Gastrointestinal Physiopathology Week 1

What is the outer covering of the GI tract except for the esophagus?

Visceral Peritoneum (Serosa)

What are the components of the muscular externa?

Longitudinal muscle, circular muscle, myenteric (Aurbach's) nerve plexus

Which type of muscle travels the length of the tube of the alimentary canal?

Longitudinal muscle

Which type of muscle runs circumferentially around lengths of the alimentary canal

Circular muscle

What coordinates the contraction of circular and longitudinal muscles?

Myenteric nerve plexus

Submucosa

A layer of tissue that is composed of loose-to-dense connective tissue, blood vessels, lymph vessels, and meissener's nerve plexus

Which layer of the GI tract is composed of the mucularis mucosa and the lamina propria?

Mucosa

Muscularis mucosa

Contains mucosal muscle

Lamina Propria

The innermost layer of the alimentary canal

Lumen

The empty space in the middle of the alimentary canal

Where does the GI tract get its presynaptic sympathetic fibers from?

the splanchnic nerves

Which nerve roots make up the greater splanchnic nerve?

T5-T9

Which nerve roots make up the lesser splanchnic nerve?

T10-T11

Which nerve roots make up the least splanchnic nerve?

T12

Which nerve roots make up the lumbar splanchnic nerve?

L1-L2

Which structure supplies sympathetic innervation to the liver, stomach, and pancreas?

Celiac Ganglion

Which structure supplies sympathetic innervation to the entire small intestine and ascending colon?

Superior mesenteric ganglion

Which structure supplies sympathetic innervation to the large intestine, excluding the ascending colon?

Inferior mesenteric ganglion

T or F: The effect of sympathetic activation on the stomach is excitatory

False (inhibitory)

What nerve supplies the liver, gallbladder, stomach, pancreas, small intestine, and the large intestine up to the left colic flexure parasympathetically?

CN X (Vagus)

What parasympathetically innervates the large intestine from the left colic flexure to the rectum?

Sacral plexus

What are the 5 functions of the GI tract?

Transportation

Digestion

Absorption

Excretion

Defence (immune)

What are the stages of the oral phase?

Preparation and propulsion

What is the name of the product of the preparation stage of food in the mouth?

Bolus

What structure pulls medially so that large food pieces cannot pass during the pharyngeal phase?

Palatopharyngeal fold

What nerves are responsible for the afferent impulses from the mouth in the pharyngeal phase?

CN V, IX, and X

Where are afferent signals from the mouth integrated?

Tractus solitarius

Where do efferent signals come from during the pharyngeal phase?

CN V, VII, IX, X, and XII, and the first two upper cervical nerves

When does the esophageal phase begin?

When bolus enters the esophagus

What type of peristalsis is a continuation of peristalsis of the pharynx, taking about 8-10 seconds?

Primary peristalsis

What type of peristalsis is used when the whole bolus doesn't enter the stomach?

Secondary Peristalsis

What structures initiate secondary peristalsis?

myenteric system vagal (afferent) and CN IX and X (efferent)

What two processes does the stomach use to transport bolus?

Peristalsis and pyloric pump

What two processes does the small intestine use to transport food?

segmentation and peristaltic contractions

What two processes does the large intestine use to transport food?

Haustration and peristaltic contractions

What is the name for bringing food into the mouth?

Ingestion

What is the name of the physical process that prepares food for chemical digestion?

Mechanical digestion

What is the name of the process in which enzymes break food down into basic elements?

Chemical Digestion

What is the name of the process of transportation of food from the lumen of the GI tract into blood or lymph?

Absorption

In what organ does the majority of absorption take place?

small intestine

What is the name of the process of eliminating indigestible substances from the body?

Defecation

What organ performs defecation?

Large intestine

How much saliva is produced per day?

800-1500 mL/day

What is the name of the space between the cheeks and teeth?

Vestibule

Which gland secretes mostly serous and some mucous and is located by the lingual frenulum?

Submandibular gland

Wharton's duct is an AKA for which duct?

Submandibular duct

What gland secreted mostly mucous and some serous and is located at 10-12 ducts that open into the floor of the mouth?

Sublingual gland

Rivinus duct is an AKA for which duct?

Sublingual duct

Which gland secretes only serous and is located in the vestibule next to the second upper molar?

Parotid gland

Stensen's duct is an AKA for which duct?

Parotid duct

Which gland secretes only serous and is located at the circumvallate papilla (lipase)

Ebner's gland

Ptyalin is an AKA for what?

Salivary Amylase

What type of secretion and helps turn food into bolus?

Serous secretions

What type of secretion contains oily mucin which provides a means for lubricating a bolus?

Mucous secretions

What factors are contained in saliva that destroy bacteria?

Thiocyanate ions and lysozyme

What is the afferent pathway of the parotid gland?

CN IX > tractus solitaruis > superior and inferior salivatory nuclei

What is the efferent pathway of the parotid gland?

CN IX > Otic ganglion > parotid gland

What is the afferent pathway of the submandibular and sublingual glands?

CN VII > tractus solitarius > superior and inferior salivatory nuclei

What is the efferent pathway of the submandibular and sublingual glands?

CN VII > submandibular ganglion > submandibular and sublingual glands

How many total deciduous teeth are there?

20

milk/baby teeth are an AKA for what?

Deciduous teeth

How many deciduous teeth are present in each quadrant?

2 incisors, 1 canine, 2 molars

From what age do deciduous teeth appear?

6 months - 2 years

How many total permanent teeth are there?

32

How many permanent teeth are present in each quadrant?

2 incisors, 1 canine, 2 premolars (bicuspid), 3 molars

What is the function of incisors?

Chisel, cutting, or nipping

What is the function of canines

Conical tear or pierce

What is the function of Premolar and molar crowns?

Rounded cusps for grinding

What is the name of the exposed covering of the tooth?

Enamel

What is the hardest substance in the human body?

Enamel

What percent of enamel is made of hydroxyapatite crystals?

95%

What are the primary components of hydroxyapatite crystals?

calcium and phosphate

What is the name of the yellow substance that forms the tooth?

Dentin

What percent of dentin is hydroxyapatite crystals?

45%

What is the name of the space in a tooth where arteries and nerves supplying the dentin are found?

Pulp / root canal

What is the name of the hard substance that keeps the tooth attached to the periodontal ligament?

Cementum

What percent of cementum is made up of hydroxyapatite crystals?

55%

What is the name for cavities in a tooth caused by dental plaques?

Carries

What is the name of a film of bacteria, sugars, and other debris on a tooth?

Dental Plaque

What is the primary bacterial species found in dental plaque?

Streptococcus mutans

What is the name for tartar formed by accumulation of plaque which can lead to gingivitis?

Calculus

What is the name of inflammation of the gums at the tooth/gum interface?

Gingivitis