MSN2 Chapter 37-Digestive System Introduction

MSN2: Chapter 37-Digestive System Introduction

8/12/21

Introduction

Digestive Tract: Also known as the gastrointestinal tract and the alimentary tract

Muscular Tube: 30 feet long

Consists of the mouth, pharynx, esophagus, stomach, small intestine, large intestine and anus

Accessory Organs: salivary glands, liver, gallbladder, and pancreas

Function: ingestion, digestion, absorption, and elimination

Structures

Mouth: secretes amylase (initiates the breakdown of carbohydrates), chews and grinds food

Pharynx: joins the mouth and nasal passages to the esophagus (epiglottis covers the airway during swallowing)

Esophagus: muscular tube that passes through the diaphragm into the stomach, contractions of the muscles form a wavelike movement called peristalsis

Stomach: consists of 3 sections-fundus, body, and pylorus, churns food into chyme, secretions include: rennin, pepsin, hydrochloric acid, and lipase

Structures Cont.

Small intestine: chemical digestion and absorption of nutrients, 20 feet long, has 3 sections: duodenum, jejunum, and ileum

Liver and pancreatic enzymes enter the small intestine in the duodenum

Large Intestines and Anus: function is to absorb water from the chyme and eliminate wastes

Accessory Organs

• Salivary gland

• Liver

• Pancreas

• Gallbladder

Liver (Hepatic)

Divided into 4 lobes

Kupffer cells ingest old red blood cells, RBCs, and bacteria

Parenchymal cells carry out metabolic functions

Bilirubin: product of old RBCs in the liver, liver secretes bilirubin into bile which passes through the cystic duct into the gallbladder for storage

Bile helps breakdown fat for absorption and plays a role in absorption of fat soluble vitamins and removing some toxins

Metabolism

• Glycogenesis: excess glucose molecules are taken by the liver, combined and stored as glycogen in a process called glycogenesis after a meal

• Glycogenolysis: when glucose levels fall, the process of glycogenesis is reversed and glucose is returned to the blood

• Gluconeogenesis: liver maintains blood glucose by breaking down fat and protein and making new glucose

Protein Metabolism

Albumin, globulin, and clotting factors (prothrombin and fibrinogen) are created in the liver.

The liver converts ammonia (a byproduct of amino acid metabolism) to urea. Elevated levels of ammonia in the blood are toxic to the brain.

Detoxification

Most medications are broken down in the liver. Weight, age and liver disease are all taken into account by providers when prescribing medications.

CAM Therapy: Comfrey, borage, coltsfoot, chaparral, and germander can all harm the liver.

Liver Cont.

Immunity: antibodies and other substances that help resist infection are all produced in the liver

Hormone Metabolism: the liver helps metabolize adrenocortical hormones, estrogen, testosterone, and aldosterone

Open Ended

List any medications that you know of that are metabolized in the liver:

Multiple Choice

The liver is located in which quadrant?

• RUQ

• LLQ

• RLQ

• LUQ

Biliary Tract

Made up of the gallbladder and the bile ducts.

Delivers bile from the liver to the duodenum.

Pancreas

Located in the LUQ behind the stomach.

Exocrine Function: carried out by acinar tissue that produces pancreatic fluid (trypsin, amylase, and lipase) that helps digest fats, proteins and carbohydrates

Endocrine Function: carried out by cells call islets of Langerhans (alpha, beta, delta and PP cells)

-- Alpha: produce glucagon

-- Beta: produce insulin

-- Delta: produce somatostatin

-- PP cells: produce pancreatic polypeptides

Multiple Choice

Glucagon is secreted when the blood glucose level falls.

• True

• False

Multiple Choice

Tooth loss is a normal age related change.

• True

• False

Assessment of GI Disorders (RN)

• Chief complaint/symtoms

• Past Medical History: Diagnoses, surgeries, last meal, last bowel movement, allergies, food allergies, medications, OTC medications and supplements

• Dietary habits, alcohol use, street drugs (*marijuana)

• Physical Exam: height weight, vitals, skin color (note any signs of jaundice-skin, eyes), texture, moisture, edema, turgor, posture, teeth, gums, tongue and mucous membranes

• Inspect the abdomen first, then auscultate each quadrant, then palpate

• Patient is placed in Sims position for inspection of rectum and anus

Discuss and Research

Find the most current diagnostic test for examining the small intestine...

Best practice for collecting and sending stool specimen...

Age related changes: Constipation is common in the elderly, what patient teaching is needed for stool softener use?

Multiple Choice

A test that uses a scope to visualize the anus, rectum, and entire colon.

• MRI

• CT Scan

• Colonoscopy

• Ultrasound

Multiple Choice

An infection found in peptic ulcer disease:

• Staphylococcus aureus

• Ova and parasites

• MRSA

• Helicobacter pylori

Nasogastric Tubes

• Inserted in the stomach or intestines to deliver feedings or keep the digestive tract empty

• Patient's head of bed must be elevated at least 30 degrees when delivering feedings and for thirty minutes after, always follow agency protocol, most patients will remain elevated at 30 degrees

Nasogastric Tubes Cont.

• Residual (feeding remaining in the stomach) must be monitored to prevent over filling the stomach, return all content after measuring, this is the standard of verifying tube placement, however, an x-ray may be ordered per provider every shift, auscultation is no longer the standard for placement

• Flush tubing with water after feeding per agency protocol

• Remember when delivering medications through tube that not all medications can be crushed

Nasogastric Tubes Cont.

• Dumping syndrome may occur if the tube feeding is delivered rapidly: cold sweat, abdominal distention, dizziness, weakness and rapid pulse are all symptoms

• Be sure to flush the tube with at least 30ml of water after each feeding

• If diarrhea occurs, contact the health care provider

• If an infusion pump is used, prime the pump with formula prior to connection to eliminate air in the line

Total Parenteral Nutrition or TPN

Bypasses the digestive tract by delivering nutrients directly to the blood stream. A central line or a peripherally inserted central line is used and the feeding passes directly into the superior vena cava and right atrium. Peripheral IVs cannot be used as they will cause phlebitis. The subclavian artery allows for rapid dilution.

The patient will need to be monitored closely for blood glucose changes.

Feedings given too fast can overload the patient's circulatory system.

Never give medications through the TPN line.

TPN Cont.

• Always use sterile technique when providing care at the insertion site

• Monitor the patient's temperature for signs of elevation

• Label the TPN lines

Multiple Choice

When an enteral feeding tube is inserted, placement must be confirmed by an x-ray prior to first feeding.

• True

• False