Key Concepts of the Peripheral Nervous System

This set of flashcards covers key vocabulary terms and concepts related to the spinal nerves and their importance in the Peripheral Nervous System, muscle structure, and function.

Spinal Nerves

Key components of the Peripheral Nervous System that connect the spinal cord to body parts and transmit sensory and motor information.

Sensory Information

Information that is transmitted to the brain from sensory organs via afferent nerves.

Motor Information

Signals sent from the brain to muscles to initiate movement, carried by efferent nerves.

Cervical Nerves

A series of spinal nerves (C1-C8) that innervate the neck, shoulders, arms, and hands.

Thoracic Nerves

Spinal nerves (T1-T12) that control the chest area, certain abdominal muscles, and mid-back.

Lumbar and Sacral Nerves

Spinal nerves that innervate the lower abdomen, legs, bowel, and bladder.

Phrenic Nerve

A crucial nerve for breathing that innervates the diaphragm and originates from cervical spinal nerves C3, C4, and C5.

Afferent Nerves

Also known as sensory nerves; these originate in the dorsal root ganglion and transmit sensory information to the spinal cord.

Efferent Nerves

Also known as motor nerves; they originate in the ventral horn of the spinal cord and transmit motor commands to muscles.

Skeletal Muscles

Muscle tissue composed of fibers that are involved in voluntary movements of the body.

Sarcomeres

The basic functional units of muscle fibers that facilitate contraction, made up of myofibrils.

Motor Unit

A functional unit of muscle tissue consisting of a single motor neuron and the muscle fibers it controls.

Sliding Filament Theory

The mechanism of muscle contraction where myosin filaments pull on actin filaments, shortening the sarcomere.