10. Nervous System Organization

3 classifications of neurons

1 afferent

2 efferent

3 interneurons

cell body of afferent neuron is located next to the spinal cord in the _____

Dorsal Root Ganglion

afferent neuron

receives information from the PNS and terminates it into the CNS

efferent neuron

receives information from the afferent and terminates into the PNS

interneurons

all located in the CNS, and integrate information from the afferent to the efferent

non-neuronal glial cells

make up 10% of the CNS; support the neurons physically & metabolically & homeostatically

4 types of CNS Glial Cells

1 astrocytes

2 oligodendrocytes

3 microglia

4 ependymal cells

astrocytes

many critical functions, forming gap junctions with each other and neurons, and releasing gliotransmitters that serve as neuromodulators

oligodendrocytes

form the main myelin sheath around the axon in the CNS

microglial cells

immune cells activated my infection of injury; low growth factors for for thriving and surviving

ependymal cells

line the cavities of the CNS; make up the CFS and can serve as neural stem cells

brain tumors can be found in the _____

glia or meninges

blood brain barrier

protects brain from blood-borne materials from entering the brain tissue

BBB protects the brain from ___

pathogens

hormones

drugs

ionic changes in constituency

dura mater

outer, rougher bilayer consisting of dural sinuses

arachnoid mater

vascular layer between the dura and pia mater

pia mater

inner layer touching the brain surface and spinal cord—supplies blood to ependymal cells

choroid plexuses

masses of pia mater that form the CSF via pockets from ependymal cells

cerebrum forebrain

basal nuclei & cerebral cortex

diencephalon

thalamus & hypothalamus

brain stem / medulla

life-sustaining processes = breathing, circulation

cerebellum

coordinates motor activity, body position, involuntary movement

hypothalamus

homeostatic functions

thalamus

sensory processing

cerebrum

voluntary movement, thought, language

gray matter = cerebral cortex

neuron cells bodies, dendrites, glial cells

white matter

myelinated axons

corpus callosum

connects the 2 hemispheres of the cerebrum

brain lesions

early analysis

electroencephalonograms (EEGs)

reads of EPSPs & IPSPs of the cerebral cortex

glass microelectrodes

inserted into the CNS to examine electrical activity of neurons

Positron Emission Tomography (PET) scan

scans active regions of brain through increased gamma activity in neurons

functional MRI (fMRI)

measures changes in regional cerebral blood flow and increased neuron activity

frontal lobe

responsible for voluntary motor, speaking, elaborated thought

parietal lobe

receive and process sensory input

occipital lobe

receives visual stimuli

temporal lobe

processing sound input