06 The Nervous System Free Online FlashCards

What are the nervous system’s main functions?

It detects internal and external changes, processes information, and coordinates responses that help maintain homeostasis.

What structures make up the CNS and PNS?

The central nervous system is the brain and spinal cord; the peripheral nervous system includes nerves and ganglia outside them.

What do dendrites do?

Dendrites receive many incoming signals from other cells.

How do neurotransmitters transmit signals across most synapses?

At most neuron-to-neuron synapses, an arriving signal prompts neurotransmitter release. These chemical messengers bind to receptors on a neighboring cell and can increase or decrease its likelihood of signaling.

What direction do sensory (afferent) neurons carry information?

Sensory, or afferent, neurons carry information from sensory receptors toward the central nervous system.

What does the cerebellum help coordinate?

The cerebellum helps coordinate movement and balance.

How do spinal cord gray matter and white matter differ?

Gray matter contains many neuron cell bodies and synapses; surrounding white matter contains bundles of axons traveling in pathways.

How can a withdrawal reflex begin before conscious awareness of pain?

A withdrawal reflex uses spinal circuits to activate motor neurons and pull a body part away from a painful stimulus. The brain also receives information, but the spinal response can begin before conscious pain awareness.

How do somatic and autonomic nervous system functions differ?

The somatic nervous system controls skeletal muscle, supporting voluntary movement as well as reflexes. The autonomic nervous system regulates many functions that usually occur without conscious effort.

How do sympathetic and parasympathetic divisions generally differ?

The sympathetic division helps coordinate responses to challenge or increased demand; the parasympathetic division supports functions such as digestion and recovery. Their effects depend on the organ and the body’s needs.

What is the axon’s role, and how can myelin help?

An axon carries signals away from the cell body. Myelin can insulate it and help signals travel efficiently.

What do interneurons do?

Interneurons connect and process signals within the central nervous system.