Sensory Systems

Question 1

Sensation

Answer 1

Allows organisms to react to stimuli

Question 2

What are the four stages of sensation?

Answer 2

1. Reception-detection of stimulus and receptors receive signal
2. Transduction-neurons fire action potentials and signals are sent via transduction cascade
3. Transmission-signal is sent to the brain to be processed
4. Perception-brain processes signal

Question 3

What are the 5 classes of sensory receptors?

Answer 3

Mechanoreceptors, chemoreceptors, electromagnetic receptors, thermo receptors, and nociceptors

Question 4

Mechanoreceptors

Answer 4

Respond to touch, vibration, audition, stretch, pressure; Ex: whiskers, ears

Question 5

Chemoreceptors

Answer 5

Respond to osmolarity, smell, taste; Ex: tongue

Question 6

Electromagnetic receptors

Answer 6

Respond to electrical current, light, magnetic fields; Ex: eye (senses light waves)

Question 7

Thermo receptors

Answer 7

Respond to hot and cold; Ex: snakes have infrared vision

Question 8

Nociceptors

Answer 8

Respond to pain

Question 9

Perception

Answer 9

Neural representation of the world

Question 10

Olfaction

Answer 10

Oldest sense; sense of smell; chemo sense; present in bacteria; long range detection of fluid borne molecules

Question 11

What are examples of parts of the body that detect smell?

Answer 11

Nares (nostrils), antennae, tentacles, olfactory epithelium, echinoderms also can sense smell

Question 12

What is the pathway of smell?

Answer 12

1. Reception: Olfactory receptor cells express olfactory receptors that bind to odorants and each olfactory cell expresses only one type of receptor.
2. Transduction: Odorants bind to ORs to trigger action potentials in olfactory receptor cells.
3. Transmission: Odor intensity is encoded in how many olfactory cells were stimulated; sent to olfactory processing part of the brain.
4. Perception: combination of olfactory cells being stimulated=identification of that specific odor

Question 13

Odorants

Answer 13

Odors are mixture of chemicals

Question 14

Vision

Answer 14

Has evolved many times; sight; an electromagnetic sense

Question 15

Example of eyes with no lenses.

Answer 15

Eyespots on flat worms, eyecup, and pinhole eyes

Question 16

Examples of camera lens eyes.

Answer 16

Compound eyes, simple eyes on spiders, chambered eyes

Question 17

Photoreceptors

Answer 17

Contain opsins

Question 18

Opsins

Answer 18

In photoreceptors and are proteins that contains retinal

Question 19

Retinal

Answer 19

Photosensitive pigments that respond to light

Question 20

What happens to the cis-retinal when a photo hits it?

Answer 20

The kink is removed and it becomes a trans-retinal and is ejected out of the opsin; this is detection of light

Question 21

Rods

Answer 21

Photo sensory cell in the retina that detects around 500 nm (between blue and green); not good w/ red; is there to detect light

Question 22

Cones

Answer 22

Photo sensory cells in the retina that detects blue, green, and red; sees specific wavelengths

Question 23

Are there more rods or are there more cones?

Answer 23

There are more rods than cones

Question 24

What is the pathway of vision?

Answer 24

Light travels through the cornea, pupil, lens and reaches the retina.

1. Photoreceptor cells (rods and cones) receive the light.
2. Transduction: the signal travels from rods and cones to other cells.
3. Transmission: signal reaches the optic nerve where it will be sent to the brain for processing.
4. Perception: it reaches the occipital lobe where it processes vision.

Question 25

Left and right visual fields are processed separately? T or F?

Answer 25

T

Question 26

What does the loss of cones result in?

Answer 26

Color blindness

Question 27

The color purple

Answer 27

A non spectral color (not on the chart)

Question 28

What can animals w/ 4 cones perceive?

Answer 28

5 non spectral colors