _______ synapses
1000 - 10000
The human brain contains at least ____ neurones
10^11
About how many connections are there in the human brain?
10^14
What does cephalised mean?
Concentration of organs, visual system etc in the head
What is the fish brain like?
A tube that carries nerves from distal parts of body to a central point
Mechanical and unconscious
What is the reptilian brain like?
Nerves sorted into specialised modules Light sensitive for vision Chemosensitive for smell Bulge on rostral area of spinal cord Connected to cerebellum
What is the mammalian brain like?
Hypothalamus allowing reaction to more stimuli
Thalamus developed to allow vision, smell and hearing to be used together
Thalamus tells action potentials where they need to go
Limbic system generates emotions but not able to experience them as its unconscious
Amygdala and hippocampus, involved in crude memory
What is the human brain like?
Larger cortex pushing cerebellum to current position
Skull bones pushed outwards forming high, flat forehead and domed head
How long ago did the human brain enlarge?
1.5 million years ago
Explosive enlargement of areas associated with thinking, planning, organising and communicating
Sagital plane
Down the midline of the brain
Horizontal plane
Horizontal line through the middle of the head (through the nose)
Coronal plane
Line through from ear to ear
Why is the outer layer of the brain grey?
Lack of myelin
What is the grey matter?
Cortex
Cell bodies
Computing centre
What is the frontal lobe involved in?
Personality
Phineas Gage case
What is the temporal lobe involved in?
Hippocampus is deep inside
Involved in memory
What is the parietal lobe involved in?
Mathematical processing
Eienstein had a big parietal lobe
What is the occipital lobe involved in?
Visual processes
Primary visual cortex (area 17)
What is the cerebellum involved in?
Balance and movement
Higher cognitive functions like reading and writing
What is a ridge called?
Gyri (gyrus)
What is a crease called?
Sulci (sulcus)
Why does the white matter look white?
Myelinated axons appear white
What does the white matter do?
Allows for connections to occur between cell bodies
Allows all various units to ‘talk’ to each other
Share information
Divide the work up
Check the conclusions are reasonable
Sends information to specialised areas
Broadmann’s Areas
Systematic map of brain based upon cell types
Broca’s area (44)
Used for language production - motor area which controls things like lips, tongue, larynx etc
Wernicke’s area (22)
Holds the grammatical rules for language, allows you to produce grammatical speech
Primary motor cortex (4)
Produce movement in all areas except for speech
Visual cortex (14)
Processes visual information
Which part of the brain is plastic throughout your life?
Hippocampus
Produces new cells - hyperplasia
Makes new connections
What is a plastic change?
A permanent functional transformation in particular systems of neurones as a result of appropriate stimuli or combination
What is a change due to excitability?
Nerve cells reacting and changing due to incoming impulses
Why do we have the modern head shape?
Pre-frontal lobes jut out in the front of the brain, pushing frontal dome and forehead forwards giving modern head shape
Frontal lobes expanded by ____ to create the neocortex
40%
