Chapter 3 Flashcards
section 1.8
LO: Distinguish between the two basic divisions of the nervous system
LO: Distinguish between the functions of distinct types of neurons
LO: Describe the structure of the neuron
LO: Describe electrical and chemical changes that occur when neurons communicate
LO: Describe how antagonists can influence the action of neurotransmitters
Central Nervous System (CNS)
- Brain
- Spinal Cord
- CNS sends signals to SNS to initiate movement
Peripheral Nervous System (PNS)
All nerve cells that aren’t part of the CNS
- includes somatic and autonomic nervous systems
Somatic Nervous System (SNS)
- transmits sensory signals and motor signals between the CNS and the skin, muscles, and joints
- specialized receptors send sensory info to the spinal cord which sends it to the brain
Autonomic Nervous System (ANS)
- transmits sensory signals and motor signals between the CNS and the body’s glands and organs
- regulates internal environment
- carry somatosensory signals to CNS (ex. being full, anxious, etc.)
Neurons
- basic units of the nervous system
- cells that receive, integrate, and transmit information
How do neurons operate?
electrical impulses
How do neurons communicate with other neurons?
chemical signals
Reception Phase
neurons take in chemical signals from other neurons
Integration
incoming signals are assessed
Transmission
Neurons pass their signals to other neurons
Sensory Neurons
detect info from the physical world and pass it to the brain
Somatosensory Neurons
sensory nerves that provide info from the skin and muscles
- sensations from within the body
Motor Neurons
direct muscles to relax and contract
Interneurons
relay stations facilitating the communication between sensory and motor neurons
- when working together they control movement
Dendrites
detect information from other neurons
Cell Body
where information from other neurons is collected and integrated
Axon
where information is conducted from the cell body to the terminal buttons
Terminal Buttons
- end of axons
- small nubs that release chemical signals from the neuron into synapse
Synapse
- gap between terminal buttons of a “sending” neuron and the dendrites of a “receiving” neuron
- where chemical communication occurs between neurons
Membrane
- fatty barrier that acts as a bouncer for what can pass through
- selectively permeable
Ion channels
pores on the membrane that allow ions to pass through
Q: What is the positional order of neuronal cell structures (cell body, dendrites, terminal buttons, and axon), from receiving component to sending component?
dendrites, cell body, axon, terminal buttons
Action Potential
Electrical signal that passes along the axon and causes the release of chemicals from the terminal buttons
Resting Membrane Potential
Electrical charge of a neuron when it is not active
What does it mean when a neuron is polarized and what does this process promote?
- More negative ions inside the neuron than outside the neuron
- this process creates the electrical energy in order to fire the neuron
Excitatory Signals
- depolarize = decrease negative charge inside cell
- increases likelihood that neuron will fire
Inhibitory Signals
- hyperpolarize = increase negative charge inside cell
- decrease likelihood that neuron will fire
Sodium-potassium pump
- ## helps maintain resting membrane potential
