Chapter 16 - Sensory, Motor, and Integrative Systems (Part 1)

Somatic senses

touch, temperature, pain, proprioception

Visceral senses

sensations of our internal organs (ex. pressure, stretch, hunger)

Special senses

smell, taste, vision, hearing, balance

Free nerve endings

bare dendrites

Encapsculated nerve endings

dendrites enclosed in a connective tissue capsule

Sensory cells

specialized cells that respond to stimuli by releasing a neurotransmitter

Exteroceptors

sensory receptors located near surface of body (for external stimuli)

Interoceptors

sensory receptors located in blood vessels, organs, muscles, and nervous system (for internal stimuli)

Proprioceptors

sensory receptors located in muscles, tendons, joints, and inner ear (for body position, movement, and equilibirum)

Mechanoreceptors

detects mechanical stimuli

Thermoreceptors

detects temperature

Nociceptors

free nerve endings that detects pain (located in nearly every body tissue)

Photoreceptors

detects light in retina

Chemoreceptors

detects chemical stimuli (taste and smell)

Osmoreceptors

detects osmotic pressure in fluids

Tactile corpuscles

detects low-frequency vibrations (found in hairless skin)

Hair root plexuses

senses movements on skin surface hairs (found in hairy skin)

Nonencapsulated sensory corpuscles

senses continuous touch and pressure (found touching stratum basale)

Bulbous corpuscles

senses skin stretching and pressure (found in dermis)

Lamellar corpuscles

detects high-frequency vibrations (found in dermis, subcutaneous tissue)

Pressure

sustained tactile sensation that is felt over a larger area than touch

Vibration

tactile sensations that result from rapidly repetitive sensory signals

Itch sensation

a sensation resulting from stimulation of free nerve endings by various substances

Tickle sensation

a sensation resulting from stimulation of free nerve endings

Thermal sensation

a sensation resulting from stimulation of thermoreceptors

Fast pain

sharp acute pain that travels through medium-diameter, myelinated nerve fibers (superficial)

Slow pain

chronic aching pain that travels through small, unmyelinated nerve fibers (superficial, deeper tissues)

Superficial somatic pain

stimulation of pain receptors in skin

Deep somatic pain

stimulation of receptors in skeletal muscles, joints and tendons

Visceral pain

stimulation of pain receptors in visceral organs

Proprioception

the awareness of body position and movement

Muscle spindles

proprioceptors that monitor changes in the length of skeletal muscle

Tendon organs

proprioceptors that protect muscles from excessive tension (junction of a tendon and muscle

Joint kinesthetic receptors

proprioceptors that respond to changes of movement in joints (articular capsules of synovial joints)

First-order neurons

neurons that carry impulses from somatic receptors to brainstem/spinal cord

Second-order neurons

neurons that carry impulses from brainstem/spinal cord to thalamus

Third-order neurons

neurons that carry impulses from thalamus to primary somatosensory