AP Psychology - Unit 1.6b Other Senses

Olfaction

• sense of smell

Olfactory Receptor Cells

• located in the olfactory epithelium

• odor molecules bind to these cells

Olfactory Bulb

• chemical signals are transduced into neural impulses

Difference of Smell Compared to Other Senses

smell signals are not relayed in the thalamus

signals are sent to the amygdala and hippocampus

• explains why smell can trigger strong emotions and memory

Phermones

• chemical signals released by organisms to communicate with other members of their species

• useful in mating

Gustation

• sense of taste

Six Basic Tastes

1. Sweet - signals energy rich foods

2. Sour - can warn us of spoiled foods

3. Salty - helps regulate our electrolytes

4. Bitter - warns us about potential toxins or harmful food

5. Unami - linked to savory, protein-rich foods

6. Oleogustus -connected to fats and oils

Papillae

• contains small structures called taste buds

Taste Buds

• contain receptor cells that transduce chemical signals into neural signals

Supertasters

• people who have a higher than average number of taste receptors

• experience taste more intensely

Medium Tasters

• individuals with an average number of taste receptors

• have a more balanced sensitivity to different tastes

Non-tasters

individuals that have fewer taste receptors

• less sensitive to certain tastes

• may prefer foods with stronger flavors

Facial Nerve

• nerve that innervates facial muscles

• sensory receptors for some of the ear and tongue

Taste and Smell Relationship

gustation (taste) and olfaction (smell) interact closely to create the full sensation of flavor

• taste buds detect the basic taste

• the olfactory receptors identify the aromas released from the food

Touch Sensory System

connected to the somatosensory cortex in the parietal lobes

• allows us to detect things like pressure, temperature, pain, and texture

Epidermis

• outermost layer of the skin

Dermis

the layer of skin beneath the epidermis

contains;

• nerve endings

• blood vessels

• hair follicles

Hypodermis

• layer of fat before bones and organs

4 Main Skin Senses

1. Heat/Warmth

2. Cold

3. Pain

4. Pressure

Nociceptors

located in the dermis

help detect harmful stimuli like;

• extreme temperatures

• damage

• chemical irritants

Thermoceptors

• detect and respond to an increase (warm receptors) and decrease (cold receptors) in temperature

• when we encounter something extremely hot, it can activate both the warm and cold receptors simultaneously 

Mechanoreceptors

respond to mechanical stimuli like;

• touch

• pressure

• vibration

• stretch

Gate Control Theory

an explanation for pain control that suggests that the spinal cord contains a neurological “gate” that can either block pain signals or allow them to pass through to the brain

gate is influenced by the activity of different types of nerve fiber

• Large Diameter Fibers: typically carry non-painful stimuli, and their activity can “close the gate,” reducing the perception of pain

• Small Diameter Fibers: relay pain signals, and their activity “opens the gate,” allowing pain signals to reach the brain

Factors that Influence Pain

• analgesic drug usage

• endorphin production

• attention to pain

• empathy of others’ pain

• psychological state

Phantom Limb Sensation

happens when someone has lost a limb, but still feels pain or sensations in the missing body part

• can occur due to the brain’s neural map of the body, which may still include the missing limb

• brain and spinal cord can still send or interpret signals as if the limb were still there

Congenital Insensitivity

• people with this condition do not feel what is hurting them

Placebo Effect

• a response to a placebo (fake drug) caused by the subject’s belief they are taking real drugs

Pain Tolerance

• the threshold of pain varies enormously from person to person

Vestibular Sense

helps maintain balance and spatial orientation, essentially this is what allows you to stay upright

made possible by the semicircular canals and vestibular sacs in the inner ear

• these structures detect changes in head movement, tilt, and acceleration by sensing how fluid moves inside them

Kinesthesis

sense of body position and movement

the ability to know where your limbs are, even without looking

Proprioceptors

• located in the muscles, tendons, and joints

• provide constant feedback to the brain about the body’s position, movement, and tension

• responsible for kinesthesia