Lower Digestive System Flashcards
Four regions of stomach
- Cardia
- Fundus
- Corpus (body)
- Pylorus
The stomach is concerned with _____ and _____ of food. In humans with simple stomach, _____ is not important – ruminants have multi-chambered stomach where storage is a major function of stomach.
- Storage
- Digestion
- Storage
Contraction of smooth muscles in the stomach causes _______. Secretion of gastric juices causes ______ of food forming ______.
- Mechanical grinding
- Chemical modification
- Chyme
The Gastric Mucosa is grayish pink, is thrown into folds called ____ in empty stomach, small folds in rugae are called _________, foveolae are ______ with gastric glands.
- Rugae
- Gastric pits or foveolae
- Continuous
Gastric epithelium is ______ after abrupt transition at the junction of esophagus and stomach and has ______.
- Simple columnar
- Basal nuclei
The Gastric Epithelium is covered with _________ of mucus which protects epithelium from abrasion by the food.
Lubricating layer
In the Gastric Epithelium, the apical surface of cells contains microvilli with _______ and cytoplasmic granules with _____ mucigen which is converted into mucin after its release into the lumen.
- Glycocalyx
- PAS+
The cells of Gastric Epithelium are rich in _____, Golgi complex, and mitochondria.
Rough ER
Three kinds of gastric glands
- Cardiac
- Oxyntic
- Pyloric
Cardiac glands of the stomach _____ from shallow foveolae around esophagus-stomach junction and from a _______ with mainly mucous cells.
- Arise
- Narrow zone
Occasional ______ are also found in the cardiac glands of the stomach which secrete ______, a polypeptide hormone that stimulates secretory activity of glands in corpus.
- Endocrine cells
- Gastrin
The Oxyntic Glands of the stomach are found in _____ and _____ of stomach and make _______ contribution to gastric juices.
- Fundus
- Corpus
- Greatest
The Oxyntic Glands of the stomach extend _____ of mucosa and there is an estimated _____ in 3.5 million gastric pits.
- Entire thickness
- 15 million
Five cell types of the Oxyntic Glands of the stomach
- Mucous neck cells
- Stem cells
- Chief (zymogenic) cells
- Oxyntic (parietal) cells
- Endocrine cells
3 regions of oxyntic glands
- Isthmus
- Neck
- Base or fundus
The _____ of oxyntic glands is confluent with foveolae and contain _____ cells.
- Isthmus
- Mucous
The _____ of oxyntic glands contains mucous neck cells, stem cells and occasional oxyntic cells.
Neck
The _____ of oxyntic glands forms greater part of the gland.
Base or fundus
The Base or fundus of oxyntic glands has numerous _____ cells, ______ cells, and occasional _____ cells.
- Chief or zymogenic
- Oxyntic
- Mucous neck
The Base or fundus of oxyntic glands has isolated ______ found in all segments and _____ activity is confined to stem cells.
- Endocrine cells
- Mitotic
The _____ cells of the oxyntic gland of the stomach are columnar, lodged between large rounded oxyntic cells, has its nucleus displaced in the base of the cell, and PAS+ secretory granules in cytoplasm with ______.
- Mucous Neck Cells
- Mucigen
The ______ cells of the oxyntic gland of the stomach are responsible for continuous _______ - surface mucous cells are replaced every four days.
- Stem
- Renewal of gastric mucosa
The ______ cells of the oxyntic gland of the stomach are most conspicuous, ______ with large spherical nucleus, produce ____, have broad rounded bases and large mitochondria.
- Oxyntic or Parietal Cells
- Pyramidal
- HCl
The ______ cells of the oxyntic gland of the stomach have apical surface has invaginations called _________, microvilli project into the lumen of secretory canaliculi, cytoplasm has no _________.
- Oxyntic or Parietal Cells
- Secretory canaliclui
- Secretory granules
The ______ cells of the oxyntic gland of the stomach have ______ increase in secretory canaliculi and microvilli when they are active, and 60-80 % of the increase is due to proton pump _______ for acid secretion.
- Oxyntic or Parietal Cells
- Five fold
- H+ / K+ ATPase
The Oxyntic or Parietal cells of the oxyntic gland of the stomach have many ______ (about 40% of cell volume) and they produce ________.
- Mitochondria
- Gastric intrinsic factor (GIF) for absorption of vitamin B 12
Deficiency of GIF produced in the Oxyntic or Parietal Cells cells of the oxyntic gland results in erythrocyte immaturity and _______. Deficiency of acid results in _______.
- Pernicious anemia
- Achlorhydria
The gram negative bacteria _____ inhabits gastric mucosa. Its mode of transmission is unclear but the infection rate is significant.
Helicobacter pylori
Helicobacter pylori may cause inflammation of the stomach (_____) and gastric ulcers via ______, which damages the mucosa. Chronic infection may lead to __________. Treatment with antibiotics is usually very effective.
- Gastritis
- Urease
- Gastric adenocarcinoma
______ cells of the oxyntic gland of the stomach are found in lower third of oxyntic glands, absent in cardia, sparse in fundus and rare in pylorus. Numerous apical ________ containing ________, and a well developed Golgi complex, rough ER and lysosomes.
- Chief or Zymogenic
- Secretory granules
- Pepsinogen
______ cells of the oxyntic gland of the stomach have luminal plasma membranes that contain short stubby ______ that amplify surface are a for secretion.
- Chief or Zymogenic
- Microvilli
______ cells of the oxyntic gland of the stomach release pepsinogen which is later converted in to active _____ by the low pH produced by the hydrochloric acid. Chief cells also produce _____.
- Chief or Zymogenic
- Pepsin
- Lipase
The enteroendocrine cells of the stomach are found _______ individually among the cells of all glands.
Scattered
The enteroendocrine cells of the stomach are also called _________ cells and produce more than 30 gastrointestinal hormones.
Argentaffin or enterochromaffin
Pyloric glands are found in ______ where foveolae are deeper. The predominant cell type is ________ cells.
- Distal stomach
- Mucous secreting
The greater part of the cytoplasm of pyloric glands is filled with large _______, occasional __________, and the cells produce _________.
- Secretory droplets
- Oxyntic and enteroendocrine cells
- Antibacterial lysozymes
The lamina propria of the gastric mucosa is a ______ that occupies space between glands and musularis mucosae. Also found are collagenous and reticular fiber network, fibroblasts, plasma cells, lymphocytes, eosinophils and mast cells.
Loose CT
The __________ of the gastric mucosa is a layer of smooth muscles.
Muscularis mucosae
The ______ is moderately thicker and denser CT than lamina propria, has abundant collagen fibers, and cells as in lamina propria, adipose cells, blood and lymphatic vessels present.
Gastric Submucosa
The Gastric Muscularis Externa is composed of 3 layers of smooth muscles _____, _____, and _____.
- Outer longitudinal
- Middle circular
- Inner oblique
The ______ is a thin layer of loose CT covered with mesothelium that forms greater and lesser omentum.
Gastric Serosa
Mechanical function of stomach
-Storage
-Mixing
-Empyting
(All by smooth muscles)
Empty stomach has a volume of about _____ mL and is distensible up to ______. Volume of daily secretion: ______.
- 50-75 mL
- 4 L (1 gallon)
- 500-1000 ml
_______ is a clear fluid containing water, mucus, HCl, pepsinogen. Pepsinogen from chief cells is converted to _____ by HCl from the oxyntic cells.
- Gastric juice
- Pepsin
The digestive process continues in the ______ by secretions from intestinal glands, liver, and pancreas.
Small Intestine
There is no absorption of food in ______ (except ____ and ____), but absorption is the principal function of _____.
- Stomach
- Alcohol & aspirin
- Intestines
The Small Intestine is the portion between stomach and large intestine and consists of three segments – _____, _____, and _____.
- Duodenum
- Jejunum
- Ileum
The duodenum is ______; jejunum and ileum are covered by a ______.
- Retroperitoneal
- Mesentary
The specializations of the surface epithelium of the SI Mucosa
- Plicae circulares
- Intestinal villi (with crypts of Lieberkuhn)
- Microvilli
The epithelium of the surface epithelium of the SI Mucosa is _____ and has 5 kinds of cells which are _________.
- Simple columnar
- Enterocytes or absorptive cells
- Goblet cells
- Enteroendocrine cells
- Crypts of Lieberkuhn
- Paneth cells
Enterocytes or absorptive cells are ________ with microvilli and surface coat made of glycoproteins and a life span of _______. Mitochondria, lysosomes, rough and smooth ER present. Golgi and smooth ER play a critical role in fat absorption.
- Simple columnar
- 5-6 days
The lateral walls of Enterocytes or absorptive cells are _____ and highly _____ for ______ using ______ and nutrient absorption.
- Widened
- Infolded
- Ion transport
- H+/K+ ATPase
Digestion occurs at the ______ by the integral membrane enzymes such as _____________.
- Surface
- Disaccharidases
- Peptidases
- Enterokinase
- Lipases
______ of surface epithelium of SI mucosa are unicellular exocrine cells secreting PAS+ mucus.
Goblet cells
Enteroendocrine cells of surface epithelium of SI mucosa, also called ________, are scattered at the base of epithelium, secrete ______ into lamina propria, and are common in ______, fewer in jejunum.
- Enterochromaffin or argentaffin cells
- Hormones
- Duodenum
Enteroendocrine cells of surface epithelium of SI mucosa, also called ________, are scattered at the base of epithelium, secrete ______ into lamina propria, and are common in ______, fewer in jejunum.
- Enterochromaffin or argentaffin cells
- Hormones
- Duodenum
A or alpha cells are found in _____, secrete the hormone ______, and function in ________.
- Pancreas, stomach
- Glucagon
- Carbohydrate metabolism
B or beta cells are found in _____, secrete the hormone ______, and function in ________.
- Pancreas
- Insulin
- Carbohydrate metabolism
D or delta cells are found in _____, secrete the hormone ______, and function in ________.
- Pancreas, stomach, and intestine
- Somatostatin
- Inhibition of secretion of glucagon and insulin
D1 cells are found in _____, secrete the hormone ______, and function in ________.
- Pancreas, stomach, and intestine
- Vasoactive intestinal peptide
- Vasoconstriction
EC cells are found in _____, secrete the hormone ______, and function in ________.
- Pancreas, stomach, and intestine
- Serotonin
- Vasoconstriction
ECL cells are found in _____, secrete the hormone ______, and function in ________.
- Fundic stomach
- Histamine
- Vasodilation
G cells are found in _____, secrete the hormone ______, and function in ________.
- Duodenum, pyloric stomach
- Gastrin
- Stimulation of gastric secretion
I cells are found in _____, secrete the hormone ______, and function in ________.
- Jejunum, ileum
- Cholecystokinin
- Inhibition of gastric juices, stimulates pancreatic juices and bile ejection from gallbladder
S cells are found in _____, secrete the hormone ______, and function in ________.
- Jejunum, Ileum
- Secretin
- Inhibition of gastric juices and stimulates pancreatic juices
The ________ of surface epithelium of SI mucosa are intestinal glands at the base of the villi and produce ________ which serve as solvent for digested nutrients.
- Crypts of Lieberkuhn
- Watery intestinal juices
The Paneth Cells of surface epithelium of SI mucosa are small group of cells at the _______ that produce and release antibacterial ______ and ________.
- Base of crypts of Lieberkuhn
- Lysozyme
- Phospholipase A2
The Lamina Propria of SI mucosa consists of ______ that fills space between villi. It
contains reticular cells, lymphoid organs and collagen and reticular fibers. Also lymphocytes, plasma cells, eosinophils and macrophages
Loose CT
______ are important features in lamina propria of SI mucosa, are surrounded by smooth muscles, and are lymphatic terminals for ________.
- Lacteals
- Absorption of fats
The lamina propria of the SI musosa also contains numerous _________. In some areas, groups of lymphoid nodules coalesce to form aggregated lymphoid nodules called _______, which are primary found in the ______ but can also be scattered.
- Solitary lymphoid nodules or follicles
- Peyer’s Patches
- Ileum
Peyer’s patches tackle microorganisms entering with food, are a component of a _________ and produce __________, and are covered with epithelial cells called _______ which are involved in uptake of antigens.
- Secretory immune system
- Immunoglobulin G
- M cells
Muscularis mucosae of the SI mucosae consists of ______ smooth muscles and elastic fibers.
-Inner circular and outer longitudinal
The SI submucosa contains _______, abundant elastic fibers and adipose cells.
Moderately dense connective tissue
________ are important features in the SI submucosa but present _______; their ducts open in crypts of Lieberkuhn. Brunner’s glands have numerous mitochondria, rough ER, and GC, and their secretion is clear, viscous and very alkaline - pH ______.
- Submucosal glands of Brunner
- ONLY in duodenum
- 8.9-9.3
Primary functions of Brunner’s glands are:
- To produce _______ to neutralize acidic chyme from stomach and protect intestinal mucosa
- To secrete _______, a polypeptide and a powerful inhibitor of gastric secretion; it also is found in the urine
- Alkaline juices
- Urogastrone
The SI Muscularis Externa has inner circular and outer longitudinal with _________ in between for peristalsis
At the junction of ileum and cecum there is an _________.
- Myenteric nerve plexus
- Ileocecal sphincter
The SI Serosa
Consists of loose connective tissue with mesothelium, called _______. Mesentery consists of parietal and visceral peritoneum. Bacterial infection of peritoneum can cause _______.
- Mesentery
- Peritonitis
Order of parts of the large intestine
- Cecum
- Colon (ascending, transverse, descending and sigmoid)
- Rectum
- Anus
The Cecum is a blind pouch with ________.
Vermiform appendix
Appendix is a blind end of cecum thickened by development of lymphoid tissue. Cross section of appendix shows ________.
_____ are absent in appendix but _______ are present.
Appendix is frequently infected resulting in ________.
- Angular outline
- Villi
- Crypts of Lieberkuhn
- Appendicitis
Special features of the Simple columnar epithelium of the cecum and colon
- No plicae circulares
- No villi beyond ileocecal sphincter
- Numerous crypts of Lieberkuhn
- No Paneth cells
- Abundant goblet cells
The ______ of the cecum and colon is loose connective tissue, and the _____ is well developed with inner circular and outer longitudinal.
- Lamina Propria
- Muscularis Mucosae
The ______ of the cecum and colon is dense connective tissue and the ______ is unusual with adipose tissue forming a protuberance (swelling) called _______.
- Submucosa
- Serosa
- Appendices epiploicae
The Muscularis Externa of the cecum and colon have longitudinal muscles arranged in ______ evenly spaced bands called ______ which are partially constricted to form _______.
- Three
- Taenia coli
- Haustrae
In the rectum and anus, the large intestine is swollen to form ______ then narrowed abruptly to form _______.
- Rectal ampulla
- Anal canal
In the anal canal, the mucosa forms folds called _________, crypts of Lieberkuhn shortened and epithelial cells change from columnar to _________.
- Rectal columns of Morgagni
- Stratified squamous
The lamina propria of the rectum and anus contains ______ which are source of ______.
- Plexuses of large veins
- Hemorrhoids
The Muscularis of the rectum and anus has an inner circular _____ muscles form ________ and outer distal _______ muscles form __________.
- Smooth
- Internal anal sphincter
- Striated
- External anal sphincter
_______ and ______ are main activities of SI. Each day _____liters of water are processed. Also 100 g of fats, 50-100 g of amino acids and several 100 g of carbohydrates are absorbed from SI.
- Digestion and absorption
- 8-9
Three types of secretions that accomplish digestion in SI.
- Liver
- Pancreas
- SI secretions
Liver –>
Gallbladder –>
_____ –>
Emulsification of fat
Bile
Pancreas –>
Pancreatic juices –>
_______ splitting enzymes
Lipolytic, proteolytic and carbohydrate
SI secretions (succus entericus) are product of crypts of Lieberkuhn. The enzymes here are _________.
- Leucine aminopeptidase
- Sucrase
- Lactase
- Maltase
Absorption in SI involves active movement of microvilli; enzymes are ______ into the lumen but _________.
- Not secreted
- Work on the surface of epithelium
The function of LI is to _________ of food by absorbing ______ and _______ and move feces for elimination.
- Concentrate the indigestible residues
- Water and electrolytes
Bacterial population in large intestine produces ______ and __ which are required for _______.
- Vitamin B12 and K
- Erythropoiesis
The blood and lymphatic vessels of the stomach (celiac a.), SI (superior mesenteric a. ) LI ( inferior mesenteric a.) are all _______.
Heavily branched
Extensive branching of lymphatics, important in fat absorption. Milky white lymph loaded with fat is called _____ and is carried by the lacteals.
Chyle
Congenital disorders include lack of _____ in infants.
Lactase
GI is innervated by divisions of ________. The parasympathetic and sympathetic constitute ______ and enteric constitutes _______.
- Autonomic nervous system
- Extrinsic division
- Intrinsic division
The ______ is located within the walls of the GI tract. It is autonomous and works without CNS.
Intrinsic Division
The Intrinsic Division is superficial in subserous area but contains a deeper and more conspicuous ________ between longitudinal and circular muscles, ______ which is the mucosal aspect of circular muscles, and _________.
- Myenteric (Auerbach’s) plexus
- Deep muscular plexus
- Submucosal (Meissner’s) plexus
