Gross Anatomy of The Brain Pt. I Flashcards
What do the cerebral hemispheres do?
Involved in basic functions such as receiving and analysing sensory impulses, storing memories and controlling the skeletal muscles on opposing sides of the body
What is the dominant cerebral hemisphere involved in?
Complex functions such as language, reading, writing and speech
What is the non-dominant cerebral hemisphere involved in?
Non-verbal functions such as orientation of the body in relation to its environment, visual experiences and interpreting musical patterns
How are the cerebral hemispheres connected?
Through the corpus callosum
What separates the brain into quarters superiorly?
The longitudinal cerebral fissure and the central sulcus
What makes up the cerebral cortex?
Six layers of neuronal cell bodies which constitute gray matter
More inferiorly the axons of these cells are myelinated which gives them a white appearance - white matter
How is white and gray matter arranged in the brain and spinal cord?
Brain - gray matter surrounds white matter
Spinal cord - white matter surrounds gray matter
What characterised the cerebral cortex superficially?
Gyri (folds)
Sulci (grooves)
Fissures (clefts)
They increase surface area of the brain and are very variable between individuals
How are the cerebral hemispheres divided?
Each into 4 lobes which are named after the overlying bone
The insula (fifth lobe) is deep to the other 3 doesn’t correspond to a bone so is named for its appearance
Where is the cerebellum found?
Inferior to the posterior part of the cerebrum and posterior to the pons and medulla, beneath the tentorium cerebella in the posterior cranial fossa
What makes up the cerebellum?
2 lateral hemispheres that are united by a narrow middle part called the vermis
What characterises the vermis?
Surface has ridges called folia and grooves
What is the tree like appearance of the cerebellum called?
Arbor vitae
What is the function of the cerebellum?
Control of balance ipsilaterally
What is the function of the brainstem?
Connects the brain and spinal cord
What are the different parts of the brainstem?
The midbrain
The pons
The medulla oblongata
Where is the midbrain found and which CNs are associated with it?
The junction of the middle and posterior cranial fossa
CN III - occulomotor, CN IV - the trochlear
Where is the pons found and which CNs are associated with it?
Bulging area in the anterior part of the posterior cranial fossa and is associated with CN V - the trigeminal
Where is the medulla found and which CNs are associated with it?
Continuous with the spinal cord and lies in the posterior cranial fossa
Associated with CN IX, X and XII, the glossopharyngeal, vagus and hypoglossal nerves
CN VI-VIII, abducens, facial and vestibulocochlear, emerge at the junction of the pons and medulla
What is the diencephalon?
The epithalamus, thalamus and hypothalamus
Forms the core of the brain
What are the different lobes of the cerebrum?
Frontal lobe
Temporal lobe
Parietal lobe
Occipital lobe
Limbic lobe
What does the frontal lobe occupy?
The anterior cranial fossa
What separates the frontal and parietal lobes?
The central sulcus
What separates the frontal and parietal lobes from the temporal lobe?
The lateral sulcus
What does the temporal lobe occupy?
The lateral part of the middle cranial fossa
What separates the parietal and occipital lobes?
No obvious separation but on the medial side the parieto-occipital sulcus
What is the opercula?
The lines at which the lateral sulcus can be pulled apart at
Sometimes called the lips
How is the insula found?
By pulling apart the lateral sulcus at the opercula
What are the other names for the opercula?
Island of Reil
Limbic cortex
Which is the largest lobe of the brain?
The frontal lobe
What are the different parts of the frontal lobe?
Prefrontal cortex
Motor cortex
Broca’s area
What is the prefrontal cortex important for?
Problem solving
Complex planning and decision making
Personality
Depth of feeling
What is the motor cortex important for?
Planning
Control
Execution of voluntary movement
What are the different areas of the motor cortex?
Pre motor cortex
Supplementary motor area
Primary motor cortex (found in precentral gyrus)
What is the premotor cortex responsible for?
Learned movements
What is the supplementary motor area responsible for?
Can be stimulated to instigate movement of contralateral limbs
What is the primary motor cortex responsible for?
Specific areas correspond to specific areas of the body for voluntary motor function and movements
Where is Broca’s area found and what is it responsible for?
Located near the motor cortex in the dominant hemisphere and utilised in speech production
How does Broca’s area function?
Regulates breathing patterns while speaking and vocalisations required for normal speech, and coordinates the activities of the muscles of respiration, the larynx, pharynx, cheeks, lips, jaws and tongue to bring about the formation of words.
What happens if there is damage to Broca’s area?
Broca’s Aphasia - sounds can be made but words cannot be formed
What is the parietal lobe responsible for?
Processing of sensory information
What are the different areas of the parietal lobe?
Primary somatosensory cortex
Posterior parietal cortex
Where is the primary somatosensory cortex found and what is it responsible for?
Located in the post central gyrus
Responsible for tactile sensation, conscious perception of pain, pressure, taste, temperature and touch
What is the posterior parietal cortex responsible for?
Integration of sensory information from other areas
Spatial perception
Spatial attention
Cognitive function
What is somatotropin localisation?
The concept that specific areas of the body correspond to a specific point on the central nervous system
Where is somatotopic localisation evident in the cerebral cortex?
The somatosensory and motor cortex
What is the occipital lobe responsible for?
Visual processing
What is found within the occipital lobe?
The primary visual cortex - located around the calcarine sulcus
Surrounded by the secondary visual area
What happens in the primary visual cortex?
Receives visual information relayed via the thalamus and it allows for conscious perception of visual stimuli.
What is the temporal lobe responsible for?
Processing sensory information, especially the conscious perception of hearing and the sense of smell
What is found within the temporal lobe?
Auditory cortex
Wernicke’s area
What is the auditory cortex responsible for?
Hearing
Speech
Words
Pitch
Tone
What is Wernicke’s area responsible for?
Language comprehension
What is Wernicke’s Aphasia?
Leads to someone being able to speak words easily, but often with meaningless word pieces or vocalisation of phonemes
Where is the insula found?
Deep to the lateral sulcus
What is the insula responsible for?
Planning and coordinating articulatory movements necessary for speech
Also has connections with the olfactory cortex
What are the anterior and posterior insula responsible for?
Anterior - language
Posterior - integrating information relating to touch, vision and hearing
