View
- Term
- Definition
- Both Sides
Study
- All (30)
Shortcut Show
Next
Prev
Flip
NRSC 2100: EXAM 1
Types of Glial Cells
|
Oligodendrocytes, Schwann Cells, Astrocytes, Microglia, Ependymal Cells
|
Oligodendrocyte
|
Create myelin sheaths for multiple axons within the CNS
|
Schwann Cell
|
Creates myelin sheaths for single axons in the PNS
|
Astrocytes
|
Provides nutrients and oxygen to neurons (at Blood-Brain Barrier), regulates concentration of K+, removes waste products
|
Microglia
|
act as phagocytes, cleans up waste and dying cells/cell debris
|
Ependymal Cells
|
Lines the ventricles and other cavities in the brain, also might make Cerebrospinal fluid
|
Egyptian Beliefs
(2500-600 BC)
|
Thought the heart to be the seat of the soul. Did not consider the brain to be important at all
|
Greek Beliefs
(500-200 BC)
|
Hippocrates- Believed the brain to be an organ of sensation and the seat of intelligence
Aristotle- believed the heart to be the seat of intelligence and that the brain was just a cooling unit for blood
|
Roman Era
(0-200 AD)
|
Galen- named major nerves in the brain, supported Hippocrates' views, differentiated between cerebellum (for muscle control) and cerebrum (for the senses)
|
Early Renaissance Era (c. 1500)
|
Janssen- invented compound microscope (~1663)
Hooke- discovered cells by looking at cork slices
|
Bell and Megandie (1810)
|
Identified distinction between motor and sensory neurons, also that they are often bundled together
|
Gall (1827)
|
developed notion of phrenology, believed size of brain regions correlates to certain functions
|
Flourens (1823)
|
believed mental function to be equally localized
|
Broca (1861)
|
provided evidence that certain functions *are* localized (Broca's area, for producing organized speech)
|
Pre-Civilized Humans (~7000 BC)
|
performed trepenation to cure symptoms, obviously thought brain to be of some importance
|
Basic Structure of a Neuron
|
1) cell body (called soma or perikaryon)
2) dendrites and dendritic spines
3) Axon
4)Myelin Sheaths
5) Nodes of Ranvier
6) Axon Terminals
7) Axon Hillock
|
Cellular Components of a Neuron
|
Cell membrane, cytoplasm, nucleus, ribosomes and Rough ER, Golgi Apparatus, Mitochondria, Smooth ER,
|
Microtubules
|
~20 nm, made of tubulin, regulated by “tau”. Provides structure to axon-- not in axon terminals
|
Neurofilament
|
~10 nm, made of actin, attaches to cell membrane
|
Microfilament
|
~5 nm, made of actin, wraps up in strands of polymers like a rope- protein transport
|
Axon Hillock
|
takes incoming signals and integrates them. If a threshold is reached, the cell fires an action potential down the axon
|
Axon
|
a long myelinated strand that conducts an electrical signal down to the axon terminals (the pre-synaptic component)
|
Axoplasmic Transport
|
Antereograde- kinesin carries vesicles away from soma
Retrograde- dynein travels up towards soma, informs of metabolic changes
|
Electrical Synapse
|
Allows for direct ion transfer through Gap Junction. Gap Junctions are made up of two "connexons", each of which are made up of three "connexins"
|
Chemical Synapse
|
Chemicals (neurotransmitters) are released by vesicles into synaptic cleft, which bind to protein receptors in post-synaptic membrane
|
Types of Chemical synapes based on Connection
|
Axo-dendritic,
Axo-sematic,
Axo-axonic
|
Types of chemical synapses based on Neurotransmitter
|
Excitatory synapse (glutamate, aspartate)
Inhibitory Synapse (GABA, glycine)
Modulatory Synapse (Adrenergic, such as dopamine and adrenaline)
|
Forces that Act upon Ion concentration
|
Diffusion- ions move down concentration gradient to reach equilibrium
Electrical Forces- like-repels-like, positive ions will repel one another until equilibrium is reached
|
Depolarization
|
inside of neuron becomes less negative. Na+ ions flow into cell
|
Hyperpolarization
|
Inside of cell becomes more negative. Cl- ions flow in, or K+ ions flow out of cell
|