Explain the process of digestion from mouth to the kidney?

Question

Hi there... F.Y.I this supposed to be my Physiology assignment which I need to hand in by next week... I'm lost in this topic.... Hee~ I really need you guys to make this topic looks simple and easier.... X)

Answer 1

Hi there.

Digestion happens in the mouth. Mastication (the action of chewing and mechanically breaking down food) triggers you're exocrine glands to excret a watery liquid called saliva. This dampens the food making it more chewable but saliva also contains digestive enzymes called salivary amlyase that help break down the food into more digestable sugars.

When you want to swallow, you're brain triggers waves of muscular contractions that sqeeze food along you're eosophogas, at about 2 inches per second.

The chewed food then enters you're stomach. It is here that the food undergoes mechanical (peristaltic contractions) digestion. This allows the food to mix with the strong, acidic digestive juices secreted by the stomach lining. The hydrochloric acid in the stomach is about the same or even more powerful than laboratory hydrochloric acid! The three layers of the stomach walls (longitudinal, circular, and oblique) are arranged to allow the mechanical churning of the food to break it down succesfully. The enzyme pepsin (a protease) is realeased from the stomach to help break the peptide bonds between amino acids in proteins.

After several hours of stomach digestion, the food moves into the small intestine. The small intestine is about 20 feet (6 meters) long and has three parts: the duodenum, jejunum, and ileum. Most digestion within the small intestine occurs within the duodenum. Bile released from the liver and stored in the gallbladder allows the food (at this point now called chyme) to be emulsified into smaller particles. Bile is especially secreated to break down lipids and fats using a digestive enzymes called lipases. Digestive enzymes from the pancreas and intestinal walls includes enzymes called trypsin (for protein digestion), amylase (for carbohydrate digestion), and lipase (for lipid digestion) which helps break down more complex food molecules into simpler and more absorbable particles.

Food passes through the jejunum and ileum. On the walls of these parts of the small intestine are small finger like projections called villi. On the villi small hair like projections are called microvilli. The point of these villi and microvilli allow the small intestine's surface area to become extremely large allowing the absorption of nutrients and molecules to be extremely efficient. During this absorption, cappilaries absorb small molecules of protein and carbohydrates into the blood stream for them to be transported around the body for respiration and to gain energy. Lymph vessels (lacteals) within the villi absorb products of fat digestion and eventually lead to the bloodstream.

From here, digestion carrys on to the liver, one of the largest and most versatile organs of the body. Within the liver Hepatocytes (liver cells) detoxify the blood of any harmful subtances such as ammonia or alcohol. This is why excessive alcohol intake results in the liver to be damaged. And, hepatocytes store fat-soluble vitamins and excess substances such as glucose (sugar) for release when the body requires extra energy! Which is good!

Digestion now takes to the large intestine. The digested food now contains mostly undigestable subtances which must be disposed of. It enters the large intestine which is composed of 6 parts: the cecum, ascending colon, transverse colon, descending colon, sigmoid colon, and r****m

The large pouch-shaped cecum marks the beginning of the colon. Attached near the cecum bottom is the vermiform (worm-like) appendix. The appendix contains lymphoid tissue and intercepts pathogenic microorganisms that enter the digestive tract. Sometimes, fecal matter may become trapped in the appendix, resulting in appendicitis (infection and inflammation).

The other parts of the colon absorb water and minerals from the undigested food and compact the remaining material into f***s. Defecation is the digestive process final stage: f***s (undigested waste products) are carried to the r****m through peristalsis and eliminated through the a**s.

I hope that is what you needed. I hope you feel special... it took me a bloody long time!! Lol

If it's too complicated then think of it as at each organ more and more stuff is being added to the food to eventually allow it to be small enough for it to diffuse through cells and into the bloodstream.

i dont know how old you are but this is a kids one i think

http://kidshealth.org/parent/general/bod...

But heres a more complicated one

http://www.besthealth.com/besthealth/bod...

GOOD LUCK in you're assignment :]