Week 6 Sensory Biology

Question 1

Define absorbance

Answer 1

Light extracted from incidental light, a filter absorbs light and transmits light that isn’t absorbed
→ we see light that is not absorbed

Question 2

Define reflectance

Answer 2

Light that bounces off an object

Question 3

Define iridescence

Answer 3

Reflected light that is “edited” by subtraction or addition

Question 4

Define fluorescence

Answer 4

Light of a given wavelength that is absorbed the emitted at a longer wavelength

Question 5

Define luminescence

Answer 5

Light” created “without incidental light through a chemical reaction

Question 6

Can we see heat?

Answer 6

• Every object emits some electromagnetic radiation
• amount of inferred is dependant on its temp

Question 7

How do snakes see heat?

Answer 7

Snake pit organs have TRPA1 channels that absorb infrared light and trigger a response

Question 8

Define pigment

Answer 8

Macromolecules that have colour

Question 9

What are the major pigments

Answer 9

Heme’s (red)
Carotenes (yellow/red)
Melanins (black / Brown/ red/ orange)
Guanines (whites / iridescent)

Question 10

What are respiratory pigments

Answer 10

They have colour but the colour is fairly irrelevant to the animal

Question 11

How do organism detect photoperiod

Answer 11

Depend on circadian rhythm of photosensitivity

Question 12

What does it mean to “sense” something?

Answer 12

Translating chemical physical stimulus into cellular change to elect a response

Question 13

Neuronal receptors are….

Answer 13

A neuron that uses AP to communicate and act as a receptor (afferent)

Question 14

Non-neuronal receptors are…

Answer 14

Regulate afferent neurons
→ use second messages and NT releases

Question 15

What are pheromones

Answer 15

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

Question 16

What do smell and taste involve

Answer 16

Chemosensing

Question 17

What happens in chemosensing?

Answer 17

Receptors bind specific chemicals that trigger a signalling cascade

Question 18

How do taste and smell differ?

Answer 18

Taste = sensory cell is not a neuron
Smell= sensor is a neuron

Question 19

Electro - sensing…

Answer 19

Generate an electric field and enables direction and physical situation

Question 20

Magnetosensing…

Answer 20

Magnetic field detects change in orientation

Question 21

What is bioluminescence?

Answer 21

Light production used by animals to communicate

Question 22

What are statocysts

Answer 22

Organ of equilibrium found in aquatic animals that is typically a fluid filled vesicle lined with sensory hairs that detect position

Question 23

What’s sensory transduction?

Answer 23

Conversion of stimulus energy to change in membrane potential

Question 24

Direct transmission..

Answer 24

Produces action potentials and have an axon that extends into Cns

Question 25

Indirect transmission...

Answer 25

Chemical synapses with sensory neurons and typically responds to stimuli by increasing afferent signals

Question 26

Define amplification

Answer 26

Strength of a sensory signal during transduction

Question 27

Define adaptation

Answer 27

Tendency of neurons to become less sensitive to stimuli

Question 28

Does the direction of hair projections matter?

Answer 28

Yes, one direction will depolarize and the other will hyperpolerize

Question 29

What does the inner ear do besides process auditory info?

Answer 29

Detect body movement, position, and balance

Question 30

What do fish/amphibians use to detect position?

Answer 30

Lateral line system

Question 31

What is a compound eye?

Answer 31

Several thousand light detectors (ommatidia) →efficient in movement detection and colour vision

Question 32

What is single lens

Answer 32

Works like a camera (spiders/worms)

Question 33

Why does the brain "see"

Answer 33

Processes light into from retina - rods/ cones depolarize and relate NT glutamate

Question 34

Define lateral inhibition

Answer 34

Sharpens/ enhances contrast of precieved image by inhibiting receptors lateral to those that responded

Question 35

Define optic chiasm

Answer 35

2 optic nerves meet and axons are segregated

Question 36

Why are male more commonly colour blind?

Answer 36

Red/green pigments are on the X chromosome

Question 37

What are taste buds?

Answer 37

Collection of modified epithelial cells on the tongue or in the mouth

Question 38

How do we smell?

Answer 38

Sensory cells/neurons on the upper portion of the nasal cavity send impuses along axon directly to brain

Question 39

What is hydrostatic skeleton

Answer 39

Fluid held under pressure in closed body compartment → control movement by using muscles to chance shape of fluid

Question 40

Define exoskeleton

Answer 40

Hard encasement deposited on animal surface

Question 41

Define endoskeleton

Answer 41

Hard internal skeleton buried in suf tissue

Question 42

What forces must animals over come

Answer 42

Gravity and friction

Question 43

What is the role of calcium?

Answer 43

Interaction between actin and myosin controlled by proteins

Question 44

What is transverse tables

Answer 44

In folding of plasma membrane of muscle → acts as storage (sarcoplasmic recticulum)

Question 45

What does myoglobin do?

Answer 45

Move oxygen binding proteins

Question 46

Why do fast twitch muscle move faster?

Answer 46

Have more extensive t-tubules → higher densities of channels t pump ions back and forth

Question 47

Describe cardiac muscles

Answer 47

→ Have ion channels that cause rhythmic depolarization which allows for AP without input from nervous system → have longer AP and refractory period

Question 48

Describe smooth muscle

Answer 48

→ 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