Sense organ

Question 1

Characteristics of Sense organs

Answer 1

1. Projection
2. After-image
3. Adaptation
4. Local sign
5. Contrast
6. Intensity

Question 2

projecting sensation to source of stimulation

Answer 2

Projection

Question 3

sensation persists in consciousness after cessation of stimulation

Answer 3

After-image

Question 4

continuous stimulus- one gets used to it or ignores it

Answer 4

Adaptation

Question 5

ability to recognize point of application of stimulus

Answer 5

Local sign

Question 6

sensation is affected by events which preceded or accompany it

Answer 6

Contrast

Question 7

dependent on number of receptors stimulated and rate of transmission

Answer 7

Intensity

Question 8

*Produce the somatic senses
*Widely distributed
receptors

Answer 8

General Senses

Question 9

*Produce the special senses
*Grouped in localized areas

Answer 9

Special senses

Question 10

Receptor is any structure specialized to detect a stimulus (simple nerve ending or sense organ)

Answer 10

Sensory receptors

Question 11

receptors are free nerve endings; respond to a variety of stimuli as mechanical stretching, extremes in temperature to produce pain

Answer 11

Pain and temperature

Question 12

respond to stimuli that ‘deform’ or change their shape and placement and that move hair

Answer 12

Touch and Pressure receptors

Question 13

receptor for heavy touch, pressure, joint movements & skin stretching

Answer 13

Ruffini corpuscles

Question 14

receptors for light touch & texture

Answer 14

Meissner corpuscles

Question 15

tactile corpuscles in mucous membranes

Answer 15

Krause end bulb

Question 16

receptor for deep pressure, stretch, tickle, itch & vibration

Answer 16

Lamellated (pacinian) corpuscles

Question 17

Types of organic sensations

Answer 17

• Hunger
• Thirst

Question 18

• projected to stomach
• associated with rhythmic contractions and weakness, trembling, nausea, headache
• NS is hyper-excitable

Answer 18

Hunger

Question 19

• projected to pharynx
• due to low water levels
• extreme thirst leads to mental anguish

Answer 19

Thirst

Question 20

Three groups of stimuli in visceral sensations

Answer 20

• Dilation/distension
• Spasm/strong contraction
• Chemical irritation

Question 21

occurs because of the common nerve pathways leading from skin and internal organs.

Answer 21

Referred pain

Question 22

• is misinterpreted pain
  – Visceral impulse and cutaneous impulse share the same neurons to brain
  – Results in confusion

Answer 22

Referred pain

Question 23

Example of Referred pain

Answer 23

Angina pectoris
Pneumonia

Question 24

spasm of smooth muscle in coronary arteries of heart

Answer 24

Angine pectoris

Question 25

pain in abdomen

Answer 25

Pneumonia

Question 26

The special senses

Answer 26

Taste-Gustation Smell-Olfaction Vision Hearing Balance

Question 27

The Chemical Sense

Answer 27

Taste

Question 28

specific receptor cells for taste and smells

Answer 28

Chemoreceptors

Question 29

is the sensation of taste resulting from the action of chemicals on the taste buds

Answer 29

Gustation

Question 30

Small raised structures on the tongue that give it its rough texture and are importantfor taste

Answer 30

Lingual papillae

Question 31

4 types of Lingual papillae

Answer 31

- Filiform - Foliate - Fungiform - Circumvallate

Question 32

* at rear of tongue * contains 1/2 of taste buds

Answer 32

Circumvallate

Question 33

(no taste buds) * most abundant

Answer 33

Filiform

Question 34

at tips & sides of tongue

Answer 34

Fungiform

Question 35

Physiology of taste

Answer 35

1. To be tasted, molecules must dissolve in saliva 2. 5 primary sensations: salty, sweet, sour, bitter & umami (taste of amino acids such as MSG) 3. Taste is also influenced by food texture, aroma, temperature, and appearance.

Question 36

Factors that influced taste

Answer 36

- Food texture - Aroma - Temperature - Appearance

Question 37

Projection pathways for taste

Answer 37

Innervation of the Taste Buds (Gustatory cells) --> Medulla oblongata --> Thalamus --> Postcentral gyrus of the cerebum