The nervous system coordinates body activities by gathering information, processing it, and directing responses. This lesson introduces its major functions and compares nervous system organization across animals.
The nervous system performs many tasks at once. It processes visual information, directs eye movements, supports attention, and regulates essential activities such as breathing and body temperature. In general, it acquires sensory information, processes that information, and may produce a response.
All flashcards
What are the main functions of a neuron’s soma, dendrites, and axon?
The soma maintains the cell, dendrites commonly receive signals, and the axon carries signals toward its terminals.
What establishes a neuron's resting membrane potential?
Unequal ion concentrations and selective membrane permeability create an electrical difference across the membrane.
How does myelin support signaling along an axon?
It insulates the axon; the signal is renewed at gaps called nodes of Ranvier.
How does nervous system signaling compare with endocrine signaling?
Nervous signals are generally rapid and targeted; endocrine hormones travel through the circulation and often act more slowly.
What are the CNS and PNS in vertebrates?
The CNS consists of the brain and spinal cord; the PNS consists of nerves outside the CNS.
Quiz questions
What happens when a neuron's membrane depolarizes to the threshold of excitation?Answer: Voltage-gated sodium channels open and initiate an all-or-nothing action potential.
How does a chemical synapse typically transmit a signal to a receiving cell?Answer: Neurotransmitters cross the synaptic cleft and bind to receptors on the receiving cell.
Which brain region supports balance, coordination, and learning motor tasks?Answer: The cerebellum.
Which cerebral lobe contains the hippocampus, important in memory formation?Answer: The temporal lobe.
What is a typical function of the thalamus?Answer: Relaying sensory and motor information to and from the cortex.
Based on Concepts of Biology by Samantha Fowler, Rebecca Roush, James Wise (OpenStax), licensed CC BY 4.0. Adapted into a summary, flashcards and quizzes.