ILA 7 - Weakness Flashcards
What is the function of the Frontal lobe?
- Primary motor cortex (pre-central gyrus)
- Motor function
- Personality
- Long term memory
- Judgement/social and sexual behaviour
- Broca’s area - important for language production (productive aphasia), Bodmann’s 44/45
What is the function of the Parietal lobe?
- Contains primary somatosensory lobe - homunculus (post-central gyrus)
- Secondary somatosensory lobe
- (dominant lobe, L perception and interpretation of sensory input and complex motor response, language and maths)
- (non dominant, R visiospatial)
- Body orientation
What is the function of the Temporal lobe
- Auditory reception area
- Expressed behaviour
- Receptive speech
- Memory/info retrieval
- Contains wernickle’s lobe - language comprehension (receptive aphasia) in sub temporal gyrus = bodmann’s 22
What is the function of the Occipital lobe?
- Primary visual lobe
- Primary visual association
What is the function of the Cerebellum?
Coordination and control of voluntary movement
-Contains two hemispheres which are connected by the VERMIS (a narrow midline area)
What is the function of the Midbrain?
MESENCEPHALON (middle)
- Cerebral peduncle, corpora quadrigemina (or colliculi) and the cerebral aqueduct
- Mid brain connects into from fore-brain to hind-brain
- It enables the brain to integrate sensory info from eyes and ears (inferior and superior colliculi) with muscle movements = fine tuning of movements
- also controls resp muscles, vocal cords, pharyngeal, oral and nasal passages
- CN XII, X, IX, V, VII
What is the function of the Pons?
METENCEPHALON (after)
- Located between the midbrain and medulla (pons means bridge)
- CN V-VIII = sensory roles in hearing, equilibrium, and taste, and in facial sensations such as touch and pain and motor = eyes movement, facial expressions, chewing, swallowing, secretion of saliva and tears
What is the function of the Medulla?
- Regulates breathing, heart and blood vessel function, digestion, sneezing, and swallowing
- Resp and circulation
What is the function of the corona radiata?
Contains descending motor tracts (radiates out to
- White mater = axons
- corticospinal tract, the corticopontine tract, and the corticobulbar tract.
What is the function of the internal capsule?
Contains ascending and descending tracts
What are the functional divisions of the cerebellum?
- Cerebrocerebellum - involved in planning movements and motor learning, input from cerebral cortex and pontine nucleus, out to thalamus and red nuclei
Also regulates coordination of muscle activation and is important in visually guided movements - Spinocerebellum - the vermis and the intermediate zone of the cerebellar hemispheres. involved in regulating body movements by allowing for error correction
Also receives proprioceptive info - Vestibulocerebellum - (flocculus and nodulus of the vermis) Involved in controlling balance and ocular reflexes, mainly fixation on a target. Receives input from the vestibular system and sends outputs back to the vestibular nuceli
What supplies the cerebellum with blood?
- Superior cerebellar artery (SCA) - branch of basilar
- Anterior inferior cerebellar artery (AICA) - branch of basilar
- Posterior inferior cerebellar artery (PICA) - branch of the vertebral artery
What is the venous drainage of the cerebellum?
- Drained by the superior and inferior cerebellar veins
- These drain into the transverse and sigmoid sinuses
Where path do the fibres from the inferior retina take?
-Info of the superior visual field from the inferior retina
go via Meyer’s loop
-This loops laterally around lateral geniculate body through parietal lobe then posteriorly
-A lesion will cause damage in superior quadrant = pie in the sky
Where path do the fibres from the superior retina take?
- Info of the inferior visual field from the superior retina goes via Baum’s loop
- This loops superiorly through the parietal lobe to the occipital lobe via the internal capsule
- Damage is less likely as they take the shorter path, will cause ‘pie in the floor’ which is loss of inferior quadrant in visual field
What the function and route of the corticospinal tract?
- Conscious control of the eye, jaw and face
1. primary motor cortex (and premotor cortex, somatosensory etc)
2. Through corona radiata to the internal capsule
3. Brainstem - cortinuclear fibres, activate CN motor nuceli
4. Enters pyramid at the medulla
5. Most DECUSSATE and from the lateral corticospinal tract and terminates in ventral horn
6. About 10% enter the ANTERIOR CST and terminate in the ventral horn of the cervical and upper thoracic
Anterior = ipslateral, proximal muscles Lateral = contralateral, limbs
What the function and route of the corticobular tract?
Pyramidal
- primary motor cortex of the frontal lobe
- The tract descends through the corona radiata and genu of the internal capsule
- In the midbrain, the internal capsule becomes the cerebral peduncles. The white matter is located in the ventral portion of the cerebral peduncles, called the crus cerebri.
- The middle third of the crus cerebri contains the corticobulbar and corticospinal fibers.
- The corticobulbar fibers exit at the appropriate level of the brainstem to synapse on the lower motor neurons of the cranial nerves.
- Controls the muscles of the face, head and neck
What synapses at the medial geniculate? Superior/Inferior peduncle?
I AM AUDITORY
Inferior peduncle = medial geniculate =auditory
What synapses at the lateral geniculate? Superior/Inferior peduncle?
I AM AUDITORY
Superior peduncle = lateral geniculate = visual
What are the 3 pyramidal tracts?
- Cortibulbar (neck, head, face)
- Lateral corticospinal (limbs)
- Anterior corticospinal (proximal muscles- muscles closest to midline)
What is the insula cortex associated with?
Imagining pain, pain of others
-Deep in lateral sulcus
(also anger, fear, disgust, joy, and sadness. Its most anterior portion is regarded as part of the limbic system)
What does the Anterior cerebral artery supply? (ACA)
Supplies frontal, pre-frontal, supplementary motor cortex, and parts of primary motor and primary sensory cortex
(motor, sensory, broca’s)
What does the middle cerebral artery supply? (ACA)
Lateral surface of frontal, parietal and temporal lobes
-includes primary motor and sensory cortices (excluding lower limb), serves auditory cortex and insula (deep in lateral sulcus)
(broca’s, wenickle’s, motor, sensory)
What does the posterior cerebral artery supply? (ACA)
Supplies occipital lobe, inferior part of temporal lobe and deep structures including thalamus and posterior limb of internal capsule
(primary and secondary visual areas, splenium of corpus callosum)
