Lecture Notes on the Peripheral Nervous System

A set of vocabulary flashcards covering key concepts from the Peripheral Nervous System.

Peripheral Nervous System (PNS)

Links the Central Nervous System (CNS) to the body and external environment; detects sensory stimuli and delivers information to CNS.

Somatic Sensory Division

Detects internal and external stimuli; general sense from skin and special sense from special organs.

Visceral Sensory Division

Relays internal information such as blood pressure from abdominal and thoracic organs.

Motor Division

Composed of motor (efferent) neurons that carry out motor functions of the nervous system.

Somatic Motor Division

Controls voluntary motor functions by triggering skeletal muscle contractions.

Visceral Motor Division (Autonomic Nervous System)

Maintains homeostasis through involuntary motor functions and is divided into sympathetic and parasympathetic.

Sympathetic Nervous System

Known as the 'fight or flight' division; prepares the body for emergency situations.

Parasympathetic Nervous System

Known as the 'rest and digest' division; responsible for digestion and maintaining homeostasis at rest.

Mixed Nerves

Peripheral nerves that contain both sensory and motor neurons.

Spinal Nerves

Originate from the spinal cord and are involved in innervating structures below the head and neck; mixed in function.

Golgi Tendon Organs

Mechanoreceptors located within tendons that monitor tension generated by muscle contractions.

Reflex Arc

A three-step sequence of events that enables programmed, automatic responses to stimuli.

Muscle Spindles

Sensory receptors in muscles that detect stretch and play a role in reflex actions.

Referred Pain

The phenomenon where pain from an organ is perceived as cutaneous pain due to shared neural pathways.

Thermoreceptors

Sensory receptors that detect temperature changes; includes cold and warm receptors.

Afferent Neurons

Sensory neurons that transmit sensory information to the CNS.

Efferent Neurons

Motor neurons that carry signals from the CNS to muscles and glands.

Sensory Transduction

The process by which a stimulus is converted into an electrical signal.

Two-Point Discrimination Threshold

A method for measuring the relative size of receptive fields in sensory neurons.

Cranial Nerves

Nerves that attach to the brain and primarily innervate structures in the head and neck.