Coronal suture
Stitches the frontal and parietal skull bones
Squamous suture
Stitches the temporal and parietal skull bones
Sagittal suture
Stitches the two parietal bones
Lambdoid suture
Stitches the parietal and occipital skull bones
Dura mater
Outer most layer of meninges
Arachnoid mater
Thin transparent membrane below dura mater
Subarachnoid space
Where CSF resides
Pia mater
Inner most layer of the meninges (wraps the brain and spinal cord)
Functions of CSF
1) Impact absorption
2) Osmotic homeostasis
3) Waste disposal
4) Neutrophic factor secretion
Glymphatic system
Regulates/permits the circulation of CSF through the brain tissue (movement based on blood vessel pressure and rate of flow modified by glial cells)
Factors affecting CSF production
Why is the retina considered part of the CNS?
Advantages of chemical synapses
Ependymal cells
Myelin
Electrical insulation that also supplies axons with structure, nutrients, and neurotrophic factors
Schwann cells
Can myelinate only one axon in the PNS (can guide regeneration)
Oligodendrocytes
Can myelinate multiple axons in the CNS
Microglia
Microglia dichotomy
M1: causes inflammation and neurodegeneration
M2: suppresses inflammation and promotes neural repair
Astrocytes
Astrocytes CNS
Get activated to form a barrier to protect CNS neurons (side effect of preventing regeneration)
Astrocyte dichotomy
A1: causes inflammation and neurodegeneration
A2: suppresses inflammation and promotes neural repair
Pupillary reflex
1) Photoreceptors (rods + cones) = Afferent/sensory neurons that convert light into electrical signals
2) RGCs relay visual information to the midbrain via optic nerve
3) Ciliary ganglion neurons = Effector neurons that synapse with ciliary muscles and adjust pupil size
Patellar reflex
1) Striking patellar ligament stretches spindle and activates sensory neuron
2) Sensory neuron relays information down axon to its axon terminal which inerrvates a motor neuron at the spinal cord
3) Motor neuron stimulates (releases Ach) muscle to contract