S4) General Organisation and Functional Anatomy of the Brain and Brainstem Flashcards
Identify the basic components of the CNS
- Cerebral hemispheres
- Brainstem and cerebellum
- Spinal cord
Identify the basic components of the PNS
- Dorsal and ventral roots
- Spinal nerves
– cranial nerves
- Peripheral nerves
Compare and contrast the CNS and PNS in terms of:
- Regeneration
- Sophistication
- Myelination
- Tumours
- Immunity
Where are the inferior and superior parts of the brain located?
Because the human brain ‘flexes’ at around the level of the midbrain:
- The superior part of the hemisphere = dorsal
- The inferior part of the hemisphere = ventral
Identify the three parts of the brainstem
What is the role of the midbrain/mesencephalon?
Regulates eye movements and reflex responses to sound and vision
What is the role of the pons?
- Regulates feeding
- Regulates sleep
Describe the structure and function of the medulla
- Structure: contains medullary pyramids (major motor pathway)
- Function: regulates cardiovascular and respiratory systems
Define the term decussation
Decussation is the principle that the body is controlled by the contralateral side of the brain
What are gyri?
Gyrus (pl. gyri) is a ‘ridge or fold’ in the brain
What are sulci?
Sulcus (pl. sulci) is a ‘groove or furrow’ in the brain separating adjacent gyri
Identify the central sulcus
What are fissures?
Fissure is a large ‘crack’ or ‘split’ between adjacent large areas of the brain (giant sulcus)
Identify the frontal lobe and explain its role
- Higher cognition
- Motor function
- Speech
Identify the parietal lobe and explain its role
- Sensation
- Spatial awareness
Identify the temporal lobe and explain its role
- Smell
- Memory
- Hearing
Identify the occipital lobe and explain its role
Vision
Identify the cerebellum and explain its role
- Co-ordination
- Motor learning
Where are motor and sensory structures located in the brain?
Motor – anterior ( sends signals to peripherals)
Sensory – posterior (sends signals from peripherals to the brain)
Identify the optic chiasm and explain its role
Optic chiasm is a site where fibres in the visual system cross over
Identify the uncus of the brain and explain its role
Uncus is a part of the temporal lobe that can herniate, compressing the midbrain
Where are medullary pyramids located?
Medullary pyramids are in the location of descending motor fibres
What is the corpus callosum?
Corpus callosum are fibres connecting the two cerebral hemispheres
contains lots of neurone axons
What is the hypothalamus?
Hypothalamus is an essential centre for homeostasis
What is the thalamus?
Thalamus is a sensory relay station projecting to sensory cortex
Identify the components of the forebrain
- Cerebrum
- Diencephalon
Identify the components of the diencephalon
- Thalamus
- Hypothalamus
- Pituitary gland and stalk
- Pineal gland
Identify the components of the hindbrain
- Pons
- Medulla
- Cerebellum
Identify the following structures on the diagram below:
- Right cerebral hemisphere
- Left cerebral hemisphere
- Cerebral folia
- Tonsils
- Vermis
Identify the following structures on the diagram below:
- Postcentral gyrus
- Precentral gyrus
- Parieto-occipital sulcus
- Calcarine sulcus
- Cingulate gyrus
Identify the following structures on the diagram below:
- Septum pellucidum
- Lateral ventricle
- Third ventricle
- Fourth ventricle
- Cerebral aqueduct
- Fornix
Identify the following structures on the diagram below:
- Thalamus
- Hypothalamus
- Pituitary gland
- Pituitary stalk
- Pineal gland
Identify the following structures on the diagram below:
- Central sulcus
- Occipital notch
- Lateral fissure
- Medullary pyramid
- Occipital pole
Identify the following structures on the diagram below:
- Corpus callosum
- Anterior commisure
- Posterior commisure
- Midbrain
- Pons
- Medulla
Identify the longitudinal fissure on the diagram below:
Identify the following structures on the diagram below:
- Primary motor cortex
- Primary somatosensory cortex
- Primary visual cortex
- Primary olfactory cortex
- Primary auditory cortex
What is epilepsy?
Epilepsy is a common neurological condition where there is a tendency towards the spontaneous firing of neurons (activation of action potentials) within a specific region of the cortex
What are the symptoms of epilepsy?
Symptoms depend on the regions of the brain affected by this abnormal ‘firing’, which may remain local to the focus of origin, or spread to involve the whole hemisphere or even both hemispheres
What is generalised tonic-clonic epilepsy?
- Generalised tonic-clonic epilepsy is a severe form of epilepsy where the abnormal firing of action potentials spreads to both hemispheres of the brain
- The person loses consciousness before involuntary jerking involving all four limbs begin
Most epilepsy is managed with oral medication, but surgical intervention is required in severe and uncontrolled epilepsy such as a corpus callostomy
What is the benefit of this?
A corpus callosotomy is an operation that severs the corpus callosum, interrupting the spread of seizures from hemisphere to hemisphere to reduce the violence and severity of refractory epilepsy
What composes the cerebellum?
- Vermis
- Tonsils
- Cerebellar peduncles
what is the grey matter made of in the cortex?
- outer surface of the brain
- high density of nerve cell bodies
- has sulcus (dip) and gyrus (ridge) to increase surface area for more cell bodies
what is the white matter made of in the brain?
- inside part of the brain
- full of nerve axons (fat)
what is the thin layer covering the gap of the corpus callosum called?
- septum pellucidum
what is the orientation of the brain?
- top is dorsal
- bottom is ventral
- front is rostral
- back is caudal
where is the location of primary motor complex and the primary somatosensory cortex in relation to the central sulcus?
- primary motor complex is in front of the central sulcus
- the primary somatosensory sulcus is found behind the central sulcus
what does the central sulcus separate
- frontal and parietal lobes
what does the Pareto occipital sulcus separate
- occipital and parietal
what does the lateral fisscia separate
temporal lobe from all the others
understand how the the Brain can be a tropical representation of the body
describe the journey of a message from the cortex to the peripheral nervous system
- cortex → mid brain → pons → signal crossses at the level of the medulla → synapses onto a motor nerve
some cranial nerves can communicate from the ipsilateral cortex why?
- as a backup
- eg is someone had a stroke
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what I the contents of the brainstem
- mid brain
- pons
- medulla
- cerebellum
