Digestive Part II Flashcards by Christopher Waller

What is clinically indicated when the lower esophageal sphincter fails to close adequately after food enters the stomach & contents reflux into the esophagus?

Gastroesophageal Reflux Disease (GERD)

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This can be associated with esophageal cancer?

GERD

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How many amino acids are considered essential because they cannot be produced in the body and must be part of our diet?

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What is the form fat is usually found in the human diet?

Triacylglycerol (TAG)

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What are the smaller components fat must be hydrolyzed into in order to be absorbed?

Free Fatty Acids

Monoglycerides

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What are some of issues that arise concerning the aging GI System?

Hiatal Hernia
Gastritis
Peptic Ulcer Disease
Appendicitis
Gallbladder Problems
Acute Pancreatitis
Janundice/Cirrhosis

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What is the reflex that is triggered by distention of the stomach while eating/immediately after triggers mass peristalsis in the colon?

Gastrocolic Reflex

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The Gastrocolic Reflex is usually triggered how long after eating?

30-45 minutes

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This reflex is activated with entry of feces into the rectum that causes distention, increased signals to descending & sigmoid colon (via myenteric plexus) increases peristalsis pushes fecal matter to anus and cause anal sphincter to relax?

Intrinsic Myenteric defecation reflex

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What is the nerve impulse pathway for the defecation reflex pathway?

Sensory impulses to sacral spinal cord triggered by stretch receptors (mechanoreceptors) in rectum
Motor impulses travel along parasympathetic nerves to descending & sigmoid colon, rectum & anus

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The motor impulses trigger a contraction of what muscle in regards to defecation?

Longitudinal rectal muscles

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Voluntary contractions of diaphragm & abdominal muscles along with parasympathetic stimulation cause what to relax?

internal Anal Sphincter

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What sphincter is completely voluntary and if it is relaxed feces exits the anus if constricted defecation is postponed?

External Anal Sphincter

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What factors affect the frequency of Bowel Movements?

Diet
Health
Stress

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The normal (typical) range of number of Bowel movements daily & weekly are?

1-3 per day

3-4 per week

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What is defined by increase in frequency, volume, or fluid content caused by increased motility & decreased absorption by the intestines?

Diarrhea

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Name some of the reasons for excessive motility of the intestines?

Lactose Intolerance
Stress
Microbes that irritate mucosa

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What is defined by Infrequent or difficult defection caused by decreased motility of the intestines?

Constipation

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What happens as feces remains in the colon for longer periods of time?

Excessive water reabsorption/absorption causing feces to become dry & hard

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Name some of the causes of constipation?

Delaying defecation
Spasms of the colon
Insufficient fiber or water in diet
Lack of exercise
Emotional stress
Drugs (Narcotics)

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Name some of the treatments for constipation?

Laxatives (habit forming)
Increasing Fiber
Increasing exercise
Increasing Water

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What portion of the digestive tract is considered to be the terminal portion?

Large Intestine

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What is the overall function of the Large Intestine?

Complete process of absorption
Produces vitamins (Vit. K & Biotin)
Forms feces
Excretes feces from body

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What are the four major regions extending from ileum to anus?

Cecum
Colon
Rectum
Anal Canal

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What is the length & diameter of the large Intestine?

approx. 5 feet long | approx. 2.5 in diameter

What is the Large Intestine attached to?

Posterior Abdominal wall by the Mesocolon (peritoneal fold)

This is the opening from the ileum to the large intestine & allows materials to pass from small intestine into the large intestine?

Ileocecal Sphincter (Value)

This is inferior to the ileocecal valve & is a small pouch (approx. 2.4 in long)?

Cecum

What is attached to the cecum & is approx. 3in long?

Appendix (vermiform appendix)

This is proceeded by obstruction of the lumen by chime, fecolith, foreign body, carcinoma, stenosis, or kinking, & characterized by high fever, elecvated WBC, neutrophil count >75%?

Appendicitis

What are the four portions of the colon?

Ascending Transverse Descending sigmoid

This portion of the colon lies retroperitoneal, ascend on the right side of abdomen to lower border of the liver?

Ascending Colon

What is the abrupt left turn of the colon called at the transition of the ascending to transverse colon?

Right Colic (Hepatic) Flexure

This portion of the colon lies in the peritoneal & crosses the abdomen until on the left side it makes an abrupt turn inferiorly?

Transverse Colon

What is the abrupt inferior turn of the colon called at the transition of the transverse colon to descending colon?

Left Colic (Splenic) Flexure

This portion of the colon lies retroperitoneal and descends on left side to the level of the iliac crest?

Descending Colon

This portion of the colon lies in the peritoneal & begin near left iliac crest, projects medially to midline & terminates at the rectum (about 3rd sacral vertebra)?

Sigmoid Colon

What is the name of the digestive tract that is the last 8 inches, lies anterior to sacrum & coccyx with the terminal 1inch being called the anal canal?

Rectum

What are the folds created by the mucous membrane of the anal canal arranged longitudinally called?

Anal Columns

What is contained within the anal columns?

Arteries & veins

The opening of the anal canal is the anus and has two sphincters, what are they named?

Internal anal sphincter | External anal sphincter

This anal sphincter is made up of smooth muscle and we have involuntary control over it?

Internal Anal Sphincter

This anal sphincter is made up of skeletal muscle and we have voluntary control over it?

External Anal Sphincter

At the anus, what can be caused by Pregnancy, hard stool, pushing too hard?

Hemorrhoids

What are the four layers of the Large Intestine walls?

Serosa Muscularis Submucosa Mucosa

This layer has Omental appendices that attach to teniae coli?

Serosa

What are Omental Appendices?

Small pouches of visceral fat attached to the teniae coli

The Muscularis layer; External & Internal smooth muscle layers run in which directions?

External: Longitudinal Internal: Circular

What are the portions of the Muscularis layer that are thickened, forming three bands?

Teniae Coli

The Teniae Coli contract causing what to occur with the large intestine?

Gather together like pouches (Haustra)

What gives the colon it's "puckered" appearance?

Haustra

What is not found within the large intestine?

Plicae (circular folds) or villi

This clinical finding arises from the mucosal layer of the colon & usually are benign growth, asymptomatic, but if symptoms occur usually cause diarrhea, blood in feces, &/or mucus being discharged from the anus?

Polyps

What sphincter is normally partially closed to regulate material transitioning from ileum to cecum, the Gastroileal reflex intensifies peristalsis in the ileum & forces material through this sphincter?

Ileocecal sphincter

What does the hormone gastrin secreted into bloodstream by the stomach help do?

Relax the Ileocecal Sphincter

What is the term given to the build up of material in the cecum & up the ascending colon until distension occurs triggering contraction of walls forcing material forward?

Haustral Churning

What is the rate in which peristalsis occurs in the large intestine?

3-12 per minute

This is the final type of movement in the colon & is a strong peristaltic wave that starts at middle of transverse colon & pushes material from colon into rectum?

Mass Peristalsis

On average many people have to evacuate bowels within what time frame after eating?

30-45 minutes

What is secreted by the cells of the colon & what is not secreted?

Mucus is secreted | Enzymes are not secreted

What provides for chemical digestion in the colon?

bacteria

The bacteria ferment remaining carbohydrates and this process releases what?

Hydrogen, Carbon Dioxide, & Methane Gases

What is the term that describes excessive gas?

Flatulence

What gives feces its odor?

Bacteria breaking down protein into indole & Skatole

Bacteria help decompose this into stercobilin & it gives feces its brown color?

Bilirubin

How much of the remaining water is absorbed & excreted by the large intestine?

0.5-1.0L enter 900mL absorbed 100mL excreted

How long does Chyme remain in the large intestine on average?

3-10 hours

The chyme becomes a solid or semisolid due to water absorption/reabsorption and it is then called what?

Feces

What does feces chemically contain?

``` Water Epithelial Cells Bacteria Product of bacterial decomposition Unabsorbed digested materials Indigestible parts of food ```

What do lipids first have to undergo prior to digestion beginning on them?

Emulsification

This is produced in the liver & secreted into the small intestine where it mixes with lipids pulling them apart?

Bile

What enzyme starts to digest the emulsion droplets still in the lumen of intestine into FFA & MG?

Pancreatic Lipase

These are 200 times smaller than emulsion droplets?

Micelles

Micelles transport FFAs & MGs where?

Apical Surface of the enterocytes to be absorbed

Resynthesized FFAs & MGs into TAGs are packaged with cholesterol, vitamins, & proteins (apolipoproteins) into what?

Chylomicron

These are so large that they cannot enter blood capillaries & have to enter a lacteal & get transported to the subclavian veins to be circulated?

Chylomicrons

What are some of the functions of Cholesterol?

``` Found in every cell -Essential for hormone production Testosterone, progesterone, aldosterone -Used to make Vit. D -Part of Bile ```

The stomach serves as what?

Mixing chamber | Holding Chamber

What is the most distensible part of the GI tract & the mucosa lies in rugae?

Stomach

What is occurring to food (bolus) in the stomach?

- Carbs stop breaking down due to amylase being deactivated by stomach acid - Lipids begin to break down (activation of lingual lipase) - Proteins begin to break down - Semisolid bolus converted to liquid - Some absorption

What are the 4 main regions of the Stomach?

Cardia Fundus Body Pyloric (divided into three parts)

What are the three parts of the Pyloric region of the stomach?

``` Pyloric Antrum (connects the body to stomach) Pyloric Canal (Leads to third region) Pylorus (connects duodenum via pyloric sphincter) ```

What is the Histology (Layers) of the stomach?

Serosa Muscularis (3 layers of smooth muscle) Submucosa Mucosa

This layer of the stomach on the greater curvature of stomach continues as greater omentum & on lesser curvature projects upward towards the liver as lesser omentum?

Serosa

What are the three layer of smooth muscle that make up the Muscularis layer of the stomach?

Outer Longitudinal Layer Middle Circular Layer Inner Oblique Layer (only in stomach)

What kind of tissue makes up the Submucosa of the Stomach?

Connective Areolar Tissue

What are the three layers of the Mucosal Layer of the Stomach?

``` Muscularis Mucosae (Smooth Muscle) Lamina Propria (Connective Areolar Tissue) Mucosa (Simple Columnar Epithelial Cells) ```

What are the simple columnar epithelial cells of the mucosa layer of the stomach called?

Surface mucous Cells

The Surface Mucous Cells form columns of secretory cells open into the lumen surface (gastric pits) these are called?

Gastric Glands

What are the three types of exocrine gland cells that are found in Gastric Glands?

Mucous Neck Cells/Mucous Cells Chief Cells Parietal Cells

Which cells secrete mucous?

Mucous Cells/ Neck Cells

These cells secrete pepsinogen & gastric Lipase?

Chief Cells

These cells secrete hydrochloric acid & intrinsic factor?

Parietal Cells

What is the importance of Intrinsic factor?

Needed to aid in absorption of Vitamin B12/Cyanocobalamin

What will occur if B12/Cyanocobalamin is not absorbed?

Pernicious Anemia

Approx. how much Gastric Juice is secreted by all three gland cells per day?

2000-3000mL per day

What other cell is included with the gastric glands and is an enteroendocrine cell?

G-Cells

Where are G-cells found?

Only in the Pyloric Antrum

What do G-cells do?

secrete Gastrin into the bloodstream (hormone)

What role does gastrin have in digestion?

Signals Ileocecal Sphincter to relax

How often do Peristaltic waves occur in the stomach?

Every 15-20 seconds

The Mixing waves help macerate food, mix it with gastric secretions & reduce it to a soupy liquid called?

Chyme

The process of approx. 3mL of chyme being ejected into the duodenenum with each wave & the remainder being pushed back into the body of the stomach where mixing continues is called?

Gastric Emptying

What is significant about Pepsin?

Only proteolytic (Protein Digesting) Enzyme in the stomach

How is Pepsin activated and inactivated?

Active in an acidic environment | Inactivated by alkalytic environment

The stomach epithelial cells (protein containing) are protected by what?

1-3mm thick layer of alkaline mucous

What is absorbed in the stomach?

Water, ions, short-chain fatty acids & some drugs

How long does it take for the stomach to empty its contents into the duodenum?

2-4 hours after ingesting a meal

This gland is retroperitoneal, approx. 5-6in long & 1in thick & lies posterior to the greater curvature of the stomach?

Pancreas

The pancreas consist of what?

Head- portion near duodenal curve Body- Superior to & to the left of the head Tail- Tapering, left most portion

The pancreatic Duct is also known as?

Duct of Wirsung

What does the Pancreatic Duct join with & form?

Common Bile duct from Liver & Gallbladder to enter the duodenum as Hepatopancreatic Ampulla

The Hepatopancreatic Ampulla is also known as?

Ampulla of Vater

Where is the Ampulla of Vater located?

Opens Approx. 4in inferior to pyloric sphincter

How is the Hepatopancreatic Ampulla (Ampulla of Vater) regulated?

Mass of smooth muscle called Sphincter of the Hepatopancreatic Ampulla

The Sphincter of the Hapatopancreatic Ampulla is also known as?

Sphincter of Oddi

What is the name of the other major duct of the pancreas that comes off the pancreatic duct & empties into the duodenum approx. 1in superior to the Ampulla of Vater?

Accessory Duct

The Accessory Duct is also known as?

Duct of Santorini

What is the Pancreas made up of?

``` Acini Cluster Cells (Exocrine) Pancreatic Islets (Islets of Laangerhans) (endocrine) ```

What type of cells & how much of the pancreas is made up of Acini?

Small clusters of glandular epithelial cells 99% (exocrine)

The Pancreatic Islets (Islets of Laangerhans) make up how much of the pancreas?

1% they are the endocrine portion

How many mL's per day of pancreas juice is produced?

1200-1500mL

What are the characteristics of pancreas juice?

``` Clear, colorless liquid Water Salts Sodium Bicarb Enzymes ```

What role does the Sodium Bicarb play in the pancreatic juice?

Alkaline pH 7.1-8.2 - Buffers acidic gastric juices in chyme - Stops action of pepsin from stomach - Creates proper pH for digestive enzymes in small intestine

What enzymes are part of the pancreatic juice?

``` Pancreatic Amylase- starch digestion Trypsin- Protein digestion Chymotrypsin- Protein digestion Carboxypeptidase- Protein digestion Elastase- Protein digestion Pancreatic Lipase-Principle Triglyceride digestion Ribonuclease- Digests RNA Deoxyribonuclease- Digest DNA into nucleotides ```

What are the names inactivated names of the protein digesting enzymes produced in the pancreas?

Trypsinogen- Trypsin (active) Chymotrypsinogen- Chymotrypsin (active)Procarboxypeptidase- Carboxypeptidase (active) Proelastase- Elastase (active)

This is a severe condition in which pancreatic cells release trypsin instead of trypsinogen or insufficient amount of trypsin inhibitor, causing digestion of the pancreatic cells leading to bleeding, severe inflammation, & fat necrosis?

Acute Pancreatitis

What are some causes of Acute Pancreatitis?

``` Alcoholism (70%, ages 30-40 usually) Cystic Fibrosis Hypercalcemia Hyperlipidemia Drugs Autoimmune diseases ```

What brings fresh blood from the heart to the Liver?

Hepatic Artery

What brings blood from the intestines to the Liver?

Portal Vein

What vessel returns blood to the heart from the Liver?

Hepatic Vein

This organ is almost completely covered by visceral peritoneum & divided into two principal lobes by the Falciform Ligament?

Liver

Which lobe of the liver is largest right or left?

Right Lobe

This portion associated with the Liver extends from the undersurface of the diaphragm between the two lobes of the liver & allows attachment to the ventral surface of the abdominal cavity?

Falciform Ligament

What extends from within the free aspect from Falciform Ligament to umbilicus?

Ligamentum Teres (round ligament)

What is significant about the round Ligament (Ligamentum Teres)?

Remnant of umbilical vein of fetus

What enzymes are part of the pancreatic juice?

What are the names inactivated names of the protein digesting enzymes produced in the pancreas?

Trypsinogen- Trypsin (active) Chymotrypsinogen- Chymotrypsin (active)Procarboxypeptidase- Carboxypeptidase (active) Proelastase- Elastase (active)

Acute Pancreatitis

What are some causes of Acute Pancreatitis?

``` Alcoholism (70%, ages 30-40 usually) Cystic Fibrosis Hypercalcemia Hyperlipidemia Drugs Autoimmune diseases ```

What brings fresh blood from the heart to the Liver?

Hepatic Artery

What brings blood from the intestines to the Liver?

Portal Vein

What vessel returns blood to the heart from the Liver?

Hepatic Vein

This organ is almost completely covered by visceral peritoneum & divided into two principal lobes by the Falciform Ligament?

Liver

Hepatocytes form a crucially important cell layer that separates what?

Sinusoidal blood from Canalicular Bile

This portion associated with the Liver extends from the undersurface of the diaphragm between the two lobes of the liver & allows attachment to the ventral surface of the abdominal cavity?

Falciform Ligament

What extends from within the free aspect from Falciform Ligament to umbilicus?

Ligamentum Teres (round ligament)

What is significant about the round Ligament (Ligamentum Teres)?

Remnant of umbilical vein of fetus

What is included in the first part of the Biliary tree?

- Bile ducts inside the Liver - Common Hepatic Duct (outside of the Liver) - Gallbladder & its cystic duct - Common Bile Duct - Ducts of the Pancreas

What are the Functions of the Liver?

``` Carbohydrate (Starch) Metabolism Lipid Metabolism Protein Metabolism Bile Synthesis Activation of Vitamin D Processes drugs & hormones Excretion of bilirubin Storage Phagocytosis ```

What are the two sources the Liver receives blood and approx. how much(%)?

Hepatic Artery 25% Oxygenated | Portal Vein 75% Deoxygenated + Nutrients

What organ is like a factory & warehouse that packages goods & sends it out to the rest of the body where needed or stores it right there for later use?

Liver

The Liver is a common site of what from GI tract since it receives so much blood from digestive system?

Metastasis

What are the major functional units of the Liver called?

Hepatic Lobules

These are Hexagonal in shape, comprise rows of hepatocytes that radiate out from a central point & perform a wide array of metabolic, secretory, & endocrine functions in the Liver?

Hepatic Lobules

What makes up 80% of the mass of the Liver & are specialized polygonal epithelial cells interspersed throughout the Liver?

Hepatocytes

Hepatocytes are the location of synthesis of what?

- Transport proteins like albumin & fibrinogen - Lipoproteins, fatty acids, trigylcerides - Cholesterol & Bile

What do the Portal Triads found at the corners of the hepatic lobules consist of?

Bile Duct (flows away from central vein) Branch of hepatic artery (flows towards central vein) Branch of portal vein (flows towards central vein)

What is the part of the Liver internal anatomy that is highly permeable blood capillary between rows of hepatocytes that receives oxygenated blood from branches of hepatic artery & receives nutrient rich deoxygenated blood from the portal vein?

Hepatic Sinusoids

These are fixed phagocytes found within sinusoids that help "clean" blood & destroy worn-out red & white blood cells, bacteria, & other foreign matter?

Stellate Reticuloendothelial (Kupffer) Cells

What are the Functions of the Liver?

``` Carbohydrate (Starch) Metabolism Lipid Metabolism Protein Metabolism Bile Synthesis Activation of Vitamin D Processes drugs & hormones Excretion of bilirubin ```

What role does the carb metabolism play for the body within the liver?

Keeps blood sugar at normal levels

What occurs within the Liver if Plasma Glucose is low?

Glycogenolysis | Liver breaks down glycogen to glucose & releases it

What occurs within the Liver if Plasma Glucose is High?

Glycogenesis | Liver converts glucose to glycogen & triglycerides as storage

What role does the Lipid metabolism play for the body within the Liver?

``` Synthesizes & stores triglycerides Breaks down fatty acids to generate ATP Synthesize lipoproteins Synthesize cholesterol Uses cholesterol to make bile salts ```

In protein metabolism within the Liver what do the Hepatocytes do?

Deaminate AA's (remove Amino group) for use for ATP production or converted to carbs or fat

Protein metabolism within the Liver includes doing what with the ammonia ion left after deamination?

Converted to urea & transported to kidneys to be excreted in urine or used for osmotic gradient

Protein metabolism within the Liver synthesizes what?

Plasma proteins (Alpha & Beta Globulins, Albumin, Prothrombin, & Fibrinogen)

Liver excretion of Bilirubin occurs how?

Bilirubin is reabsorbed from broken down RBC's & excreted in the bile, which is then metabolized in small intestine by bacteria & eliminated in feces

What is clinically indicated if the skin, mucous membranes, & sclera of eyes have a yellowish color?

Jaundice

What is the medical term for stones in the gallbladder?

Cholelithiasis

How much bile is secreted by hepatocytes daily?

600-1000mL each day

What are the characteristics of Bile?

Yellow, Brownish, or olive-green liquid pH 7.6-8.6 Important role in fat digestion & absorption Means for excretion of waste products from blood

What does bile consist of?

- Bile solids (bile salts/acids, phospholipids, cholesterol, bilirubin) - Water - Electrolytes

Where is Bile stored & concentrated?

Gallbladder

What is the pear shaped sac located in a depression of the posterior/inferior aspect of the Liver?

Gallbladder

What is the function of the Gallbladder?

Stores & concentrates bile made by the Liver | up to 10x's more concentrated

Bile is made in the Liver and released into what?

Common Hepatic Duct & into common bile duct

Name the parts of the Gallbladder?

Fundus (projects inferiorly) Body Neck Cystic Duct (duct from gallbladder neck joins common hepatic duct)

What is the histology of the Gallbladder & what does it lack?

-Mucosa: simple columnar epithelium arranged in rugae (-Walls lack submucosa) -Smooth muscle -Visceral Peritoneum/Serosa

How is the gallbladder supplied with blood and returns blood to systemic supply?

- Branch of Hepatic artery into cystic artery that feeds gallbladder walls - Venous blood drains into portal vein directly

What is the medical term for stones in the gallbladder?

Cholelithiasis

What are some causes of Cholelithiasis?

``` Bile contains insufficient bile salts or lecithin Excess cholesterol (may crystallize) ```

Medical term for Stones in common bile duct?

Choledocholithiasis

Medical term for Biliary tree inflammation & infection?

Cholangitis

What are the layers of the Small Intestine?

Serosa Muscularis Submucosa Mucosa

How does the spleen provide for the immune system?

- Arterial blood flows into spleen via trabecular artery - Peri-arterio Lymphatic Sheath (PALS) filter the blood - Bacteria detected signal initiation/mobilization of Ab's

How does the spleen Recycle RBC's?

- Filtered into Large venous sinusoids | - RBC's migrate through & are scanned by macrophages

Where does the most of digestion & absorption of nutrients occur?

Small Intestine

What increases the surface area of the Small Intestine?

Folds, VIlli, & Microvilli

Where does the Small Intestine Begin & end?

Pyloric Sphincter of stomach | Ileocecal Sphincter

What is the approx. length & diameter of the Small Intestine in a living person?

10ft long | 1in diameter

What are the three regions of the small intestine?

Duodenum Jejunum Ileum

This portion of the small intestine is the shortest (10in) & is retroperitoneal, starting after the pyloric sphincter & merges with jejunum?

Duodenum

This portion of the Small Intestine is 3 feet long and is between the duodenum & Ileum?

Jejunum

This portion of the Small Intestine is the longest 6 feet, begins at the end of the jejunum & extends to ileocecal sphincter?

Ileum

What portion of the Small Intestine does not have Serosa Layer?

Proximal Aspect of Duodenum

The Serosa is also known as?

Visceral Peritoneum

What are the characteristics of the Muscularis Layer?

``` Inner Layer circular fibers of smooth muscle Myenteric Plexus (Plexus of Auerbach) in between Outer Layer longitudinal fibers of smooth muscle ```

What is contained within the Submucosa of the Small Intestine?

``` Brunner's Glands Submucosal nerve (Meissner's) Plexus ```

What do Brunner's Glands do?

Secrete alkaline mucous that neutralizes gastric acid in chyme

What are the layers of the Mucosa Layer of the Small Intestine?

Epithelial Cells Lamina Propria Muscularis Mucosae

What does the Muscularis layer of the Mucosal layer consists of?

Smooth Muscle

What is does the Lamina Propria Contain of the Mucosal Layer of the Small Intestine?

Areolar Connective Tissue | Mucosa-Associated Lymphatic Tissue (MALT)

What are the deep crevices found in the epithelial layer of the Mucosal Layer of the Small Intestine Called?

Intestinal Glands (Crypts of Lieberkuhn)

These are fingerlike projection in mucosa (1-5mm long), 20-40 per square millimeter & vastly increase surface area?

Villi (Gives velvety appearance)

These cells digest & absorb nutrients from chyme?

Absorptive Cells

These cells secrete Mucous?

Goblet Cells

These cells secrete lysozyme (bactericidal enzyme), are capable of phagocytosis & may play a role in microbial population?

Paneth Cells

What are the three types of enteroendocrine cells in the small intestine?

S Cells CCK Cells K Cells

These cells secrete secretin that stimulates pancreatic juice flow & inhibits gastric juice flow?

S Cells

These cell secrete Cholecystokinin which help satiety & stimulates pancreatic juice flow & stimulates gallbladder contraction?

CCK Cells

These cells secrete glucose-dependent insulinotropic peptide (GIP)?

K Cells

This structural feature are permanenet ridges (folds of mucosa & submucosal layers) 10mm in length begin near proximal portion of duodenum & end near mid-portion of ileum?

Plicae Circulares (Circular Folds)

The Plicae Circulares allow for what regarding surface area & how chyme moves in the small intestine?

Increases surface area for reabsorption | Causes chyme to spiral, allowing more dissolution

These are fingerlike projection in mucosa (1-5mm long), 20-40 per square millimeter & vastly increase surface area?

Villi (Gives velvety appearance)

These make up the Brush border & are projections of the apical membrane of the absorptive cells & contain several enzymes?

Microvilli

Approx. how many microvilli per square millimeter are there?

200 Million

What continues digestion of proteins & is provided inside the pancreatic juice?

Trypsin, Chymotrypsin, Carboxypeptidase, & Elastase

What are the characteristics of the small intestine juice?

Clear, yellow liquid Slight alkaline at pH 7.6 Absorptive cells synthesize digestive enzymes Absorptive cells slough off 5-7 days

The absorptive cell digestive enzymes called Brush border enzymes are?

``` Carb Digesting -Alpha-Dextrinase -Maltase -Sucrase -Lactase Protein Digesting (Peptidases) -Aminopeptidase -Dipeptidase Lipid Digesting -Phospholipase B1 ```

What are the two components of Mechanical Digestion within the Small Intestine?

Segmentation Movements | Migrating Motility Complex (MMC)

These are localized contraction/relaxation of intestine when distended by large amount of chyme?

Segmentation Movements

Apporx. how many Segmentation Movements occur per minute near the duodenum & the more towards the ileum?

12 per min near duodenum | 8 per min towards ileum

This peristaltic wave starting at lower portion of stomach in pyloric antrum, pushes chyme forward, slow taking 90-120 minutes to reach the end of the ileum & after one completes another begins?

Migrating Motility Complex

What provides for chemical digestion in the Small Intestine?

Pancreatic Juice Bile Intestinal Juices

What cleaves the leftover carbs found in chyme within the small intestine?

Pancreatic Amylase

This is indigestible plant fiber & is a large component of feces, coming from vegetable/fruit skin, whole grains (brown rice)?

Cellulose

Protein is absorbable & digestion of protein ends when it is in what form?

Single AA's

How much of the absorption occurs in the small intestine?

90%. the rest is in the stomach & large intestine

What are the total amounts of water that enters the small intestine daily?

9.3L

Approx. how much water comes from ingestion of food & liquids?

2.3L

Approx. how much water comes from various gastrointestinal secretions?

7.0L

The small intestine absorbs approx. how much water?

8.3L

The Large intestine absorbs approx. how much water?

0.9L

Approx. how much water is excreted in feces each day?

0.1L (100mL)