Gastrointestinal Anatomy Outcomes Flashcards
Where is the temporomandibular joint?
Between the articular surface of the temporal bone and the condylar processes of the mandible.
Describe the muscles of mastication that open the jaw.
The lateral pterygoid is the only muscle responsible for opening the jaw.
Describe the muscles of mastication that close the jaw.
Temporalis, masseter, and medial pterygoid.
What innervates the muscles of mastication?
The mandibular division of the trigeminal nerve - CN V3.
Describe the medial pterygoid.
Muscle of mastication. CLOSES jaw. From the angle of the mandible (medial side) to the pterygoid plates of the sphenoid bone.
Describe the lateral pterygoid.
Muscle of mastication. OPENS jaw.
From the condyle of the mandible to the pterygoid plates of the sphenoid bone.
Describe the temporalis muscle.
Muscle of mastication. CLOSES jaw. From the coronoid process of the mandible to the temporal fossa.
Describe the masseter muscle.
Muscle of mastication. CLOSES jaw. From the angle of the mandible to the zygomatic arch.
Major features of the oral cavity?
Hard palate superiorly. Pharynx posteriorly. Tongue inside. Mandible and teeth anteriorly. Muscle of the floor of the mouth, hyoid bone & epiglottis inferiorly.
Describe the anterior anatomy of the tongue.
Anterior 2/3rds = horizontal part. In the oral cavity, responsible for taste (CNVII) - foliate, vallate & fungiform papillae. General sensory (CNV3)- filiform papillae: touch, temperature etc.
Describe the posterior anatomy of the tongue
Posterior 1/3rd = vertical part. In the oropharynx. Enables taste and general sensation (CNIX)
Which nerve provides innervation to the lingual nerve branch of the anterior 2/3rds of the tongue?
Chorda tympani branch of CN VII: connects to the lingual nerve branch of CN V3 providing taste to the anterior 2/3rd of the tongue. Parasympathetic.
which parasympathetic nerve supplies secretomotor innervation to the submandibular salivary gland?
CN VII parasympathetic axons.
which parasympathetic nerve supplies secretomotor innervation to the sublingual salivary gland?
CN VII.
what provides the superior half of the oral cavity with general sensation?
CN V2
What provides the inferior half of the oral cavity with general sensation?
CN V3
Describe the components of the gag reflex.
protective reflex against foreign body entry into the pharynx/larynx.
Sensory part carried out by CN IX.
Motor part carried out by CN IX and CN X.
Pharynx constricts, attempting to close off entry.
Describe parotid gland.
Parotid duct crosses the face & secretes into the mouth by the upper 2nd molar.
Describe submandibular gland.
Submandibular duct enters the floor of the mouth & secretes via the lingual caruncle.
Describe the sublingual gland.
Lays in floor of mouth secretes via several ducts superiorly.
Extrinsic muscles of the tongue.
Change tongue position. 4 pairs: hyoglossus, styloglossus, genioglossus, palatoglossus. All innervated by CN XII, EXCEPT PALATOGLOSSUS.
Intrinsic muscles of the tongue
4 pairs. Modify shape of tongue. Innervated by CN XII.
Function of the pharynx.
Contracts sequentially - peristaltic.
Describe pharynx structure.
External layer of circular constrictor muscles, voluntary & overlap each other. Innervated by CN X.
Describe inner longitudinal muscles of the pharynx.
Inner layer - supplied mainly by CN X and IX. Elevate pharynx & larynx.
Function of longitudinal muscles of the pharynx.
Contract to shorten pharynx.
Raise the larynx to close over the laryngeal inlet.
Enteric Nervous system
Extensive nerve network.
Found only in walls of GI tract.
Independent of other parts of the nervous system - but can be influenced by autonomic motor nerves.
Lower oesophageal sphincter.
Physiological rather than anatomical sphincter. Due to contraction of diaphragm, slightly higher intra-abdominal pressure than intragastric & the oblique angle at which the oesophagus enters the cardia of the stomach.
Presence of this reduces effectiveness of lower oesophageal sphincter.
Hiatus hernia.
Anatomical location of lower oesophageal sphincter.
Immediately superior to gastro-oesophageal junction. Abrupt change in type of mucosa lining the wall - z-line.
areas of the stomach.
Cardia, fundus (superior), greater curvature, body, pyloric antrum, lesser curvature. Pyloric sphincter.
Anatomical location of the stomach.
Mainly in the left hypochondrium, epigastric & umbilical regions when supine.
Anatomical relations of the stomach.
Lesser omentum superiorly.
Greater omentum inferiorly.
Left hemi-diaphragm superiorly.
Composition of the small intestine
Duodenum, jejunum, ileum.
Large intestine
colon, rectum anal canal, anus
Colon
Caecum, appendix, ascending colon, transverse colon, descending colon, sigmoid colon.
foregut organs
Oesophagus, stomach, mid-duodenum, liver, gallbladder, spleen, 1/2 of pancreas.
Midgut organs
Mid-duodenum to proximal 2/3 of transverse colon, 1/2 of pancreas
Hindgut organs
distal 1/3rd of transverse colon to proximal 1/2 anal canal.
nine areas of the abdomen
R&L hypochondrium L&R lumbar L& R inguinal Epigastric Umbilical Pubic
muscles of the anterolateral abdominal wall
Rectus abdominis
External oblique
Internal oblique
Transversus abdominus
Peritoneal Cavity
The peritoneal cavity lies between the visceral & parietal layers of the peritoneum.
Peritoneum
Peritoneum is a thin, transparent, semi-permeable continuous membrane. Lines walls of the abdominopelvic cavity & organs.
intraperitoneal organs
almost completely covered in visceral peritoneum, minimally mobile.
Intraperitoneal organs with a mesentery
Covered in visceral peritoneum which wraps behind the organ to form a double layer - mesentery.
Mesentery
Suspends an organ from the posterior abdominal wall - very mobile.
retroperitoneal organs
only has visceral peritoneum on its anterior surface, located in the retroperitoneum.
omentum
double layer of peritoneum that passes from stomach to adjacent organs
peritoneal ligaments
double layer of peritoneum connecting organs to one another or the body wall.
greater omentum
four layered, hangs like an apron. Attaches greater curvature of stomach to transverse colon.
Lesser omentum
Double layered, runs between the lesser curvature of the stomach & duodenum to the liver. Has a free edge.
Greater and lesser sacs.
omenta divide peritoneal cavity into a greater and lesser sac.
Lesser sac is much smaller, two sacs communicate through ommental foramen.
Lies at the free edge of the lesser omentum
Portal triad.
peritoneum drapes over the superior aspect of pelvic organs to form pouches. how do they differ in males & females?
One pouch in the male - RECTOVESICAL POUCH.
Two pouches in the female - VESICO-UTERINE & RECTO-UTERINE POUCH.
Pouch of douglas
Recto-uterine pouch
abdominocentesis/paracentesis
needle placed lateral to the rectus sheath to drain ascetic fluid from the peritoneal cavity
Inferior epigastric artery
ascends in the anterior abdominal wall deep to rectus abdominis,
Arises from the external iliac, medial to the deep inguinal ring.
Biliary tree
set of tubes connecting liver to the 2nd part of the duodenum.
Liver
Largest organ in the body. Receives nutrients absorbed from GI tract.
Liver surface anatomy
mainly located in RUQ, protected by ribs 7-11, location changes in breathing.
anatomical lobes of liver
right, left, caudate and quadrate lobes
porta hepatis
site of entrance for portal triad structures
Functional lobes of the liver allow for what
segmentectomy: branch of hepatic artery, hepatic portal vein, bile drainage (bile duct), venous drainage (to IVC).
how many hepatic veins join together before entering the IVC.
Hepatic veins join together as 3 veins before entering the IVC.
Portal triad
Hepatic portal vein, hepatic artery proper, the bile duct.
First of three midline branches of the aorta, retroperitoneal, leaves aorta at T12 vertebral level.
Supplies organs of the foregut.
Coeliac trunk
trifurcates into 3 branches: splenic artery, left gastric artery & common hepatic artery.
Coeliac trunk
Intraperitoneal organ within the left hypochondrium. Protected by ribs 9-11
Spleen
Artery with a very tortuous course that runs along the superior border of the pancreas.
Splenic artery.