Chapter 1.1: The Cells of the Nervous System Flashcards
Neurons p. 28
Neurons receive information and transmit it to other cells. Less than glia (100 billions).
Motor Neurons p.30
Has its soma in the spinal cord. It receives exitation from other neurons and conducts impulses along its axon to a muscle.
Sensory Neurons p.30
They are specialized to a particular type of stimulation.
Intrinsic Neurons or Interneuron p.32
Neurons of the same single structure.
Glia or Neuroglia p. 33
They do not transfer information over long distances. Perform many other actions.
Astrocytes p. 33
They wrap around the presynaptic terminals of a group of functionally related axons: 1. taking up ios released by the axons and them releasing them back to axons, 2. help sychronize the activity of the axons(send messages in waves), 3. remove waste material when neurons die, 4. control the amount of blood flow to each brain area 5. In case of heightened activity they dilate blood vessels to bring more nutrients into that area, 6. they are recycling system of chemicals.
Oligodendrocytes p.33
They are located in the BRAIN (#Schwann cells). They build the myelin stealths that surround and insulate certain vertebrate axons.
Schwann cells p.33
They are located in the PERIPHERY of the body. They build the myelin stealths that surround and insulate certain vertebrate axons.
Microglia p.33
Very smalls cells. Also remove waste material as well as viruses, fungi, and other microorganisms.
Radial Glia p.33
They guide the migration of neurons and theri axons and dendrites during embryonic development.
Myelin Stealth 30
3
Cell Body p.30
Containds the nucleus, ribosomes, mitochondria. Most of the metabolic work of the neuron occurs here. They could have synapses on their surface (like dendrites).
Axon p.30
Thin fiber with constant diameter, in most cases longer than dendrites. They are they neuron’s information convey sender, conveying an impulse toward other neurons, organ, or muscle.
Dendrites p.30
They are fibers that getting narrower near their ends. They have specialized synaptic receptors (post-synaptic) at which dendrites receives information from other neurons.
Dendritic Spines p.30
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Presynaptic terminal p.30
This is the point from which the axon releases chemicals that cross through the junction between one neuron and the next.
Afferent Axon p.30
Brings information into a structure
Efferent Axon p.30
Carries information away from a structure
Active Transport p.34
A protein mediated process that expend energy to pump chemicals from the blood into the brain: (glucose, amino acids, purines, choline, iron, few vitamins and certain hormones).
Mebrane p.29
A structure that seperates the iinside of the cell from the outside environment. Most chemicals cannot cross the membrane. There are specific protein channels permit a controlled flow of water, oxygen, sodium, potassium, calcium, chloride, and other important chemicals.
Endoplasmatic reticulum p.29
A network of thin tubes that transport newly synthesized proteins to other locations.
Mitochondrion p.29
Is the structure which performs the metabolic activities providing energy to the cell.
Ribosomes p. 29
Where the cell synthesizes new protein molecules.
Nucleus p.29
Structure which contains chromosomes.
Glucose p.35
Source of energy for the brain.
Thiamine p.35
Vitamin B1, thiamine, helps the body to use glucose. Prolonged dificiency (chronic alcoholism) leeds to death of neurons (called Korsakoff’s syndrome).
Nodes of Ranvier p. 30
The interuptions between myelin stealths.
Blood-brain Barrier p.34
The mechanism that excludes most chemicals from vertebrate the brain. It is a wall along the sides of the brai’n’s blood vessels. This wall keeps out most of the viruses, bacteria, and harmful chemicals.