Unit 2: Nervous System- Cerebral Hemsipheres

What are the 5 main components of the CNS?

1. Cerebral cortex

2. Cerebellum

3. Diencephalon

4. Brainstem

5. Spinal cord

What are the 2 main components of the PNS?

1. Cranial nerves

2. Spinal nerves

When a movement plan is generated, in what structure is sensory input used to fine tune the plan"?

Cerebellum

When a movement plan is generated, what structure integrates the plan with background movement?

Basal ganglia

Motor control arises from what regions of the cortex?

Precentral regions

Sensory input is received by receptors in what regions of the cortex?

Postcentral regions

What are the most common kind of neuron?

Interneurons

What is grey matter?

Neural tissue consisting of cell bodies

What are the 3 names for grey matter?

1. Cortex

2. Nucleus

3. Ganglion

What does cortex refer to?

Perimeter of the cerebrum/cerebellum

What does nucleus refer to?

Subcortical nuclei or brainstem nuclei

What does ganglion refer to?

Clusters of cells in the PNS near the brainstem

What is white matter?

Collection of myelinated axons

What is gastrulation?

Process whereby the bilaminar embryonic disc undergoes reorganization to form a trilaminar disc

What is neurulation?

Process whereby the neural plate forms into a neural tube

What structures are found within the telencephalon (cerebral hemispheres)?

1. External gray matter (cerebral cortex)

2. Internal gray matter (fiber tracts)

3. Internal gray matter (basal ganglia, amygdala, hippocampus)

4. Lateral ventricles

What are the 6 cell layers of the cerebral cortex?

1. Axons & glial cells

2. Many stellate + small pyramidal cells

3. Some stellate & medium-sized pyramidal cells

4. Densely packed stellate cells (sensory)

5. Large pyramidal cells only (motor)

6. Stellate & pyramidal cells

What are the 3 relevant sulci to the frontal lobe?

1. Lateral fissure

2. Central sulcus

3. Precentral sulcus

What are the 4 relevant gyri to the frontal lobe?

1. Precentral gyrus

2. Superior frontal gyrus

3. Middle frontal gyrus

4. Inferior frontal gyrus

What is the primary region of the frontal lobe?

Primary Motor Cortex (M1) / Precentral Gyrus

What primary region serves as the origin for corticospinal & corticobulbar tracts?

Primary motor cortex

What are the unimodal association regions in the frontal lobe? (3)

1. Premotor cortex

2. Supplementary motor area

3. Inferior frontal gyrus/Broca’s area

What is the multimodal association regions in the frontal lobe?

Prefrontal cortex

What is the premotor cortex responsible for?

Sensory-guided movement (i.e- planning & coordination of movement)

What is the supplementary motor area responsible for?

Decision-making about movement

What is the inferior frontal gyrus/Broca’s area responsible for?

Planning & articulation of speech

What are the main responsibilities of the frontal lobe? (5)

1. Voluntary motor control

2. Planning & decision making

3. Speech production

4. Emotional regulation

5. Social behavior

What are the main responsibilities of the parietal lobe? (3)

1. Processing sensory information

2. Spatial orientation

3. Body awareness

What is the primary region of the parietal lobe?

Primary somatosensory cortex

What is the primary motor cortex responsible for?

Voluntary movement of muscles

What is the primary somatosensory cortex responsible for?

Receiving tactile information regarding pressure, touch, & pain

What is the unimodal association region in the parietal lobe?

Somatosensory association area

What is the somatosensory association responsible for?

Interpreting sensory input

What are the multimodal regions in the parietal lobe? (3)

1. Parieto-tempo-occipital region (PTO)

2. Supramarginal gyrus

3. Angular gyrus

What is the PTO region responsible for?

Integration of multiple sensory inputs

What is the surpamarginal gyrus for?

Receiving auditory, visual, & somatosensory information (phonological processing)

What is the angular gyrus responsible for?

Receives auditory, visual, & somatosensory information (semantic processing)

What are the main responsibilities of the temporal lobe? (3)

1. Auditory processing

2. Language comprehension

3. Memory

What is the primary region of the temporal lobe?

Primary auditory cortex/Heschl’s gyrus

What is the unimodal association region of the temporal lobe?

Auditory association area/Wernicke’s area

What is the multimodal association region of the temporal lobe?

It does not have one

What is Heschl’s gyrus responsible for?

Processing sound information

What is Wernicke’s area/auditory association area responsible for? (2)

1. Receptive language processing

2. Auditory word recognition

What is the main responsibility of the occipital lobe?

Visual processing

What is the primary region of the occipital lobe?

Primary visual cortex/calcarine sulcus

What is the primary visual cortex/calcarine sulcus responsible for?

Primary reception area for visual input

What is the unimodal association area of the occipital lobe?

Interprets shape, color, motion, & object recognition

What is the multimodal area of the occipital lobe?

It does not have any

What is the insula responsible for? (4)

1. Has a role in human emotion & behavior

2. Sensory processing & integration

3. Involved in motor planning & execution (motor programming)

4. Visceral motor activities

What areas do association tracts connect?

Cortical areas within a hemisphere

What do short association tracts connect?

Primary areas to unimodal areas

What do long association tracts connect?

Cortical regions across lobes (ex: articulate fascicules extend from Wernicke’s to Broca’s area)

What areas do commissural tracts connect?

Connects the left & right hemispheres via the corpus callosum

What do projection tracts connect?

Regions of the cerebral cortex to lower parts of the CNS via the internal capsule

What is the major function of the basal ganglia?

Assists in regulating initiation & termination of movements and regulating its intensity