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Flashcards in Module 10: Special Senses Deck (313)
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121

Body Fluids and Salts in Exercise

• 10 lbs of body weight (mainly water) maybe lost in one hour of athletic event
- May lead to muscle cramps, nausea, etc.
• Sodium and potassium lost with sweat
• Sweat glands may acclimatize to hot and humid conditions because of Aldosterone

122

Drugs and Athletes

• Caffeine: inconsistent results on effects on athletic performance
• Testosterone: increases muscle strength and aggressiveness; May also cause M.I. and strokes due to Hypertension, inc LDL, dec HDL
• Amphetamines and Cocaine: psychological effects only; may cause VFib

123

BODY FITNESS PROLONGS LIFE

• Mortality is 3x less in most fit people than in least fit people
• 2 evident reasons:
- Body fitness and weight control reduce cardiovascular disease
- Athletically fit people has more body reserves when he/she becomes sick

124

What is the Primary Organ of taste?

Tongue - Taste Buds

125

Colds and taste perception. Why?

• Taste is 80% smell
• Texture and Temperature of food from Trigeminal nerve (CN V)

126

Primary Sensations of Taste

1. Sour
2. Salty
3. Sweet
4. Bitter
5. Umami

127

• Caused by ACIDS
• H+
• Hydrochloric Acid
• Hydrogen Ion concentration
• Intensity of taste is proportional to the logarithm of the hydrogen ion concentration

SOUR

128

• Caused by IONIZED SALTS
• Na+ (sodium ion concentration)
• Soduim Chloride
• Anions of salt also contribute to a lesser extent

SALTY

129

• Not caused by any single class of chemicals
• Caused by SUCROSE, sugars, glycols, alcohols, aldehydes, ketones, amides, esters, some amino acids, some small proteins, sulfonic acids, halogenated acids, and inorganic salts of lead and beryllium.
• Mostly ORGANIC CHEMICALS

SWEET

130

What substance first taste SWEET but has a BITTER aftertaste?

Saccharin - has a bitter aftertaste (dark chocolates has saccharin)

131

• Not caused by any single type of chemical agent
• Almost entirely ORGANIC SUBSTANCES
• QUININE
• Protection against POISONS or DEADLY TOXINS (alkaloids)
• *Rejection of the Food

BITTER

132

2 Substances likely to cause bitter sensation:

1. long -chain organic substances that contain Nitrogen
2. alkaloids

133

• Japanese word meaning “delicious”
• Usually foods containing L-glutamate
• Exact molecular mechanism: UNKNOWN
• Meat extracts, aging cheese

UMAMI

134

Threshold for Taste

SOUR: 0.0009N

SALT: 0.01M

SWEET: 0.01M

BITTER: 0.000008M

135

Bitter taste, more sensitive than the others. Why?

It has a protective function against dangerous toxins

136

Other taste factors

• Pain –pepper, mustard, ginger
• Cold receptors –Menthol, mint
• Heat receptors –Pepper

137

Hot vs Cold

• Hot food have stronger taste than Cold food
• Molecules move faster and dissolve faster hence stronger taste

138

• Occurs in 15-30% of the population
• Reduction in sensitivity (Tt)
• Inability to taste different types of thiourea (CH4N2S) compounds
• Usually an autosomal recessive trait (tt)

Taste Blindness

139

• PTC is often used
• Phenylthiocarbamide
• You have two bags of test paper: Control Paper and PTC Paper
• Touch one of the paper strips from the bag labeled "Control Paper" to the tip of your tongue
• Touch one of the paper strips from the bag labeled "PTC Taste Paper" to the tip of your tongue
• Both papers just taste like paper = Non-Taster for PTC. If one tastes bitter and the other tastes like paper, you are a Taster.

Taste test

140

- Found on the:
• Papillae (Circumvallate, Fungiform, Foliate)
• Palate
• Tonsillar pillars
• Epiglottis
• Proximal Esophagus

Taste Bud

141

• found on the Walls of the troughs
• forms a V on the posterior surface of the tongue
• Usually 8-12 large papillae
• Bitter and sour

Circumvallate papillae/ Vallate

142

• Concentrated over the flat Anterior surface of the tongue
• MOST ABUNDANT Scattered among filiform papillae
• Mushroom-shaped
• Sweet and Salty

Fungiform papillae

143

• Both lateral surface of the tongue
• 4-5 fold

Foliate papillae

144

Taste Bud vary according to age

• Adults have 3,000 to 10,000 taste buds
• Children have more taste buds = more sensitive!
• >45 years taste buds begin to degenerate thus
- Decrease in taste sensitivity

145

Taste Bud

• One taste bud = One primary taste
- When in low concentration

• One taste bud = Two or more primary taste
- At high concentration

146

Stimulation of Taste Buds

• Lock and key system
• Tongue -> Papillae -> Taste buds (stimulated)
-> Taste cell -> depolarization -> impulse -> relayed to CNS

147

How is the stimulus removed?

Washed away by Saliva

148

REMEMBER (Gustatory)

• The type of receptor protein in each taste villus determines the type of taste which will be perceived.
• ION CHANNELS - Na, H+ (salty, sour)
• SECONDARY MESSENGER - Sucrose, quinine (sweet, bitter)

149

Nerve impulse (Gustation)

• Stimulus (within fraction of a second) ->Peak discharge from nerve fibers -> Adapts (within seconds) -> Weaker/Lower continuous signal
(as long as there is stimulus)

150

Transmission to CNS (Anterior Tongue)

• Anterior 2/3 tongue -> lingual nerve -> chorda tympani -> Facial Nerve (CNVII) -> Tractus Solitarus (NTS) -> VPM(thalamus) -> lower tip of the postcentral gyrus (parietal cortex) -> sylvian fissure -> opercular insular area