Ch.5.2 Sensory System

Hyper

High, beyond, excessive,

Hypo

Under beneath

Algesia

Pain

Esthesia

Feeling, sensation

Afferent Neurons

Sensory nerves responsible for bringing sensory information to the brain.

Efferent neurons

Motor Neurons, responsible for carrying signals from the brain to the rest of the body to perform an action.

Haptic perception

Perception of touch

Nociception

Perception of pain

Proprioception

Perception of body movement and where it is in the environment.

Thermoception

Perception of temperature

Somatosensory system

Sense of touch. A widespread neural network that brings sensory input from the body to the brain. 4 types of touch receptors.

Mechanoreceptors

Detect pressure and texture

Thermoreceptors

Sense changes in temperature

Proprioreceptors

Detect the movement and position of the body.

Nociceptors

Sense pain.

Hyperalgesia

Abnormally heightened sensitivity to pain. Can be caused by damage to nociceptors or peripheral nerves or from long term opioid use.

Hypoesthesia

Numbness. A common side effect of a variety of pathologies. Mainly caused by nerve damage and blood vessel blockage.

Naso

Nose

-osmia

Smell

Rhino

Nose

Sinuso

Sinus cavity

Anosmia

Loss of sense of smell

Dysosmia

Distortion of smells

Hyperosmia

Overly acute sense of smell

Hyposmia

Decreased sense of smell

Parosmia

All substances smell bad

Phantosmia

Smelling things that aren’t there

Nasal epithelium

Covers upper portion of the nasal cavity and is full of olfactory receptors. These receptors have 2 ends: peripheral dendrites and filaments.

Olfactory bulb

Neural structure located in the forebrain that receives input from the olfactory receptors and passes them on to the amygdala and hippocampus.

Aceto

Sour

Acrio

Bitter

-guesia

Taste

Glosso, linguo

Tongue

Glyco

Sweet

Gusto

Prefix Taste

Oro, Stomato

Mouth

Palato

Palate

Salino

Salty

Ageusia

Lack of sense of taste

Dysguesia

Distorted sense of taste

Hypogeusia

Decreased sense of taste.

Tongue

Only skeletal muscle in the human body with sensory capabilities. Can detect 5 basic flavors: salty, sour, bitter, savory, and sweet.

Vallate papillae

Located on the anterior dorsum (back) of tongue. These structures house 50% of all tastebuds.

Foliate papillae

Rough, close folds on the sides of the tongue’s posterior and contain several hundred tastebuds.

Fungiform papillae

Mushroom shaped structures. Roughly 200-400 of them concentrated on the sides and tip of the tongue. Each one have 3-5 taste buds, as well as mechanoreceptors and thermoreceptors.

Filiform papillae

Most numerous structures on the tongue. They have mechanoreceptors, but no actual taste buds, and enters the pores.

Gustatory Cells

As food comes into contact with the taste buds and enters the pores, these cells detect flavor present. The signal travel along the sensory nerve fibers to the VII and IX insular cortex.