diet, disease, and digestion eva murdoch, phd assistant professor, anatomy and physiology department...

Diet, Disease, and Digestion

Eva Murdoch, PhDAssistant Professor, Anatomy and PhysiologyDepartment of Natural SciencesJoliet Junior College

Organs of the Digestive System

1. Gastrointestinal tract (GI):

mouth, esophagus, stomach,

small & large intestine

2. Accessory organs: salivary

glands, liver, gall bladder,

pancreas

Functions of the GI tract and Accessory Organs

• GI tract: continuous muscular tube which passes, digests, and absorbs food molecules, and eliminates the indigestible residue

• Accessory organs: release digestive juices into the muscular tubule, and aid in the breakdown of nutrients

Digestive System

• Living organisms must obtain

nutrients from their environment to

sustain life

• The digestive system breaks down

large nutrient molecules to small

nutrient molecules that all body cells

can then use to:

– Synthesize ATP (cell’s energy supply)

– Perform structural maintenance, repair

and support growth

Digesting and Absorbing Nutrients

• Salivary glands, pancreas and liver help with the digestion of large food molecules to small molecules by secreting enzymes

• Digestion Absorption– Carbs monosacchrides blood– Fats fatty acids blood– Proteins amino acids blood

Cell Metabolism

• All chemical reactions that occur in a cell– Synthesis of ATP– Synthesis of new organic molecules, and other cell

functions that require ATP

Nutrient Molecules

1. Carbohydrates / Sugars

− Function: short-term energy supply 4 Cal / 1 gram (calories are a unit of energy)

− Found in: grains (wheat, rice, oats, corn), fruits, veggies

2. Lipids / Fats– Function: energy reserve, padding, insulation 9 Cal / 1 gram– Found in: nuts, red meat, milk, eggs, butter

3. Proteins– Functions: enzymes, hormones, muscle, last resort

for energy 4 Cal / 1 gram– Found in: meat, nuts, beans, dairy, eggs

Diet Pyramid

Disease

• GERD – gastro-esophageal (acid) reflux disease– Cause: stomach acid in the esophagus, due to weak

esophageal sphincter– Pathology: erosion of esophageal tissue pain– Treatment: largely preventable by changes in lifestyle,

medication, surgery

• Stomach ulcer– Cause: inflammation due to H. pylori

infection– Pathology: bleeding in stomach– Treatment: antiacid, antibiotics, anti-

inflammatories

• Stomach cancer– Cause: H. pylori infection, genetics– Pathology: abnormal growth (tumor) in

stomach tissue– Treatment: surgery, chemotherapy

• Colon polyp– Cause: irritable bowl syndrome (IBS)

history– Pathology: abnormal growth, rectal

bleeding– Treatment: surgery

• Colon Cancer (3rd most commonly diagnosed cancer)– Cause: genetic, polyps, diet, smoking, excessive drinking– Pathology: uncontrolled cell growth in colon, rectal

bleeding– Treatment: surgery, chemotherapy, radiation therapy

• Liver cirrhosis – Cause: chronic alcoholism and hepatitis C infection– Pathology: liver cells (hepatocytes) are replaced by

fibroblasts (cells found in tendons, can’t perform liver functions)

– Treatment: liver transplant

• Pancreatic Cancer– Cause: genetics, age, smoking, diet, diabetes– Pathology: mutations in the pancreatic cell and tumor growth– Treatment: surgery, chemotherapy