Digestive System Test

What are nutrients and what are they needed for?

They are substances needed for the body, 1)Growth 2)Maintenance 3)Repair

What is digestion?

Process of breaking down food into nutrients

What are the 2 types of digestion?

Chemical and mechanical

What is the alimentary canal?

Primary orans for digestive system, called the GI tract.

What are the organs of the alimentary canal?

Mouth, pharynx, esophagus, stomach, small and large intestine

What are the accessory organs and glands?

Salivary glands, teeth, tongue, pancreas, liver and gal bladder

What are the functions of the digestive system?

Ingestion, propulsion, mechanical digestion, chemical digestion, absorption and defecation

What is ingestion?

Voluntary process of taking food or drink into the body
through the mouth.

What is propulsion?

Forceful movement of food from one organ to the next

What is peristalsis?

It is the alternating waves of contraction and relaxation that push food along GI tract

What is mechanical digestion

The physical breakdown of food into smaller particles, ex tongue mixes food in mouth, teeth tearing food apart

What is chemical digestion?

Large food molecules are broken down into building blocks by enzymes

What are enzymes

proteins that speed up chemical reactions in the body

What is absorption?

When nutrients travel from GI tract into the bloodstream in small intestine. Bloodstream carries nutrients to cells throughout body

What is defecation

Elimination of solid waste from body, combination of undigested/unabsorbed food, water, bacteria, called feces

What activates the inhibit of glands and muscles of digestive system?

The brainstem

Mechanoreceptors

They detect stretching of organ walls

Chemoreceptors

Detect factors such as solute concentration, PH substrates and end of products

How is mechanical digestion done in the mouth

By the teeth and tongue

How is chemical digestion in the mouth

The salivary glands produce enzymes that begin chemical digestion

Describe anatomy of the mouth

-Lined the mucous membrane , -lips to protect anterior opening, - cheeks form lateral walls, - hard and soft palate form roof tongue occupies floor of mouth, tonsils located in back of throat

What is mastication?

Physical breakown of food by teeth

What is the ball of partially digested food called?

Bolus

When does chemical digestion begin?

When salvia, which contains salivary amylase begins the digestion of carbohydrates.

What are broken down into smaller fragments?

Polysaccharides such as starch and glycogen

What are the 3 pairs of salivary glands

Parotid, submandibular and sublingual

What does salvia contain

Water, salivary amylase, mucus, antibacterial substances

What do accessory organs perform?

Initiation of swallowing, chewing and chemical digestion. of starches

What is the masseter?

A powerful chewing muscle

What does swallowing involve?

The coordinated activity of the tongue, soft palate, pharynx, esophagus and several muscles to push the food bolus to the back of the mouth, starts voluntaily and then involuntary reflexes take ovre

What is the pharynx

The area behind the nose and mouth

What are the oropharynx and laryngopharynx?

Common passageways for food, air and liquids

Where does the bolus pass through?

The pharynx and esophagus

Where does the esophagus extend from and how long is it?

The stomach and is 25 cm long

How does the esophagus conduct food bolus?

By peristalsis

Describe the stomach

-J-shaped muscular organ
that expands from the
inferior end of the
esophagus.

-Secretes enzymes that
digest protein,

-Muscle contractions
contribute to mechanical
digestion

Where does food go through in the stomach?

Through the cardiac or cardioesophagael sphincter?

Where is the pyloric sphincter located?

At the end of the terminal before duodenum

What type of muscle layers does the stomach have and how many?

Layer of oblique muscle in addition to circular longitudinal layers, has 3 layers which allow for churning and mixing of food as it moves through stomach

What is stomach lined with?

Mucous membrane that secretes protective mucus

What are gastric pits?

Small pores that secrete gastric juice

What is in gastric juice?

Enzymes such as pepsinogen that break down proteins, intrinsic factors, allow vitamin B to be absorbed, Hydrochloric acid, muscus to coat the stomach and hormones such as gastrin

What does the stomach do?

Stores food, initates protien digestion

What is chyme

Partially digested food mixed with stomach fluids.

What the body’s major digestive organ?

The small intestine

What are the 3 subdivision of the small intestine?

duodenum, jejunum, ileum

How long is the small intestine

3-4 m and 2.5 cm in diameter

What is the mesentary

A fold of tissue that attaches the intestines to the abdominal wall and contains blood vessels, nerves, and lymphatics. It supports the small intestine and helps in nutrient absorption.

What are plicae circulares?

deep folds of intestinal lining

What are villi and microvilli

Villi are fingerlike projections of intestinal lining, and microvilli are tiny projections of the plasma membrane of epithelial cells on surface of villi

What the duodenum

First portion of the small intestine, where enzymes from the intestinal cells and pancreas along with bile from the liver complete chemical breakdown of food in the duodenum

What is intestinal juice?

Composed of mostly water and alkaline mucus, is secreted by glands at base of villi, it helps to neutralize the acidic chyme entering the stomach

What are brush border enzymes

Enzymes bound to the surface of microvilli complete the final stages of carbohydrate and protein digestion, they create a fuzzy apperance called a brush border

What is the largest internal organ

Liver

What is the main function of the liver

To produce bile which is a slightly alkaline solution that digest fats

Where is bile stored

In the gal bladder

How is bile released

In the duodenum through the bile duct, is controlled by the hormones and CCK and secretin

What does the pancreas do?

produces pancreatic juice that enters the duodenum through the pancreatic, it contains powerful enzymes that break down all types of nutrients

What is the purpose of the large intestine

Produces no digestive enzymes, absorbs water and a few other substances, dries out indigestible food residue to produce solid waste

How long is the large intestine and where does it extend to

1-5 m in length extends from small intestine to anus, sub visions include cecum, appendix, colon, rectum and anal canal

what are the 4 regions of the colon

1) Ascending 2)Transverses 3)Descending 4) Sigmoid

What is the entrance to large intestine

The ileocecal valve, which prevents food from re-entering the small intestine, and the cecum is a pouch just below the valve

What the appenxdix

A fingerlike projection suspended from cecum, plays a role in immune system defense

What the Sigmoid colon store

Feces, contains rectum and anus

What is the purpose of the large intestine

To absorb water and salts, and to store and compact feces before elimination.

What are bowel movements

Long, slow-moving contractions of the colon, push contents of colon towards rectum

How is Gastroesophagael reflux caused

Week cardioesophagael sphincter, occurs when stomach acids back up into the esophagus

What are stomach uclers

A hole or damage area of stomach lining, called peptic or gastric ulcer

What are gallstones

Hard deposits composed of cholesterol, pain is often when stones move through bile duct

What is hepatitis

Inflammation of liver caused by viral infections, toxins, or alcohol, type C is most deadly infectous disease in US

What is pancreatitis

Inflammation of pancreas that occurs when digestive enzymes are activated too soon and caused pancreas damage, caused by galstones or acholol use

What is Inflammatory Bowel Disease

Chronic inflammation of digestive tract, includes Crohns disease and ulcerative colitis

What is Appendicitis

Sererve pain in lower right abdomen, loss of appetite nausea and vomiting, treatment is surgical remvoal, can be fatal

What is cystic fibrosis

Inherited disease that caused thick mucus to form in lungs, pancreas of other organs, mucus blocks secreation of digestive enzymes and bicarboate soluntion

What are hemorrhoids

Swollen veins in lower rectum and anus, cause pain itching and bleeding

What is vomiting

Forceful explusion of stomach contents

What is diarrhea

Frequent discharge of watery feces

What is cleft lip and palate

Lip or palate may fail to close propertly during developlement, one of most common birth defeacts

What is Pheynkeltonuria

A genetic disorder that causes a build-up of amiono acidphenylalanine due to a deficiency in the enzyme phenylalanine hydroxylase, which can lead to intellectual disability and other neurological issues if untreated.

What are babies born with?

Rooting reflex which causes babies head to turn towards anything that touches cheek or mouth and sucking relfex which causes anything that touches roof of mouth

What is the biggest risk factor in dieases

Aging