Insaanon mein Paachan

Class 7 Science · Chapter 9: Jaanwaron mein Jeevan Prakriyaayein · NCERT Curiosity section 9.1.1

Seekho

Lunch mein Ishaan shart lagaakar roti ka tukda poore minute chabaata. "Arre, ye meetha ho raha!" wo kehta. Kabir hairaan. Khaane mein carbohydrate, protein aur vasa itne jatil ki shareer seedhe use nahi kar sakta. Inhe saral roop mein todna padta: paachan. Ye munh se gudaa tak ek lambi nali, aahaar naal, mein hota.

Munh mein daant khaana peeste-chabaate (yaantrik paachan). Laar use geela karti aur starch ko cheeni mein todti, isliye roti meethi lagti. Jeebh naram gola bhojan nali mein dhakelti, jiski deewaarein lehron mein sikud-phailkar khaana neeche le jaati. Daant swasth rakhne ko din mein do baar brush aur khaane ke baad kulla.

Aamaashay khaana mathta aur paachak ras, acid aur shlesma milaata. Ras protein todta; acid madad karta aur haanikaarak bacteria maarta; shlesma aamaashay ki parat bachaata. Khaana ardh-tarl bankar nikalta. Iska bahut kuch 1822 mein pehli baar pata chala, jab ek doctor mareez ke kabhi na bharne wale ghaav se paachan dekh paaya.

Chhoti aant, lagbhag 6 m lambi, sabse lamba hissa. Yakrit pitt (halka basic) bhejta, jo acid neutral karta aur vasa ko boondon mein todta; agnaashay basic ras bhejta jo carbohydrate, protein aur vasa pachaata; aant ki deewaar apna ras jodti. Phir hazaaron chhote ungli jaise ubhaar saral poshak tatva khoon mein avshoshit karte.

Bina pacha khaana badi aant (lagbhag 1.5 m, chaudi par chhoti) mein jaata, jo paani aur lavan sokhti, aur ardh-thos mal banta. Wahaan madadgaar bacteria fibre todte; fibre wala aur dahi-chhaachh jaisa khameer wala khaana ise swasth rakhta. Mal malaashay mein jama hota aur gudaa se nikalta: malotsarg.

Explore: kya laar starch badalti?

1. Har tube iodine se jaanchkar sort karo.

Explore: khaane ka safar.

1. Hisse kram mein lagao.

Yaad rakho

• Paachan: munh (chabaana, starch par laar) → bhojan nali → aamaashay (acid, protein) → chhoti aant (pitt, agnaashay ras, avshoshan).
• Badi aant paani sokhti; mal gudaa se nikalta (malotsarg).

Quick check

Zyaadatar pache poshak tatva khoon mein kahaan jaate?

1. small intestine
2. stomach
3. large intestine
4. food pipe

Socho

Bahut kam aamaashay acid wala vyakti kharaab khaane se zyaada beemar kyun ho sakta?

Practice

Teen levels (easy, medium, hard) ke naye sawaalon se practice karo, kuch hands-on, hints aur hal ke saath. Topic poora karne ke liye pichhle 5 mein se 4 sahi karo.