Nervous System and The Reflex Arc

Flashcards focusing on key vocabulary and concepts related to the nervous system and reflex arcs.

Nervous System

The system responsible for sensing changes in the environment, evaluating these changes, and eliciting responses.

Reflex Arc

The basic functional unit of the nervous system, consisting of receptors, sensory neurons, interneurons, motor neurons, and effectors.

Central Nervous System (CNS)

The part of the nervous system that includes the brain and spinal cord.

Peripheral Nervous System (PNS)

The part of the nervous system that includes all nervous tissue outside the CNS, including nerves and ganglia.

Autonomic Nervous System (ANS)

A motor system that controls glands, cardiac muscle, and smooth muscle; operates involuntarily.

Somatic Nervous System (SNS)

The part of the PNS responsible for voluntary control of skeletal muscles.

Sensory Level

The first level of functional classification of the nervous system, responsible for detecting changes in the environment.

Integrated Level

The level of the nervous system responsible for decision-making based on the sensory input.

Motor Level

The level of the nervous system that evokes responses in muscles or glands.

Afferent Nervous System

The division of the PNS that transmits information into the CNS.

Efferent Nervous System

The division of the PNS that transmits information out of the CNS.

Sympathetic Division

Part of the ANS that prepares the body for activity; increases blood pressure, heart rate, and blood flow.

Parasympathetic Division

Part of the ANS that has a calming effect on bodily functions, promoting rest and digestion.

Cervical Enlargement

A swelling of the spinal cord that supplies nerves to the upper body.

Lumbar Enlargement

A swelling of the spinal cord that supplies nerves to the lower body.

Medullary Cone (Conus Medullaris)

The tapered end of the spinal cord marking the termination of the spinal cord.

Cauda Equina

A bundle of spinal nerves and spinal nerve rootlets that extend from the lumbar and sacral regions of the spinal cord.

Filum Terminale (Terminal Filum)

A thin thread of fibrous tissue anchoring the spinal cord to the os coxae.

Gray Matter

Regions of the spinal cord that contain neuronal cell bodies and dendrites, organized into horns.

White Matter

Regions of the spinal cord primarily composed of myelinated nerve fibers organized into columns.

Posterior Horn

The part of the gray matter in the spinal cord that receives sensory information.

Anterior Horn

The part of the gray matter in the spinal cord that contains motor neurons.

Gray Commissure

The area of gray matter that connects the two sides of the spinal cord.

Dorsal Root Ganglion

A cluster of sensory neuron cell bodies located in the PNS.

Interneuron

A neuron that serves as a connection between sensory and motor neurons in the reflex arc.

Receptor

Specialized structures that detect stimuli and convert them into nerve impulses.

Effector Organ

The muscle or gland that responds to the motor neuron impulse in the reflex arc.

Sensory Neuron

Neurons that carry sensory information from receptors to the CNS.

Motor Neuron

Neurons that transmit impulses from the CNS to effectors.

Stimulus

Any event or situation that evokes a response from the nervous system.

Pia Mater

The delicate innermost layer of tissue covering the brain and spinal cord.

Arachnoid Mater

The middle layer of the three meninges that surround the brain and spinal cord.

Dura Mater

The tough outermost layer of the meninges that protect the brain and spinal cord.

Central Canal

A fluid-filled space in the center of the spinal cord.

Anterior Median Fissure

A deep groove that divides the spinal cord into right and left halves.

Posterior Median Sulcus

A shallow groove that runs along the back of the spinal cord.

Reflex Action

An involuntary and automatic response to a stimulus, typically without conscious thought.

Types of Reflexes

Various involuntary responses like sneezing, coughing, and blinking.

Pain Reflex

An automatic reflex to withdraw from painful stimuli before the sensation of pain is processed.

Voluntary Movement

Actions that are consciously controlled and coordinated by the brain.

Conscious Sensation

Sensations like touch and pain that require processing in the brain.

Memory Formation

The process of creating long-term associations in the brain, crucial for learning.

Neurological Examination

A test used to assess the integrity of the nervous system.

Two-Point Discrimination Test

A test to evaluate sensory control in specific body parts.

Patellar Reflex

A reflex that causes extension of the leg when the patellar tendon is tapped.

Babinski Reflex

A reflex action in infants where the big toe extends upward when the sole of the foot is stroked.