Digestive System

Based on the slideshow provided by Mr. Crocetti

Ingestion

Ingestion

The taking in of food into the body

Mechanical Processing

Food into smaller pieces and mixing it together

Secretion

Of water, acids, enzymes and buffers to aid in digestion

Digestion

The chemical breakdown of large food molecules into smaller ones

Absorption

Of nutrients from food into the bloodstream

Excretion

The removal of water products

Mastication

Occurs as the teeth physically tear the food into smaller pieces. Increases the surface area of food, allowing it to dissolve and chemically digest more quickly.

Salivary Amylase

Three pairs of salivary glands and is an enzyme that breaks down starch (polysaccharide) into maltose (disaccharide)

Three salivary glands

Sublingual Gland, Submandibular Gland, & Parotid Gland

Enamel

The outermost layer of the tooth. Its made of pure calcium phosphate, the hardest biologically-made subtance.

Dentin

Less mineralised and yellowish in colour. Covered by Cementum.

Cementum

Attaches teeth to underlying ligaments

Pulp Cavity

The hollow area inside the tooth. Each tooth has 1-4 hollow conceals that contain nerves and blood vessels.

Periodontal Ligaments

Attach teeth to the maxilla or mandible

Incisors

Blade-shaped teeth at the front of the mouth (Clipping or Cutting)

Canines

Cone-shaped with pointed tip (Tearing or Slashing)

Premolars and Molars

Flattened tops (Crushing, Mashing, & Grinding)

Wisdom Teeth

An additional set of molars that often develop in location where they cannot erupt

Cavities

Occur when bacteria produce waste acids that dissolve the calcium phosphate of the enamel, creating a hole

Root Canal

A procedure that removes the contents of the pulp cavity, replacing it with solid filling

Bolus

A ball of chewed, softened food that is swallowed which the tongue produces

Uvula

Folds back, closing off the nasopharynx and forcing food down the laryngopharynx

Epiglottis

A flap of tissue that closes off the opening to the larynx and trachea

Peristalsis

The bolus passes through the pharynx and esophagus through a series of involuntary wavelike contractions of smooth muscle. Is visible on x-rays.

Cardiac Sphincter

Food enters the stomach through it, which prevents it from going back up the esophagus

Rugae

The stomach’s internal folds

Mucous Cells

Produce mucus need to protect the stomach from digesting itself

Parietal Cells

Secrete hydrochloric acid

Chief Cells

Secrete pepsin

Pepsin

Digests proteins into amino acids

The cardiac and pyloric regions…

produce mucus

The fungus and body produces…

pepsin and HCl

Chyme

The partially digested food, mucus, and acid mixture

Duodenum

Where most of the digestion in the small intestines occurs. Receives secretions from the gallbladder and pancreas. Also add its own secretions

Duodenum Enzymes

Sucrase, Lactase, and Maltase

Duodenum Substrates

Sucrose, Lactose, Maltose

Duodenum Products

Monosaccharides (e.g. glucose, fructose)

Pancreas Enzyme

Trypsin, Lipase, Amylase

Pancrease Substrate

Protein, Lipids, Starch

Pancreas Products

Amino Acids, Fatty Acids and Glycerol, Maltose

Bicarbonate

Neutralised the stomach acid, the pancreas releases it

Bile Salts

The liver produces it through the gallbladder. There emulsify fat globules into smaller droplets that can be digested more easily. Similar in action to detergent or soap.

Jejunum

Middle segment of the small intestine

Ileum

The last segment of the small intestine

Villi

Increases surface area of small intestines

Hepatic Portal System

A series of blood vessels that deliver nutrients to the liver

Cecum

A pouch, the first part of the large intestine. Appendix is attached here.

Segments of the large intestine

Ascending, Transverse, Descending, Sigmoid Colon

Gut Flora

A complex community of beneficial bacteria and live in the large intestines. Responsible for production of intestinal gases.

Internal Anal Sphincter

An involuntary muscle that opens when the rectum is full

External Anal Sphincter

Must be voluntarilty relaxed

Rectus Abdominis and Transversus Abdominis

Muscles compress the rectum, removing the feces

Pancreas

Controls blood sugar

Islets of Langerhans

Contain the calls that actually produce these hormones

Insulin

Lowers blood sugar by absorbing glucose into the liver and muscles

Glucagon

Has the opposite effect, raising blood sugar

Greater Omentum

The stomach is help in place with the other abdominal organs. Major fat storage area.

Menestery

Holds the intestines together and contains all intestinal veins and arteries

Mumps

A viral infection that causes painful swelling of the salivary glands, especially the parotid. Airborne and highly contagious

Heartburn

Caused by an influx of stomach acid into the esophagus

Peptic Ulcers

Occurs in the stomach

Duodenal Ulcers

Occur in the duodenum

Vomiting

An involuntary opening of the stomach

Diarrhea

The presence of abnormally loose or liquid feces cause by an excess of water inside the intestines. Caused by bacteria or laxatives.

Lactose Intolerant

Stop producing the lactase enzyme when breastfeeding ends

Type I Diabetes

The result of the immune system destroying the insulin-producing cells of the pancreas.

Type II Diabetes

Occurs because cells int he liver, muscles, and fat do not respond adequately to insulin