Chapter 5 Flashcards
Soma
Cell body
Dendrite
Branches of neural membrane from the cell body. receives messages from other neurons in the nervous system.
Axon
Long branch of neural membrane. The transmitting antenna of the nerve cell. Takes an electrical signal from the cell body out to its end where it delivers the message to another neuron.
Axon Hillock
Most proximal piece of the axon. The spot where the electrical signal is created.
Presynaptic terminal
The bit of neural membrane that is before the synapse and that delivers the information to the synapse.
Synaptic cleft
Space of the synapse
Postsynaptic terminal
The dendrite or cell body that receives the chemical message that has been delivered across the synapse
4 functions of Neurons
Receives chemical messages from other neurons.
Integrate all of the input into one common message.
Transmit the signal electrically from cell body to the presynaptic membrane.
transfer across the synapse.
Anterograde
in the usual direction of function
Retrograde
backwards of the usual direction of function
Bipolar neuron
Two major trunks extended away from the cell body. One major trunk is the dendritic branch and the other major trunk it the axon branch. Neurons found in our eyes. converts light into electrical signals for brain to interpret.
Psuedounipolar neuron
One major trunk that splits into two major trunks that extend peripherally and the other centrally. Peripheral branch acts like a dendrite and the central branch acts like an axon. These cells are found in the somatosensory system (allow use to feel touch on the hand, stretch of the muscle, position of a joint. cells of body sensory system).
Multipolar neuron
have many major dendritic trunks that extend away from the cell body. one axon trunk that extends away from cell body. cells found in our brain (thinking) and the cells of somatic motor system.
Interneuron
Multipolar in its construction. 4 major dendritic trunks and one major axon trunk. extremely tiny and positioned between the axon of one neuron and and the dendrite of another neuron. it delivers but can also modify the message to another big neuron.
Leak (non-gated) channel
Open all the time and ions and other formed elements can pass down their electrochemical gradient all the time. as long as they can fit they can go through.
Modality-gated channel
gate in the middle that is opened by any kind of physical modality (a mechanical touch or temperature).
Ligand-gated channel
(protein) neurotransmitter- a protein of the nervous system that when it attaches to membrane channel it opens the gate to allow ions and other formed elements to flow through the channel.
Voltage-gated channel
a change in the relative charge along the membrane can open the gate and allow ions and other formed elements to flow through. (action potential)
Resting potential
negative inside the cell and positive charge outside the cell.
Local potential
can be localized around one particular membrane channel. Small short distance change of polarity. starter signals. Have the capacity to spring the start of an action potential. depolarizing or hyperpolarizing.