digestive system

Mechanical processing

Mastication(chewing)

Secretion

Production of digestive, enzymes, stomach acid, and mucus

Digestion

Contents of G.I. track, broken down into component nutrition

Absorption

Nutrition transported across mucosal layer into circulatory system

Elimination

Undigested materials excreted(feces)

List the five major digestive processes

Mechanical processing, secretion, digestion, absorption, elimination

What type of tissues is the mucosa layer made of?

Epithelium

What is the function of the mucosa layer?

Secretion, absorption, reduced friction, protects cells from digestion

What tissues is the submucosa layer made of?

Dense areolar connective tissue

What is the function of the submucosal layer?

Regulate movement of the mucosa, Vasco constriction of blood vessels, innervates secretory cells of mucosa

What tissues are the muscularis layer made of?

Skeletal muscle and smooth muscle

What is the function of the muscularis?

Regulate G.I. movements and churning and mixing

What tissues the serosa layer made out of?

Areolar connective tissue

What is the function of the serosa layer

Surrounds and protects other three layers of the G.I. track and attaches G.I. track to body walls

Salivary Amylase

Breaks down starch into simple sugar

Mucin

Hold food together and lubricate passageway

Lingual lipase

Digests fats

Lysozyme

Antimicrobial protein

Put the G.I. organ incorrect order starting from the mouth

Mouth, pharynx, esophagus, cardia of stomach, pyloric sphincter, duodenum jejunum, ileum, ascending colon, transverse colon, sigmoid colon, anus

Voluntary stage

Bolus pushed into oropharynx by tongue

Pharyngeals stage

Respiratory tract is temporarily closed while food passes by glottis and laryngopharynx

Esophageal stage

The upper esophageal sphincter open and allow food into the esophagus, then peristaltic contraction moves through downwards, lower esophagus sphincters open, allowing food to enter stomach(involuntary)

What’s secretions does the stomach produce?

HIC, pepsinogen, mucus, intrinsic factor

What cells are produced in the stomach?

parietal cells,G cells,Mucous Neck Cells, chief cells

What secretions does the liver produce?

Bile

What cells are produced in liver?

Hepatocytes

Function of hepatocytes

Regulate nutrient and remove toxins from the blood before it moves through the rest of the systematic circulation

Function of parietal cells

Denature protein

Function of chief cells

Produces and secretes pathogens to inactivate enzymes that activate in the presence of HCI

Function of mucous neck cells

Produce a thick alkaline mucus, rich in bicarbonate to protect the gastric epithelium from damaged by HCL

Function of G cells

Stimulate parietal cells to produce acid

What secretions are produced in the pancreas?

Sodium bicarbonate, trypsin,lipase,deoxyribonuclease

What cells are produced in the pancreas?

Ducal cells & Acinar cells

Function of ductal cells

Secretes a large volume of water and bio carbonated rich fluid that neutralizes acidic gastric juices in the duodenum and prevents pancreatic autodigestion

Function of acinar cells

Synthesize store and secret, powerful digestion, enzymes to breakdown, protein, fats, and carbohydrates

what secretions are produced in the small intestine?

Secretin, CCK, lactase

What cells are produced in the small intestine?

Golblet cells, enteroendocrine cells, paneth cell, absorptive cells

Function of Goblet cells

Access as a guardian of the intestinal barrier by preventing pathogens from reaching the epithelial cell

Function of enteroendocrine cells

The Intestinal gland Secrete hormones into the blood

Function of paneth cell

Act as crucial guidance of intestinal health and homeostasis

Function of absorptive cells

Absorbs, nutrition, vitamin electrolyte, and water formed digestive food into the bloodstream

Stomach

Food storage and intentionally protein digestion

Small intestine

Absorption of most food molecules

Mouth

Mastication

Large intestine

Absorption of vitamins and excess water

Liver

Detoxification and inter conversion of energy molecules

Pancreas

Production of bicarbonate and trypsin

Cephalic phase

Odor and taste of food initiate secretion of stomach juices and secretion of gastrin into blood

Gastric phase

Food entering stomach causes peach right and stomach stretch, PHN stretch are detected by receptors, which signal NS, impulses from MS stimulate gastrin and ACH production, increase peristalsis, mucus, and acid secretion crossing pH to drop

Intestinal phase

Activation of receptors in small intestine causes digestion and stomach to slow in order to avoid overloading small intestine

Which food would digest most quickly

Cheerios(any carbohydrate)

How does the pH of the digestive system change from the mouth to the small intestine?

Start slightly acidic/neutral in the mouth because highly acidic in the stomach for digestion and shifting to a slightly basic/neutral environment in the small intestine to enable nutrition absorption

Nutrition absorbed from the small intestine, travels first to the______ via the haptic portal vein

Liver

Which are functions of the liver

Production of bile, synthesizes of albumin, and other plasma proteins, deamination of amino acids

What four factors contribute to the large absorption surface area of the small intestine

Length, circular folds, vili, microvilli

Given the primary function of the small intestine in absorption, what type of epithelium is it composed of

Simple columnar epithelium

Lacteal

Specialize lymphatic capillaries found within the villi of the small intestine and transports lipids absorbed through G.I. track

Chylomicrons

Exit epithelial cells via exocytosis and enters Lactelas and is removed from bloodstream by liver

Segmentation

Localized mixing contraction that mixes food with digestive enzymes

Migrating motility complex

Directly move of food through the small intestine towards the large intestine

haustral churning

Haustra fill until distended & then contracts, forcing contents into extra haustra

Mass peristalsis

Begins midway along transverse colon and quickly dried contents into rectum

Gastrocolic reflex

Initiated by food and stomach