sensation lecture (2nd day)

FLASHBACK… : 

FLASHBACK…

Slide 2: 

Sensation vs. Perception

Slide 3: 

Importance of studying sensation & perception Sensory systems Thresholds Absolute threshold Just noticeable difference (jnd)

Some more SENSATIONal concepts : 

Some more SENSATIONal concepts Transduction transformation of environmental stimuli to a form which can be perceptible to the nervous and perceptual system (electrical and chemical form) Sensory adaptation a change in the responsiveness of the sensory system based on the average level of surrounding stimulation Synaesthasia a neurological condition in which stimulation of one sense also evokes another

Parts of the Eye : 

Parts of the Eye Sclera outer white part of the eye Iris colored part of the eye Pupil opening in the center of the iris Cornea A clear membrane on the front surface of the eye

Parts of the Eye : 

Parts of the Eye Lens A transparent and some what flexible ball–like entity at the front of the pupil Retina The light sensitive surface at the back of the eye Contains the rods and cones

Slide 8: 

Rods the receptors in the retina that are exquisitely sensitive to light but are not very useful for color vision Cones receptors in the retina for color perception

Slide 10: 

Blind spot an area on the retina, directly in front of the optic nerve, that does not contain any receptors

Ishihara Test for Colorblindness : 

Ishihara Test for Colorblindness

Parts of the Ear : 

Parts of the Ear Outer Ear Pinna – outer, visible part of the ear. External Auditory Canal – funnels sound waves to the middle ear Middle Ear Eardrum – first structure that sound touches in the middle ear; a membrane that vibrates in response to sound Malleus, Incus, Stapes – a chain of three bones which translate sound waves in water (lymph) so they can be processed further in the inner ear

Parts of the Ear : 

Parts of the Ear Inner Ear Oval Window – the membrane unto which the stapes is connected; it transmits the waves to the cochlea Cochlea – long, tubular, fluid–filled structure that is coiled up like a snail Basilar Membrane – housed inside the cochlea and runs through its entire length Organ of Corti –sits on the basilar membrane and contains the ear’s sensory receptors which change the energy of sound waves into nerve impulses that can be processed by the brain

Skin senses : 

Skin senses Touch We detect mechanical energy or pressure against the skin in touch Our sensitivity to touch is not equally good across all areas of the skin Temperature Thermoreceptors, which are located under the skin, respond to increases and decreases in temperature.

The skin : 

The skin

Skin senses : 

Skin senses Pain The sensation that warns us that damage is occurring to our bodies. Pain receptors are scattered throughout the body but they differ in the type of physical pain they respond to

The skin : 

The skin

Slide 24: 

Gate-control theory States that the spinal column contains a neural gate that can be opened (allowing the perception of pain) or closed (blocking the perception of pain)

The sense of taste : 

The sense of taste Taste The tongue has rounded bumps on the surface called papillae which contain the taste buds, the receptors for taste.

Slide 28: 

The fifth basic taste? UMAMI!!!! Savoriness or umami is produced by the free glutamates commonly found in fermented and aged foods, and in the additive MSG

The sense of smell : 

The sense of smell Olfactory Epithelium located at the top of the nasal cavity, contains a sheet of receptor cells for smell 7 basic odors Floral, fruity, citrus, green/vegetal, woody, herbal/camphor, spicy

Slide 30: 

Pheromones special chemicals secreted by many animals that float through the air as a primitive means of communication with others members of the same species Sensory interaction The principle that one sense may be influenced by another

Slide 31: 

Kinesthetic sense The sense of the location of body parts in relation to the ground and each other Involves the proprioceptors Vestibular sense The sensations of movement, balance, and body position Involves the otolith organs and the semicircular canals