Digestive system Flashcards
Digestive system
Organ system responsible for food ingestion, transport, digestion, absorption and excretion
Organs of the gastrointestinal tract
Oral cavity, pharynx, oesophagus, stomach, small intestine and large intestine
Gingirae
Gums
Labial frenulum
Thin mucosa fold attaching the internal surface of the lips to the gingirae
Uvula
Structure extending posteriorly from the soft palate which extends during swallowing to close off the nasopharynx
Fauces
The throat, the opening between the oral cavity and oropharynx
Structures laterally binding the fauces
Palatoglossal arch and palatopharyngeal arch between which the palatine tonsils are housed
Lingual frenulum
Mucous membrane conecting the tongue to the floor of the oral cavity
Bolus
An easy to digest globular mass of ingested food
Gustation
The sense of taste, the responsibility of gustatory cell located in taste buds
Papillae
Small rounded projections on the surface of organs, such as taste buds
Parotid salivary glands
Largest salivary glands located anterior and inferior to the ears. A duct runs parallel to the zygomatic arch, piercing the buccinator muscle. It secrets 25-30% of saliva and amylase
Submandibular salivary glands
Reside inferior to the mandible, produce 60-70% of saliva. A submandibular duct transports saliva to each side of the lingual frenulum
Sublingual salivary glands
Inferior to the tongue, produce 3-5% of saliva. Extends multiple tiny ducts to the inferior surface of the oral cavity
Dentition
The teeth collectively, made up of an exposed crown, a constricted neck and one or more roots. Comprised primarily of dentin, covered externally in enamel. Covered in the roots by cementum. The center of the teeth is pulp.
Apical foramen
Opening in the root canal to the pulp through which blood vessels and nerves run
Mesial surface
Towards the midline
Distal surface
Towards the back of the mouth
Buccal surface
Towards the cheek
Labial surface
Towards the lips
Lingual surface
Towards the tongue
Occlusal surface
Where upper and lower teeth meet
Deciduous teeth
20 teeth that erupt between 6 and 30 months and later fall out
Permanent teeth
32 teeth that replace the deciduous teeth
Incisors
Anterior, chisel shaped, single rooted teeth
Canines
Lateral to incisors with pointed tips
Premolars
Posterior to canines, flat crowns with ridges called cusps
Molars
Thickest and most posterior teeth
Pharynx
Shared by digestive and respiratory systems, has three pairs of constrictors, blood supply through carotid artery amd jugular vein
Oesophagus
Tubular passageway 25 cm long between trachea and vertebral column
Oesophageal hiatus
Opening in the diaphragm the oesophagus passes through
Superior and inferior oesophageal sphincter
Sphincters that close off each end of the oesophagus
Chyme
Paste like soup that develops in the stomach from the bolus
Stomach
Located in the upper left quadrant of the abdominal cavity, serves to continue chemical and physical digestion
Layers of muscle in the stomach starting externally
Longitudinal, circular and oblique
Four regions of the stomach
Cardia, nesr the oesophagus, fundus, at the stomach’s superior pole, pylorus, near the intestines and the body
Lesser curvature
Superior edge of the stomach
Greater curvature
The inferior edge of the stomach
Gastric rugae
Folds lining the inner surface of the stomach
The stomach is lined with
Simple columnar epithelium with gastric secretary cells: surface mucous cells in the surface and mucous neck cells, parietal cells, chief cells, and enteroendocrine cells in gastric pits
