Structures and Functions Flashcards
Cerebral Hemispheres as Paired Structures
The paired lobes are part of telencephalon and include gray matter of gyri and sulci. The cerebral hemispheres are paired consisting of 4 lobes and two specialized cortices on each side. These are the frontal, parietal, temporal, occipital lobes as well as the insular and limbic cortices.
Right Cerebral Hemisphere:
- Movement of the left side of the body
- Processing of sensory information from the left side of the body.
- Visual reception from left field
- Visual-spatial processing
- Left motor praxis
- Nonverbal memory
- Attention to incoming stimuli
- Emotion
- Processing of nonverbal auditory information
- Interpretation of the abstract information
- Interpretation of tonal inflections
Left Cerebral Hemisphere
- Movement of the right side of the body
- Processing of sensory information from the right side of the body
- Visual reception from right field
- Visual verbal processing
- Bilateral motor praxis
- Verbal memory
- Bilateral auditory reception
- Speech
- Processing of verbal auditory information.
Longitudinal Cerebral Fissure
Separates the two hemispheres
Corpus Callosum
The largest group of myelinated nerve fibers connecting the two hemispheres.
Frontal Lobe
Front of the brain extends to the central sulcus of Rolando.
-Laterally separated from temporal lobes by the Sylvian fissure.
Contains: Pre-central gyrus, the prefrontal cortex, the pre-motor cortex, and Brocas Area
Central Sulcus (frontal lobe)
Separation between frontal lobe from parietal lobe.
Precentral gyrus (frontal lobe)
- Brodmann’s Area 4)
- Primary Motor Cortex (for voluntary muscle activation)
Premotor cortex, Prefrontal cortex, and Broca’s area (Brodmann’s Areas 44, 45) (frontal lobe)
- Enables planning of movements, which controls motor aspects of speech
- Controls emotion judgments, higher order cognitive functions such as ideation and abstraction
Parietal Lobe
- Located posteriorly to frontal lobe.
- Primary function in the integration of sensation and reception of sensation.
- Contains: Parieto-occipital sulcus, Postcentral gyrus, Primary somatosensory Cortex, Sensory association cortex
Parieto-occipital sulcus (Parietal Lobe)
Separates parietal lobe from the occipital lobe.
Postcentral gyrus (Parietal Lobe)
- Brodmann’s Area 3,1,2
- Primary somatosensory Cortex
- Primary sensory cortex for integration of sensation.
Sensory Association Cortex (Parietal Lobe)
(Brodmann’s Areas 5,7,39.40)
-Tertiary somatosensory cortex, posterior parietal association area, parietal- temporal-occipital association cortex
Temporal Lobe
Laterally located the temporal lobes have important function with auditory sensory input, both receiving and processing, as well as association and comprehension. Contains: Lateral Fissure (Sylvian Fissure), Primary auditory cortex (41, 42), Wernicke’s area/ auditory association cortex (22)
Lateral Fissure (temporal lobe)
- aka Sylvian Fissure
- Separates the frontal and temporal lobe.
Primary Auditory Cortex (temporal lobe)
(Brodmann’s Areas 41,42)
-Responsible for hearing, located at the superior temporal gyrus
Wernicke’s area (temporal lobe)
- aka auditory association cortex
- (Brodmann’s Area 22)
- Hearing and speech (higher-order auditory cortex)
Occipital Lobe
-In the posterior aspect of the brain, involved with vision: receiving, processing and association
-Contains: Calcarine Fissure, Primary Visual Cortex (Brodmann’s 17), Secondary Visual Cortex
(Brodmann’s Area 18), Tertiary Visual Cortex (Brodmann’s Area 19)
Calcarine Fissure (occipital lobe)
Begins above occipital pole and joins the parietal-occipital sulcus. It forms the upper boundary for the Para hippocampal gyrus.
Primary Visual Cortex (occipital lobe)
(Brodmann’s 17)
-Receives and processes visual stimuli
Secondary Visual Cortex (occipital lobe)
- Brodmann’s Area 18
- Processes visual stimuli and make meaning of what is seen.
Tertiary Visual Cortex (occipital lobe)
- Brodmann’s Area 19
- Middle temporal visual area. Processes vision, color, motor depth.
Brainstem
-Connection between spinal cord and brain.
-Located at the base of the cerebral hemispheres.
-Home to all major sensory, motor, cerebellar and cranial nerve pathways.
-Also contains many nuclei that control cranial nerves, consciousness, cerebellar circuits, cardiac and respiratory functions.
-Bottom, most caudal, is the corticomedullary junction, (location of pyramidal decussation and foramen magnum).
Contains: Midbrain, pons, and medulla
Midbrain (brainstem)
- Connects brainstem to diencephalon at midbrain diencephalic junction.
- Home to inferior and superior colliculi on posterior surface.
- Anterior surface has crus cerebri (cerebral peduncles) containing fibers of corticospinal tract and corticobulbar tracts.
- Anterior section in front of the 4th ventricle is the tegmentum which is home to both ascending and descending tracts such as medial lemniscus and anterolateral tracts.
- Also, home to the red nucleus, substantia nigra in ventral tegmental area and periaqueductal gray.
Pons (brainstem)
- Directly below midbrain and above medulla oblongata.
- Posteriorly separated from the cerebellum by the 4th ventricle.
- Basilar artery runs along anterior/ventral surface.
- Descending tracts passing through include corticospinal and corticobulbar.
- Ascending tracts passing though the pons include medial lemniscus and spinothalamic.
Medulla (brainstem)
- Most inferior aspect of brainstem and is continuous with both pons and the spinal cord below.
- Anterior surface is the anterior median fissure, which is continuous except for the decussation of pyramids.
- On posterior surface fasciculus cuneatus and gracilis can be seen separated by the posterior intermediate sulcus
