Ch. 15 Digestive System Flashcards

Question

Salivary glands receive parasympathetic stimulation that triggers the production of a large volume of..

Answer 1

Watery saliva at the thought, sight, or smell of food

Answer 2

- Parotid glands: - Lie in the front of the ear - Largest of the major salivary glands - Secrete a clear, watery (serous) fluid rich in amylase - Submandibular glands: - Located in the floor of the mouth - Secrete a more viscous fluid (serous and mucous) than parotid glands - Sublingual glands: - Inferior to the tongue - Smallest of the major salivary glands - Secrete a saliva that is thick and stringy (mucous)

Answer 3

Cavity lying posterior to the mouth (Connects mouth to esophagus)

Answer 4

Muscular tube leading from pharynx to stomach (Connects pharynx to stomach)

Answer 5

Connects the nasal and oral cavities with the larynx/voice-box and esophagus

Answer 6

- (1) Nasopharynx: Top portions, air passage behind nasal cavity (Behind the nose) - (2) Oropharynx: Middle portion, passageway for food and air (Behind the oral cavity) - (3) Laryngopharynx: Bottom portion, passageway to esophagus (Larynx— Voice-box)

Answer 7

Top portions, air passage behind nasal cavity (Behind the nose)

Answer 8

Middle portion, passageway for food and air (Behind the oral cavity)

Answer 9

Bottom portion, passageway to esophagus (Larynx— Voice-box)

Answer 10

- 1st Stage: - Voluntary stage - Food is chewed and mixed with saliva, forming a bolus - Bolus is is forced into the oropharynx with the tongue - 2nd Stage: - Sensory receptors in the oropharynx sense food, which triggers swallowing reflex - Soft palate and uvula elevate to block the nasal cavity - Hyoid bone and larynx elevate, and the epiglottis closes off the larynx - Tongue presses against the soft palate to seal off the oral cavity from the nasopharynx - Pharyngeal muscles contract, pulling the pharynx upward - Muscles of the laryngopharynx relax, opening the esophagus - Peristaltic wave begins in the pharynx, and proceeds toward the esophagus - Breathing is inhibited briefly - 3rd Stage: - Peristalsis transports food from the esophagus to stomach

Answer 11

- Sensory receptors in the oropharynx sense food, which triggers swallowing reflex - Soft palate and uvula elevate to block the nasal cavity - Hyoid bone and larynx elevate, and the epiglottis closes off the larynx - Tongue presses against the soft palate to seal off the oral cavity from the nasopharynx - Pharyngeal muscles contract, pulling the pharynx upward - Muscles of the laryngopharynx relax, opening the esophagus - Peristaltic wave begins in the pharynx, and proceeds toward the esophagus - Breathing is inhibited briefly

Answer 12

- Peristalsis transports food from the esophagus to stomach [Peristalsis: Wavelike movement of food through the GI Tract]

Answer 13

Acts as a passageway

Answer 14

- Straight, collapsible food passageway leading to the stomach - Extends downward through an opening in the diaphragm, the esophageal hiatus (Opening in the diaphragm so the esophagus can go from the thoracic cavity to the abdominopelvic cavity) - Mucuous glands scattered throughout submucosa produce mucus to moisten and lubricate the inner lining of the tube - Lower esophageal (cardiac) sphincter (Gastroesophageal Junction): helps to prevent regurgitation of the stomach contents into the esophagus - [Regurgitate— To come back] - Act as a valve so food does not go back into the esophagus - Eating spicy food (”Heartburn”) — Relax the lower esophageal sphincter as well as delay stomach emptying and therefore cause acid reflux

Answer 15

Helps to prevent regurgitation of the stomach contents into the esophagus

Answer 16

Upper left abdominal quadrant

Answer 17

The stomach

Answer 18

Distention

Answer 19

- Receives food from esophagus - Mixes food with digestive juices - Begins digestion of proteins - Limited absorption of nutrients occurs in stomach - Propels food to the small intestine

Answer 20

A small region near opening to the esophagus

Answer 21

A small rounded region superior to the cardia

Answer 22

Main portion of the stomach, between fundus and pylorus

Answer 23

A distal portion, near small intestine - Pyloric canal is a narrowed area close to small intestine - Pyloric sphincter, at end of pyloric canal, is a muscular ring that controls release of food from stomach into small intestine

Answer 24

- Cardia: A small region near opening to the esophagus - Fundus: A small rounded region superior to the cardia - Body region: Main portion of the stomach, between fundus and pylorus - Pylorus: A distal portion, near small intestine - Pyloric canal is a narrowed area close to small intestine - Pyloric sphincter, at end of pyloric canal, is a muscular ring that controls release of food from stomach into small intestine

Answer 25

- Mucus - Pepsin - Hydrochloric acid

Answer 26

- Source: Mucous cells - Function: Provides a viscous, alkaline protective layer on the stomach’s inner surface

Answer 27

- Source: Formed from pepsinogen in the presence of hydrochloric acid - Function: A protein— Splitting enzyme that digests nearly all types of dietary protein into polypeptides

Answer 28

- Source: Parietal cells of the gastric glands - Function: Provides the acid environment needed for the production and action of pepsin

Answer 29

- Gastric juice production occurs continuously, but rate can be modified neurally and hormonally - Gastric secretions are enhanced by parasympathetic impulses, via release of acetylcholine (ACh), and the hormone gastrin, which is released from gastric glands - As food enters the small intestine, the presence of acid stimulates sympathetic impulses, which inhibit further secretion of gastric juice - Presence of fats and proteins in the upper small intestine causes the release of the hormone cholecystokinin from the intestinal wall, which decreases gastric motility

Answer 30

- Water - Certain salts - Alcohol - Some lipid-soluble drugs

Answer 31

- After a meal, mixing actions of the stomach turn the food into a pasty (thick) mixture of food and gastric juice, called chyme - Chyme is passed toward the pyloric region using peristaltic waves - Chyme enters the duodenum of the small intestine in small amounts, through the pyloric sphincter

Answer 32

- Proteins, lipids, carbohydrates pass through quickly - Fats may be in the stomach for 3 to 6 hours

Answer 33

Add secretions to the mixture

Answer 34

- Contents of stomach and intestines are emptied in reverse direction, through the mouth - Causes: Emotional upset, pain, stretching of the stomach, irritants, sensory overload - Vomiting center in medulla oblongata controls reflex - Motor response results in squeezing stomach from all sides, forcing contents through esophagus, pharynx, and out of the body through the mouth

Answer 35

- Exocrine function is to produce pancreatic juice that aids in digestion - Exocrine glands— Called acini, secrete the following enzymes: (Together are called: Pancreatic juice) - Amylase— Digestion of carbohydrates - Lipase— Digestion of fat - [Fatty acid— Building block of fat] - Trypsin— Digestion of protein - [Amino acid— Building block of protein] - Endocrine glands— Called islets of langerhans, secrete the following hormones: - Beta Insulin - Alpha Glucagon - Delta Somatostatin

Answer 36

- Amylase— Digestion of carbohydrates - Lipase— Digestion of fat - [Fatty acid— Building block of fat] - Trypsin— Digestion of protein - [Amino acid— Building block of protein]

Answer 37

- Insulin - Glucagon - Somatostatin

Answer 38

- The pancreas is closely associated with the small intestine - Pancreatic acinar cells make up most of the pancreas; these cells produce pancreatic juice - Acinar cells cluster around tiny tubes that merge to form larger ones, and then give rise to the pancreatic duct - The pancreatic and bile ducts join, and empty into the duodenum of the small intestine together - The hepatopancreatic sphincter (sphincter of ODDI) regulates passage of pancreatic juice and bile into the duodenum

Answer 39

- Pancreatic amylase: Breaks down starch into disaccharides - Pancreatic lipase: Breaks down triglycerides to glycerol and fatty acids - Two nucleases break down nucleic acids to nucleotides - Proteolytic enzymes, trypsin, chymotrypsin, and carboxypeptidase, each split certain bones between amino acid, to break down proteins to dipeptides

Answer 40

Breaks down starch into disaccharides

Answer 41

Breaks down triglycerides to glycerol and fatty acids

Answer 42

- The pancreas is retroperitoneum - [Retro: Behind] - Lies horizontally in epigastric region and extends to the left hypochondriac region - Lies between duodenum and spleen - Anterior to aorta and inferior vena cava (which are also retroperitoneum) - Aorta and IVC is posterior to the pancreas

Answer 43

Located in the upper right quadrant of the abdominal cavity - Right hypochodriac region and extends into the epigastric region

Answer 44

Liver - Largest organ within intraperitoneum

Answer 45

Functional tissue (Which perform the function of a organ)

Answer 46

Connective tissue (Which are in between perenchyma)

Answer 47

- Hepatocytes perform the function of the liver (Parenchyma) - Divided into large right and left lobes (by the falciform ligament), and is enclosed by a fibrous capsule called the glisson capsule - Also contains minor quadrate and caudate lobes - Each lobe is separated into hepatic lobules consisting of hepatic cells radiating from a central vein - Hepatic sinusoids, channels filled with blood, separate groups of hepatic cells - [Hepatic sinusoids: Larger capillaries in the liver] - Blood from the hepatic portal vein carries blood rich in nutrients to the liver - Blood passes from the sinusoids into the central vein of a lobule and exits the liver via the hepatic veins - Kupffer cells carry on phagocytosis in the liver - [Phagocytosis: Engulfing by projection of cell membrane called pseudopods; The trapped particle can either be destroyed or get digested by an enzyme present in the cell] - Bile and secretions from hepatic cells are collected in bile canaliculi, which empty into bile ductules, that converge to become hepatic ducts and finally form common hepatic duct - The common hepatic duct transports bile out of the liver

Answer 48

- Metabolism of carbohydrates, lipids, and proteins because all nutrients is transported to the liver by the portal vein - Breaks down into smaller forms - What remains (extra) is stored in the liver - Maintains glucose levels and stores extra sugar in the form of glycogen (also stores vitamins and nutrients) - Synthesizes plasma proteins all produced by the hepatocytes - 3 groups of plasma proteins: albumin, globulins, fibrinogen - (1) Albumin— Keeps plasma inside blood vessels (Produced in liver) - Excessive filtration of albumin in the urine will cause plasma to go out of the tissues, causing edema - (2) Globulins - (3) Fibrinogen— (One of the factors) to help to form clots - Kupffer cells filters the blood, removing viruses, bacteria, and toxins - Secrete bile

Answer 49

- A yellowish-green liquid that hepatic cells secrete continuously - Composed of water, bile salts, bile pigments, cholesterol, and electrolytes - Bile pigments (bilirubin and biliverdin) are breakdown products of hemoglobin from worn out red blood cells - Only the bile salts have a digestive function

Answer 50

- (1) Stores bile produced by the liver - (2) Absorbs excess water from the bile

Answer 51

The gallbladder

Answer 52

- The gallbladder is a pear-shaped sac on the inferior surface of the liver - Stores bile between meals and reabsorbs water to concentrate the bile - Contraction of its muscular wall releases bile into the duodenum - It is connected to the cystic duct, which joins the common hepatic duct to form the common bile duct - The common bile duct leads to the duodenum, where it joins the pancreatic duct - The hepatopancreatic sphincter (sphincter of ODDI) controls the release of bile from the common bile duct (and pancreatic juice from the pancreatic duct) - In certain conditions, cholesterol may precipitate in the gallbladder to form gallstones (Choleithiasis), which often have to be surgically removed

Answer 53

1. Chyme with fat enters the duodenum 2. Cells of the intestinal mucosa secrete the hormone cholecystokinin (CCK) into the bloodstream - Functions of cholecystokinin (CCK) - Contract gallbladder to produce bile - Stimulate the hepatocytes to produce more bile - Release sphincter of ODDI - Stimulate acini to produce pancreatic enzymes 3. CCK Stimulates muscular layer of gallbladder wall to contract 4. Bile passes down the cystic duct and bile duct to the duodenum 5. Hepatopancreatic sphincter (sphincter of ODDI) relaxes and bile enter duodenum

Answer 54

1. Contract gallbladder to produce bile 2. Stimulate the hepatocytes to produce more bile 3. Release sphincter of ODDI 4. Stimulate acini to produce pancreatic enzymes

Answer 55

- Gastrin - Cholecystokinin (CCK) - Secretin

Answer 56

- Bile salts help cartain digestive enzymes break down fat molecules/complex food - Bile salts accomplish emulsification: - [Emulsification: Breakdown of fat] - Involves breaking down large fat globules into smaller droplets; this increases their solubility in water - Increases surface area of fats; this makes chemical digestion by enzymes called lipases more effective - Bile salts aid in the absorption of fatty acids, cholesterol, and fat-soluble vitamins

Answer 57

- A long tubular organ which runs from the stomach to the beginning of the large intestine - Fills a large part of the abdominal cavity

Answer 58

- Receives chyme from the stomach - Receives pancreatic juices from pancreas and bile from liver and gallbladder - Finishes digestion of nutrients that arrive in the chyme - Absorbs digestive end products - Transports the remaining residue to the large intestine

Answer 59

- Duodenum, jejunum, and ileum - The jejunum and ileum are suspended from the posterior abdominal wall by a double-layered fold of peritoneum called mesentery - [Mesentery: A double layer of visceral peritoneum which covers the small intestine and attached to the posterior abdominal wall - The mesentery contains blood vessels, nerves, and lymphatic vessels that service the intestinal wall - Greater omentum drapes over the intestine; it is a double fold of peritoneal membrane

Answer 60

The shortest and most fixed portion of the small intestine; the stomach empties chyme directly into the duodenum - The duodenum is divided into 4 parts (2 horizontal, 2 vertical) - The ampulla of VATER opens into the 2nd part of the duodenum

Answer 61

Makes up the proximal 2/5th of the small intestine, has a slightly larger diameter than the ileum, and is more active in the digestion process

Answer 62

Most distal portion - Opens into the large intestine

Answer 63

- The inner wall of the small intestine is lined with finger-like intestinal villi, which greatly increase the surface area available for absorption and aid in mixing actions - Each villus consists of simple columnar epithelium with a core of connective tissue, housing blood capillaries and a lymphatic capillary called a lacteal - Blood capillaries and lacteals transport absorbed dietary nutrients out of the alimentary canal - Between the bases of adjacent villi are tubular intestinal glands - Epithelial cells lining the small intestine are replaced every 3 – 6 days

Answer 64

- Mucus: secreted in the small intestine by goblet cells, which are abundant throughout the mucosa, and mucus-secreting glands located in the submucosa of the duodenum - Watery fluid: carries digestive products into the villi, secreted by intestinal glands at the bases of the villi - Enzymes: secreted by epithelial cells of the mucosa, and embedded in their microvilli

Answer 65

Secreted in the small intestine by goblet cells, which are abundant throughout the mucosa, and mucus-secreting glands located in the submucosa of the duodenum

Answer 66

Carries digestive products into the villi, secreted by intestinal glands at the bases of the villi

Answer 67

Secreted by epithelial cells of the mucosa, and embedded in their microvilli

Answer 68

- Segmentation— Mixing movements - In segmentation, contractile rings break up chyme and move it back and forth, mixing it and slowing its movement down the intestine - Peristalsis— Propelling movements - Weak - Push chyme forward - A strong peristaltic rush, resulting from over distension or irritation moves the chyme too quickly, causing diarrhea - The ilieocecal sphincter at the junction of the small is large intestine usually remains closed (Unless a gastroileal reflex) - The ileocecal sphincter is between the small (ileum) and large intestine (the first part called the cecum)

Answer 69

- Function: Absorb extra fluid - Defecation— Stimulated by defecation reflex, that forces feces into the rectum where they can be expelled

Answer 70

Diameter is larger than that of the small intestine

Answer 71

About 1.5 meters long

Answer 72

Begins in lower right portion of abdominal cavity at the cecum, ascends on right, crosses to left side, and descends on left side

Answer 73

The large intestine

Answer 74

- Cecum: a pouch at the beginning of the large intestine, with the appendix projecting downward from it - Colon: consists of the ascending (reaches the liver), transverse, (reaches the spleen) descending, and sigmoid regions - Rectum: a straight section of the large intestine, which lies next to the sacrum - Anal canal: opens to the outside as the anus; guarded by an involuntary internal anal sphincter and a voluntary external anal sphincter - Anus

Answer 75

A pouch at the beginning of the large intestine, with the appendix projecting downward from it

Answer 76

Consists of the ascending (reaches the liver), transverse, (reaches the spleen) descending, and sigmoid regions

Answer 77

A straight section of the large intestine, which lies next to the sacrum

Answer 78

Opens to the outside as the anus; guarded by an involuntary internal anal sphincter and a voluntary external anal sphincter

Answer 79

- There are 4 anatomical lobes (right and left lobe which are divided by the falciform liver in the superior aspect and the quadrate and caudate on the inferior aspect) - The liver is covered by a fibrous capsule called the glisson capsule - From the hepatocytes, the small bile ductule from the right side form the right hepatic duct, and the small bile ductules from the left side form the left hepatic duct - The right and left hepatic ducts join to form the common hepatic duct - The common hepatic duct descends down and joins the duct from the gallbladder, called the cystic duct - The cystic duct joins the common hepatic duct and forms the common bile duct - The common bile duct descends down and joins the pancreatic duct from the pancreas - When they both join, there is a slight dilation which is called ampulla of VATER - The ampulla of VATER opens into the first part of the small intestine, called duodenum by a sphincter/door, called the sphincter of ODDI

Answer 80

- The liver is highly vascular structure - The portal vein is bringing the nutrients from the digestive tract and enters the liver - inferior mesenteric vein, [splenic vein + superior mesenteric vein] → [portal conference] → portal vein - The common hepatic artery (branch of celiac trunk) becomes the proper hepatic artery which takes oxygenated blood to enter the liver to supply oxygen - The celiac trunk (an unpaired branch of the abdominal aorta) → Common hepatic artery → Proper hepatic artery → Liver - O2 is needed because the liver does 24hr work because of eating - The hilum of the liver called the: Porta hepatis - [Hilum/hilus: Door in which vessels move in and out] - Bile is then produced by the hepatocytes in liver and is transported out by the common hepatic duct - Right and left hepatic ducts → Common hepatic duct (Then descends down and joins gallbladder) → [Cystic duct + Common hepatic duct] → [Common bile duct] (Then descends down and joins the pancreas) → Pancreatic duct → (Forms a slight dilation called) Ampulla of VATER → (Opens into the duodenum by the) Sphincter of ODDI - Hepatic vein drains into the IVC → Right atrium

Answer 81

Ileum → Cecum (Pouch like structure) → (Ascends upward) Ascending color → (Reaches where the liver is, turns towards the left side) Right colic (hepatic) flexure → (Moves transversely) Transverse colon → (Reaches the spleen) → Left colic (splenic) colon → (Goes downward) Descending colon → (Forms an S shape) Sigmoid colon → Rectum → Anal canal → Anus

Answer 82

- Mesocolon - [Mesentery: A double layer of visceral peritoneum which covers the small intestine and attached to the posterior abdominal wall - The mesentery contains blood vessels, nerves, and lymphatic vessels that service the intestinal wall

Answer 83

Gastrin, cholecystokinin, and secretin

Answer 84

- Source: Gastric cells, in response to food - Function: Increases secretory activity of gastric glands

Answer 85

- Source: Intestinal wall cells, in response to proteins and fats in the small intestine - Function: Decreases secretory activity of gastric glands and inhibits gastric motility; stimulates pancreas to secrete fluid with a high digestive enzyme concentration; stimulates gallbladder to contract and release bile

Answer 86

- Source: Cells in the duodenal wall, in response to acidic chyme entering the small intestine - Function: Stimulates pancreas to secrete fluid with a high bicarbonate ion concentration

Ch. 15 Digestive System Flashcards

(111 cards)