Week 6 Sensory Biology Flashcards
Define absorbance
Light extracted from incidental light, a filter absorbs light and transmits light that isn’t absorbed
→ we see light that is not absorbed
Define reflectance
Light that bounces off an object
Define iridescence
Reflected light that is “edited” by subtraction or addition
Define fluorescence
Light of a given wavelength that is absorbed the emitted at a longer wavelength
Define luminescence
Light” created “without incidental light through a chemical reaction
Can we see heat?
- Every object emits some electromagnetic radiation
- amount of inferred is dependant on its temp
How do snakes see heat?
Snake pit organs have TRPA1 channels that absorb infrared light and trigger a response
Define pigment
Macromolecules that have colour
What are the major pigments
Heme’s (red)
Carotenes (yellow/red)
Melanins (black / Brown/ red/ orange)
Guanines (whites / iridescent)
What are respiratory pigments
They have colour but the colour is fairly irrelevant to the animal
How do organism detect photoperiod
Depend on circadian rhythm of photosensitivity
What does it mean to “sense” something?
Translating chemical physical stimulus into cellular change to elect a response
Neuronal receptors are….
A neuron that uses AP to communicate and act as a receptor (afferent)
Non-neuronal receptors are…
Regulate afferent neurons
→ use second messages and NT releases
What are pheromones
Signalling factors produced/ released into the environment
→when they reach the target cell the dissolve into the surrounding fluid
→ bind onto a receptor on a sensory neuron either opening a channel or triggering signalling pathway
→ phéromone-responsive neurons send signals to the brain to initiate an appropriate behaviour
What do smell and taste involve
Chemosensing
What happens in chemosensing?
Receptors bind specific chemicals that trigger a signalling cascade
How do taste and smell differ?
Taste = sensory cell is not a neuron
Smell= sensor is a neuron
Electro - sensing…
Generate an electric field and enables direction and physical situation
Magnetosensing…
Magnetic field detects change in orientation
What is bioluminescence?
Light production used by animals to communicate
What are statocysts
Organ of equilibrium found in aquatic animals that is typically a fluid filled vesicle lined with sensory hairs that detect position
What’s sensory transduction?
Conversion of stimulus energy to change in membrane potential
Direct transmission..
Produces action potentials and have an axon that extends into Cns
Indirect transmission…
Chemical synapses with sensory neurons and typically responds to stimuli by increasing afferent signals
Define amplification
Strength of a sensory signal during transduction
Define adaptation
Tendency of neurons to become less sensitive to stimuli
Does the direction of hair projections matter?
Yes, one direction will depolarize and the other will hyperpolerize
What does the inner ear do besides process auditory info?
Detect body movement, position, and balance
What do fish/amphibians use to detect position?
Lateral line system
What is a compound eye?
Several thousand light detectors (ommatidia)
→efficient in movement detection and colour vision
What is single lens
Works like a camera (spiders/worms)
Why does the brain “see”
Processes light into from retina
- rods/ cones depolarize and relate NT glutamate
Define lateral inhibition
Sharpens/ enhances contrast of precieved image by inhibiting receptors lateral to those that responded
Define optic chiasm
2 optic nerves meet and axons are segregated
Why are male more commonly colour blind?
Red/green pigments are on the X chromosome
What are taste buds?
Collection of modified epithelial cells on the tongue or in the mouth
How do we smell?
Sensory cells/neurons on the upper portion of the nasal cavity send impuses along axon directly to brain
What is hydrostatic skeleton
Fluid held under pressure in closed body compartment
→ control movement by using muscles to chance shape of fluid
Define exoskeleton
Hard encasement deposited on animal surface
Define endoskeleton
Hard internal skeleton buried in suf tissue
What forces must animals over come
Gravity and friction
What is the role of calcium?
Interaction between actin and myosin controlled by proteins
What is transverse tables
In folding of plasma membrane of muscle
→ acts as storage (sarcoplasmic recticulum)
What does myoglobin do?
Move oxygen binding proteins
Why do fast twitch muscle move faster?
Have more extensive t-tubules
→ higher densities of channels t pump ions back and forth
Describe cardiac muscles
→ Have ion channels that cause rhythmic depolarization which allows for AP without input from nervous system
→ have longer AP and refractory period
Describe smooth muscle
→ in the walls of hollow organs
→lack serrations, actin/myosin aren’t arrayed along cell
→ contract slowly
→ don’t have troponin complex, +-tubules, and sr not developed
