Lecture 25

Question 1

What does sensation allow organisms to do?

Answer 1

It allows organisms to react to stimuli.

Question 2

What are the steps of sensation in animals?

Answer 2

Reception-Transduction-Transmission-Perception. RTTP

Question 3

Define Sensory Receptors

Answer 3

They are either neurons or attached to neurons.

Question 4

What are the 5 classes of sensory receptors?

Answer 4

Mechanoreceptors-Chemoreceptors-Electromagnetic Receptors-Thermoreceptors-Nociceptors MCET-N

Question 5

What do mechanoreceptors do?

Answer 5

Touch, vibration, audition (noise)

Question 6

What do chemoreceptors do?

Answer 6

Osmolarity, taste, smell

Question 7

What do electromagnetic receptors do?

Answer 7

Electrical current, light (vision)

Question 8

What do thermoreceptors do?

Answer 8

Hot,cold

Question 9

What do nociceptors do?

Answer 9

PaIN

Question 10

Define Perception

Answer 10

A neural representation of the world.

Question 11

What is the oldest sense?

Answer 11

Olfaction

Question 12

Define Olfaction

Answer 12

The long-range detection of fluid-borne molecules.

Question 13

What are some of the structures involved in olfaction?

Answer 13

Nares-Antennae-Olfactory Epithelium-Tentacles

Question 14

In terms of movement from structure to structure, how does olfaction happen?

Answer 14

Olfactory receptor cells to nasal epithelium to bone to olfactory bulb to brain.

Question 15

Define Odors

Answer 15

Mixtures of chemicals called odorants.

Question 16

What are the steps that happen in olfaction?

Answer 16

1) Olfactory receptor cells express olfactory receptors that bind to odorants. Each olfactory cell only expresses one type of olfactory receptor.

2) Odorants bind to olfactory receptors, triggering action potentials in olfactory receptor cells.

Question 17

How is odor intensity encoded?

Answer 17

Based on how many olfactory cells were stimulated.

Question 18

What would happen if olfactory cells expressed more than one olfactory receptor?

Answer 18

We wouldn’t be able to distinguish between smells.

Question 19

_____ has evolved many times.

Answer 19

Vision

Question 20

What types of eyes are present?

Answer 20

Eyes with no lenses- Camera Lens Eyes.

Question 21

What are examples of eyes with no lenses?

Answer 21

Eyespots, eyecups, pinhole eyes.

Question 22

What are examples of eyes with lenses?

Answer 22

Chambered, compound, and simple eyes.

Question 23

What is the relationship between wavelength and energy?

Answer 23

Inverse relationship between wavelength and energy

Question 24

How can the energy of photons be characterized?

Answer 24

They have different amounts of energy..

Question 25

What are the colors included in the visible spectrum and what is the range?

Answer 25

ROYGBIV; 400 to 700 nm (700 is red and 400 is violet)

Question 26

What proteins do photoreceptors contain?

Answer 26

They contain proteins called opsins with a photosensitive pigment retinal.

Question 27

What is the function of the retinal?

Answer 27

To respond to light.

Question 28

How can the cis-retinal structure be characterized?

Answer 28

It has a bend.

Question 29

What happens to the cis-retinal structure with the addition of a specific photon?

Answer 29

It turns into the trans-retinal shape, removing the bend.

Question 30

Where are opsins found?

Answer 30

Photosensory neurons called rods and cones.

Question 31

What is the main difference between rods and cones?

Answer 31

Rods have a larger photoreceptive region.

Question 32

Within the rods and cones, where can the opsins be found?

Answer 32

In the photoreceptive regions.

Question 33

What is another name for the photoreceptive region of the rods and cones?

Answer 33

Membrane folding

Question 34

Where do opsins span?

Answer 34

The membrane- dense folding increases membrane surface area.

Question 35

How do photosensory cells respond to wavelengths?

Answer 35

They respond to a specific wavelength range.

Question 36

Where are phtosensory cells embedded?

Answer 36

In the retina.

Question 37

Are there more rods or cones?

Answer 37

Many more rods than cones.

Question 38

In order, how does light transfer in the eye?

Answer 38

It goes to the cornea, pupil, iris, lens, retina, and optic nerve. C-PIL-RO

Question 39

How can the structure of the retina be characterized?

Answer 39

It is composed of layers.

Question 40

What does it mean for the left and right visual fields to be processed separately?

Answer 40

The left visual field is processed by the right side of the brain and viceversa.

Question 41

What does the loss of cones result in?

Answer 41

Color blindness.

Question 42

What is an example of a non-spectral color?

Answer 42

Purple; it is not included in the chart.

Question 43

Animals with 4 cones perceive how many non-spectral colors?

Answer 43

At least 5.