Digestive System Chp.24

Created by laurenmm3 

Upgrade to
remove ads

30 terms

Digestive organs

These are the organs which the food and liquid passes through during the process of digestion. The pathway is called the ALIMENTARY CANAL and includes the oral cavity, pharynx, esophagus, stomach,small intestine, and large intestine.

Accessory Organs

These organs aid in the process of digestion by secreting chemicals that break down the food and liquids we eat. The organs include salivary glands, pancreas, gall bladder, and the liver.

Absorption

Digested products pass through and into the blood for distribution into other organs. Most materials are first delivered to the liver for further processing.

Enteric Nervous System

Composed of extensive nerve plexuses in walls of digestive organs. Three plexuses are 1)Sensory neurons to CNS 2) AMS motor neurons to organs 3) Enteric neurons only in digestive system. This system acts locally to control contraction of the organ walls, regulate blood flow to organs, and control secretion of digestive juices. Special interstitial cells mediate impulse of transmission from ENS to nerve cells to smooth muscle cells & regulate gastrointestinal movement by forming pacemakers along the tract.

ANS in Digestive system

REflex control of general digestive functions is also controlled by this system which acts in conjunction with ENS. The parasympathetic division acting through the vagus nerve acts to speed up digestion which the sympathetic slows down the process.

Deglutination

Process of moving food into and through the pharynx.

Voluntary phase of Deglutination

Food is moved to the back of the mouth.

Pharyngeal Phase of Deglutination

Reflex action occurs controlled by the medulla oblongata and food bolus closes the epiglottis. The constrictor muscles force the food along the pathway.

Esophageal Phase of Deglutination

Where the upper esophagus sphincter muscles relax and allow food to enter the esophagus. Then food is removed by peristalsis through the esophagus. Peristalsis is controlled by the vagus nerve of the parasympathetic ANS.

Achalasia

Disorder of the esophagus where the valve does not open and causes chest pain and difficulty in eating. Nervous control problem.

Mucous Gastric Secretions

Thick material that lubricates food and coats stomach lining to protect against strong gastric secretions.

Intrinsic Factor Gastric Secretions

Produced with Hcl; Binds to vitamin B-12 to aid its absorption in the small intestine;[ B-12 DEFICIENCY (Pernicious Anemia)- Reduced red cell production and reduced oxygen in blood with feelings of fatigue, muscle weakness, and can be fatal and treatment is liver and B-12 injections.]

Hydrochloric Acid Gastric Secretions

Lowers pH to 1.5-2.5 during digestion and is activated by digestive enzymes and breaks down connective tissue in foods.

Pepsinogen Gastric Secretions

Hcl activates Zymogen to form pepsin enzyme; It digests proteins, breaks down bonds btwn amino acids to form smaller peptide chains.

Gastrin Gastric Secretions

Hormone made in gastric glands and stimulates production of other digestive juices.

Cephalic Phase

Phase where taste and smell of food starts salvation process. Cranial Nerve activates salivary glands. Vagus Nerve starts gastrin secretion.

Gastric Phase

Phase where activation of digestive processes in the stomach are stimulated by distention of stomach walls activating the vagus nerve, gastric hormone, and presence of material in stomach such as proteins, alcohol, and caffeine.

Gastrointestinal Phase

Phase where the small intestine acts to control stomach secretions in order to digest the materials being moved into it from the stomach.

Secretin

Increases bile production.

Cholecystokinin

Causes gall bladder to contract and empties into duodenum into small intestine.

Vagus Nerve

Presence of food in small intestine activates nerve to aid in contraction of gall bladder and controls bile secretions and delivery.

Protein Synthesis

When the liver makes special blood proteins.
HEPARIN-anticoagulant
FIBRINOGEN-needed for clotting
ALBUMIN-needs water in blood vessels to maintain blood pressure.

Glycogen Formation

When the liver stores glucose in the form of glycogen starch. Glycogen can be later converted back to glucose for maintaining blood sugar levels.

Vitamin Storage

Stores excess fat soluble vitamins in liver and also stores vitamin B-12.

Vitamin Synthesis

Aids process of vitamin D production by the body and cholesterol is converted to vitamin D when skin is exposed to sunlight.

Detoxification

Forms glucuronides where water soluble products to be excreted by kidneys.

Hepatitis

Inflammation of the liver. Symptoms are yellowing of the skin and eyes. Causes are chemical exposure, viral infection, bacterial infection, hepatitis C.

Cirrhosis

Condition of fatty infiltration of liver cells. Cells replaced by fat and connective tissue. Causes are excess alcohol consumption and toxic exposure to chemicals.

Pancreatic Secretions

Secretes insulin, and glucagon.

Pancreatic digestive enzymes

Enzymes are trypsin, chymotrypsin, and carboxypeptidase.

Please allow access to your computer’s microphone to use Voice Recording.

Having trouble? Click here for help.

We can’t access your microphone!

Click the icon above to update your browser permissions above and try again

Example:

Reload the page to try again!

Reload

Press Cmd-0 to reset your zoom

Press Ctrl-0 to reset your zoom

It looks like your browser might be zoomed in or out. Your browser needs to be zoomed to a normal size to record audio.

Please upgrade Flash or install Chrome
to use Voice Recording.

For more help, see our troubleshooting page.

Your microphone is muted

For help fixing this issue, see this FAQ.

Star this term

You can study starred terms together

NEW! Voice Recording

Create Set