Exam 3: Ch.7 Digestive System Pt.1 Flashcards
What are the 8 functions of the digestive system?
- Ingestion
- Mastication
- Secretion
- Absorption
- Elimination of Wastes
- Motility
- Hormone Release
- Chemical Digestion
What does the oral cavity include? What is it lined with?
- tongue
- teeth
- minor and major salivary glands
- tonsils
- lips
- -lined with oral mucosa
What are the 3 types of oral mucosa?
- Masticatory Mucosa
- Lining Mucosa
- Specialized Mucosa
What is the Masticatory mucosa of the oral cavity found on?
gingiva and hard palate
What is the surface epithelium of the Masticatory Mucosa of the oral cavity? What should we “note” about it?
keratinized or parakeratinized stratified squamous
note: superficial cells of parakeratinized stratified squamous epithelium keep their nuclei
What are the two parts of the Lamina Propria of the Masticatory Mucosa? What type of CT are they made out of?
- Papillary Layer–> thick loose CT
2. Reticular Layer–> dense CT
What does the Papillary Layer of the Lamina propria of Masticatory mucosa contain?
(thick loose CT)
- blood vessels
- nerves
- sensory receptors
- some Meissner’s corpuscles
What is the Lining Mucosa of the oral cavity found on?
- soft palate
- underside of tongue
- floor of mouth
- cheeks
- lips
What is the surface epithelium of the Lining Mucosa of the oral cavity? (3)
generally–> stratified squamous epi
occasionally–> parakeratinized stratified squamous
lips, vermillion zone (reddish part)–> keratinized stratified squamous
Are the areas of stratified squamous or keratinized stratified squamous epithelium thicker in the Lining Mucosa?
areas of stratified squamous epi are thicker (the general/majority of the make up of it)
Describe the Lamina Propria of the Lining Mucosa?
loose CT with blood vessels and nerves
What type of CT is the Submucosa of the Lining Mucosa made up of? What can it contain?
dense CT--> found in most places Can have: - minor salivary glands - sebaceous glands (mouth corners) - larger blood vessels - nerves
Where is the Specialized Mucosa of the oral cavity found?
on dorsal surface of tongue
taste buds are here
What is the surface epithelium type of the Specialized Mucosa of the oral cavity? (2)
keratinized stratified squamous on Filifrom papillae
stratified squamous on all other papillae
What are the general functions of the Specialized Mucosa of the oral cavity?
- move food
2. taste
Where is the mucosa of the tongue thicker? What about thinner?
thicker–> dorsally
thinner and smoother–> on lower surface
What is the surface epithelium of the Mucosa of the tongue?
specialized epithelium
What does the surface epithelium of Mucosa of the tongue contain?
papillae–> filiform, fungiform, foliate, vallate (circumvallate)
small salivary (von Ebner) glands are assoc. with Vallate papillae
What is assoc. with the Vallate papillae? What is their function?
small salivary (von Ebner) glands
Fxn: produce serous fluid to cleanse the taste buds on these papillae
What papillae are taste buds located on?
ALL papillaie; EXCEPT filiform papillae
all = fungiform, foliate, vallate
Describe the Lamina Propria of the Tongue.
loose CT; adipose possible
Does the tongue contain a Submucosa? If so, what does it contain?
yes, usually considered present; adipose possible
contains lingual salivary glands
What contains the lingual salivary glands in the oral cavity?
in the Submucosa of the Tongue
What do the Lingual Salivary Glands produce?
same product as the major salivary glands–>
What type of muscle are the intrinsic muscles of the tongue? Where do they attach externally?
skeletal muscle; have NO external attachment
How many alternating muscles does the tongue have and what is the arrangement from the top to bottom w/in the tongue?
4 alternating muscles
- Superior longitudinal muscle
- Vertical muscles alternating with Transverse muscles
- Inferior longitudinal muscle
What is the function of the intrinsic tongue muscles?
change tongue shape
List the six layers from outside to inside of a developing tooth before eruption through the gingiva.
- Ameloblasts
- Enamel
- Dentin
- Predentin
- Odontoblast
- Dental Papilla
What layer of the developing tooth has the function to produce enamel?
Ameloblasts
What type of cells make up the Ameloblasts of the developing tooth? What happens to the Ameloblasts after tooth eruption?
polarized columnar cells
lose following tooth eruption (these cells die–therefore no more enamel being produced)
About how thick is the enamel of a tooth? What is it made up of?
~2mm thick
made of interlinked enamel rods
What is the hardest substance in the body?
enamel
T/F. We continually produce more enamel once the tooth erupts through the gingiva.
False– we CANNOT produce more after tooth eruption
What is the precursor to dentin before mineralization?
Predentin
What type of cells are the Odontoblasts of a developing tooth and what do they line? Do they exist in adults? What is their function?
columnar cells lining pulp cavity
survive in adults
Fxn–> repair, produce and maintain dentin
What cell layer in a developing tooth functions to repair, produce and maintain dentin?
Odontoblasts
What is another name for the Dental Papilla of a developing tooth? What does it contain?
= dental pulp
CT with many blood vessels and nerves
What is the potential problem assoc. with the Dental Papilla/dental pulp?
extensive inflammation–> may lead to root canal
What are the three salivary glands?
- Parotid Gland
- Submandibular Gland
- Sublingual Gland
What is the largest salivary gland? What percentage of total salivary output does it contribute?
Parotid gland
only ~30% of total salivary output
What disease is the Parotid Gland most affected by? What passes through it?
Mumps
Facial nerve
What happens to the Parotid gland as we age?
commonly becomes infiltrated with adipose
What does the Parotid Gland produce?
100% serous producing Products: 1. Salivary amylase (Fxn: break down carbs) 2. lysozyme 3. secretory IgA
What gland secretes Salivary amylase and what is this enzymes function?
Parotid gland
Fxn: break down carbs
What salivary gland produces ~60% of total salivary output? Is it the largest?
Submandibular gland
smaller gland (not the smallest though)
What does the Submanidbular Gland produce? How much of the total salivary output does it produce?
~60%
MIxed gland–> produces mucus and serous products
primarily ~80-90% serous producing
has serous demilunes
What is the smallest salivary gland? What percentage of salivary output does it account for?
Sublingual Gland
~5% of total salivary output
What does the Sublingual Gland produce?
Mixed Gland-> producing both mucus and serous products
~80% mucus producing
What do all the serous products of Sublingual Glands come from?
serous demilunes; no separate acini
What are the three Salivary Glands and what do they produce?
- Parotid Gland: 100% serous producing
- Submandibular Gland: MIxed gland–> ~80-90% serous
- Sublingual Gland: Mixed gland–> ~80% mucus
What are the 6 functions of Saliva?
- Lubricating and cleansing oral cavity
- Antibacterial activity
- Dissolve food materials for taste sensation
- Initiate digestion: salivary amylase and salivary lipase
- Aid swallowing by food moistening and helps bolus formation
- Wound healing due to clotting factors and epidermal growth factor being present
What stimulates saliva secretion?
autonomic efferent impulses
What effect do parasympathetic impulses have on saliva secretion? What about sympathetic impulses?
parasym. –> increase amount of watery secretion
symp. –> decrease amount of saliva with a thicker consistencey (result = dryer oral cavity)
Review: In general what are the Digestive Luminal Wall Structure/layers?
- Mucosa–> surface epithelium, Lamina propria, Muscularis mucosae
- Submucosa (Meissner plexus)
- Muscularis externa (smooth ms)
- Serosa or adventitia
In generall, what does the Mucosa of the luminal wall contain? Describe them.
- Surface epithelium–> varies
- Lamina Propria–> loose irregular CT
- muscularis mucosae–> discontinuous layer made of smooth muscle
In general, what does the SUbmucosa luminal wall layer contain?
- dense irregular CT
- larger blood vessels
- submucosal (Meissner) plexus
What is the function of the Submucosal (Meissner) plexus? Where is it found?
Fxn: influence the mucosa
in Submucosa luminal wall layer
In general, what is the Muscularis Externa contain?
typically smooth muscle
Typical fiber orientation = inner circular, outer longitudinal layer = normal pattern
Myenteric (Auerbach) Plexus
What is the function of the Myenteric (Auerbach) plexus? Where is it found?
Fxn: influence muscularis externa
w/in Muscularis Externa layer of luminal wall
In general, where is the Serosa or adventitia located in assoc. with the luminal wall layers?
next to the Muscularis Externa
Describe serosa and adventitia that is next to the Muscularis Externa luminal wall layer.
Serosa = edge of serous producing simple squamous epithelium; can include some CT
Adventitia = CT
What is the function of the esophagus?
transfer bolus to stomach from oropharynx
What is the surface epithelium of the Mucosa in the Esophagus? What cells does it contain?
stratified squamous epithelium
Langerhans Cells–> an APC with some phagocytosis possible
Describe the make up of the Lamina Propria of the Esophagus. What does it contain?
loose areolar CT
can have Esophageal Cardiac Glands
Where are the Esophageal Cardiac Glands located and what is their function?
Location: In LP of Esophagus
- often near pharynx: ~1st inch
- Near stomach: ~last inch
Fxn: produce neutral mucus to protect esophgeal epithelium
Describe the Muscularis Mucosae in the Mucosa layer of the Esophagus.
discontinuous layer of longitudinal smooth muscle
Describe the make up of the Submucosa of the esophagus. What does it contain?
dense firboelastic CT
Contains:
- Esophageal (Proper) Glands
Where are the Esophageal (Proper) Glands located? What is their function?
Location: scattered along length of Submucosa of esophagus
Fxn: produce slightly acidic mucus to lubricate movement of food
In general, what does Parasympathetic and sympathetic innervation to the gut cause?
Parasym.–> stimulate peristalsis, inhibits sphincters and activates secretion
Symp.–> inhibits peristalsis, and contracts sphincters and controls blood flow to gut
How does parasympathetic and sympathetic innervation get to the gut?
Parasym.–> from Vagus N; except descending colon and rectum from sacral nerves
Symp.–> from splanchnic nerves
Does the Muscularis Externa of the esophagus have a normal pattern? Is there anything unique?
Yes; inner circular and outer longitudinal layers
Upper 1/3 = all skeletal ms
Middle 1/3 = mixture
Lower 1/3 = all smooth ms
Does the Esophagus have Adventitia or Serosa?
Both:
- Primarily Adventitis
- last 1-2 inches (after diaphgram) = serosa
What are the two Esophageal Associated Sphincters? Where are they located? What type of sphincters are they–anatomical or physiological?
- Pharyngoesophageal Sphincter–> b/c oropharynx and esophagus
- Gastroesophageal Sphincter –> b/w esophagus and stomach
~physiological sphincters
What Sphincter associated with the Esophagus is prone to problems? why?
Gastroesophageal sphincter (lower one) abrupt change of epithelium from stratified squamous in esophagus to simple columnar in stomach
What are two characteristics for Physiological Sphincters?
- NO thickening of circular muscle in Muscularis Externa (ME)
- Pressure gradient aids movement (muscle contractions and gravity helps)
What four complimentry forces does the lower esophageal sphincter involve?
- Diaphragm contraction
- Greater intra-abdominal pressure than intra-gastric pressure being exerted on abd. part of esophagus
- Peristalsis
- Maintenance of correct anatomical arrangements of structures
What does GERD stand for and what causes it?
Gastroesophageal (esophageal) reflex
Cause: stomach chyme backing up into lower esophagus
What are 5 possible contributing factors to GERD?
- Chronic gastritis: inflammation of stomach lining
- Hiatal Hernia
- Pregnancy
- Incompetent lower esophageal sphincter
- Subluxations: (problems with Myenteric plexus?)
What are three ways to reduce reflux assoc. with GERD?
- keep food diary, spices, and drinks consumed along with reflux episodes
- limit how much is eaten at one time
- do not eat less than 3 hours before bed
What are some problem foods associated with causing GERD?
- spices (pepper, garlic, onion, peppermint, cinnamon)
- Acidic foods (citrus, tomatoes)
- Acidic beverages (fruit juices, carbonated drinks, coffee, tea
- fatty foods
- alcohol
What is it called when stratified squamous epithelium is replaced by mucus-secreting simple columnar epithelium in lower esophagus?
Barret’s Esophagus
this is metaplasia due to chronic problem
What is Barrett’s Esophgus?
stratified squamous epithelium is replaced by mucus-secreting simple columnar epithelium in lower esophagus
this is metaplasia due to chronic problem
