Week 1: Chewing Swallowing and Churning Flashcards
What makes up the upper gastrointestinal tract?
Oesophagus, stomach and duodenum (liver, gall bladder and pancreas.
What are the accessory organs of digestion?
Liver, Gall bladder and Pancreas
What is the roof, floor and posterior border of the mouth?
Roof= Hard Palate and Soft Palate
Floor = Mylohyoid muscle
posterior = palatoglossal fold
What is gingivae?
Teeth and gums
What is the nerve supply to the salivary glands?
Secretion is controlled by sympathetic and parasympathetic branches of the ANS and somatosensory fibres
What is the opening of the parotid gland?
The parotid duct travels across the masseter, through the buccinator, and into the vestibule at M2 level (molar 2)
What is the opening of the submandibular gland
Sublingual Papilla underneath the lingual frenula
What is the opening of the sublingual gland?
There are sublingual ducts open on an elevated ridge on either side of the frenulum
What are the nerve supply to the maxillary teeth?
Trigeminal Nerve > Maxillary Nerve > Superior Alveolar Nerves
What is the nerve supply to the mandibular teeth?
Trigeminal Nerve > Mandibular Nerve > Inferior Alveolar Nerves
What is the Blood supply to the Maxillary Teeth?
Maxillary Artery > Posterior and Anterior superior alveolar artery
What is the blood supply of the Mandibular teeth?
External Carotid Artery > Maxillary Artery > Inferior Alveolar Artery
What are the the superficial muscles of mastication?
Masseter and Temporalis (Both Jaw closing)
What are the deep muscles of mastication?
Medial Pteregoid (Jaw closing) and lateral pteregoid (Jaw opening as it pull the mandible down)
What is the nerve supply to the muscles of mastication?
Mandibular Branch of Trigeminal Nerve
What is the blood supply of the muscles of mastication?
Maxillary artery and superficial and temporal (with corresponding veins)
where does the mastication system hinge?
condoyle of temporomandibular joint
What is an accessory muscle of Mastication?
Buccinator
What do the intrinsic muscles of the tongue do?
They shape the tongue
What do the extrinsic muscles of the tongue do ?
They move the tongue
What are the extrinsic muscles of the tongue?
What are the intrinsic muscles of the tongue?
What is the primary blood supply to the tongue?
primarily the lingual artery and veins (secondary supply – tonsillar branch of facial artery and ascending pharyngeal artery)
What is the motor nerve supply of the tongue?
(motor): hypoglossal nerve (XII), with exception of the palatoglossus = vagus nerve (X).
What is the general sensory innervation to the tongue?
posterior 1/3rd tongue = glossopharangeal (IX), anterior 2/3rd = lingual nerve (mandibular division of trigeminal nerve V3 )
Anatomy of tongue?
Where does the pharynx end?
C6
What muscles shuts off the nasopharynx with the palate and uvula?
Levator veli palatini and musculus uvulae
What triggers the swallowing reflex?
Pharyngeal plexus - formed by branches of glossopharyngeal and vagus
What are the 3 phases of swallowing?
1) Oral
2) Pharyngeal
- Tongue
- Soft Palate
- Vocal Folds
- Larynx up and epiglottis closes
- upper oesophageal sphincter opens
3)Oesophageal
How long is the oesophagus?
C6 -T10 and 25cm
What does the oesophagus pass through in the diaphragm?
oesophageal hiatus
Features of the Upper Oesophageal Sphincter?
Skeletal Muscle - can control
cricopharyngeus and inferior constrictor muscles
Relaxes during Swallowing
Features of the lower oesophageal sphincter (Gastroesophageal sphincter)
smooth muscle
reinforced by right diaphragmatic crus
Prevents oesophageal sphincter
What are the 3 anatomical constrictions in the body?
Pharyngo-oesophageal junction
Tracheal bifurcation (T5-T6)
Gastro-oesophageal junction
What is the change in histology at the oesophago-gastric junction?
The epithelium changes from non-keratinised stratified squamous to simple columnar
What is the distance between the incisors and the GO junction?
40cm
Is the stomach peritoneal or retroperitoneal?
Peritoneal - covered on both sides by a serous membrane
What is the arterial supply to the stomach?
Aorta > coeliac trunk > 5 seperate arteries which are : Right gastric artery, left gastric artery, Right gastroepiploic artery, left gastroepiploic artery, short gastric artery(come off spleen)
What are the veins from the stomach?
The gastric veins are similar in position to the arteries along the lesser and greater curvatures. These veins drain either directly or indirectly into the portal system.
The left gastric vein runs to the left along the lesser curvature, receiving the esophageal veins below the esophageal hiatus in the diaphragm. It usually drains directly into the portal vein at the superior border of the pancreas.
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The right gastric vein runs along the lesser curvature to the right toward the pylorus. Posterior to the first part of the duodenum, it joins the portal vein. It also receives the prepyloric vein, which receives the veins from the first 2 cm of the duodenum.
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The left gastroepiploic vein passes to the left along the greater curvature and, with the short gastric veins, drains into the splenic vein or its tributaries. The splenic vein is joined by tributaries from the pancreas as well as the inferior mesenteric vein; these ultimately form the portal vein with the superior mesenteric vein.
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The right gastroepiploic vein runs toward the right to the head of the pancreas. Usually it joins the superior mesenteric vein and thus drains into the portal vein.
What is the lymphatics in the stomach?
Coeliac nodes
What is the nerve supply to the stomach?
Vagus > Secretomotor > Peristaltic and secretory action
Sympathetic Nervous system: Visceral Pain and Vasculature
What are the folds inside the stomach called?
Rugae
Anatomy of the stomach
What plane is the pyloric sphinchter found?
Transpyloric Plane
Features of the Duodenum?
25cm long
Peritoneal and Retroperitoneal
4 parts: superior, descending, horizontal, ascending
Features of D1 - Superior
Peritoneal
Duodenal Cap Radiologically seen
Common Bile Duct and Gastroduodenal artery posteriorly
Features of D2 - Descending
Retroperitoneal
Receives CBD and PD via hepatopancreatic ampulla (of vater) at the major duodenal papilla
Features of D3 - Horizontal
Retroperitoneal
Superior mesenteric artery anterior
IVC and aorta posterior
Features of D4 - Ascending
Duodenojejunal flexture held by Ligament of treitz
What structures in the upper GI tract appear dark with air in an X ray?
Duodenal Cap and Fundus of stomach
What angle does the stomach rotate in embryology?
90 degrees
