Neuroanatomy - CNS & Cerebral Cortex Flashcards
What are the subdivisions (structural organization) of the brain?
Cerebral hemispheres
Diencephalon (thalamus, hypothalamus, epithalamus)
Brain stem (midbrain, pons, medulla)
Cerebellum
Explain the Gray matter and where is it found?
Gray matter represents the short and non myelinated neurons and neuron cell bodies.
GM can be organized into nuclei (looking like spots), which can be found on the cerebrum, cerebellum, and brain stem.
Some is at the outer layer of the cerebrum, known as the corticoid areas.
Butterfly region of spinal cord
Explain the White matter.
White matter represents the long, and mostly white myelinated (insulated) neurons.
What fills up the ventricles of the brain?
Cerebral Spinal Fluid, lined by ependymal cells
Explain how the ventricles connect to each other.
The pair lateral ventricles are separated by the septum pellucidum.
The lateral ventricles communicate with the 3rd ventricle via the interventricular foramen.
The 3rd ventricle connects to 4th ventricle via the cerebral aqueduct and the 4th is continuous with central canal.
What are the 3 apertures and what are they for?
The 4th ventricles has paired lateral apertures and a median aperture. The 3 connect the ventricles to the subarachnoid space.
Explain the shapes and sections of the hemispheres.
What are the two main fissures?
Sulci (plur.) are the “hills”, separated by the gyri “valleys”.
We have the central gyrus in between the precentral gyrus (motor) and the postcentral gyrus (sensory).
Lateral sulcus & parieto-occipital sulcus…
We have the longitudinal fissure and the transvers cerebral fissure separating the cerebrum from the cerebellum.
Lobes: F, T, P O, and insular
What is the function of the cerebral cortex GM?
Conscious behaviour
What are the areas of landmarks called on the cerebral cortex?
Brodmann areas
What are the 4 generalizations of the cerebral cortex?
- Motor, sensory, association areas
- Contralateral: each hemisphere handles the opposite side of body
- Lateralization: symmetrical but not the same in function
- No functional areas of cortex acts alone - all conscious behaviour involves the entire cortex.
Where is the primary motor cortex situated?
Precentral gyrus of frontal lobe
What cells allow for the control of skeletal muscles?
Pyramidal cells: large neurons in which the axons project to the spinal cord, following the corticospinal tract –> voluntary motor functions
Mapping of the body in CNS
Somatotopy
(Face, hands, tongue represented the largest)
Explain what happens during a stroke
Contralateral: damage on R hemisphere paralyzes the L side of body.
ONLY voluntary movement lost while reflex still possible.
Which part of the motor area helps to plan movement and allow to do complex tasks, and depends on sensory feedbacks?
(Sometimes referred to as muscle memories)
Premotor cortex.
Explain an example of a damage to premotor cortex.
Keyboard typing:
Damage to premotor cortex would mean that you can still move your fingers but no memory to know where to place your fingers before typing a word.
(No memories of series of motor response used before)
Motor speech area (language production) and planning on the L hemisphere
Broca’s area
What are the 4 motor areas?
- Primary motor cortex
- Premotor cortex
- Broca’s area
- Frontal eye field
Where is the primary somatosensory cortex situated?
Postcentral gyrus
How does the primary somatosensory cortex receives info?
From receptors of the skin & proprioceptors (muscles & joints) - spatial discrimination
Somatosensory association cortex
Integrate/analyze somatic input and uses prior experiences and knowledge for interpretation
Name the two visual areas and their role.
Primary visual cortex - map of visual space on retina (damage = loose vision)
Visual association area - interprets visual image
(damage = can see BUT not recognize)
What is the inability to recognize something that you see?
Visual Agnosia
What does the olfactory cortex covers on the medial aspect of temporal lobe?
Uncus (–> limbic system)
What are the 8 sensory areas?
- Primary somatosensory cortex
- Somatosensory association cortex
- Visual area (PVC & VAA)
- Auditory cortex (2)
- Vestibular cortex
- Olfactory cortex - uncus
- Gustatory cortex - insula
- Visceral sensory area
What are the steps to reach the multimodal association cortex?
- Sensory receptors
- Primary sensory cortex
- Sensory association cortex
- Multimodal association cortex
Which part of the multimodal association cortex that is responsible for the working memory, judgement, reasoning, planning, conscience?
Matures slowly and linked with limbic system?
Linked with developments of personalities
Anterior association area (prefrontal cortex)
Which part of the multimodal association cortex is for the storage of complex memories & link sensory inputs?
Posterior association area
Which area is responsible for the understanding of language?
Wernicke’s area
What is contralateral neglect
Cannot see or localize - don’t see one side of body as a part of them
What is cerebral dominance?
Hemisphere dominant for language - LEFT
Right cerebral dominance are L-handed or…
Ambidextrous
Which fibers (WM) are responsible to connect areas of the two hemispheres?
Commissural fibers (ex. corpus callosum)
Which fibers (WM) are responsible for connections within a hemisphere? (connect gyri, lobes)
Association fibers
Which fibers (WM) are responsible to connect cortex to the rest of NS? (vertical)
Projection fibers
What are the 3 parts of the basal nuclei?
Caudate nucleus (ring), Putamen (lateral), Globus pallidus (medial)
The basal nuclei is responsible for what?
No direct to motor pathways
Roles overlap with cerebellum: start/stop
Filtering
Associated with cognition and emotion
Which disease is associated the degeneration of caudate nucleus, in which the patient is unable to control feelings, thoughts or movement?
Huntington’s disease (huntingtin protein accumulates)
Which disease is associated the degeneration of dopamine-releasing neuron of substantia nigra?
Parkinson’s disease
Lists the parts of the diencephalon and which ventricle does it enclose? What are the key roles?
= thalamus, hypothalamus, epithalamus
- enclose the 3rd ventricle
- key roles: mediating, motor activities, cortical arousal, learning, memory
What connects the two masses of the thalamus GM
Interthalamic adhesion
Where is the epithalamus and what does it contain?
Dorsal of diencephalon, roof of 3rd ventricle
- Pineal gland for melatonin
- Choroid plexus for production of CSF
What does the hypothalamus regulate? (7)
- ANS
- Emotional response and behavioural
- Body temp regulation
- Sleep and wake regulation
- Water balance and thirst regulation
- Control endocrine system
- Regulation of food intake
What release melatonin (sleep-awake cycle)?
Suprachiasmatic nucleus
What releases ADH and oxytocin?
Supraoptic & paraventricular nuclei
