Give reasons.
a) If we press tongue against the palate, we can recognise taste easily.
A. Reason:
- When the tongue is pressed against the palate, the food substance is pressed against the opening of the taste bud letting it to reach the taste cells and triggering taste signals.
- Finally, the taste is recognized in the brain.
b) We can’t identify taste when food is very hot.
A. Reason : - Most of the taste buds on the tongue are killed when the food is hot.
- This prevents the person identifying the taste.
- The perception of taste decreases when the temperature of the food rises beyond 35°C.
- But we don’t pay attention to it because we become worried about the burning feeling. ■
c) If glucose level falls in blood, we feel hungry.
A. Reason: - When glucose levels in the blood fall, we get hunger pangs in stomach.
- Hungry feeling start to occur in the stomach due to hunger generating signals that reach the brain from the stomach due to the secretion of the hormone ‘Ghrelin’.
d) Small intestine is similar to a coiled pipe.
A. Reason: - Small intestine is coiled so as to fit in the human body.
. 2) It is coiled to increase surface area and maximum nutrient absorption when food
passes through it.
e) Urination increases when we take lot of fluids.
A. Reason : - When we take lot of fluids, the kidneys will efficiently throw that water out by forming more urine than usual.
- When there is excess water in the body, the brain usually produces less of a hormone called vasopressin, which inturn causes the kidneys to produce a lot of dilute urine, until excess water is removed.
f) The process of digestion goes on in a person whose central nervous system has been largerly affected.
A. Reason: - The enteric nervous system embedded in the walls of the long tube of our gut or alimentary canal control gut functions often independently of the brain.
- The mass of neural tissue of enteric nervous system filled with important neurotransmitters reveals that it does much more than merely handle digestion.