Chapter 3 Midterm 1 Flashcards
What Camillo golgi do?
Stained brain tissue and determined brain worked through a nerve net with info flowing around it
What did santiago Ramon y Cajal do?
studied small chicks brain tissue, said it’s made of discrete cells that get complicated as you grow, came up with the nuron hypothesis- more neurons is more ocmplex behaviour
What are the parts of a neuron?
dendrites, cell body (soma)- contains nucelus, goes down to axon hillock, then axon, then branches off into axon collateral, telodenria and terminal button
How does information flow through a neuron?
info from neurons is collected at dendrites, is then processed in the cell body and then passed to axon which channels info into single message and then to the terminal where it is passed on to its target
What do neurons accomplish through this passing of info?
regulate body processes: such as breathing, heartbeat, temp
regulate cognitive processes: such as learning, decision making, thougths
What are neural networks?
Functional groups of neurons that connect wide areas of the brain and spinal cord
What are the three kinds of neurons? Desccribe em
sensory neurons- bring info to CNS/spinal cord from sensory recpetors in or on body- can have a bipolar neuron (one dendrite, one axon) or a somatosensory neuron (has soma face one way)
Interneurons- link up sensory and motor neurons within the CNS, can have association cells (goes from thalamus to CNS), pyramidal cells (goes from cortex to brain and spinal cord), and Pukinje cell (carries info from cerebellum to rest of the brain and spinal cord)
Motor neurons- send signals from brain and spinal cord to muscles, have big dendritic networks, large cell bodies and large axons that connect to muscles- all efferent info must pass through them.
Describe slide 11
Robot orientsitself towards crcket with just exciartory wires, when having inhibotory only goes towards cricket when it’s dark
How do neurons determine if they will be active or not?
By summing all the signals they get, if more ecxcitatory they go if more inhibitory they stop.
What are glial cells?
help neurons transmit info by binding them together and providing nutrients, support, and protection
What are the four types of glial cells? Describe them
Ependymal cell- secretes CSF
astrocyte- forms blood brain barrier, heals scarring, gives nutrients, support, and repair. Contributes to info transfer
Microglial cell- Small, derived from blood, removes dead tissue, migrate into brain
Oligodendroglial cell- forms myelin around CNS axons in the brain and spinal cord
Schwann cell- wraps around peripheral nerves to form myelin
Errors in glial cell production causes what?
tumours
What is the blood brain barrier?
astrocytyes (star shaped glia) has extension that attach to blood vessels and the brains lining, binds blood vessels together preventing substances from entering brain through blood vessel walls
What is myelin?
formed by schwann and oligodendroglial cells- helps neurons by acting as insulin of “wires” stopping them from short circuting and sends info fast
How is multiple scelrosis caused?
loss of myelin in the CNS
When does paralysis occur?
Occurs during severing of motor neuron axons and sensory fibers- causing loss of sensation and movement
How do people recover from paralysis?
microglia and schwann cells help repair axons in the PNS
In the CNS does axon repair take place?
No, repair of axons does not take place, oligodendroglial cells provide myselin wrapping
How do schwann cells help during paralysis? microglia cells?
schwann cells shrink and divide across dead axon, forms glial cells along the former axons path, the neuron sends out axon sprouts, one finds the schwann cell path and the schwann cells cover it in new myelin forming a new axon.
microglia take the damaged brain cells, engulf it and remove via phagocytosis
How are our chromosomes organized?
23 pairs, 1-22 autosomes, 23 sex chromosomes
What does penetrance mean, use an example?
penetrance is the word used to describe the degree to which a genotype leads to a phenotype, ex: hunintongs has almost 100% oenetrance, will go to kid if parents have it
What is epigenetics?
describes how a single code produces a different cell types, but a genome can code for many phenotypes through environmental modification
Why does canada have high rate of parkinsons?
Because of chemicals put in soil and water supply, farmers have it the worst as they’re close to it.
How does the brain work?
Materialistically
Anatomically and Functionally
Cellularly (Genetically and Epigenetically
