Video Summaries Flashcards
(217 cards)
The nervous system
- consists of two types of cells: neurons and glial cells
Neurons
- communicate info within the nervous system
Glial cells
- provide neurons with structural support, insulation, And nutrients
Structure of a neuron
- May vary in size and shape, but I’ll have one or more dendrites a cell body( soma) and an axon
Dendrites
- receive information from a presematic neuron
Cell body
- contains nucleus, mitochondria, and other elements essential for cell survival
Axon
- transmits info to a postsynaptic cell
Synapse
- Small space between presynaptic cells axon and receptor on a postsynaptic cell
Mylien
- some axons are insulated by this
+ Speeds up conduction
Multiple sclerosis
- destruction of mylien that insulates axons in the brain and spinal cord caused by a malfunctioning immune system
- symptoms very depending on location of damage
- impaired coordination and vision, pain, fatigue, slurred, speech, tremor
Neurotransmitters
+ chemicals that transmit information from presynaptic neurons to the adjacent Post-Synaptic neuron
+ Many have excitatory or inhibitory effects depending on the type of a post-synaptic cell and others are primarily one or the other
Excitatory
- released into the synapse is likely that an action potential will occur in a post- synaptic cell
Inhibitory
+ release into synapse decreases the likelihood that an AP will occur in a postsynaptic cell
Inhibitory
+ release into synapse decreases the likelihood that an AP will occur in a postsynaptic cell
Action potential
- electrical impulse that travel the length of cells axon and is responsible for the release of neurotransmitters into the synapse
- occurs when there is sufficient stimulation from a pre-synaptic neuron
-All or nothing
+ Always occurs at the same frequency
Dopamine
+ movement, learning, mood, sleep, and the reinforcement effects of drugs
Abnormal levels of dopamine
- Parkinson’s disease, Huntington’s disease, tourette’s disorder, ADHD, depression, and schizophrenia
Dopamine hypothesis
+ original: schizophrenia is due to excessive or hyperactivity of dopamine receptors
+ Revision: positive symptoms are due to dopamine hyperactivity in the subcortical regions of the brain
- negative symptoms are due to hypoactivity and cortical regions of the brain, especially the prefrontal cortex
Acetylcholine
- voluntary movements: controls contractions of the skeletal muscles
- regulate smooth and cardiac muscles
- arousal, attention, and memory
Low acetylcholine
- in hippocampus linked to early memory loss associated with Alzheimer’s
Cholinetarse inhibitors
- reduce the breakdown of ACH
- temporarily reverse or slow down memory loss or other cognitive impairments associated with people who have mild to moderate Alzheimer’s
Glutamate
- primarily excitatory
- movement, emotions, learning, and memory
- involved in long-term potentiation which is essential for the formation of long-term memory
Long-Term potentiation
,- essential for the formation of long-term memories
- rapid and or high frequency stimulation cause an increase in efficiency and strength of a synaptic transmission
Excessive glutamate
- glutamate induced excitotoxicity causes cell damage or death believed to contribute to brain damage associated with stroke, seizures, TBI, or several neurogenitive disorders like Alzheimer’s and Huntington’s disease