Chapter 2 - Basic Neurochemistry

make sure to know the anatomical planes. find a blank diagram and fill it out.

Central Nervous System (CNS)

brain and spinal cord

Peripheral Nervous System (PNS)

spinal and cranial nerves present outside the CNS

Parts of the spinal cord

skin, joints, muscles, spinal nerves (dorsal root and ventral root)

two parts of the autonomic nervous system

sympathetic and parasympathetic

functions of neurons

process information, command body responses, sense environmental changes and communicate these changes to other neurons

neuronal membrane

barrier that encloses cytoplasm

3 parts of the neuron

cell body (soma), dendrite, axon

cell body

metabolic center of neuron (contains the same organelles as in all cells)

dendrite

receives signals from axons on other neurons

axon

transmits information from soma to different target sites

rough ER

major site for protein synthesis (ribosomes)

smooth ER and Golgi apparatus

sites for preparing/sorting proteins for delivery, regulating substances

mitochondria

site of cellular respiration

components of axon (3)

axon hillock (beginning), axon proper (middle), axon terminal (end)

synapse

site of signal transmission

anterograde transport

soma to terminal (typical)

retrograde transport

terminal to soma (rare)

Nissl substance

substance of RNA granules

postsynaptic

receies signals from axon terminal

cytoplasmic region

determines the shape of a neuron

3 filamentous elements of a neuron

microfilaments, microtubules, neurofilaments

microfilaments (what it’s made of, what it makes up)

made of actin, makes up majority of growth cone

microtubules (function, what it’s made of)

train tracks to help deliver things to body, made of MAP proteins (Tau protein), containws + end and - end

pick’s disease

frontal lobe shrinks, pick bodies on frontal lobe, diminished spacial skills and behavioral issues

Tau hyperphosphorylation

adding a phosphate group leads Tau protein to weaken and the microtubule to disintegrate

Tau tangles

clumped Tau protein, indicator of Alzheimers

4 general types of neurons

multipolar, bipolar, pseudounipolar, unipolar

multipolar neurons

most common, multiple dendrites and one long axon

bipolar neurons

dendrites on one end, axon on the other, cell body in middle

pseudounipolar neuron

one cell body, 2 branches (peripheral projects to periphery, branch 2 projects to CNS)

unipolar neuron

single neurite, dendrites on one end and axon on same site

stellate cells

star-shaped

pyramidal cells

triangle/pyramid shaped

Classification of neurons: 3 types based on connection with the CNS

primary sensory neurons, motor neurons, interneurons

Classification of neurons: 2 types based on axonal length

Golgi type I, Golgi Type II

3rd way to classify neurons

based on neurotransmitter type (ex Cholinergic = acetylcholine at synapses)

glia

control environment in CNS; insulates, supports, and nourishes neurons

types of glial cells

astrocytes, oligodendrocytes, microglia, ependymal cells

astrocytes

stellate, regulate chemical and extracellular environment, influence neurite growth

2 types of myelinating glia

oligodendroglia and schwann cells

oligodendrocytes

axon myelination in CNS

Schwann cells

axon myelination in PNS

myelin sheath

insulates axon

nodes of ranvier

portions of axons uninsulated by myelin, can produce action potentials

microglia

smallest type of glial cell, repair damage due to injury via phagocytosis