GI System Flashcards
Describe the general layers of the GI tract (inner to outer)
Mucosa, submucosa, tunica muscularis, serosa/adventitia
What are the accessory digestive organs?
Liver, gallbladder, pancreas, (spleen)
What is the blood supply to the foregut structures?
Coeliac trunk
What is the blood supply to the midgut structures?
Superior mesenteric artery
What is the blood supply to the hindgut structures?
Inferior mesenteric artery
What is the blood drainage structure?
Hepatic portal vein (takes nutrients from the gut to the liver to be synthesised/detoxified)
What is the parasympathetic innervation of the GI tract?
Vagus nerve (CNX) supplies the foregut and midgut; pelvic splanchnic nerves supply the hindgut, reproductive viscera and bladder
What is the sympathetic innervation of the GI tract organs?
Sympathetic efferents arising from T1-L2 and synapsing in the relevant ganglia (coeliac/mesenteric)
What are the muscles of the dorsal/posterior abdominal wall?
Quadratus lumborum, psoas, iliacus
Which nerves innervate the muscles of the abdominal wall?
Anterior/ventral rami of spinal nerves T7-L1
What is the blood supply to the abdominal wall?
Superior/inferior (cranial/caudal) epigastric artery
What is the peritoneum composed of?
Single layer of mesothelium supported by fibroelastic tissue
Which organs are intraperitoneal? (SALTD SPRSS)
Stomach, appendix, liver, transverse colon, duodenum (first part)
Small intestines, pancreas (tail), rectum (upper third), spleen, sigmoid colon
Which organs are retroperitoneal? (SAD PUCKOR)
Suprarenal glands, aorta, duodenum (last 2/3rds)
Pancreas (not tail), ureter, colon, kidneys, oesophagus, rectum
What is the embryological origin of the mesentery?
Dorsal and ventral mesogastrium
What is the sphincter muscle surrounding the mouth?
Orbicularis oris
Where is the tongue attached to?
Hyoid bone and mandible
What type of epithelium does the tongue have?
Non-keratinised stratified squamous
Which cranial nerve supplies motor control of the tongue?
CNXII Hypoglossal nerve
Which cranial nerve supplies sensory information of tongue?
Glossopharyngeal (CNIX) and mandibular division of trigeminal nerve (CNV3)
What are the 3 major types of dentition?
Acrodont, pleurodont, thecodont
Which type of salivary glands do humans have?
Parotid, sublingual and submandibular
Which type of salivary glands do quadrupeds have?
Parotid, sublingual, mandibular and buccal/zygomatic (cheek)
What are the muscles of mastication?
Temporalis, masseter, lateral pterygoid and medial pterygoid
What nerve supplies the muscles of mastication?
Mandibular division of trigeminal nerve (CNV3)
What is the purpose of the crop in birds?
Storage and softening of food before entry into the proventriculus
What are the 4 parts of the ruminant stomach?
Rumen, reticulum, omasum, abomasum
What is the function of the abomasum?
Highly acidic enzymatic digestion
What is the special digestive structure found in infant ruminants?
Ruminoreticular groove to bypass rumen
which wiggly artery is the pancreas closely associated with?
Splenic artery
What type of epithelium lines the small intestine?
Simple columnar
Which nerve innervates the jejunum/ileum?
Vagus nerve
What are Brunner’s glands?
Glands in the duodenum secreting alkaline mucus to neutralise the acidic chyme from the stomach
Which species have a spiral-shaped small intestine?
Ruminants (flat spiral) and pigs (conical spiral)
