Peripheral Nervous System (PNS) and Autonomic Nervous System

These flashcards cover key terms and definitions related to the Peripheral Nervous System and the Autonomic Nervous System, important for understanding bodily functions and responses.

Autonomic Nervous System (ANS)

A division of the peripheral nervous system that controls involuntary bodily functions.

Somatic Nervous System

A division of the peripheral nervous system associated with voluntary control of body movements.

Central Nervous System (CNS)

The part of the nervous system consisting of the brain and spinal cord.

Efferent Neurons

Nerve cells that carry signals away from the central nervous system to target cells.

Afferent Neurons

Nerve cells that carry sensory signals to the central nervous system.

Parasympathetic Nervous System

A part of the autonomic nervous system responsible for rest-and-digest activities.

Sympathetic Nervous System

A part of the autonomic nervous system responsible for the fight-or-flight response.

Homeostasis

The process by which organisms maintain a stable internal environment.

Enteric Nervous System

A subdivision of the autonomic nervous system that governs the function of the gastrointestinal system.

Neurotransmitter

A chemical substance that transmits signals across a synapse from one neuron to another.

Acetylcholine (ACh)

A neurotransmitter that plays a role in muscle activation and autonomic nervous system functions.

Norepinephrine (NE)

A neurotransmitter involved in the body’s fight-or-flight response.

Dual Innervation

The fact that most organs are innervated by both sympathetic and parasympathetic fibers.

Preganglionic Neurons

Neurons that synapse with postganglionic neurons in the autonomic nervous system.

Postganglionic Neurons

Neurons that connect autonomic ganglia to target organs in the autonomic nervous system.

Vagus Nerve (Cranial Nerve X)

A major component of the parasympathetic nervous system, affecting heart rate, digestion, and respiratory rate.

Muscarinic Receptors

A type of acetylcholine receptor that operates through G proteins and signaling pathways.

Nicotinic Receptors

A type of acetylcholine receptor found in the neuromuscular junction and autonomic ganglia.

Adrenal Medulla

The inner part of the adrenal glands that secretes epinephrine and norepinephrine.

Sympathetic Chain Ganglia

A series of ganglia located along the sympathetic trunk that organizes sympathetic pathways.