Exam 2: Somatosensory System

Question 1

Somatosensory System

Answer 1

The system responsible for detecting touch, pressure, temperature, pain, and body position.

Question 2

Primary Somatosensory Cortex

Answer 2

The region of the brain that processes somatosensory information from the body, located in the postcentral gyrus.

Question 3

Somatotopic Organization

Answer 3

The orderly mapping of the body’s surface onto the somatosensory cortex, where adjacent body parts are represented in adjacent cortical areas.

Question 4

Sensory Homunculus

Answer 4

A visual representation of the body mapped onto the somatosensory cortex, with exaggerated areas for more sensitive regions (e.g., hands and lips).

Question 5

Secondary Somatosensory Cortex

Answer 5

A brain region that integrates complex sensory information and is involved in higher-order sensory processing.

Question 6

Cutaneous Mechanoreceptors

Answer 6

Receptors in the skin that detect mechanical stimuli, such as pressure, vibration, and stretch.

Question 7

Slowly-Adapting Mechanoreceptors

Answer 7

Mechanoreceptors that respond to sustained pressure and slowly adapt to continuous stimuli.

Question 8

Rapidly-Adapting Mechanoreceptors

Answer 8

Mechanoreceptors that respond to changes in stimuli, such as light touch or vibration, and adapt quickly.

Question 9

Merkel’s Discs

Answer 9

Touch receptors that detect fine details and texture, located in the skin’s surface layers.

Question 10

Pacinian Corpuscles

Answer 10

Receptors in the skin that detect deep pressure and high-frequency vibration.

Question 11

Meissner’s Corpuscles

Answer 11

Touch receptors sensitive to light touch and low-frequency vibration, involved in grip control.

Question 12

Ruffini Endings

Answer 12

Receptors in the skin that detect skin stretch and help with the perception of hand shape and object manipulation.

Question 13

Receptive Fields in the Skin

Answer 13

Specific areas of skin that a single sensory neuron is responsible for detecting stimuli.

Question 14

Two-Point Discrimination Task

Answer 14

A task used to measure tactile spatial acuity by determining the minimum distance at which two points of touch can be distinguished.

Question 15

Dorsal-Column Medial Lemniscus (DCML) Tract

Answer 15

A major sensory pathway that transmits fine touch, vibration, and proprioceptive information from the body to the brain.

Question 16

Spinothalamic Tract

Answer 16

A sensory pathway that transmits pain, temperature, and crude touch information from the body to the brain.

Question 17

Thermoreceptors

Answer 17

Sensory receptors in the skin that detect temperature changes, including cold and heat.

Question 18

Cold Receptors

Answer 18

Detect temperatures from 59°F to 86°F (TRPM8 channels), also activated by menthol.

Question 19

Warm Receptors

Answer 19

Detect temperatures from 86°F to 113°F (TRPV3 & TRPV4 channels).

Question 20

Nociceptive Thermoreceptors

Answer 20

Specialized receptors that detect painful extremes of temperature, leading to sensations of burning heat or freezing cold.

Question 21

TRP Channels

Answer 21

Ion channels in sensory neurons that respond to temperature changes and chemical irritants, involved in sensing pain and temperature.

Question 22

TRPM8 Receptor

Answer 22

A type of TRP channel activated by cold temperatures and compounds like menthol, producing cooling sensations.

Question 23

TRPV1 Receptor

Answer 23

A type of TRP channel activated by heat and chemical stimuli like capsaicin (the compound in chili peppers), producing sensations of heat or burning.

Question 24

Aδ Fibers

Answer 24

Thin, myelinated nerve fibers that transmit sharp, localized pain quickly to the brain.

Question 25

C Fibers

Answer 25

Unmyelinated nerve fibers that transmit dull, aching pain more slowly to the brain.

Question 26

Gate Control Theory

Answer 26

Pain perception is modulated by a "gate" in the spinal cord that can be influenced by sensory input, emotions, and attention. Non-painful stimuli can "close the gate," reducing pain signals to the brain.

Question 27

Nociceptors

Answer 27

Sensory receptors that detect painful or noxious stimuli, such as extreme temperatures, mechanical damage, or chemical irritants.

Question 28

Mechanical Nociceptors

Answer 28

Nociceptors that respond to physical damage or pressure, such as cuts or crushing injuries.

Question 29

Thermal Nociceptors

Answer 29

Nociceptors that respond to extreme heat or cold, causing pain when temperatures become harmful.

Question 30

Chemical Nociceptors

Answer 30

Nociceptors that detect chemical irritants, such as those released during inflammation or tissue damage.

Question 31

Polymodal Nociceptors

Answer 31

Nociceptors that respond to a variety of stimuli, including mechanical, thermal, and chemical irritants, and are involved in generalized pain responses.

Question 32

Withdrawal Reflex

Answer 32

An automatic reflex that causes an immediate withdrawal of a body part from a painful stimulus (e.g., pulling your hand away from a hot surface).

Question 33

Proprioception

Answer 33

The sense of the position and movement of the body and its parts, allowing coordination and balance without the need for visual input.

Question 34

Muscle Spindles

Answer 34

Sensory receptors in muscles that detect changes in muscle length and the speed of stretching, contributing to proprioception and reflexes.

Question 35

Knee-Jerk Reflex

Answer 35

A simple reflex where tapping the patellar tendon causes a quick contraction of the quadriceps muscle, resulting in a kick.

Question 36

Golgi Tendon Organs

Answer 36

Sensory receptors located at the junction between muscles and tendons that monitor tension, helping to prevent excessive force that could cause injury.