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Overview of Nervous System - Coggle Diagram
Overview of Nervous System
Functions
Input: Sensory infomration from external/internal environents
Processings: Integrating infomraiont
Output: Responding to stimuli
Cells
Neurons
Unipolar/Pseudo-unipolar: Sesnory neuorns in dorsal root ganglia
Bipolar: In retina
Components
Cell body: Large nueclues, ribosomes, and cytoskeleton components
Dendrites: Tapered appendages that receive information from other cells
Axon: Up to 1 meter Long and conducts information from cell body
Astrocytes
Mechanical suppport, metabolic support, responds to injury
Forms part of blood-brain barrier
Oligodendrocyte
Contrinutes myelin to many axons
Microglia
Migrate to CNS during development, or derived from blood monocytes
Signalling
Neurotransmitters
Amines (Ach, Serotonin, Catecholamines, Norepi, dopamine), Amino acids, Neuropeptides
Components of Nervous System
CNS: Brain, spinal cord
PNS: Peripheral nervous system
Left Side: Logic, Components, Sequences, Language, color
Right Side: Whole picture, Patterns, images, Music, Creativity
Anatomy
Surface Anatomy
4 Sulci
Central, lateral, Parieto-occipital, Cingulate
Insula: Additional lobe not usually included in other 5 lobes
Lobes
Frontal: Motor, cognition
Parietal: Sensory
Temporal: Auditory/Memory
Occipital: Visual
Limbic: Emotion/Memory
White Matter: Axons connecting the brain to brain and to lower centers (corpus callosum, internal capsule)
Basal ganglia
Caudate, Lenticular nuclei (putamen, and globus pallidus)
Diencephalon
Thalamus: Mass of deep grey Matter
Hypothalamus: Gland for homeostasis
Epithalamus: Midline pineal gland
Subthalamus: Connections with BG
Brain Stem
Contains midbrain, pons, medulla, and contains nuclei for CNS (acts as conduit for ascending and descending information)
Cerebellum
2 Hemispheres and vermis, and coordinates motor movements, for balance and limb control
Coverings
Protected by 3 layers (Dura, arachnoid, Pia)
Blood Supply
Neck: 2 carrotid and 2 vertebral arteries
Head: circle of Willis
Spine: 1 anterior and 2 posterior spinal arteries
Drainage: Veins and venous sinuses
CSF: Brain is hollow, filled with fluid, and flows through the ventricles (2 lateral, 1 in diencephalon, 1 abutting brainstem/cerebellum)
Peripheral Nervous System
Outside of CNS, lacks meningeal coverings,a nd convers information to CNS and from CNS
Roots of Nerous System
Dorsal: Sensory afferent, Ventral: Motor Efferent
Myotomes
Muscles innervated by same ventral root
Wiring Principles
Multi-neuron Systems
1st order, 2nd order, and 3rd order
Sesnory afferent (1st order in periphery)
Motor efferent (1st order in the brain)
Somatosensory Rules
Pimrary afferents 1st order sesnory nerus (enter CNS wihtout crossing)
2nd Order Neurons: Cross somewhere between their origin in spinal cord and destinaton in contralateral thalamus
3rd Order thalamic neurons: Terminate in post-central gyrus
Voluntary Motor
1st Order
Cortical Motor Neurons: Cross at level of medulla and terminate in contralateral spinal ventral horn
2nd Order Motor Neurons
Leave the CNS without crossing midline
Cerebellar Rules
Multiple inputs/outputs pertaining to movement: Exerts indirect ipsilateral control over coordination
Basal ganglia Rules
Receives input from cortex, processes, and loops it into cortex