Sensory Systems Flashcards
What can you see in a lateral view of human anatomy?
The anterior/vestral and the posterior/dorsal.
What can you see in an anterior view of human anatomy?
A view from left to right, including the midline and medial.
Why is the top of the human brain referred to as dorsal?
Humans went from walking on 4 limbs to walking on only 2.
Which part of the peripheral nervous system controls our “internal environment”?
The autonomic nervous system.
Which part of the peripheral nervous system controls our “external environment”?
The somatic nervous system.
Name the theory that suggested the nervous system wad made up of a single, interlinking network.
Reticular theory
Name the theory that suggested the nervous system was made up of discrete individual cells.
Neuron Doctrine
What did development of microscopy in the 1950s reveal about the CNS?
Synapses
What is proprioception?
The perception of the position of limbs in space.
What is kinethesis?
The perception of body movements.
What is haptic perception?
A combination of touch perception of patterns on the skin surface and proprioception of hand movements.
What is a complex tone?
A tone that consists of 2 or more pure tones (first harmonic and higher harmonics).
Where are the cochlea and the receptors for hearing?
The inner ear.
Name the 3 small bones in the middle ear that transmit vibrations from the outer to inner ear.
Ossicles
What is the name for the perceived quality of a sound?
Pitch
What is a pure tone?
A tone with pressure changes that can be described by a single sine wave.
Name the organs that sense head motion and head orientation with respect to gravity.
Vestibular organs
What do semicircular canals sense?
Angular motion
What do otolith organs sense?
Linear acceleration and gravity
What is interaural time difference?
When there is a difference in the time of sound arrival in the ears.
What is the minimum stimulus energy for an observer to detect it?
Absolute threshold
What is the minimum detectable difference between 2 stimuli?
Difference threshold
Name the law stating that the ratio of the difference threshold to the stimulus intensity is constant.
Weber’s law
What is the name for a “device” that converts a signal in one form of energy into another?
Transducer
Where is grey matter?
Surrounding the central cavity of the brain.
Where is white matter?
Exterior to grey matter.
Which type of glial cell myelinates axons in the PNS?
Shwann cells
Which type of glial cell myelinates axons in the CNS?
Oligodendrocytes
What is the name given to a small change in membrane potential?
Graded potential
Which pathway carries information about skin temperature and pain?
Spinothalamic pathway
Which pathway carries signals from skin, muscles and joints?
DCLM pathway
What are mechanoreceptors?
Receptors which respond to touch (e.g. Pressure, stretching, vibration).
What are nocioceptors?
Receptors which respond to stimuli that are damaging to the skin (I.e. Pain).
What are thermoreceptors?
Receptors which respond to temperature.
Describe the somatosensory system.
The cutaneous sense and proprioception.
What are the 5 basic tastes the tongue has receptors for?
Salty, sour, sweet, bitter and unami.
Where on the tongue are circumvallate papillae located?
The back.
Where on the tongue are foliate papillae located?
The sides.
Where on the tongue are fungiform papillae located?
The tip.
What are the 2 ways transduction occurs during taste?
Tastings contain charged particles which directly change MP or are bound by receptors which trigger a chain of processes.
What is the olfactory epithelium?
The region inside the nose that contains the receptors for smell.
Give 2 theories for how odorants are transduced?
Shape theory and molecule vibration theory.
How is information from odorants transmitted to the cortex?
Odortopy
Which sense shows the most intense emotional recollection?
Smell
Name the principle that describes how the magnitude of sensation increases proportionally to the logarithm of the stimulus intensity.
Fechner’s law
How is sound pressure perceived by humans?
As loudness.
How is sound frequency perceived by humans?
As pitch.
What is timbre?
The perceived quality that makes 2 tones sound different, even with the same pitch, loudness and duration.
Which part of the hear serves as an amplifier?
The middle ear.
Where are the smallest skeletal muscles in the body?
The middle ear.
What are sound waves?
The pattern of pressure changes in a medium.
What is frequency?
The number of times per second that pressure changes of a sound stimulus repeat.
What area should be thought of as the body’s microphone?
The organ of Corti in the cochlea.
What are the receptors for sound?
Hair cells in the cochlea.
Which hair cells are primarily responsible for auditory transduction?
Inner
Which hair cells are primarily responsible for amplifying basilar membrane vibration?
Outer
How does interaural time difference indicate direction of sounds?
The sound reaches one ear faster than the other.
How does interaural level difference indicate direction of sounds?
The difference in sound pressure in each ear creates an acoustic shadow in the far ear.
What is electromagnetic radiation?
Radiant energy propagating through space via electromagnetic waves and/or photons.
What is referred to as visible light?
The range of EMR that is visible to humans.
What does the iris control and how does it do so?
It controls the amount of light that can enter the eye by changing the pupil size.
What is the main focusing element of the eye?
The cornea
In vision, what is accommodation?
The change in the shape of lenses to focus at different distances.
In vision, what is the near point?
The nearest point to the eye at which an object can be accurately focused on the retina at full accommodation.
Which area of the retina is located directly opposite the pupil on the line of sight?
Fovea
What causes the blind spot?
It it the area where the optic nerve leaves the back of the eye so there are no visual receptors.
What are the 2 components of gangial cells?
Excitatory centre and inhibitory surround.
Which ganglion cells have large receptive fields, are indifferent to wavelengths and adapt rapidly?
M cells
Which ganglion cells have small receptive fields, are sensitive to wavelengths and adapt slowly?
P cells
Briefly describe the transmission of visual information to the cortex.
Stimulus -> Retinal image -> Retiontopic mapping in left V1
What is colour?
The sensation that allows us to discriminate 2 unstructured surfaces of equal luminance.
What is the theory that colour vision is based on 3 classes of receptors for 3 primary colours?
Thrichromatic theory
Which colour deficiency is due to the absence of S-opsin?
Tritanopia
Which colour deficiency is due to the absence of M-opsin?
Deuteronopia
Which colour deficiency is due to the absence of L-opsin?
Protanopia
What are the 3 opponent systems in colour processing?
White vs. black, red vs. green and blue vs. yellow.
Describe synesthesia.
A condition where stimulation of one modality results in experience of another modality.
