W2: CNS, Meninges, Cerebral Cortex Flashcards
What forms the Neural Plate
Notochord inducing the ectoderm to thicken in the dorsal midline.
Neural Folds
Edges of the neural plate that fold toward each other.
Neural Tube
Created when the neural folds meet dorsally.
Ventricle
Central cavity of the neural tube.
What are the 3 zones that compose the neural tube?
1) Ventricular Zone
2) Intermediate Zone
3) Marginal Zone
Ventricular Zone of neural tube
Site where mitosis occurs.
Intermediate Zone of neural tube
Where postmitotic cells form gray matter.
Marginal Zone of neural tube
Location of axonal pathways that will form future white matter.
Dorsal Root Ganglion
Derived from the neural crest
Primary Brain Vesicles
1) Forebrain (Prosencephalon)
2) Midbrain (Mesencephalon)
3) Hindbrain (Phombencephalon)
Secondary Brain Vesicles
1) Telencephalon
2) Diencephalon
3) Midbrain - Mesencephalon
4) Pons/Cerebellum - Metencephalon
5) Medulla - Myelencephalon
Adult Brain Structures
1) Cerebrum
2) Diencephalon (Thalamus, hypothalamus, epithalamus)
3) Midbrain (Brainstem)
4) Pons (Brainstem)
5) Cerebellum
6) Medulla (Brainstem)
7) Spinal Cord
Adult Neural Canal Regions
1) Lateral ventricles
2) Third ventricle
3) Cerebral aqeuduct
4) Fourth ventricle
5) Central Canal
encephalon
“related to the brain”
What adult brain structures does the Prosencephalon grow into?
1) Cerebrum
2) Diencephalon (Thalamus, hypothalamus, epithalamus)
3) Laterval Ventricle
4) Third Ventricle
What adult brain structures does the Mesencephalon grow into?
1) Midbrain
2) Cerebral aqueduct
What adult brain structures does the Phombencephalon grow into?
1) Pons
2) Cerebellum
3) Medulla
4) Fourth Ventricle
Meninges
Location: 3 connective tissue membranes that surround the outside of the CNS. Made of: 3 layers of connective tissue 1) Dura Mater 2) Arachnoid Mater 3) Pia Mater Function: 1) cover & protect CNS 2) contain blood vessels for the CNS 3) acts as veins and drains cerebral spinal fluid (CSF)
Dura Mater
“Tough Mother”
Location: Outer most layer of the meninges
Made of: dense fibrous connective tissue
Function: protective covering around CNS
Arachnoid Mater
“Spider Mother”
Location: Just deep to the dura mater. Creates the subdural space and the subarachnoid space
Made of: fine and elastic tissue and large blood vessels.
Function: Protect the CNS.
Pia Mater
“Small mother”
Location: inner most layer of meninges attached directly to the surface of the brain.
Made of: delicate connective tissue richly vascularized with fine blood vessels.
Function: Anchor for meninges and protective layer around CNS.
Ventricles
Line the inside of the CNS
Ventricular System
Location: inside lining of CNS
Made of: a series of canals (lateral ventricles, interventricular foramen, third ventricle, cerebral aqueduct, fourth ventricle central canal of spinal cord)
Function: To drain CSF from the brain.
Flow of CSF in CNS
Fluid made by choroid plexus
Lateral ventricle > interaventricular foramen > 3rd ventricle > cerebral aqueduct > 4th ventricle > subarachnoid/arachnoid villi/superior sagittal sinus…
CSF
Cerebral Spinal Fluid
Location:produced in the choroid plexus running along the meninges in the lateral, 3rd, and 4th ventricles
Made of: filtered blood plasma
Function: forms liquid cushion/support around the brain within skull.
Hydrocephalus
Increased intracranial pressure caused by blockage in the ventricular system.
How many functional layers are there in the cerebral cortex?
6 Layers of Gray Matter
Where are pyramidal neurons located in the cerebral cortex?
layers III & V
Where are the interneurons located in the cerebral cortex?
layers II, IV, & VI
Where do efferent neurons (pyramidal neurons) in the cerebral cortex project to?
1) Spinal cord (Corticospinal)
2) Brainstem (Corticobulbar)
3) Other side of the cortex (Corticocortical)
What are the afferent axon projections to the cerebral cortex?
1) from the other cortical structures
2) from the thalamus
3) from the basal forebrain nuclei
Functions of the Frontal Lobe:
1) Prefrontal/primary/secondary (premotor) motor cortex
2) Broca’s area - speech
Functions of the Parietal Lobe:
1) Primary/secondary somatosensory areas
2) Wernicke’s area - speech
Functions of the Occipital Lobe:
1) Primary/secondary visual processing
Functions of the Temporal Lobe:
1) Primary/secondary auditory processing
2) Rest of Wernicke’s area
What structures make up the motor cortex?
1) Corticospinal Tract
2) Motor homunculus
Corticospinal Tract
Location:
Made of:
Function:
Motor homunculus
Representation of body parts, where parts are represented in corresponding parts of the brain. Size corresponds to number of neurons.
Somatotopy
representation of parts of the body in corresponding parts of the brain
What structures make up the somatosensory cortex?
1) somatic sense
2) sensory homunculus
Somatic senses
Pain, touch, temperature, pressure, vibration and proprioception
Visual Cortex
1) primary visual cortex around calcraine fissure
2) Secondary visual cortex is an integrative area
Auditory Cortex
1) Wernicke’s area = receptive speech
2) Broca’s area = expressive speech area
Cerebral Cortical Connections
1) Projection Axons
2) Commissural Axons
3) Association Axons
Which cerebral cortical connections are corticocortical projections?
1) Commissural axons
2) Association axons
