CM- Intro to CNS Flashcards
Why sulcus divides the frontal and parietal lobes of the brain?
What gyrus is found just anterior and posterior to the sulcus?
The central sulcus divides frontal and parietal lobes.
Frontal lobe- primary motor cortex [causes movement of contralateral body]
Parietal lobe- primary somatosensory cortex [receives senses from contralateral body]
In what hemisphere of the brain can the following be found:
- primary motor cortex
- primary somatosensory cortex
- primary auditory cortex
- primary visual cortex?
- frontal [just in front of central sulcus]
- parietal [just behind central sulcus]
- temporal [just below sylvian fissure]
- occipital
These are on both sides of the brain
What is the location and function of Broca’s area and Wernicke’s area?
Broca’s is on the left inferior frontal gyrus and controls the motor function of speech.
Wernicke’s is on the left posterior superior temporal gyrus and controls speech comprehension
What are the forebrain components of the basal ganglia?
- caudate
- putamen
- globus pallidus
What is the purpose of the internal capsule?
It is white matter that contains axons from cerebral hemispheres to targets in the brainstem and spinal cord [corticospinal fibers]
The fibers form the cerebral peduncles of the midbrain [on the brainstem]
What brain structures are responsible for the motor system [planning, initiation, cessation of movement]?
Forebrain:
- caudate
- putamen
- globus pallidus
Diencephalon:
1. subthalamic nuclei [STN]
Midbrain
1. Substantia nigra
A person has lesions in the central white matter and corpus collosum. What is your first reaction?
- MS
2. leukodystrophies
At autopsy, a patient has atrophied caudate and putamen. What is this a prominent feature of?
Huntington’s disease
The hippocampus is located on the ____________________________ and plays a critical role in _______________________.
It is usually one of the first areas to be damaged in what 2 situations?
It is on the medial aspect of the temporal lobe and plays a role in the formation of memory/learning.
It is one of the first areas to be injured in Alzheimer’s and generalized ischemic injury
What portion of the brain is supplied by the:
- anterior cerebral artery (ACA)
- middle cerebral artery {MCA}
- posterior cerebral artery {PCA}
- medial aspects of each hemisphere
- lateral aspect of each hemisphere
- occipital cortex, inferior parieto-temporal cortex
What is the portion of the brain that lies between the cerebrum and the brainstem?
What 4 components make up this area?
Diencephalon lies between the cerebrum and the brainstem.
- thalamus
- hypothalamus
- epithalamus [pineal gland]
- subthalamus
What are the 3 major functions of the thalamus?
What nuclei correlate with each function?
- Sensory
- ventral posterior [somatosensory]
- lateral geniculate [visual]
- medial geniculate [auditory] - Motor
- ventral anterior
- ventral lateral - limbic and cognitive function
- anterior thalamic
- pulvinar nucleus
What is the role of the hypothalamus?
- regulate homeostasis by:
- temp regulation
- food and water intake
- endocrine function [metabolism]
- memory - send trophic hormones to the ant. pituitary to regulate hormone release
What is the role of the pineal gland?
It is a source of melatonin and regulates circadian rhythm
What is the role of the subthalamus?
What happens if it is damaged?
It is the diencephalon component of the basal ganglia. [STN is in the “indirect” movement pathway].
If the subthalamus is damaged, it will result in hemiballism [involuntary flinging movements of contralateral limb]
What are the major landmarks of the midbrain of the brainstem?
- cerebral peduncles
- superior colliculi
- inferior colliculi
- red nucleus
- substantia nigra
- ascending sensory axons
- posterior commisure
- cranial nerve nuclei
What axons travel through the cerebral penduncles of the midbrain?
What axons travel through the ascending sensory axons?
Cerebral peduncles:
1. axons to the brainstem
2. corticospinal axons to the spinal cord
[separated by interpeduncular fossa]
Ascending sensory:
1. medial leminiscus
2. anterolateral pathway
[located in the tegmentum]
What is the purpose of the substantia nigra and raphe nuclei of the midbrain?
Substantia nigra- [pars compacta] is a source of dopamine
Raphe nuclei- source of serotonin
What is the job of the following structures of the midbrain:
- red nucleus
- superior colliculus
- inferior colliculus
- posterior commissure
- relays signals btw cerebellum and thalamus; cerebellum and inferior olive
- rapid reflexive movement of the head and eyes to sensory stimuli
- auditory relay nucleus
- carries axons involved in consensual light reflex
What 3 cranial nerve nuclei are located in the midbrain?
- oculomotor complex [3]
- Edinger-Westphal nucleus
- trochlear nucleus [4]
What are the 3 major structures of the pons?
What is the role of each?
- Basal pons :
- basal pontine nuclei cross the midline and travel to the contralateral cerebellar hemisphere
- axons descend to the medulla and spinal cord - ascending sensory axons
- medial leminiscus
-anterolateral pathway
[located in pontine tegmentum] - locus ceruleus
- noradrenergic projections
- raphe nuclei
What are the cranial nerve nuclei of the pons?
- trigeminal nuclei [5]
- abducens [6]
- facial [7]
- vestibulocochlear [8]
What are the 3 major structures of the medulla oblongata?
What is the function of each?
- Pyramids
- descending motor axons [85% cross, 15% ipsi] - Olives
- climbing fibers cross and ascend to contralateral cerebellum - Medial leminiscus
- decussating fine touch, proprioception fibers that originated in the gracile and cuneate nuclei
- ascending anterolateral pain/temp fibers
What CN originate in the medulla?
- spinal trigeminal [5]
- hypoglossal [12]
- dorsal motor nucleus of the vagus [X]
- nucleus ambiguus
- solitary nucleus
- vestibular [8]
- cochlear