Answer the following.
(a) How many types of muscles are there? Which are those types?
(b) What causes the problem of acidity? What is its effect on the body?
(c) Name the different types of teeth. What is the function of each type?
(a) How many types of muscles are there? Which are those types?
(b) What causes the problem of acidity? What is its effect on the body?
(c) Name the different types of teeth. What is the function of each type?
a. There are 3 types of muscles:
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Skeletal muscle fibre: They are found attached to the skeletal bones and are voluntary. Skeletal muscle fibres are striated and are bundled together in a parallel manner by a sheath of tough connective tissues.
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Smooth muscle fibres: They are present in the walls of internal organs such as blood vessels, stomach, etc., and are involuntary. Smooth muscle fibres are fusiform (taper at both ends) and non- striated. They are held together by cell junctions and are bundled together in a sheath of connective tissues.
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Cardiac muscle fibres: This is the only type of muscle present in the heart. They are contractile in nature and are involuntary. Plasma membranes of cardiac cells are fused together by cell junctions, and hence, the cells stick together. Communication junctions present as intercalated discs facilitate the contraction of cardiac cells as a unit.
b. Stomach contains special cells called oxyntic or parietal cells which secrete hydrochloric acid in stomach. It plays two important roles like:
1. It initiates protein digestion by activating the conversion of pepsinogen to pepsin.
2. It provides acidic medium for the activity of pepsin and other enzymes present in gastric juice.
However, if the level of this HCl exceeds its normal levels, it results in acidity/acid reflux. Higher levels of HCl can result in the following effects on the body:
- burning sensation in the stomach
- burning sensation in the throat and heart
- difficulty in swallowing
- regurgitation
- restlessness
- belching
- nausea
- prolonged sour taste in the mouth
- indigestion
Exposure to higher levels of HCl for longer durations can also result in the development of peptic ulcers/ulcers in the stomach.
c. There are 4 types of teeth which are found in humans:
1. Incisors are the teeth present at the front portion of the mouth. There are four incisors in each jaw. They are used for biting and cutting food.
2. Canines are located next to the incisors. There are two canines in each jaw. They are used for tearing and piercing food.
3. Premolars lie next to the canines. There are four premolars in each jaw. They are used for chewing and grinding food.
4. Molars lie next to the premolars at the end of the jaw. There are six molars in each jaw. They are also used for chewing and grinding food.
-
Skeletal muscle fibre: They are found attached to the skeletal bones and are voluntary. Skeletal muscle fibres are striated and are bundled together in a parallel manner by a sheath of tough connective tissues.
-
Smooth muscle fibres: They are present in the walls of internal organs such as blood vessels, stomach, etc., and are involuntary. Smooth muscle fibres are fusiform (taper at both ends) and non- striated. They are held together by cell junctions and are bundled together in a sheath of connective tissues.
-
Cardiac muscle fibres: This is the only type of muscle present in the heart. They are contractile in nature and are involuntary. Plasma membranes of cardiac cells are fused together by cell junctions, and hence, the cells stick together. Communication junctions present as intercalated discs facilitate the contraction of cardiac cells as a unit.
b. Stomach contains special cells called oxyntic or parietal cells which secrete hydrochloric acid in stomach. It plays two important roles like:
1. It initiates protein digestion by activating the conversion of pepsinogen to pepsin.
2. It provides acidic medium for the activity of pepsin and other enzymes present in gastric juice.
However, if the level of this HCl exceeds its normal levels, it results in acidity/acid reflux. Higher levels of HCl can result in the following effects on the body:
- burning sensation in the stomach
- burning sensation in the throat and heart
- difficulty in swallowing
- regurgitation
- restlessness
- belching
- nausea
- prolonged sour taste in the mouth
- indigestion
c. There are 4 types of teeth which are found in humans:
1. Incisors are the teeth present at the front portion of the mouth. There are four incisors in each jaw. They are used for biting and cutting food.
2. Canines are located next to the incisors. There are two canines in each jaw. They are used for tearing and piercing food.
3. Premolars lie next to the canines. There are four premolars in each jaw. They are used for chewing and grinding food.
4. Molars lie next to the premolars at the end of the jaw. There are six molars in each jaw. They are also used for chewing and grinding food.
