What are neurons and how do they transmit information?
Neurons are the elementary components of the nervous system, the body's speedy electrochemical information system. Sensor neurons carry incoming information from sense receptors to the brain and spinal chord, and motor neurons carry information from the brain and spinal chord out to the muscles and glands. Interneurons communicate within the brain and spinal chord and between sensory and motor neurons. A neuron sends signals through its axons and receives signals through its dendrites....
What are Neurons...Continued.
If the combined signals are strong enough, the neuron fires, transmitting an electrical impulse (the action potential) down its axon by means of a chemistry to electricity process. The neuron's reaction is an all or nothing process.
How do nerve cells communicate with other nerve cells?
When action potentials reach the end of an axon (the axon terminals), they stimulate the release of neurotransmitters. These chemical messengers carry a message from the sending neuron across a synapse to receptor sites on a receiving neuron. The sending neuron, in a process called reputake, then normally absorbs the excess neurotransmitter molecules in the synaptic gap. The receiving neuron then generates its own action potential if the signals from that neuron are strong enough.
How do neurotransmitters influence behavior and how do drugs and other chemicals affect neurotransmission?
Each neurotransmitter travels a designated path in the brain and has a particular effect on the behavior and emotions. Acetylcholine affects muscle action, learning, and memory. Endorphines are natural opiates released in response to pain and exercise. Drugs and other chemicals affect communication at the synapse. Agonists excite by mimicking particular neurotransmitters or by blocking their reuptake. Antagonists inhibit a particular neurotransmitters release or block its effect.
What are the functions of the nervous system's main divisions?
One major division of the nervous system is the central nervous system, the brain and the spinal chord. The other is the peripheral nervous system which connects the CNS to the rest of the body by means of nerves. The peripheral nervous system has two main divisions. The somatic nervous system enables voluntary control of the skeletal muscles. The autonomic nervous system through its sympathetic and parasympathetic divisions, controls involuntary muscles and glands. Neurons cluster into networks
How does the endocrine system transmit its messages?
The endocrine system i a set of glands that secrete hormones into the bloodstream where they travel through the body and affect other tissues including the brain. The endocrine system's master gland, the pituitary, influences hormone release by other glands. In an intricate feedback system, the brain's hypothalamus influences the pituitary gland which influences other glands, which release hormones, which in turn influence the brain.
What are neurotransmitters and why are they so important?
Neurotransmitters are chemical messengers that cross the synaptic gaps between neurons. When released by the sending neuron, neurotransmitters travel across the synapse and bind to receptor sites on the receiving neuron, thereby influencing whether that neuron will generate a neural pulse.
Want to see the other 7 Flashcards in Chapter Four Review?JOIN TODAY FOR FREE!