Chapter 7 Digestion Flashcards
What are the functions of the digestive system (8)?
Mastication Secretion Hormone release Motility Ingestion Absorption Chemical distraction Elimination of waste
What is included in the oral cavity?
Tongue Teeth Minor and Major salivary glands Tonsils Lips
What is the oral cavity lined with?
Oral mucosa
How many types of oral mucosa are there?
Three: Masticatory Mucosa, Lining Mucosa, Specialized Mucosa
Where is the Masticatory Mucosa found?
Found on the Gingiva and Hard Palate
What is the Surface Epithelium for the Masticatory Mucosa?
Keratinized Stratified Squamous
Parakeratinized Stratified Squamous
What does the superficial cells of parakeratinized stratified squamous epithelium keep?
Keeps their NUCLEI
How many layers of the Lamina Propria (LP) are in the Masticatory Mucosa?
2:
Papillary Layer
Reticular Layer
What is the Papillary Layer made of and what does it have in it?
Made of: Thick loose CT
Has: BV (blood vessels), Nerves, Sensory receptors, ans some Meissner’s corpuscles
What is the Reticular Layer made of?
More dense CT
Where is the the Lining mucosa found?
Found on the Soft Palate, Underside of Tongue, Floor of Mouth, Cheeks, and Lips
What is the Surface Epithelium for the Lining Mucosa?
Generally: Nonkeratinized Stratified Squamous
Occasionally: Parakeratinized Stratified Squamous
Where is the surface epithelium found on the Lining Mucosa? And what type of surface epithelium is it?
Lips, Vermillion border (reddish part)
Keratinized Stratified Squamous
What areas of the the surface epithelium is thicker?
The non keratinized stratified squamous epithelium is thicken than the areas of keratinized stratified epithelium
What is the LP like in the Lining Mucosa?
loose CT with blood vessels and nerves
What is the Submucosa like in the Lining Mucosa?
More Dense CT
Where is the Submucosa found in the Lining Mucosa?
found in most places
can have minor salivary glands, sebaceous glands (corner of mouth), larger blood vessels and nerves too
Where is the Specialized Mucosa found?
Found on dorsal surface of tongue
What is the Surface Epithelium for the Specialized Mucosa?
Keratinized Stratified Squamous on Filiform Papillae
Stratified Squamous on all other Papillae
What are the general functions of the Specialized Mucosa?
Move food
Taste buds
What type of mucosa is on the tongue?
thicker dorsally, thinner and smoother posteriorly
What type of surface epithelium is on the tongue?
Specialized epithelium
what does the surface epithelium include on the tongue?
filiform, fungiform, foliate, vallate (circumcallate) Papillae
What are small salivary von Ebner glands associated with?
Vallate Papillae
What is the function of the Vallate Papillae?
Produce serous fluid to CLEANSE THE TASTE BUDS on these papillae
What papillae do not have taste buds associated with them?
filiform papilae
What is the LP like on the tongue?
Loose CT; adipose possible
Submucosa of the tongue is considered?
present on the tongue; adipose possible
What is contained in the Submucosa on the tongue?
contains LINGUAL salivary glands; these produce the same products as the major salivary glands
What are the tongue muscles considered?
Intrinsic Tongue muscles; are skeletal muscles
What is the function of the intrinsic tongue muscles?
change the shape of the tongue
What are the four alterating muscles? how are the arranged?
Superior longitudinal muscle
Vertical muscle alternating with Tranverse Muscles
Inferior longitudinal muscles
arrangmetn from dorsal to posterior within the tongue
What is the tooth formation structure made of?
Cells and tissues
Name the layers from outside to inside of a developing tooth before eruption through the gingiva.
Ameloblast Enamel Dentin Predentin Odontoblast Dental Papilla
What is a ameloblast?
Polarized columnar cells
lose following tooth eruption
What is the function of a ameoloblast?
produces enamel
What is the hardest substance in the body that is 2mm thick?
Enamel
What is enamel made of?
interlinked enamel rods (96% hydroxyapatite)
What is harder then bone?
Dentin
What does Dentin contain?
contains thin dentinal tubules containing nerves and cell processes of Odontoid blast
What is the percentage of hyrdroxyapatite in Dentin?
70%
What is the percursor to dentin before mineralization?
Predentin
What is Odontoblast made of?
Columnar cells lining pulp cavity
What survives in adults?
Odontoblasts
What is the function of Odontoblast?
repair and produce dentin
also maintains dentin
What is dental papilla or dental pulp made of?
CT with many blood vessels and nerves
(extensive inflammation)
Meloblast?
What are the three types of salivary glands?
Parotid
Submandibular
Sublingual
What is the largest salivary gland that produces only 30% of the total salivary output?
Parotid
What is a smaller gland but produces 60% of the total salivary output?
Submandibular
What is the smallest gland and produces 5% of the total salivary output?
Sublingual
What gland is most affected by mumps and the facial nerve passes thru this glang?
Parotid
What gland has a possible fatty infiltration by midlife?
Submandibular
What gland as one ages commonly becomes infiltrated with adipose?
HAHA your all thrown off…
Parotid
What gland is 100% serous producing?
Parotid
What are the products produced by the parotid gland?
salivary amylase (function to begin break down of carbs)
lysosomes
Sec. IgA
What gland is mostly reb but with some white nuclei?
Submandibular
What is a mixed glan that produces mucus and is 80-90% serous producing?
Submandibular
What gland has serous demilunes?
Submandibular
What gland is a mixed gland producing 80% mucus and is also serous producing?
Sublingual
What gland has all serous products coming from serous demilunes with no separation of serous acini?
Sublingual
What does the luminal wall of the salivary gland consist of?
Mucosa
Submucosa
Muscularis Externa
Serosa or Adventia
What does the mucosa include?
surface epithelium
LP: loose CT
Muscularis Mucosae: Smooth muscle
What does the LP in the mucosa consist of?
Loose CT
What does the Muscularis mucosae in the mucosa consist of?
Smooth Muscle
What does the submucosa include?
More dense CT
Large BV
Submucosal (meissner) plexus
What is the function of the Submucosal plexus?
function influence of mucosa
What does the muscularis externa include?
Myenteric (Auerbach) plexus
Typically Smooth Muscle
Typically fiber orientation: inner circular and outer longitudinal =normal pattern
What is the function of the Myenteric plexus?
function influence ME
What is the ME made of?
smooth muscle
What is the typical fiber orientation?
Inner circular
Outer Longitudinal
(this is normal pattern)
What is the Serosa or Adventia next to?
next to ME
The edge of simple squamous epithelium and can include some CT is what?
Serosa
What is Adventia made of?
CT
What is teh function of Serosa?
Serous producing
What is the function of the esophagus?
transfer the bolus to stomach from the oropharnyx
What are the layers of luminal wall in the esophagus?
Mucosa Submucosa Muscularis Externa Adventitia/Serosa Esophageal Spincters
What is the type of surface epithelium in the mucosa of the esophagus?
stratifies squamous
What does the mucosa of the esophagus contain?
contains langerhan cells: an APA with some phagocytosis possible (gives immunity for food alergys)
What type of tissue is in the LP of the esophagus?
Loose areolar CT
What can the LP of the esophagus have?
Esophageal cardiac glands
Where are the esophageal cardiac glands of the enough found near?
Found near the cardiac portion of the stomach and sometimes by the pharnyx
Always in LP
What’s the function of the esophageal cardiac glands?
Produce neutral mucus to protect esophageal epithelium
What are the two regions the LP in the mucosa of the esophagus?
Often near the pharnyx -1inch (sometimes)
Near stomach- last inch (always)
What is the muscular is mucosae of the mucosa of the espionage?
Discontinuous layer of longitudinal smooth muscle
What is the type of tissue the submucosa of the esophagus?
Dense fibroelastic in CT
What does the submucosa of the esophagus contain?
Esophageal glands proper that are scattered along length
What is the function of the submucosa of the esophagus?
Produce slightly acidic mucus to lubricate the movement of food
What is the Muscularis Externa of the esophagus pattern?
Normal patten inner circular and outer longitudinal layers (like the pharynx skeletal muscle)
What is the Muscularis Externa of the esophagus upper, middle, and lower portions consist of?
Upper 1/3: all skeletal muscle
Middle 1/3: mixture of skeletal and smooth muscle
Lower 1/3: all smooth muscle
Explain the adventitia/ serosa of the esophagus layer.
Primarily adventitia except the last 1-2inch
Last 1-2 inches after the diaphragm is serosa
What are the two esophageal associated sphincters?
Two Physiological Sphincters:
Pharyngoesophageal Sphincter
Gastroesophageal Sphincter
Where is the Pharyngoesophageal Sphincter located?
between oropharynx and esophagus
Where is the Gastroesophageal Sphincter (lower esophageal sphincter) located?
Between esophagus and stomach: prone to problems; abrupt change
Associated Esophageal reflux
What does the lower esophageal sphincter control?
Four complimentary forces:
Diaphragm contraction
Greater intra-abdominal pressure than intragastric pressure being exerted upon the abdominal part of the esophagus
Peristalsis
Maintenance of correct anatomical arrangments of structures
What are the characteristics for physiological sphincters?
no thickening of circular muscle in ME
pressure gradient aids movement
(muscle contractions and gravity help)
What are the functions of the stomach?
Continue digestion of carbs
Storage (primary function)
Nutrient breakdown chemical and physical
These parts are part of what?
Concave Lesser Curvature
Convew Greater Curvature
Cardia: narrow region by gastrophageal sphincter
Fundus: domed region often filled with gas
Body (corpus): largest portion
Pylorus: constricted portion by pyloric sphincter
Rugae: longitudinal folds which allow for distention
Gastric Pits: tiny depressions in the stomach’s surface; 1 pit leads to more than one gland
Stomach
What is the luminal wall structure of the stomach?
Mucosa
Submucosa
Muscularis Externa
Serosa
What is the surface epithelium of the Mucosa of the stomach?
Stratified columnar
What are the cells of the Mucosa of the stomach?
Surfae Mucous (=surface lining) line stomach Regenerative cells- bases of pits
What is the function of the cells of the Mucosa of the Stomach?
Produce thick visible mucus
Secrete bicarbonate ions
What is the LP of the stomach composed of?
loose, vascular Ct present in small amounts between glands
What is the Muscularis Mucosae of the stomach composed of? and what is the layers order?
Smooth muscel layer that is often arranged in three layers (thin but developed)
Inner circular
Outer longitudinal
Outermost circular/oblique
What is special about the Submucosa of the stomach?
highly vascular
What is the location of the Submucosa of the stomach?
Location of AVA= arteriovenous anastomosis
What is the function of the submucosa of the stomach?
to shut down activity and secretion FAST
Where is the submucosal (meissners) plexus located in the stomach?
often next to inner circular layer of muscle
What is the function of the Submucosal Plexus in the stomach?
to influence the ……………
IE: secretion, blood flow, any limited muscle contractions
How many muscular layers are possible in the ME of the stomach? and where at?
three layers are possible: especially between cardiac region and greater curvature; all smooth muscle
- innermost oblique:sometimes
- middle circular: well developed
- outer longitudinal: thin
What type of pattern is in the ME of the stomach?
Normal pattern other locations: Inner circular and Outer longitudinal
Where is the Myenteric (Auerbachs) plexus in the stomach?
between circular and longitudinal layers of muscle
What is the function of the Myenteric (Auerbachs) plexus in the stomach?
to stimulate the ME
The serosa of the stomach…
ALL
What are the Basic three regions of the stomach?(gastric histology)
Cardiac
Gastric includes Fundus and body
Pyloric
What isthe cardiac region of the stomach like?
Shorter pigs which lead to cardiac glands with a coiled base
What are the cells like in the cardiac region of the stomach?
Primarily surface mucous, some neck mucous, and a few DNES and Parietal cells
NO CHIEF CELLS
What’s special about the cardiac region?
Smallest region and obtain much mucus
What types of glands does the gastric region of the stomach have? Where does it go into?
Gastric glands: extends from gastric pit to MM
What are the regions of the gastric gland? (Zymogenic Gland)
Isthmus
Neck
Base
What types of cells does the isthmus of the gastric gland of the stomach have?
Surface mucus
DNES cells
What does surface mucus of the isthmus of the stomach produce? How long lived?
Produces thick visible mucus that Traps bicarbonate ions
Lives 3-5 days
What is the function of the cells in the isthmus of the gastric gland of the stomach?
To protect mucosa from auto digestion and the tougher components of chyme
What is an example of DNES cells in the isthmus of the stomach?
Very few DNES cells aka enteroendocrine cells Examples DNES cells in the stomach: Type D Type EC Type G********
What does type D DNES cells do?
Produces somatostatin inhibits release of hormones by nearby DNES cells and HCL release
What does type EC DNES cells do?
Produces serotonin and substance P: increases gut motility
What does type G**DNES cells do?
Produces GASTRIN stimulates HCL and pepsinogen secretion, gastric motility, and regenerative cells in the body of stomach
What are the four types of neck cells?
Neck mucous
Regenerative
Parietal (oxynitic)
DNES
What type of neck cell produces a soluble, less alkaline mucus? How long does it live?
Neck mucous cells
Lives 6 days
What type of neck cell function is to lubricate gastric contents?
Neck mucous cells
What type of neck cell is to replace all cell types?
Regenerative cells
What type of neck cell lives 150-200 days and is odd columnar cells with intracellular canaliculi?
Parietal (oxynitic) cells
What type of neck cell produces very strong HCL made at .8 pH snd buffered immediately to 1-2 pH
Parietal cells
This neck cell (parietal cells) has gastric intrinsic factor and what is its function?
Necessary for vitamin B12 absorption
How can chronic gastritis lead to pernicious anemia?
Low number of parietal cells can lead to Leaving Soon. Amounts of intrinsic which will decrease vitamin B12 absorption which is necessary for RBC maturation
What are the three types of base cells?
Chief (zymogenic)
Parietal
DNES
What does the chief cell produce in the base? (2) How long does it live?
Produces:
Primarily pepsinogen to break down proteins
Some gastric lipase to break down fats
Lives 60-90 days
Are there a lot of parietal cells in the base?
Nope
How long to DNES cells live in the base?
60-90 days
What does the pyloric region have?
Deeper pits very twisted and branched pyloric glands
Cells
What are the cells in the pyloric region?
Primarily surface mucus DNES and parietal cells; some neck mucous cells that also produce some lysosomes
What is the pyloric sphincter?
The anatomical sphincter between the pyloric of the stomach and the duodenum
What’s the characteristics of an anatomical sphincter?
Well developed inner circular layer of muscle in the ME
Inner circular layer in ME can be independently controlled
What are the general functions of the Small intestine?
Digestion
Absorb nutrients
Produce Intestinal Horomones- using DNEs cells
What are the three surface adaptations that increase surface area by a factor of 400 plus?
Plicae Circulares
Villi
Microvilli
What are Plicae Circulares?
(valves of Kerckring) permanent folds affecting the mucosa and submucosa; found throughout duodenum, jejunum, and proximal illeum
What are microvilli?
found on the luminal wall surface
What are the intestinal wall layers?
Mucosa
Sunmucosa
Muscularis Externa
Serosa/ Adventia
What is the surface epithelium in the mucosa of the SI?
Simple Columnar
What are the cells types in the mucosa of the SI?
Surface absorptive= enterocytes Goblet DNES: Type I, K, S Regenerative Paneth M (microfold)
What are the main functions of the surface absorptive (enterocytes) in the mucosa of the SI?
Contains microvilli
Functions:
-absorb water and nutrients
-terminal digestion in glycocalyx (molecular coating): cells produce the enzymes and absorb the monosaccharides and peptides created
What is the function of the goblet cells in the mucosa of the SI?
fewest in duodenum and most in ileum
How many DNEs cells are in the mucosa of the SI?
11 types
What is the function of DNES type I in the mucosa of the SI?
produces CCK: stimulates gallbladder contraction and pancreatic secretion of enzymes from serous acini
What is the function of DNES type K in the mucosa of the SI?
produces GIP (gastric inhibitory peptide): inhibits HCL release
What is the function of DNES type S in the mucosa of the SI?
produces Secretin: stimulates pancreas secretion of bicarbonate from the pancreatic ducts; will also inhibit HCL release and the movement of chyme into the SI
Where are regenerative cell in the mucosa of the SI? how long do they live?
live 5-7 days
found in crypts
Where are paneth cells in the mucosa of the SI? how long do they live? What is the function?
Found bases of the crypts (intestinal glands)
long lived 20 days
produce lysosomes
Where are M (microfold) cells in the mucosa of the SI? What is the function?
Located????
Cell structure large intracellular pockets that are fairly open to the LP; M cells samle foreign antigens in gut lumen and transfer antigens to lyphocytes and dendritic cells that have entered the M cell pockets
Function: promote humoral immunity
>results in plasma cells producing IgA which is then tranferred to enterocytes epithelial cells and released into gut lumen
>important in maintaining appropriate gut flora
