Item 6 Flashcards
(362 cards)
The _NS is ultimately responsible for everything we perceive, do, feel and think
CNS
The CNS contains approx 100 _ neurons and 100 _ synapses, all contained within the brain and spinal cord
billion (10^11)
trillion (10^14)
CNS is protected by
glial cells
_
connective tissue
cerebrospinal fluid
bone (the skull!)
_% of the CNS is composed of glial cells (or neuroglia)
75 - 90
Glial cells are un_, and support neurons through neural communication. Humans have the most glial cells of any organism (highest on the evolutionary chain)
UNexcitable
Five types of glial cells:
astrocytes
_
Schwann cells
oligodendrocytes
ependymal
microglia
_ are the most diverse and numerous of glial cells, surrounding neurons with 20 nm gaps between that do not overlap another
astrocytes - sim to stars in the universe?
Astrocytes form a structural and functional link between neurons and non-nervous tissue and _ fluid
extracellular fluid
Astrocytes DIRECT THE DEVELOPMENT of special _ that restrict the movement of certain molecules between blood and the CNS, called the blood-brain barrier
capillaries
Astrocytes guide developing neurons, esp _, to their correct destination and regulate the development and maintenance of synapses
neurites
T or F: astrocytes may support the regeneration of damaged axons
true - astros help axons!
Astrocytes help the _cellular enviro of neurons and in maintaining normal potassium levels in the _cellular [same] environment. This also means they help remove certain neurotransmitters in the interstitial environment between synapses
EXTRAcellular (around the neurons - esp at synapses)
In efferent neurons, are they covered in oligodendrocytes or Schwann cells?
Efferent axons begin in the CNS, so they have oligodendrocytes initially, but when in the PNS they only have Schwann cells
High levels of _ are toxic and contribute to the spread of neurological damage during a stroke or other types of brain damage
glutamate
yet it’s crucial for long-term potentiation. Go figure
Astrocytes synthesize glutam_, which is then released into the interstitial fluid and picked up by other neurons to form glutam_, an excitatory neurotransmitter
Glutamine;
Glutamate
The gap between synapses is considered _ space
interstitial
Astrocytes can store _, which can be broken down to lactate; the lactate is then transported to neurons where it serves as an important energy source for active areas of the brain
lactate / orig lactic acid??
T or F: microglia are the body’s way to protect neurons from toxic substances
false - microglia and astrocytes do. Astrocytes protect neurons from oxidative stress and help remove cellular debris
Glial cells may contribute to the development of neurodegenerative diseases such as
multiple sclerosis
_ disease
Parkinson’s disease
Alzheimer’s
MS results from the loss of myelin in the CNS. It is an autoimmune disease, meaning that the immune system attacks a part of the body, in this case, _ (myelin-type cells). The loss of myelin (and some axons) in the CNS slows down or stops communication along certain neural pathways
oligodendrocytes (if it was PNS it would be Schwann cells, but it’s not)
Alzheimer’s disease is caused by the loss of cholinergic neurons in certain brain areas and the replacement of the lost neurons with scar tissue called plaques. During the degeneration of cholinergic neurons, a_ and _ become overly active. These types of cells release inflammatory chemicals that enhance further de- generation of cholinergic neurons. Thus a vicious cycle takes place.
astrocytes and microglia
Early signs of Alzheimer’s disease include
loss of memory and confusion
…
loss of communication skills
decrease in cognitive functions
motor dysfunction
Early stages of _ disease may be treated with acetylcholinesterase inhibitors (they prevent the enzymes from dissolving acetylcholine in the synaptic cleft)
Alzheimer’s
Parkinson’s disease is a degenerative disease involving the loss of dopaminergic neurons. As in Alzheimer’s disease, glial cells are thought to enhance neural degeneration through the pro- duction of _ agents.
inflammatory -