Ch. 24 Digestive System Flashcards Preview

Human Anatomy > Ch. 24 Digestive System > Flashcards

Flashcards in Ch. 24 Digestive System Deck (37)
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1
Q

FuCharacteristics

A

food- nutrients to body- synthesis

  • enzymes, growth, cell division, repair, heat
  • food must be mechanically and chemically reduced to different forms to absorb through intestinal wall and then transported to body cells by the blood
2
Q

GI tract consists of…

A
  • mouth, pharynx, esophagus, stomach, small and large intestine
    accessory: teeth, tongue, salivary glands, liver, gallbladder, pancreas
3
Q

Functions of Digestive System

A
  • ingestion
  • secretion: water, acid, buffers and enzymes into lumen cells of GI tract and accessory dig. organs
  • mixing and propulsion: alternate contraction and relaxation of smooth muscles to mix the food and secretion that lines GI tract
  • digestion: mechanical and chemical; CHO, lipids, and proteins
  • absorption: entrance of ingested and secreted fluid in lumen of blood or lymph through epithelial cells that line GI tract
  • defecation
4
Q

Mucosa

A
  • inner lining of GI tract, is a mucous membrane composed of:
    epithelial cells: specialized for absorbing digestive nutrients containis enteroendocrine cells
    lamin propria: areolar connective tissue, blood vessels and lymphatic vessels and contains MALT
    muscularis mucosa: smooth muscle fibers increases surface
5
Q

Submucosa

A
  • thin meshwork of collagenous fibers, nerves and blood vessels
  • areolar connective tissue binds the mucosa to middle layer, the muscularis
  • highly vascular and contains the submucosal plexus, or plexus of Meissner, portion of ANS called enteric nervous system
  • submucosal plexus regulated movements of mucosa and vasoconstriction of blood vessels
  • innervated secretory cells of mucosal glands
6
Q

Muscularis

A
  • consists of smooth muscle, inner sheet of circular fibers and outer sheet of longitudinal fibers
  • contains the myenteric plexus, or plexus of Auerbach
  • plexus mostly controls GI tract motility (movement)
7
Q

Serosa

A
  • superficial layer of those portions of GI tract that are suspended in abdominopelvic cavity
  • serous membrane composed of areolar connective tissue and simple squamous epithelium (mesothelium)
  • secretes a serous fluid
  • epithelial portion is also called visceral peritoneum
8
Q

Peritoneal Folds relationship to other organs

A
  • largest serous membrane of body
  • divided into parietal and visceral peritoneum
  • retroperitoneal organs
  • greater omentum
  • falciform ligament
  • leser omentum
  • mesentery
  • mesocolon
9
Q

Other organs in Dig.

A

Greater omentum: largest peritoneal fold, drapes over transverse colon and coils the small intestine
falciform ligament: attaches liver to anterior abdominal wall and diaphragm
lesser omentum: suspends the stomach and duodenum from the liver
mesentery: binds the jejunum and ileum of small intestine to posterior abdominal wall
mesocolon: bind transverse colon and sigmoid colons of large intestine to posterior abdominal

10
Q

Mouth

A
  • buccal cavity
  • formed by cheeks, hard and soft palates and tongue
  • cheeks covered externally by skin and internally by a mucous membrane
  • buccinator muscles and connective tissue lie between the skin and mucous membranes of cheeks
  • labia, labial frenulum, oral vestibule, fauces, hard and soft palate, uvula
11
Q

Salivary Glands

A

3 pairs:

  • parotid glands: parotid duct
  • submandibular glands: submandibular ducts
  • sublingual glands: lesser sublingual ducts
  • salivary glands receive both sympathetic and parasympathetic innervation
  • salvia: salivary amylase plays minor role in breakdown of starch; lingual lipase and mucus are secreted by lingual glands
12
Q

Stensen, Wharton, Rivinus

A

Parotid, Submandibular, Sublingual

13
Q

Tongue

A
  • accessory digestive system organ composed of skeletal muscle covered with mucous membrane
  • extrinsic muscles of tongue
  • intrinsic muscles of tongue
  • lingual frenulum (ankyloglossia)
14
Q

Teeth

A
  • dentes
  • gingivae
  • gum
  • periodontal ligament or membrane
    composed of: crown, neck, dentin, enamel, pulp cavity
15
Q

Centitions and Times of Eruptions

A
Deciduous teeth (milk): first and second diciduous molars; central or lateral incisors
Permanent teeth: first and second premolars (bicuspids)
16
Q

Pharynx

A
  • extends from internal nares to esophagus posteriorly and larynx anteriorly
  • composed of skeletal muscle and lined by mucous membrane
    naso/oro/laryngo pharaynx: naso is only resp.
  • deglutition/swallowing: mechanism hat moves food from mouth to stomach
17
Q

Functions of Esophagus

A
  • secretes mucus and transport food into stomach
  • upper esophageal sphincter (UES)
  • elevation of larynx causes sphincter to relax, allowing bolus to enter the esophagus
  • peristalsis
  • mucus secreted by esophageal glands lubricates the bolus and reduces friction
  • Lower esophageal sphincter (LES), called gastroesophageal or cardiac sphincter
18
Q

Stomach

A
  • enlargment of GI tract and lies inferior to diaphragm in epigastric, umbilical and left hypochondirac region of abdomen
  • connects esophagus to duodenum
  • functions as mixing area and holding reservoirs
  • position and size vary continually
  • digestion of starch that began in mouth continues, digestions of proteins and triglycerides begins, semisolid bolus is converted to liquid, and certain substances are absorbed
  • accommodate a large quantity of food, upto 6.4 iters
19
Q

Functions of Stomach

A

digestion

  • mixes saliva, food and gastric juice to form chyle
  • serves as reservoir for food before release into stomach
  • secrete gastric juice that contains HCL, pepsin, intrinsic factros
  • secretes gastrin into blood
  • propulsion and retropulsion (peristaltic waves)
  • chyme
  • gastric emptying
  • pepsin: protein digesting enzyme
  • gastric lipase: trigylceride digesting enzyme
  • pancreatic lipase: fat digesting enzyme
20
Q

Anatomy of Stomach

A
4 main regions:
- Cardia
- Fundus: storage of food
- Body
- Pyloric part: 
consists of 3 regions:
pyloric antrum (connects to body of stomach)= food mixing
pyloric canal (leads to pylorus)
plyrous (connects to duodenum)
- rugae= mucosal folds
- pyloric sphincter
- lesser curvature
- greater curvature
21
Q

Gastric Glands

A

3 types of exocrine gland cells:

  • mucous neck cells, chief cells, parietal cells
  • chief (zymogenic) cells
  • gastric juice
  • G cell
  • secretion of parietal, chief, and mucous is gastric juice (2000-3000 ml/day)
22
Q

Functions of Pancreas

A
  • pancreatic amylase= starch digesting enzyme
    enzymes that digest protein:
  • trypsin, chymotrypsin, carboxypeptidase, elastase
  • principle triglyceride (digesting enzyme in adults): pancreatic lipase, RNA and DNA digesting enzyme called ribonuclease and deoxyribonuclease
23
Q

Anatomy og Pranceas

A
  • head
  • body
  • tail
  • pancreatic duct (duct of Wirsung)
  • hepatopancreatic ampulla (ampulla of Vater)
  • major duodenal papilla
  • accessory duct (duct of Santorini)
24
Q

Relationship of Pancrea, lover, Gallbladder and Duodenum

A

right and left hepatic duct- common hepatic duct from liver
cystic duct from gallbladder-
- common bile duct- pancreatic duct from pancreas- sphincter- common bile duct- cystic duct from gallbladder

25
Q

Histology of Pancreas

A
  • Acini= cluster of cells
  • Pancreatic Juice
  • Pancreatic islets (islets of Langerhans)
26
Q

Anatomy of Gallbladder

A
  • fundus
  • body
  • neck
    Function: storage of bile
27
Q

Functions of Liver

A
  • emulsification: break down large lipid gobules into small droplets
  • absorption
  • bile storage: sphincter of hepatopancreatic ampulla
  • carbohydrate metabolsim
  • lipid metabolism
  • protein metabolism
  • processing of drugs and hormones
  • excretion of bilirubin= derived from herne of RBC
  • synthesis of bile salts= emulsification
  • storage= vitamins A, B12, D, E and K
  • Phagocytosis= Kuffer cells (reticuloendothelial cells) are immune cels
  • Activation of vitamin D
28
Q

Histology of the Liver

A
  • divided into two lobes by falciform ligament
  • quadrate and caudate lobes mostly belong to the left lobe
  • ligamentum teres (round ligament)
  • coronary ligaments
  • liver
  • hepatocytes= continuously produce bile; hapetic laminae
  • bile canaliculli
  • bile ductulesand bile ducts
  • right and left hepatic ducts
  • common hepatic duct
  • cystic duct
  • common bile duct
29
Q

Histology of Liver and Gallbladder

A

Hepatic Sinusoids: highly permable blood capillaries between hepatic laminae
- central vein
- hepatic veins
- portal triad
hepatocytes, bile duct system, and hepatic sinusoids can be organized into anatomical and functional units in 3 different ways:
- hepatic lobule, portal lobule, hepatic acinus

30
Q

Hepatic Blood Flow

A
  • oxy. blood from hepatic artery and nutrient-rich, deoxygenated blood from hepatic portal vein- hepatic sinusoids- central vein- hepatic vein- inferior vena cava- right atrium of heart
31
Q

Functions of Small Intestine

A
  • completeion of digestion and absorption occurs in small intestine
  • intestinal juice: clear, yellow fluid secreted in amounts; provides a vehicle for absorption of substances from chyme
  • brush-border enzymes: alpha-dextrinase, maltase, sucrase, and lactase; peptidases; nucleosidases and phosphatases
  • segmentations and peristalsis
32
Q

Anatomy of Small Intestine

A

3 regions

  • duodenum
  • jejnumun
  • ileum
  • illeocecal sphincter
  • valve
33
Q

Histology of Small Intestine

A
  • mucosa is composed of epithelium, lamina propria, and muscularis muscle
  • absorptive cells of epithelium digest and absorb nutrients in small intestine
  • goblet cells secrete mucus
  • small intestinal mucosa contains many deep cervices lined with glandular epithelium
  • intestinal glands secrete intestinal juice
  • paneth cells secrete lysozyme
34
Q

Histology of Small Intestine Con’t

A
3 types of enteroendocrine cells found in intestinal glands:
S cells (hormone secretion), CCK cells, K cells (glucose dependent insulinotrophic peptide)
- groups of lymphatic nodules referred to as aggregated lymphatic follicles present in ileum
- submucosa of duodenum contiains duodenal (Brunner's) glands which secrete alkaline mucous
- muscularis of small intestine consists of 2 layers of smooth muscle:
outer (thinner of longitudinal fibers); inner (thicker of circular fibers)
35
Q

Functions of Large Intestine

A
  • haustral churning= contraction and squezzing the contents into the nexthoustrum
  • peristalsis=slower wave of contraction
  • mass peristalsis= occurs in transverse colon and stronger wave
  • final stage of digestion occurs in colon: mucus, chyme, flatus, bacteria, bilirubin, stercobilin, feces
36
Q

Anatomy of Large Intestine

A
  • extends from ileum to anus
  • mesocolon
  • 4 principle regions of the large intestine: cecum, colon, rectum, canal
  • ileocecal sphincter
  • cecum
  • appendix or vermiform appendix
  • mesoappendix= mesentary of appendix
37
Q

Histology of Large Intestine

A
  • wall of intestine contains typical four layers found in rest of GI tract: mucosa, submucosa, muscularis, serosa
  • intestinal glands
  • teniae coli
  • haustra