L4 - Animal Senses and the Brain I (exteroception) Flashcards
What are key factors about SENSORY ORGANS?
- They are structures that detect specific sensory stimuli within one ‘modality’ (a category of sensation such as vision, hearing/audition, smell/olfaction, ect)
- They contain modality- specific sensory cells, which can vary in sensitivity, and in the quality of stimulus that most stimulates them (e.g. frequency of light or sound; the chemicals present in the food, ect.)
- Their sizes and structures vary, affecing their function
Label indcated arrows
- retina
- optic nerve
- lens
- iris
- retractor lentis muscle
What is the OPTIC TECTUM called in mammals?
the visual/superior colliculus
True or False?
The visual corticeis are CONTRALATERAL
True
Label this ROD CELL
- Membrane sheles lined with rhodopsin or colour pigment
- Outer segment
- Mitochondria
- Inner segment
- Outer limiting membrane
- Nucleus
- Synaptic body
Lebel this CONE CELL
- Invaginations of cell membranes that form a stack of membranous disks where photopigments exist as transmembrane proteins
- Outer segment
- Connecting cilium
- Mitochondria
- Inner segment
- Nucleus
- synaptic terminal that forms a synapse with a neuron
How many types of cone cells are there is primate (including humans) retinas and what wavelength do they peak at?
- There are 3 types of cone cells in the retina; making primates “trichromatic”
- peak at 450 (blue), 540 (green), 580 (red)
What kinds of animals are DICHROMATIC?
- Carnivores: Dogs, foxes, mink, cats, ect.
- Ungulates: Cattle, sheep, goats
- Rodents
What colours/ wavelength do most CARNIVORES see?
To us
- purplish/blue (peak 440nm)
- yellowish/green (peak 555nm)
Are dogs red-green colour blind?
Yes
Are cats red-green colour blind?
Unclear
What colour/wavelength do most UNULATES see?
To us
- Peak at 440-455 and 536-555nm
- despite this, NOT red-green colour blind: instead poor at distinguishing greens from blues and violets
What colours/wavelengths do most RODENTS see in?
- ultraviolet (359nm) & yellow-green (510nm)
- they cannot see red
- therefore redlights are used in labs to imitate darkness for the rodents.
How many different types of cone cells are in birds?
Birds have 4 different types of cone cells
This make birds tetrachromatic
Bird feathers are UV absorbant/reflective
True or False?
True
Some birds have patterns that we humans cannot see