Neural Activity Flashcards
Structure of the neuron
- Cell membrane: double plasmid hull
- Cytoplasm: the soup inside the cell.
- Nucleus
- Ribosomes: Protein Synthesis
- Mitochondria: Glucose to ATP -> carbon dioxide and water
- Endoplasmic reticulum, connected to Nucleus and Ribosomes
What are the cells in the NS
neurons and glia
Describe neurons
- Neurons receive information and transmit it to other cells.
(cell) membrane
- Double lipid membrane
○ polar surface (hydrophile/lipophobe), -> changing charge (water) (ends which form the inner and outer linings)
○ apolar tails (hydrophob/lipophil) (fat)
○ ‘double soap bubble’ plus stuff that makes it stick together - Membranes are a key element of biological cells
- Separate spaces/compartments
- Cells are highly compartmentalized
- Membranes are reaction surfaces
- Hold enzymes complexes for reactions in place
Nucleus, ER, Ribosomes
- Nucleus holds DNA
- DNA is transcribed to RNA
- Inside connected to the Nucleus
- RNA can travel inside to the Ribosomes
- Ribosomes: synthesize Enzymes as instructed by RNA
- The Endoplasmic Reticulum is essentially a folded membrane
- Endoplasmic Reticulum (main protein synthesis from DNA to RNA to protein) -> allows the protein to move out of the nuclei into the cell
Mitochondria
- Cell in the cell (DNA, Ribosomes, etc)
- Endosymbiotic theory (at some point a complex cell swallowed a bacteria and joined together)
- Main function: turn Glucose into ATP.
- The citric acid cycle remember anyone?
- The misfunction of Mitochondria are implicated in lots of diseases e.g. skeletal muscle movement, respiratory and autism
○ Brain is a power hog which consumes a lot of power
○ Mitochondria is the liver of the brain -> burns energy in our body - All in all one Glucose turned into 38 ATP, CO2 and H2O
- the brain is about 2% of body mass but consumes 20% of our Glucose.
The basic structure of a neuron
- Dendrites are the branches sticking out of the Soma
- Soma is the body and contains a nucleus
- Axon hillock connects the soma to the axon
- The axon is covered in myelin
- Axon terminals (synaptic bouton) are at the end of the axon
- They vary dramatically
- The gain information and send information from other neurons
- Smaller neurons are for larger resolutions
Dendrites
where neurons receive most of their information and are designed to pick up signals from other neurons which come in the form of chemicals called neurotransmitters
○ Signals picked up by dendrites cause electrical changes in a neuron that are interpreted in the Soma (cell body)
Soma
Takes the information from the dendrites and puts it together in the Axon hillock to travel down the axon (this is called an action potential)
Axon
covered in myelin which prevents the signal from degrading
Axon terminals (synaptic bouton)
where the signal causes a release of neurotransmitters (interacting with the next neuron)
- final stage before process is repeated in the next neuron
The categories of neurons
○ Sensory
§ Receptors in skin
§ Touch
§ Sensory cortex
§ Cognitive activity
§ Mostly bipolar cells
○ Relay
○ Motor
§ Motor cortex to muscles
§ Reflex arc in the spinal cord
○ Anaxonic Neuron
○ Bipolar Neuron
○ Unipolar Neuron
○ Multipolar Neuron
What is Glia
- Glia (glial cells) = glue
○ Surrounds and holds neurons in place
○ Supports neurons
§ Repair
§ Nutrient supply
§ Extracellular voltage control - Do not fire action potentials.
- Probably play some other role in information processing.
- Can be divided into:
○ Microglia - Primary immune defence of central nervous system
§ They travel throughout the brain and spinal cord and remove things such as damaged neurons, pathogens and other foreign substances
○ Macroglia - Don’t outnumber neurons 10:1, but maybe 2:1.
- Many different type of Glia cells, with a large range of functions
Astrocytes (Astroglia)
- Provide neuronal support, help repair damaged to the nervous tissue, regulate communication between neurons and maintain the blood-brain barrier (keeping toxic substances contained in blood from entering the brain
- Quite numerous similar number to neurons
Oligodendrocytes and schwann cells
- Responsible for coating other neurons in myelin
- Oligodendrocytes myelinate neurons in the central nervous system
- Schwann cells myelinate cells in the peripheral NS
