Structure Function of CNS Flashcards
4 Lobes
Frontal
Parietal
Temporal
Occipital
3 Fissures/Sulci
Central sulcus
Lateral fissure
Calcerine fissure
Corpus callosum
White matter connecting left and right hemispheres
Cerebellum
Base of brain responsible for balance, motor, and learning
Prefrontal Cortex Functions
Higher executive functions
Dorsolateral Prefrontal Cortex
Abstract thinking
Planning
Reasoning
Anterior Cingulate Cortex
Emotional drive
Inhibition of inappropriate emotional responses
Dysfunction: apathy, lack of motivation
Orbitofrontal Cortex
Reviewing your actions, thoughts, impulse control, evaluating things
Dysfunction: aggressive behavior, sexual promiscuity, no filter
Pyramidal Motor Systems
Central nervous system
Extrapyramidal Motor Systems
Involuntary reflexes
Voluntary movement - fine motor skills and postural adjustments
Motor learning
Broca’s Area
Motor components of speech - making sounds
Understanding sentence structure
Wernicke’s Area
Understanding language
Extra Pyramidal System Key Structures
Caudate putamen = striatum - part of basal ganglia
Substantia Nigra too
DA receptors
Dysfunction of EPS
Tremor
Loss of gait
Inability to adjust posture
Loss of fine motor skills
Medial Temporal Lobe
Hippocampus - memory
Amygdala - fear, emotional learning, emotions
Insular Cortex
Pain perception
Self-awareness and consciousness
Inner fold of cortex in temporal lobe
Cells of the Brain
Neurons 100 billion (10%)
Glial cells 10x more than that! (90%)
Types of Synaptic Connections Between Neurons
Axodendritic
Axosomatic
Axoaxonic
Types of Glial Cells
Oligodendrocytes
Microglia
Astrocytes
Functions of Astrocytes
Supportive functions
Eat up excess neutrotransmitters
Responders to injury, cytokine/inflammation, contribute to BBB
Function of Oligodendrocytes
Myelin sheath production
Where is the CSF produced?
Ventricles
What is the purpose of the CSF?
Provide buoyancy/protection of brain inside of skull and spine
Function of microglia
Phagocytes
What types of substances are in CSF and why?
Small AAs, proteins, electrolytes because large molecules can’t fit between tight junctions
How do neurons communicate with one another?
Electrochemical signals
Draw out an action potential
RMP (Na+K+ pump and K+ channels open) reaches threshold then voltage gated Na+ open then voltage gated K+ channels open then Na+ channels close and when hyperpolarization occurs, K+ channels occur until RMP is reached again
Neurotransmitter Release
Synaptic vesicles form and present to presynaptic terminal cell surface
Docking proteins grab the vesicle and extracellular Ca++ rushes in
Vesicle binds to surface and allows neurotransmitter to be released into synaptic cleft
5 Defining Features of a Neurotransmitter
- Must be made in neuron
- Must produce effect in postsynaptic neuron
- Must be release in identifiable form
- Must be in the terminal
- Must have a method of termination
Types of Neurotransmitters
Biogenic
Amino Acids
Peptides
4 Dopamine Pathways
Nigrostriatal - EPS
Mesolimbic - memories, emotions, learning
Mesocortical - executive functions
Tuberofundibular - prolactin secretion
How does a typical DA neuron work?
Release and autoreceptors on presynaptic neuron = negative feedback
What is the main difference between D1 and D2 receptors?
D1 - stimulate DA synthesis
D2 - inhibit DA synthesis
Autoreceptors on postsynaptic neuron
Norepi Circulation and Synthesis
Tyr - L-DOPA - DOPA - NE
SR Biosynthesis and Neurons
Trp - 5-HT - Melatonin
Also have presynaptic autoreceptors
Ach Biosynthesis
Choline + acetate to acetylcholine
Choline brought into terminal and converted to Ach then passed through synapse to M and N receptors and AchE (breakdown!)
Muscarinic Receptors
Excitatory OR inhibitory postganglionic receptors
Blocker - atropine
G protein coupled cAMP
Nicotinic Receptors
Postganglionic AND neuromuscular receptors
Excitatory
Blocker - curare
Ligand gated ion channel
Glutamate and GABA synthesis
Glutamine to glutamate to GABA
Mechanisms of Termination
Reuptake
Degradation
Reuptake Inhibitors
SSRIs - SR
TCAs - NE
Cocaine - DA
Tiagibine - GABA
Degradative Inhibitors
Carbidopa - DA
MAOIs - NE, SR, DA
ACHEi - Ach
