Neurophysiology: From Neurons to Reflex Arcs

Vocabulary flashcards covering core topics in neurophysiology, including neuron structure, neuron classification, divisions of the nervous system, and reflex arcs.

Neurophysiology

A branch of Physiology that studies the function of the Nervous System, explaining how neurons work, generate electrical impulses, transmit signals, and control body functions.

Central Nervous System (CNS)

The body's control center consisting of the brain and spinal cord; responsible for processing sensory information, making decisions, and coordinating reflexes.

Peripheral Nervous System (PNS)

The body's communication network consisting of 12 pairs of cranial nerves and 31 pairs of spinal nerves that connect the CNS to the rest of the body.

Brain

Part of the CNS that processes and integrates information, makes decisions, initiates responses, stores memories, and controls voluntary actions.

Spinal Cord

Part of the CNS that transmits signals between the brain and the body and acts as the center for reflex actions.

Cranial Nerves

12 pairs of nerves connecting the brain to the head and neck that control functions including vision, face movement, hearing, smell, taste, and swallowing.

Spinal Nerves

31 pairs of nerves branching from the spinal cord that innervate the trunk, limbs, and organs to carry sensory and motor signals.

Somatic Nervous System

A division of the PNS consisting of somatic sensory and somatic motor fibers that controls voluntary actions.

Autonomic Nervous System

A division of the PNS controlling involuntary functions, comprising visceral motor and visceral sensory pathways.

Sympathetic Division

The division of the autonomic nervous system responsible for the 'Fight or Flight' response.

Parasympathetic Division

The division of the autonomic nervous system responsible for 'REST & DIGEST' functions.

Dendrites

Tree-like extensions of the cell body (soma) that receive signals from other neurons or receptors and carry them toward the soma.

Soma

The cell body and hub of the neuron containing the nucleus, which integrates incoming signals.

Axon

The conductor extension of a neuron that carries electrical impulses (action potentials) away from the soma toward axon terminals.

Myelin Sheath

An insulating layer wrapped around the axon that speeds up electrical signal conduction.

Nodes of Ranvier

Tiny gaps between myelin sheath segments where electrical impulses are recharged and jump from node to node.

Axon Terminals

End branches of the axon containing synaptic vesicles filled with neurotransmitters to convert electrical signals into chemical signals.

Unipolar Neuron

A neuron that has only one process extending from the cell body, found mainly in invertebrates and rare in humans.

Bipolar Neuron

A neuron with two processes found in special senses such as the eye (retina), nose (olfaction), and ear (hearing/balance) that relays sensory information.

Pseudounipolar Neuron

A sensory neuron (touch, pain, temperature) developed from a bipolar neuron that has one process that splits into two.

Multipolar Neuron

The most common neuron type in humans, consisting of many dendrites and one axon, located in the brain, spinal cord, and motor pathways.

Reflex Arc

The pathway nerve signals follow in a reflex action, connecting a stimulus to a rapid, automatic response without requiring direct brain involvement.

Nociceptors

Pain receptors located in the skin that respond to stimuli like heat.

Sensory Transduction

The process by which sensory receptors convert stimuli (such as heat) into electrical signals (action potentials).

Interneurons

Neurons in the spinal cord (CNS) that receive and integrate sensory signals to decide on a rapid reflex response.