Other Senses

Proprioception, Olfactory, Gustatory, and Haptic Senses

Vestibular Sense

senses balance, equilibrium
- employs receptors in inner ear and vestibular sacs
- works with the cerebellum

Motion Sickness/Vertigo

disorders of the vestibular sense

Kinesthetic Sense

senses where body is in space
- helps move body parts precisely
- relies on proprioceptors

Sensory Interaction

when different senses work together

ex. when taste, smell, and touch together produce the flavor of food

Synesthesia

2+ senses coupled together
- genetically heritable
- rare

ex.
hear music + see shapes
feel object + hear sound

stimulus for olfactory sense

chemical odors

olfactory pathway

receptors on olfactory epithelium --> olfactory nerve olfactory bulb --> olfactory cortex in temporal lobe, limbic system

pheromones

substances which are secreted to the outside by an individual and received by a second individual of the same species

in animals (other than humans) can sense through olfactory

Anosmia

loss of smell

Why do smells trigger emotional memories?

smell is "wired" closely to the amygdala and hippocampus
(emotional limbic system)

stimulus for gustatory sense

chemical tastes

gustatory receptors

epithelial cells in taste buds
(epithelial, NOT nerve cells)

- contain taste hairs that stick out of the taste pore
- tastants bind to taste hairs on taste cells

5 tastes

salty, sweet, bitter, sour, umami

Lingual Papillae

small, bulbous structures on tongue
- increase surface area
- most types CONTAIN multiple taste buds in each protrusion
- so, not the same as a taste bud

Taste Bud

- many of these are found in the walls of lingual papillae
- each one consists of many epithelial cells bunched together

gustatory pathway

tastant molecule
1) enters through taste pore (small hole in epithelium)
2) binds to taste hair

signal begins in
3) Taste Receptor EPITHELIAL Cells
4) travels along taste nerve, up brain stem
5) to thalamus
6) rerouted to gustatory cortex in frontal lobe

stimuli for haptic senses

pressure, pain, temperature

haptic receptors

pain receptors = free nerve endings in top-most layer of skin
temperature and light-touch receptors = nerves further down in epidermis
strong-pressure receptors = deepest

haptic pathway

signal --> respective neuron types in skin (depending on signal type) --> somatosensory nerve --> either the reflex arc to spine and back OR goes through to thalamus and somatosensory cortex in brain

phantom limb pain

pain that feels like it's coming from a body part that's no longer there.
- post-amputation phenomenon

PJ is so cool

I agree

chronic pain

pain that lasts weeks to years
- self-explanatory?? why is this a vocab word

Gate Control Theory of Pain

there is a neurological "gate" in spinal cord that opens or closes to allow pain messages to brain

small fibers --> send pain signals --> gate opens
large fibers (like massaging) --> temporarily relieve pain

anxiety/fear --> open
laughter/distraction --> close

high adrenaline --> closed

Propioception

= awareness of our body in space and in relation to other objects

\+ awareness of what our muscles are doing

Proprioceptors

= special sensory neurons that provide info about position and movement of body parts

* found in joints, tendons, muscles, and inner ear