CHAPTER 7: NERVOUS SYSTEM - STRUCTURE AND CONTROL OF MOVEMENT Flashcards
(40 cards)
What comprises the Central Nervous System (CNS)?
Brain and spinal cord
What is the role of the Peripheral Nervous System (PNS)?
Connects the CNS to the rest of the body
What are the two main components of the PNS?
- Sensory (Afferent)
- Motor (Efferent)
What is the function of sensory (afferent) neurons?
Sends impulses from sense organs to brain
What are the two divisions of motor (efferent) neurons?
- Somatic
- Autonomic
What does the sympathetic division of the autonomic nervous system control?
“Fight-Flight” response
What does the parasympathetic division of the autonomic nervous system control?
“Rest-Digest” response
What is a neuron?
Functional unit of the nervous system
What is the role of dendrites in a neuron?
Receive and direct information toward cell body
What do axons do?
Carry electrical impulses away from cell body
What is a synapse?
Contact point between neurons
What are neurotransmitters?
Chemical messengers for neural communication
What is irritability in neural function?
Ability to respond to stimuli and convert to electrical impulse
What is conductivity in neural function?
Transmission of electrical signal along axon
What is resting membrane potential?
Cells maintain negative charge inside relative to outside
What regulates resting membrane potential?
- Ion concentration differences
- Membrane channels
- Na+/K+ pump
What happens during depolarization?
Na+ gates open, Na+ diffuses in, cell becomes more positive
What is the threshold for action potential?
~-55mV
What occurs during repolarization?
Na+ channels close, K+ channels open, K+ leaves rapidly
What is the all-or-none law?
If nerve impulse initiated, it travels entire axon at same voltage
What are EPSPs?
Excitatory postsynaptic potentials (cause depolarization)
What is temporal summation?
Several EPSPs from ONE pre-synaptic neuron
What is spatial summation?
EPSPs from SEVERAL pre-synaptic neurons
