Peripheral Nervous System

Flashcards encompassing key vocabulary and concepts related to the Peripheral Nervous System and its functions.

Peripheral Nervous System (PNS)

The part of the nervous system that transmits sensory information to the CNS and relays commands to peripheral tissues.

Sensory Division (Afferent)

The division of the PNS that carries signals from sensory receptors to the CNS.

Motor Division (Efferent)

The division of the PNS that carries commands from the CNS to muscles and glands.

Somatic Nervous System

Part of the PNS responsible for voluntary motor control of skeletal muscles.

Autonomic Nervous System (ANS)

Part of the PNS that controls involuntary functions, further divided into sympathetic and parasympathetic divisions.

Sympathetic Nervous System

Part of the ANS that prepares the body for 'fight or flight' responses.

Parasympathetic Nervous System

Part of the ANS that conserves energy and restores the body to a state of calm; 'rest and digest'.

Sensory Receptors

Structures that detect various stimuli from the environment and send signals to the CNS.

Cranial Nerves

Twelve pairs of nerves that originate in the brain and primarily serve the head and neck.

Spinal Nerves

Thirty-one pairs of nerves that emerge from the spinal cord; each innervates a specific body region.

Mixed Nerve

A nerve that contains both sensory (afferent) and motor (efferent) fibers.

Endoneurium

The delicate connective tissue that surrounds individual nerve fibers.

Fascicle

A bundle of nerve fibers within a nerve, wrapped in perineurium.

General Sensations

Sensation types that include pain, temperature, touch, pressure, vibration, and proprioception.

Special Senses

Sensations that include olfaction, vision, gustation, equilibrium, and hearing.

Visceral Sensory Division

Part of the sensory division that carries signals from internal organs to the CNS.

Visceral Motor Division

Part of the motor division that sends signals to internal organs; division of the ANS.

Homeostasis

The physiological state of balance maintained within the body.

Fight or Flight Response

The body's physiological reaction to perceived harmful events, attacks, or threats.

Rest and Digest Response

The body's state of relaxation and energy conservation when not in crisis.

Autonomic Ganglion

A cluster of nerve cell bodies in the ANS where pre- and post-ganglionic fibers synapse.

Describe the general structure of a peripheral nerve

peripheral nerve consists of axons (nerve fibers) bundled together by connective tissue. It contains myelin sheaths, endoneurium (surrounds individual fibers), perineurium (bundles fibers into fascicles), and epineurium (encloses the entire nerve)

mechanoreceptors

specialized sensory receptors that respond to mechanical pressure or distortion, such as touch, vibration, and proprioception.

thermoreceptors

specialized sensory receptors that detect changes in temperature, providing the sense of warmth or cold.

nociceptors

specialized sensory receptors that respond to pain, detecting harmful stimuli such as tissue damage or potentially damaging conditions.

photoreceptors

specialized sensory receptors that detect light and allow for vision, converting light into electrical signals for the brain.

chemoreceptors

specialized sensory receptors that detect chemical stimuli, such as taste and smell, by responding to various molecules in the environment.

Perineurium

connective tissue that surrounds each bundle of axons (fascicles) within a nerve, providing support and protection.

Epineurium

the outermost layer of connective tissue surrounding a nerve, providing protection and structural support.