Block D Part 1: Sensory Systems Flashcards
What is sensory transduction?
Sensory stimulus to neural impulses
(Lecture 1, Slide 5)
What are the 4 common features of a sensory system?
Adaptation
Sensory Coding
Receptive field
Topographic organisation
(Lecture 1, Slide 7)
What is adaptation in a sensory system and what does it allow us to do?
The way our senses adjust to different stimuli, which allows us to function in adverse or overstimulating conditions
(Lecture 1, Slide 8)
What is rate coding in a sensory system?
The way in which the nervous system encodes information about the intensity of a stimulus
(Lecture 1, Slide 10)
What is a receptive field?
A region of space in which the presence of a stimulus will alter the firing of the neuron
(Lecture 1, Slide 13)
What is topographic organisation?
The systematic spatial representation of sensory information in the brain (like a map)
(Lecture 1, Slide 16)
Which layer of the eye contains photoreceptor cells?
The retina
(Lecture 1, Slide 20)
What are the two types of photoreceptor cells?
Rods and Cones
(Lecture 1, Slide 21)
What type of light are rods used in?
Dim light
(Lecture 1, Slide 21)
What type of light are cones used in?
Bright light
(Lecture 1, Slide 21)
What are the 2 components of rhodopsin?
Retinal + opsin
(Lecture 1, Slide 22)
What can Rhodopsin trigger when receiving photons?
Phototransduction
(Lecture 1, Slide 22)
What is phototransduction?
The process by which light energy is converted to an electrical signal in the retina.
(Lecture 1, Slide 22)
What is photoreception?
The process which describes how rods and cones absorb light waves which enter the eye.
(Lecture 1, Slide 23)
What happens after initial photoreceptions?
Neural signals propagate through the retinal layers
(Lecture 1, Slide 23)
What steps does the visual pathway contain?
Retina > Optic nerve > Optic chasm > Lateral geniculate body > Primary visual cortex
(Lecture 1, Slide 24)
What are the two major components in sound?
Frequency and amplitude.
(Lecture 1, Slide 30)
What is frequency (pitch) in sound waves?
The number of times per second that a sound wave repeats itself
(Lecture 1, Slide 30)
What is amplitude in sound waves?
The relative strength of sound waves which we perceive as loudness or volume
(Lecture 1, Slide 30)
What is the hearing frequency of humans?
20 Hz (Hertz) - 20 kHz
What is the decibel threshold for hearing damage?
85 dB SPL (sound pressure level)
(Lecture 1, Slide 31)
What is the decibel threshold for pain?
130 - 140 dB SPL (sound pressure level)
(Lecture 1, Slide 31)
What happens after auditory transduction in the cochlea?
Auditory signals propagate through the auditory pathway
(Lecture 1, Slide 38)
What are the steps of the audio pathway?
Cochlea > Cochlear nucleus > Superior olivary complex > Medial geniculate body > Auditory cortex
(Lecture 1, Slide 38)
What sensory system is the sensory organ of skin in?
The somatosensory system
(Lecture 1, Slide 44)
What are the three major types of Somatosensory receptors?
Mechanoreceptors (touch)
Thermoreceptors (temperature)
Nociceptors (pain)
(Lecture 1, Slide 45)
What is the dorsal column-medial meniscal pathway in the somatosensory system for?
Touch
(Lecture 1, Slide 47)
What does the column-medial meniscal pathway in the somatosensory system consist of?
Dorsal root ganglia (first-order neurons) > Dorsal column nuclei > Ventral posterior nucleus (thalamus) > Primary somatosensory cortex
(Lecture 1, Slide 47)
What are the two fibres in the nociceptor system?
A-delta (δ) fibres and C fibres
(Lecture 1, Slide 52)
Why can the A-delta fibre send signals quickly?
As it is myelinated
(Lecture 1, Slide 52)
Is C fibres myelinated or un-myelinated?
Un-myelinated
(Lecture 1, Slide 52)
Why do we have bi-phasic pain perception?
As A-delta fibres send signals quickly whereas C fibres send signals more slowly.
(Lecture 1, Slide 52)
What 2 things is the spinothalamic tract pathway in the somatosensory system for?
Nociception (pain) and thermoreceptor (temperature)
(Lecture 1, Slide 53)
What does the spinothalamic tract pathway in the somatosensory system consist of?
Dorsa root ganglia > Spinal cord > Ventral posterior nucleus of the thalamus > Primary somatosensory cortex
(Lecture 1, Slide 53)
Where are olfactory receptor cells located?
In the nasal epithelium, which is inside the nose
(Lecture 1, Slide 57)
What do olfactory receptor cells do?
Provide signals to the olfactory bulb
(Lecture 1, Slide 57)
Where are mitral cells located?
In the olfactory bulb
(Lecture 1, Slide 57)
Where do mitral cells send their output to?
To multiple brain regions, the the main area being the “piriform” cortex which is an olfactory cortex.
(Lecture 1, Slide 58)
What are the 5 modalities in taste reception?
Bitter, Salty, Sweet, Umami (Savoury), Sour
(Lecture 1, Slide 63)
What is the gustatory pathway for?
Taste
(Lecture 1, Slide 65)
What does the gustatory pathway consist of?
Taste bud > Nucleus of the solitary tract > Ventroposterior medial nucleus > Insular cortex
(Lecture 1, Slide 65)
