Large Intestine

🍂Anatomy 'র জন্য ফরজ কাজ হলো Anatomical position.

Anatomical position :

This is the viscera of large intestine with the terminal part of the ileum.

1. Ileo-cecal junction lies postero-medially ; i.e. postero-medial to the caecum on the right side.

2. Left colic flexure is slightly higher than the right colic flexure.

3. Caecum lies higher level than the anal canal.🍂

🍀 Large gut - The large gut extends from the ileocaecal junction to the muco-cutaneous junction of the anal canal (pectinate line). 🍀

🍁এখন length and parts নিয়ে জানা যাক -

It is about 1.5 meters or 6 feet long.

Subdivisions - The large gut consists of four parts -

1. Caecum and appendix

★Caecum is 6 cm long

★ Appendix is 2 to 20 cm

2. Colon

★ Ascending - 15 cm long

★ Transverse - 50 cm long

★ Descending - 25 cm long

★ Sigmoid - 40 cm long

3. Rectum - 12 cm

4. Anal canal - 3.8 সে.মি.🍁

🍂🍂 Functions -

1. It allows absorption of about 500ml of water per day

2. The digestion of cellulose takes place in large gut with the help of putrefaction bacteria

3. Normal flora of large gut synthesize vit B complex and vit K

4. The faeces are usually stored in the descending and sigmoid colon and are voided through the rectum and anal canal.🍂🍂

🍀🍀Large intestine কিন্তু small intestine এর চেয়ে অনেক ছোট।

একে large বলার কারন luminal diameter.

Large gut এর storage function এর কারণে এটির luminal diameter বড় হয়ে থাকে।

এখানে storage function এর কারণে dialation হয় অর্থাৎ lumen dialect হয়। তাই large intestine এ luminal diameter বড় হয়।🍀🍀

🌿🌿এবার cardinal features of large gut -

এখন cardinal features বা characteristic features বা morphological features এর জন্য উত্তর একই হবে।

Cardinal features :

1. Taeniae coli : Aggregations of the longitudinal muscles of large gut ৩ টা thick bands produce করে। এরাই Taeniae coli.

এই taeniae coli vermiform appendix আর rectum এ থাকে না।

Position এর জন্য figure দেখুন।

2. Sacculations or haustrations : taeniae coli যেখানে থাকে।

3. Appendices epiploicae : Ceacum, appendix আর rectum ছাড়া পুরো large gut এ থাকে।

আরো ভালো ভাবে বুঝানোর জন্য figure দেয়া হলো। 🌿🌿

🍀🍀 এবার taeniae coli নিয়ে জানা যাক।

→ The taeniae coli are three thick bands produced by the aggregations of the longitudinal muscles of the large gut.

The taeniae are absent in the vermiform appendix and in the rectum.

They are -

a) Taenia libera

b) Taenia mesocolica &

c) Taenia omentalis.

Importance of taeniae coli :

1) Caecum আর colon এর haustration produce করে peristalsis এ সাহায্য করে।

2) It serves as a guide for identification of vermiform appendix due to all the taenia coli converge towards the base of the appendix. 🍀🍀

🍂🍂এবার Caecum নিয়ে জানা যাক -

Caecum is a large blind sac, forming the commencement of the large gut.

Types -

1) Foetal type - 2% ; Appendix arises as a straight tube from its apex.

2) Infantile type - 3% ; Appendix is attached to a depressed bottom.

3) Normal or adult type - 90% ; Appendix is situated about 2 cm below the ileo - caecal junction.

4) Exaggerated type - ( 4-5)% ; Appendix is close to the ileo - caecal junction. 🍂🍂

🌿🌿Vermiform appendix -

It is a narrow worm - like tubular diverticulum arising from the postero - medial wall of the caecum about 2 cm below the ileocaecal junction, and is supposed by a peritoneal fold known as the meso - appendix.

Position আর types নিয়ে জানা যাক -

1. Retro - caecal and retro - colic ( 12 O'clock)

2. Pelvic type ( 4 O'clock)

3. Subcaecal and paracolic ( 11 O'clock)

4. Splenic type ( 2 O'clock)

5. Promontoric type ( 3 O'clock) 🌿🌿

🌈 Nice to know -

💠 Gross features : Shorter and wider

💠 Appendices epiploicae : Present

💠 Taeniae coli : Present

💠 Sacculations : Present

💠 Distensibility : More

💠 Fixity : Greater part is fixed & immobile

💠 Villi : Absent

💠 Transverse mucosal folds : Obliterated when longitudinal muscle coat relaxes

💠 Goblet cells : Preponderant

💠 Crypts of Lieberkuhn : More numerous