Chapter 3-Neurons Flashcards
What are the functional units of the nervous system
Cells of a nervous system and its internal structures as well as genes, cells, behavior
Golgi debated…
The nervous system is composed of a “nerve net”
Cajal debated…
- Nervous system is made of discrete cells
- Neuron hypothesis-Neurons are the units of brain function
- Used the Golgi stain to prove his hypothesis
Basic neuron structure
- Cell body
- Branching extensions called dendrites
- Axon main root acts as messenger
Neurons
Most behaviors are produced by neurons whose functional groups attach to the brain and spinal cord.
Dendrites
Gather information from other neurons
Cell body
The core region with the nucleus that integrates info
Axon
Carries info to be passed on to other cells
Dendritic spines
Protrusion from the dendrite that greatly increases the surface area and is the usual point of contact with axons from other cells
Axon hillock
Space between axon and soma, where an action potential begins
Axon collaterals
Branches of an axon
Terminal button
Knob at the tip of the axon that conveys information to other neurons; also called the end foot
Synapse
Gaps between one neuron and another
Sensory neurons
Carry information from the sensory receptors in or on the body to the spinal cord
Interneurons
Associate sensory and motor activity within the CNS
Motor neurons
Send signals from the brain and spinal cord to the muscles
Bipolar neurons
Transmit afferent sensory information from the retina to the neurons that carry info to the brain’s visual centers
Somatosensory dendrite
Connects directly to its axon, so the cell body sits to on side of this long pathway
Stellate cell
Small-Many dendrites extend from the cell body
Pyramidal cell
Has a long axon, a pyramid shaped cell body, and two sets of dendrites
Purkinje cell
A distinctive interneuron with extremely branched neurons making a fan shape
Three features of neuronal networkes
- Input
- Association
- Output
Describe the language of neurons
Neurons receive many excitation and inhibition signals and the sum of these signals are taken and the neuron acts accordingly, becoming active or not
5 types of glial cells
- Ependymal cells
- Astrocyte
- Microglial cells
- Oligodendroglial cells
- Schwann cells
Ependymal cells
Small. ovoid cells found in the walls of the ventricles. Make and secrete cerebrospinal fluid
Hydrocephalus
Buildup of pressure in the brain and swelling of the head caused by the flow of CSF being blocked, leading to intellectual impairment
Astrocytes
Star shaped cells that provide structural support for the neurons, transport substances between the neurons and capillaries, play a role in scar forming, and provide fuel for the brain