Reflex Physiology and General Senses Overview

Reflex

comparatively simple automatic response to a stimulus

Reflex Arc

The pathway that a reflex follows, including receptor, sensory relay, integration, motor command relay, and effector.

Monosynaptic Reflex

Reflexes that are faster and are integrated in the spinal cord, involving only one synapse.

Polysynaptic Reflex

Reflexes that contain at least one interneuron and involve multiple synapses.

Somatic Reflex

Voluntary reflexes that involve skeletal muscles.

Autonomic Reflex

Involuntary reflexes that involve smooth muscles, glands, or visceral organs.

Acquired Reflexes

Reflexes that are learned through experience, such as driving or skiing.

Exteroceptors

Sensory receptors that monitor external conditions such as heat, cold, touch, pain, and pressure.

Interoceptors

Sensory receptors that monitor internal conditions, such as blood pH.

Chemoreceptors

Receptors that monitor chemical changes, like blood pH.

Visceral Stretch Receptors

Receptors that detect distension of visceral organs.

Proprioceptors

Receptors that provide postural information and monitor muscle position.

Free Nerve Endings

Nerve endings that detect pain and extreme temperature, located in the epidermis/dermis junction.

Merkel Cells

Cells associated with free nerve endings that detect light touch and sustained pressure.

Meissner's Corpuscles

Encapsulated receptors that detect light touch and are located more superficially.

Pacinian Corpuscle

Encapsulated receptors that detect forceful pressure and vibrations, located deeper in the skin.

Muscle Spindle

Proprioceptors that monitor muscle position and ensure muscles are not overstretched.

α-motor Neurons

Neurons that innervate the contractile region of extrafusal fibers.

γ-motor Neurons

Neurons that innervate the contractile region of intrafusal fibers.

Receptors

Transducers that convert stimuli to action potentials.

Receptor Fields

The area monitored by a receptor; smaller and denser fields indicate higher sensitivity.

Adaptation

Desensitization to constant stimuli.

2 Point Discrimination Test

A test used to measure the ability to distinguish two points of contact on the skin.