Chapter 2 Flashcards
Cell Body
the part of neuron that contains the nucleus and carries out the metabolic functions of the neuron
Dendrites
branch-like extensions of the cell body that receive signals from other neurons
axon
the slender, tail-like extension of the neuron that transmits signals to the dendrites or cell body of other neurons and to muscles, glands, and other parts of the body
axon terminal
bulbous end of the axon where signals move from the axon of one neuron to the dendrites or cell body of another
Myelin Sheath
the fatty coating on some axons that acts as insulation
synaptic clefts
the gaps between axon terminal and receiving neurons, across which signals are transmitted
synapse
the junction where the axon terminal of a sending neuron communicates with a receiving neuron across the synaptic cleft
Function of Neurotransmitters
Specialized chemicals that can facilitate or inhibit the transmission of impulses from one neuron to the next
How does neurotransmitters work?
Neurotransmitters flow in to the synaptic cleft and move toward the receiving neuron. The receptors will bind only neurotransmitters whose molecular shapes match their enclosed volumes.
Communications within the neuron
When an axon membrane carries a negative electrical potential it is referred to as resting potential. Ion channels open allowing positive ions to flow when neuron reach certain threshold. This sudden reversal of resting potential is the action potential. Ion channels open admitting positive ions close and other ion channels open forcing positive ions out of the axon. The opening and closing of ion channels continues down the length of the axon causing action potential to move along the axon.
All or none law
a neuron either fire completely or does not fire at all
Communications between neurons
When an action potential arrives at the axon terminal, synaptic vesicles move toward the cell membrane, fuse with it, and release neurotransmitter molecules. Each neurotransmitter with distinctive shape will bind with receptors which are protein molecules on the surfaces of dendrites and cell bodies.
Hypothalamus
Controls functions such as hunger, thirst, body temperature; helps control endoctrine system; involved in emotion
Cerebrum
The thinking part of the brain
Cerebral cortex
Convoluted covering of the cerebral hemispheres that is responsible for higher mental processes
