Topic 8 - GI tract Part 1 Flashcards
Explain the placement of the 3 salivary glands
Parotid at back. Submandibular on surface of mouth , sublingual to the front
Explain the types of epithelium layers
Single squamous (1 flattened cell layer)
Single cuboidal
Single columnar (long)
Stratified squamous, columnar and epithelil
What’s the difference between squamous and simple
Simple are any type of cell eg cuboidal but 1 layer vs squamous are flat cells but can be many lauers
What sort of cells are in the mouth and tongue of oral cavity
Stratified squamous cells
Why is food broken down
To increase sa for enzyme work
What do the muscles of tongue and cheek do
Pulverise the food and form a bolus
What do muscles of mastication do
Move the lower jaw
Which mastication muscle is the major large one seen on outside to elevate the jaw
Temporalis
Which other large muscle elevates but also protrudes the jaw
Masseter
Which muscles move the lower jaw laterally
Pterygoids
What is the upper jaw called
Maxilla
What sort of saliva is produced by the submandibular
Serous and mucous saliva
What do sublingual produce
Serous saliva
What does parotid produce
Mucous saliva
Where is production of saliva first before duct modification
The acinus /acini of glands
What sort of fluid is this and what enzyme present
Isotonic with a amylase in it
What does the duct do
Active filtration of ions like na, Cl, k, hco
Which ans system cause larger water saliva
PNS
What does sns cause
Thick and low amount of saliva high in mucous
Which acinus secretes most proteins
Serous acinus
The mucus acinus secretes what for lubrication
Mucin
The point where ducts meet are called what
The intercalated ducts (both serous and mucous)
What surrounds acinar cells
Myo epithelial cells
What type of duct does the saliva go to
Striated duct with striated cells
What are the functions of saliva
Lubrication via mucin Digestion eg via a amylase Speech Thirst stimulation Absorption in mouth Antibacterial
What sorts of things does it have which is anti bacteria
Thiocyanate
What are the 4 layers of the gi tract tube
Inner mucosa, submucosa, muscularis, serosa
What makes up the mucosa
Epithelium, lamina priopria and the muscularis mucosa
What type of epi can it be
Any eg squamous, stratified ,columnar etc
What is the lp
Loose connective tissue with immune cells
What is the muscularis thin mucosa smooth muscle for
Contraction of mucosa
What is the submucosa
Dense connective tissue layer
What sorts if things does submucosa have
Fat stores, submucosa plexus
What is the submucosal plexus a strand of
The enteric NS which is a part of the ans
What does it control in submucosa
Secretion and blood flow
and also relaying info from epithelium and stretch receptors in wall
Why is enteric ns different
Can operate independently of the cns
Which 2 muscle types are in the muscularis externa
Inner circular muscle and outer longitudinal muscle
What are they for
Pushing food down ie peristalsis
Which plexus part of the ens lies between the muscles and allow motility
Myenteric plexus
What is the serosa
Layer of epithelium forming part of the peritoneum
What does peritoneum do
Lines abdominal cavity and organs and anchors them to body wall
What is the first step of swallowing before a swallowing signal forms
Bolus formed and pushed to back of pharynx forming a swallow reflux signal
After the swallow signal what rises to block the nasopharynx
The soft palate
What allows closure of the trachea
Larynx rising and moving epiglottis over the trachea
What are the 4 muscles of the tongue
Styloglossus , palatoglossus, hypoglossus, genioglossus
Which muscles lift the soft palate
Palatine
What lifts the larynx
Suprahyoid muscles
Which sphincters push food down sequentially
Pharyngeal
What is the oesophageal phase of swallowing
Food pushed down via peristalsis and involuntary action of smooth muscleb
Which sphincters relax to allow food into stomach
Lower oesophageal sphincters
Which type of cells are in the oesophagus (same as mouth)
Stratified squamous epithelium
Where is the oesophagus susceptible to hiatus hernia
Point where it meets the diaphragm a stomach can be pushed up the gap and reflex
Is the lower oesophageal sphincter even a sphincter
No just a band of muscles which cause tension and block reflux from stomach
How is the muscularis externa of upper 1/3 of oesophagus different to lower
Had skeletal muscle gs smooth muscle in the lower 2/3!
What is present in the lp and submucosa of oesophagus
Mucus secretory glands
What nerve innervates the oesophagus
Vagus nerve
What is pseudostraitifejd
1 layer which acts as 2
What are the muscles of the cheek and tongue for after teeth breakdown
Pulverisation Bolus formation
Where does serous acinus meet mucous acinus
Intercalated duct then into striated duct for modification
What cells are on basal outside of the secretory glands / salivary
Myoepithelium
Why is the LP good for immunology
Good bloody supply and lymphatics
How do pharyngeal constrictors contract to push food down
Sequentially
