Functional regions of the brain Flashcards
What are the lobes of the brain?
4 lobes: frontal, parietal, temporal and occipital
What are the components of the hindbrain?
Cerebellum, pons and medulla oblaganta
What are the depressions in the brian?
Sulci
What are the elevations in the brain?
Gyri
What are the major sulci in the brain?
Central sulcus
Medial longitudinal fissure: left and right hemisphere
Parietaloccipital sulcus
Lateral sulcus
What is the corpus callosum?
A primary commisure of the brain which is formed of white matter that connects the left and right hemispheres
What are the poles of the brain?
3 poles corresponding to the 3 prominences of the brain: frontal pole, temporal pole and occipital pole
What is the blood supply to the brain?
Anterior supply to the brain is via the internal carotid artery, a branch of the common carotid
Posterior supply to the brain is via the vertebral artery, a branch of the subclavian artery
What is the anterior circulation of the brain?
Internal carotid artery branches off into an anterior cerebral artery and a middle cerebral artery. The middle cerebral artery has a posterior communicating artery to connect with the posterior cerebral artery.
What is the posterior vascularisation of the brain?
Vertebral artery continues as the basilar artery which gives off branches of the posterior cerebral artery. This communicates with the middle cerebral artery via the posterior communicating artery.
Which artery branch supplies the deeper structures of the brain?
Central and sulcate branches
Which artery branch supplies the surfaces of the brain?
Cortical branches
What areas of the brain does the anterior cerebral artery supply?
Frontal lobe and minimally the occipital lobe. Supply is primarily to the lower limbs in Brodmann’s area.
What areas of the brain does the middle carotid artery supply?
Frontal lobe and the temporal lobe. Supply is primarily to the upper limbs and the face.
What areas of the brain does the posterior carotid artery supply?
Occipital lobe and minimally the temporal lobe. Supply is signficantly to Brodmann’s area for vision and hearing.
What is the supplementary motor area?
Responsible for planning action and co-ordinating bi-lateral movement.
What is the pre-motor cortex?
Responsible for selecting the appropriate areas on the somatotropic map in the cortex for movement
What is the Brodmann’s area?
Areas of the brain with specific functions in the body
What are the major body innervations in the motor cortex?
Lower limbs and the face, mouth and jaw
How does a lesion in the middle cerebral artery affect supply?
Contralateral hemianaesthsia, weakness in the upper limbs and face muscles, preference for ipsilateral gaze due to weakness of supply to eye muscles. Contralateral hemineglect (loss of sensation)
How does a lesion in the anterior carotid artery affect supply?
Contralateral hemianaesthesia, weakness in the lower limbs, contralateral hemineglect
How does a lesion in the posterior cerebral artery affect supply?
Contralateral blindness and hemianaesthesia
What is the sensory association area?
Interprets stimuli from the sensory neurons
What are the major body innervations in the primary somatosensory cortex?
Hands, lips, tongue and face
What is the primary fissure?
Separates the anterior and posterior lobes of the cerebellum
What is the posterolateral fissure?
Separates the flocculonodular lobe from the posterior lobe.
What are the regions of the cerebellum?
Central vermis that separates the cerebellum into a left and right From medial, it is the archicerebellum, spinocerebellum and the neocerebellum
What are the cerebellar peduncles?
Allows communciation between the cerebellum and the midbrain, pons and medulla. There is a superior cerebellar peduncle and an inferior cerebellar peduncle.
What are the components of the intersposed nucleus?
Globose and emboliform nuclei, part of the spinocerebellum
What is the function of the fastigial nucleus?
Vestibular system for co-ordination of axial muscles for balance.
What is the archicerebellum?
AKA vestibulocerebellum. Consists of vermis, fastigial nuclei and the floccuonodular lobe. It has afferents and efferents with the vestibular nuclei of the pons via the superior cerebellar peduncles. It creates the vestibulospinal tract to co-ordinate axial muscles and the vestibulo-ocular tract to co-ordinate the eye muscles
What is the spinocerebellum?
Consists of the vermis, globose nuclei and emboliform nuclei. It has afferent from the spinocerebellar tract and efferent and travels through the superior cerebral peduncles to create output with the rubrospinal, vesitbulospinal and reticulospinal tract. It decassates to enter the red nuclei of the mid brain. It travels up to the thalamus to the primary motor cortex. It co-ordinates agonist-antagonist muscles.
What is the spinocerebellum?
Consists of the vermis, globose nuclei and emboliform nuclei. It has afferent from the spinocerebellar tract and efferent and travels through the superior cerebral peduncles to create output with the rubrospinal, vesitbulospinal and reticulospinal tract. It decassates to enter the red nuclei of the mid brain. It travels up to the thalamus to the primary motor cortex. It co-ordinates agonist-antagonist muscles.
What is the cerebrocerebellum?
AKA neocerebellum. Consists of the dendate nuclei and receives afferents from the cortico-ponto cerebellar fibres. Superior cerebral peduncles where it decassates to enter the red nuclei of the mid brain and pons. It travels up to the thalamus to the primary cortex. It controls fine movement, cognition and sensory co-ordination.
What is the flocculonodular lobe?
Consists of the flocculi and nodulus which are involved in vestibular system for eye movement control
What is the flocculus?
Component of the floccuonodular lobe in the archicerebellum/vestibulocerebellum for co-ordination of eye movement
What is the arbor vitae?
White matter of the cerebellum
What are the nuclei in the pons?
Pontine nuclei have input with the cerebellum and the cortex to control motor activity.
What is the dendate nucleus?
Most lateral in the cerebellum. It is part of the cerebrocerebellum/neocerebellum for the co-ordination of fine voluntary movement and sensory input and cognition.
What is the fastigial nucleus?
Part of the archicerebellum/vestibulocerebellum. In the vestibular system for co-ordination of the axial muscles for posture and balance and gait control.
What is the interposed nucleus?
Globose nuclei and the emboliform nuclei which are part of the spinocerebellum for co-ordination fo agonist/antagonist muscles.
What is the consequence of a cerebral lesion?
Contralateral symptoms due to decassation.
What is the consequence of a cerebellar lesion?
Ipsilateral presentation of symptoms.
What is the extrapyramidal system?
Group of suprasinal centres (nuclei) whhich create tracts to influence the final common pathway of the alpha motor neuron for innervation of muscles in the body.
What are the components of the extrapyramidal system?
Vestiubalr nuclei, colliculi, red nuclei and reticular formation.
How does innervation change from medial to lateral in the grey matter ventral horns?
Axial muscles including trunk -> proximal muscles -> distal muscles including fingers and toes
Which tracts terminate in the medial group of the ventral horn?
Medial vestibulospinal tract and medial reticulospinal tract
Which tracts terminate in the lateral group of the ventral horn?
Lateral vestibulospinal tract and lateral reticulospinal tract.
Which tracts terminate in the dorslateral group of the ventral horn?
Rubrospinal tract and lateral corticospinal tract
What is the vestibular nuclei?
Group of 4 nuclei in the pons and the medulla which lie on the roof of the 4th ventricle. They receive input from the cortex and cerebellum
What is the vestibulospinal tract?
Output tract from the vestibular nuclei which has a medial branch to control the axial muscles for the extensors and the lateral vestibulospinal branch to control the appendicular muscle flexors for balance and posture.
What is the reticulospinal tract?
Reticular formation is in the pons and the medulla which creates an output tract called the reticulospinal tract. This has a medial branch to control the axial extensor muscles and the lateral tract to control the appendicular flexor muscles.
What is the rubrospinal tract and tectospinal tract?
Rubrospinal tract arises from the red nucei of the midbrain and decassates and gives an output tract called rubrospinal tract. This goes to the dorsolateral surface of the ventral horn.
Tectospinal tract arises from the superior colliculi of the brain and is the only path of the vesitbulomedial pathway to decassate. It endsat the cervical spinal cord to control the muscles of the head and shoulder girdle and neck.
