Lab 9 - Sensory organs

Question 1

Sexual cycle in…

1. Horse
2. Cattle
3. Sheep
4. Goat
5. Swine
6. Dog
7. Cat

Answer 1

1. 21 (15-26) days
2. 21 (17-24) days
3. 17 (13-19) days
4. 21 (15-24) days
5. 21 (17-25) days
6. 50-80 days
7. 14-28 days

Question 2

Oestrus duration in…

1. Horse
2. Cattle
3. Sheep
4. Goat
5. Swine
6. Dog
7. Cat

Answer 2

1. Horse: 5 (3-9) days
2. Cattle: 15 (6-24) hours
3. Sheep: 30 (18-48) hours
4. Goat: 30 (22-60) hours
5. Swine: 50 (12-96) hours
6. Dog: 9 (3-21) days
7. Cat: 4-10 days

Question 3

Pregnancy period in…

1. Horse
2. Cattle
3. Sheep
4. Goat
5. Swine
6. Dog
7. Cat
8. Rabbit

Answer 3

1. Horse: 310-365 days
2. Cattle: 280-290 days
3. Sheep: 144-152 days
4. Goat: 144-152 days
5. Swine: 111-116 days
6. Dog: 60-68 days
7. Cat: 60-65 days
8. Rabbit: 30-32 days

Question 4

Which side is sensory side, and which is acting side?

Answer 4

• Sensory: receptor - afferent nerve

- Acting: effector - efferent nerve

Question 5

How to measure wavelength?

Answer 5

wavelength = c (wave speed) / f (frequency)

Question 6

Three important attributes of sound waves?

Answer 6

1. Wavelength
2. Frequency (f)
3. Velocity (c)

Question 7

Hearing range in humans?

Answer 7

20-20000 Hz

Question 8

What is the decibel scale?

Answer 8

Measure the volume, dB=10log(I1/I2)

Question 9

What is Rinne experiment?

Answer 9

Demonstrates how the sound is transferred from outer ear to inner ear

Question 10

Min. hearing treshold?

Answer 10

The first value where the test subject can hear the sound

Question 11

Max. hearing treshold?

Answer 11

The first value where the test subject can hear a very quiet shrill noise

Question 12

Borders of the eye

Answer 12

Cornea, queuos humor, lens, vitreous body

Question 13

What does the accommodative triad consist of?

Answer 13

The adaptable curvature of the lens, eye movements and pupil function

Question 14

What does the accommodative triad do?

Answer 14

Ensure constant focus for perfect vision

Question 15

How is the direction of the two eyes coordinated?

Answer 15

By extraocular skeletal muscles

Question 16

Divergent eye movements

Answer 16

The axes of the two eyes are able to move away from each other

Question 17

Covergent eye movements

Answer 17

The axes of the two eyes get closer to each other

Question 18

What is astigmatism?

Answer 18

An optical defect, where the vision is blurred, due to an inability of the optics of the eye to focus a point object into a sharp image of the retina

Question 19

How can we investigate astigmatism?

Answer 19

With a keratoscope or Placido´s disk

Question 20

What does ophtalmoscopy examinate?

Answer 20

Diseases of the refractive state of the eye-layers and the condition of the capillary circulation (id. of blind spot, the macula and the problems in blood vessels)

Question 21

Where is the blood vessels in the eye found?

Answer 21

In the upper layers of the retina, almost everywhere except in the center of the macula

Question 22

How can retinal blood vessels be recognized?

Answer 22

By sclera light

Question 23

What is the near point?

Answer 23

The nearest point, from which the light rays can be still focused on the macula

Question 24

What is the viewing angle?

Answer 24

The max. angle, at which the display can be viewed with acceptable visual performance

Question 25

What is the minimal viewing angle?

Answer 25

The angle of two separated points, which can be still distinguished from each other

Question 26

What is the value of min. viewing angle measured by?

Answer 26

Min of arc (arcminute, arcmin)

Question 27

What is a healthy eyes viwing angle limit?

Answer 27

1´ arcmin

Question 28

What is visual acuity or visus?

Answer 28

The value of the actual viwing angle limit relative to the physiological 1´ viewing angle limit

Question 29

What is Snellen charts used for?

Answer 29

Determination of vision acuity

Question 30

What is field of vision?

Answer 30

The part of the outer world seen by the animal

Question 31

How does the field of vision variate?

Answer 31

By different colours

Question 32

How can field of vision be determinated?

Answer 32

By a perimeter; consist of rotable semicircular arc and chin-rest

Question 33

What is the blind spot?

Answer 33

In the retina, where the optic nerve, retinal arteries and veins leave the eye. At this point no photosensitive receptors are located.

Question 34

Ways to find the blind spot

Answer 34

1. Mariotte card; thick cross and a circle | 2. Perimeter

Question 35

What are "cones"?

Answer 35

The color-sensitive photoreceptors of the retina

Question 36

Types of cones?

Answer 36

Red, green and blue

Question 37

Most common form of color blindness?

Answer 37

Red-green

Question 38

How to test red-green color blindness?

Answer 38

Ishihara test chart; show different symbols on a background

Question 39

How is the info. of the eye processed?

Answer 39

By the visual cortex and previous memories

Question 40

How does "discoloration" of Hermann grid happen?

Answer 40

The ganglion cells work in a contrast sensitive manner and they are sensitive to contrast differences on the surface boundaries

Question 41

What is stereoscopic vision?

Answer 41

The perception of depth and 3D structure obtained on the basis of visual info. deriving from two eyes

Question 42

What are stereograms?

Answer 42

Stereoscopic images created for the illusion of 3D image from a given 2D image

Question 43

What is binocular disparity?

Answer 43

When an image of the world is given in 3D even though the image that project onto our retina is 2D. Means that there is a given distance bw. the two eyes.

Question 44

What is visual attention?

Answer 44

A mechanism that selectively filters visual info.

Question 45

What is Stroop effect?

Answer 45

Measures the selective attention, by reading words out load

Question 46

Types of sensory receptors?

Answer 46

Thermoreceptors, mechanoreceptors

Question 47

What are thermoreceptors?

Answer 47

Non-specialized sensory receptors that codes absolute and relative changes in temp.

Question 48

What is Weber´s illusion?

Answer 48

The exact perception of certain objects is different in various skin regions due to the number of receptors located in the given area.