exam 2 Flashcards

Question

Teeth structure

Answer 1

Two major regions: crown and root Root: portion of tooth embedded in the jaw bone

Answer 2

1. Crown Is exposed part of the tooth above gingiva or gum 2. Neck Connects the crown and the root 3. Cavity result from bacterial action that gradually demineralized enamel and underlying dentin 4. Gingiva Surrounds tooth like a tight collar 5. Cells Odontoblast: cell type that secretes and maintains the dentin

Answer 3

- ONLY passageway for food - straitified squamous epithilium

Answer 4

10 inches long Mucosa- Stratified squamous to simple columnar & Folds when empty Submucosa- Areolar CT contains Esophageal glands Muscularis externa is Skeletal to smooth muscle Instead of Serosa its fibrous CT

Answer 5

Super acidic pH (1-3) Gastroesophageal reflux Gastric juices may enter esophagus when diaphragm does not reinforce sphincter

Answer 6

* mastication- chewing * deglutition: **Buccal phase:** voluntary, it ends when food bolus or "bit of saliva" leaves the mouth and stimulates tactile receptors in posterior pharynx * Deglutition: **pharyngeal-esophageal phase**:Involuntary and is controlled by the swallowing center in the brain stem (medulla, lower pons) | Deglutition has two phases

Answer 7

* Once food hits pharynx respiration is momentarily inhibited and all routes except desired one into the digestive tract are blocked off * Pass food from mouth to stomach

Answer 8

Anatomy Lies in the upper left quadrant of peritoneal cavity, nearly hidden by liver and diaphragm 6-10 inches long Histology Mucosa - simple columnar epithelium Submucosa Muscularis externa - smooth muscle Oblique (deepest) Circular Longitudinal Serosa

Answer 9

Propulsion- exhibits peristalsis Mechanical breakdown - churring action provided by stomach smooth muscle during peristalsis Digestion - protein digestion begins & is main type of enzyme breakdown that occurs. HCL produced by stomach glands denatures dietary proteins to prepare of enzymatic digestion Absorption- Not much is absorbed in stomach but two common lipid soluble substances

Answer 10

Brain VAGUS NERVE Gastric secretion occurs before food enters stomach sight and thought Stimulation of taste and smell receptors Long reflexes

Answer 11

Stomach distension activates stretch receptors Long(medulla & vagus nerve) and short reflexes Food chemicals & rising pH activate chemoreceptors G cells → Gastrin release to blood ## Footnote -During this phase gastrin plays major role in stimulating parietal cells to secrete HCL -Once food reaches stomach local neural and hormonal mechanisms initiate gastric phase

Answer 12

presence of partially digested foods in duodenum or distention of duodenum when stomach beings to empty→ intestinal (enteric) gastrin release to blood

Answer 13

Cephalic- loss of appetite, depression Gastric- excessive acidity (pH lower than 2); fear, stress, anxiety or flight/fight inhibits Intestinal- distention of duodenum; presence of fatty, acidic, or hypertonic chyme trigger both neural and hormonal signals to tell stomach enough

Answer 14

Stomach contractions cause emptying Stomach usually empties within 4 hrs after a meal Solids remain until they are well mixed w gastric juices and converted to the liquid state

Answer 15

- When parietal cells are stimulated H+ is actively pumped into the stomach lumen by h+ K+ ATPases (proton pump) . - As acid is pumped into the stomach, base (HCO3) is exported into the blood; called alkaline tide

Answer 16

- As chyme enters the duodenum receptors in its wall respond to chemical signals and to stretch - Initiates enterogastric reflex and hormonal mechanisms that inhibit gastric secretion; prevent further duodenal filling

Answer 17

Bile duct- ducts fuse with cystic duct draining gallbladder to form bile duct Pancreatic duct- carry pancreatic juice from pancreas, unit in the wall of duodenum Hepatopancreatic duct- (ampulla) opens into duodenum via major duodenal papilla Hepatopancreatic sphincter- smooth muscle valve

Answer 18

Jejunum- (8ft)extends from duodenum to ileum Ileum- (12ft) joins large intestine at ileocecal valve They both hang in central lower part of abdominal cavity

Answer 19

Circular folds - slowing movement and allowing time for full nutrient absorption - deep permanent folds of mucosa and submucosa, folds force chyme to spiral through the lumen Villi - Digested foodstuff are absorbed through enterocytes into both capillary blood and lacteal - most active absorption, gradually narrow and shorten along the length of small intestine Microvilli (brush border) - complete the digestion of carbohydrates and proteins in small intestines - densely packed cytoplasmic extension of absorptive cells of mucosa

Answer 20

- Mucosa- studded w/ tubular glands called intestinal crypts - Submucosa- areolar CT w/ duodenal glands - Muscularis externa- typical and bilayered - Retroperitoneal

Answer 21

Carbohydrates and proteins are partially degraded, fat digestion begins, most water and nutrients are absorbed

Answer 22

Lobes- 4 lobes Left lobe, quadrate lobe(next to gallbladder), caudate(top), right lobe(biggest) Anatomy- occupies most of right hypochondriac and epigastric regions, extending farther to the right of the body midline than left

Answer 23

* Producing bile * store fat soluble viatmins * detox drugs * process nutrient rich blood

Answer 24

Hepatocytes- liver cells,can secrete some bile, process blood-borne nutrients, store fat soluble vitamins, play important roles inn detoxification Portal Triad- six corners made of bile duct, portal vein, & hepatic portal arterial Sinusoids- enlarged, heavily fenestrated; blood from both hepatic portal vein and hepatic artery proper percolates from traid regions through sinusoids and empties through central vein Kippfer cells- (hepatic macrophages) remove debris like bacteria and worn out blood cells from blood flow Bile canaliculi- tiny canals that secreted bile flows through

Answer 25

nonalcoholic fatty liver disease; most common liver disease, caused by obesity and increased insulin resistance associated w/ abnormal lipid metabolism & liver inflammation, no symptoms associated

Answer 26

last stage of progressive chronic inflammation of liver Result from severe chronic inflammation of liver due to excessive use of alcohol, NAFLD, or viral hepatitis

Answer 27

Thin-walled muscular sac may appear green when filled w/ bile, next to inferior surface of liver

Answer 28

Stores bile that is not immediately needed for digestion & concentrates it by absorbing some of its water and ions. When empty its mucosa is thrown into honeycomb like folds, allow organ to expand as it fills | Muscular walls contract to expel; bile into the cystic duct, from there

Answer 29

Can obstruct the flow of bile from gallbladder Caused by too much cholesterol or not enough bile salts | High risk: Forty + yrs, Fat, Fertile, Female

Answer 30

Hormones and neural stimulations regulate both the secretion of bile and pancreatic juice and release into the small intestine.

Answer 31

The hormones are cholecystokinin (CCK) and secretin Secretin- released by low pH and goes to pancreas to release bicarbonate CCK- helps release/relax sphincter , CCK is stimulated by proteins and fat chyme

Answer 32

Soft gland that extends across abdomen from its tail (next to spleen) to its head which is encircled by c shape duodenum. Most pancreas is retroperitoneal and lies deep to the greater curvature of stomach

Answer 33

acini: cluster of secretory acinar cells that produce enzyme rich components of pancreatic juice. Cells are full of rough ER & exhibit staining zymogen granules, granules contain inactive digestive enzymes

Answer 34

The pancreas releases digestive enzymes into the ducts. The pancreas also helps regulate appetite, stimulates stomach acids, and tells the stomach when to empty.

Answer 35

Absorb most of remaining water from indigestible food residue, stores residues temporarily, eliminate it from the body as feces

Answer 36

No circular folds,villi, or brush borders Mucosa is thicker, its abundant crypts are deeper (crypts contain hella goblet cells) Mucosa is simple cuboidal epithelium

Answer 37

* Propulsion- propels feces towards rectum by mass movements * Motility- As haustra fills w/ food residue the distension stimulates its muscles to contract. - These movements mix residue which aids in water absorption Movements mainly seen in colon are haustral contractions, slow segmentation movements last abt 1 min and occur about every 30 min * Defecation- reflex triggers by rectal distention, eliminates feces from body

Answer 38

starts in Mouth, salivary glands break carbs down into oligosaccharides

Answer 39

* Stomach Begins in stomach when pepsinogen is secreted by chief cells is activated as pepsin Pepsin functions in acidic pH range, cleaves bonds involving amino acids, breaking the proteins down into polypeptides & free amino acids * Small intestine Pancreatic protease break down proteins & protein fragments into smaller pieces & some amino acids Protein enzymes: trypsin, chymotrypsin, pepsin Brush border enzymes break oligo- & dipeptides into amino acids

Answer 40

1. small intestine, pancreatic amylase breaks down starch & glycogen into oligosaccharides and disaccharides 2. brush border enzyme break oligo- and disaccharides into monosaccharides 3. monosaccharides are contransported across apical membrane of enterocytes 4. monosaccharides exit across basolateral membrane by facilitated diffusion

Answer 41

1. Amino acids are cotransported across apical membrane of enterocytes 2. Amino acids exit across the basolateral membrane via facilitated diffusion