BIO 201: Peripheral Nervous System and Autonomic Divisions

Comprehensive vocabulary flashcards covering the organization of the peripheral nervous system, somatic motor pathways, and autonomic divisions.

Peripheral Nervous System (PNS)

The nervous system division that serves as the link between the body and the outside world or internal consciousness; composed of sensory receptors, peripheral nerves and their glial cells, and motor neurons.

Central Nervous System (CNS)

The structural division of the nervous system consisting solely of the brain and spinal cord.

Afferent Neurons

Sensory neurons that carry sensory and visceral information away from the peripheral receptors toward the central nervous system.

Efferent Neurons

Motor neurons that exit the central nervous system to carry motor commands to effector organs like muscles and glands.

Somatic Nervous System (SNS)

The efferent division under voluntary control that utilizes motor neurons to stimulate skeletal muscles.

Autonomic Nervous System (ANS)

The involuntary efferent branch controlled by the hypothalamus that regulates smooth muscle, cardiac muscle, and endocrine glands.

Sensory Reception

The initial phase of a nervous pathway during which internal or external sensory stimuli are gathered by sensory receptors.

Sensory Transduction

The process of converting incoming sensory stimuli into neural electrical impulses (action potentials).

Integration

The processing and interpretation of incoming sensory signals within the central nervous system (spinal cord and brain).

Motor Response

The final stage of the response pathway in which the CNS transmits action potentials to muscles or glands to enact an action.

Dual Innervation

The condition where sympathetic and parasympathetic divisions supply the same internal organ, allowing opposing influences to balance homeostatic control.

Antagonistic Effects

The opposing physiological actions exerted by the sympathetic and parasympathetic divisions upon the same target organs.

Sympathetic Division

The autonomic division that prepares the body for potential danger through the 'fight or flight' response, increasing heart rate, dilating pupils, and shunting blood to skeletal muscles.

Parasympathetic Division

The autonomic division responsible for 'rest & digest' and 'feed & breed' activities, which slows heart rate, constricts pupils, and restores calm.

Enteric Nervous System

The specialized autonomic division associated with the parasympathetic response whose neural networks extend across the alimentary canal to regulate digestion, digestive glands, and smooth muscle.

"D Division"

A designation for the parasympathetic system referencing its stimulation of Digestion, Defecation, and Diuresis (urination).

"E Division"

A designation for the sympathetic system referring to its activation during states of Exercise, Excitement, Embarrassment, or Emergency.

Hypothalamus

The brain structure that oversees and provides central, involuntary control over the autonomic nervous system.

Upper Motor Neuron

A neuron originating in the cerebral cortex that conveys motor commands down the spinal cord to synapse with a lower motor neuron.

Lower Motor Neuron

A motor neuron situated in the spinal cord that receives input from an upper motor neuron and innervates target skeletal muscle at neuromuscular junctions.

Glycogenolysis

The sympathetic-stimulated breakdown of stored liver glycogen into circulating blood glucose to provide immediate cellular energy.