Stomach anatomy and motility Flashcards
Label this section through the GIT
Describe the anatomy and function of the mucosal layer of the GIT
epithelial layer, protective, secretes + absorbs
Connective tissue layer (BVs, nerves, lymphatics)
Muscularis mucosae - thin smooth muscle layer
Describe the anatomy of the submucosal layer of the GIT
connective tissue
BVs and nerves
Describe the anatomy of the muscularis layer of the GIT
2 layers of smooth muscle (circular and longitudinal)
Myenteric plexus (network of nerve cells)
Describe the anatomy of the serosa layer of the GIT
thin layer of connective tissue
peritoneum (epithelial cells)
Describe the process of swallowing
Oral phase:
- food mixed with saliva
- tongue moves bolus to back of mouth
Pharyngeal stage:
- vocal folds close
- epiglottis covers entrance to trachea
Oesophageal phase:
- upper sphincter of oesophagus opens
- food passes into oesophagus
- entrance to trachea reopened and upper oesophageal sphincter closes (breathing resumes)
- swallowing centre in medulla initiates wave of contractions in circular layer of striated muscle (peristaltic)
- bolus move down oesophagus
Label the stomach
Label the histology of the stomach
Describe the vascular supply to the stomach
Coeliac artery:
- hepatic
- splenic
- L gastric
Venous drainage via hepatic portal vein
Describe the anatomy and function of the non-glandular region of the stomach
Protective function
- cornified/keratinised
- stratified, squamous epithelium
Describe the function and anatomy of the glandular regions of the stomach
Mucus producing
- simple/one layer
- columnar epithelium
What type of stomach tissue is this?
Non-glandular
What kind of stomach tissue is this?
Glandular
Which part of the stomach is non-glandular?
Eosophageal part
What is the margo plicatus?
folded margin between non-glandular and glandular portion of stomach
Why are gastric ulcers common in horses?
non-glandular regions not well protected from gastric juices so gastric juices splash up and cause damage -> ulcers
In which part of the stomach does most of the gastric juice get produced?
corpus and pylorus
Label this cross section of stomach tissue
Describe the nervous supply of the stomach
Sympathetic and parasympathetic fibres
Intrinsic fibres of enteric nervous system
Describe the general anatomy and function of the enteric nervous system
Controls:
- peristalsis
exocrine and endocrine secretions
- microcirculation of the GIT
- regulating immune and inflammatory processes
Largely controlled by reflexes:
- long reflex arcs involve the CNS
- short reflex arcs are contained within the wall of the GIT
What do the plexuses of the enteric nervous system contain?
What is the function and anatomy of the interstitial cell of Cajal
Modified smooth muscle cells central to GI motility regulation
Function as pacemaker for gut contraction
Describe some problems/diseases that relate to the enteric nervous system
Ileus - GI stasis due to stress/dehydration/other primary condition
Spasmodic colic - change in gut activity causes muscular spasm of the intestines
Vagal indigestion - motor disturbances that hinder the passage of ingesta from reticulorumen, abomasum or both
