Bolus
Chewed food mixed with saliva
Chyme
Bolus after it has been processed by the stomach
Digestive Organs (GI Tract)
Oral cavity, pharynx, esophagus, stomach, small intestine, large intestine
Accessory Digestive Organs
Teeth, tongue, salivary glands, liver, gallbladder, and pancreas
Functions of digestive system
Ingestion, digestion, propulsion, secretion, absorption, and elimination of wastes
Mechanical digestion
Physical break down of ingested material
Chemical digestion
Break down of ingested material by enzymes
Mastication
Chewing
Two types of movement involved in propulsion
Peristalsis and segmentation (churning/mixing in small intestine)
Mucus
Mucin + Water
Epithelial Lining of Oral Cavity
Stratified Squamous
Two regions of oral cavity
vestibule and oral cavity proper
Oral Vestibule
Space between cheeks/lips and gums
Oral Cavity Proper
central to alveolar processes of alveolar processes of the mandible and maxillae
Lips
Orbicularis Oris muscle
Cheeks
Buccinator muscle
Labial Frenulum
Thin mucosa fold connecting lips to gums
Palate
Separates oral and nasal cavity
Hard palate
Anterior 2/3 of palate. Formed by maxillae and palatine bones.
Soft palate
Posterior 1/3 of palate. Primarily composed of skeletal muscle.
Uvula
Extension of soft palate. Elevates during swallowing to block nasopharynx.
Fauces
Opening between oral cavity and oropharynx. Bounded by muscular folds (palatoglossal and palatopharyngeal arches)
Palatine tonsils
Within fauces (between palatoglossal and palatopharyngeal arches)
Parotid duct
Extends from parotid gland to oral vestibule near second upper molar
Submandibular duct
Extends from submandibular gland to floor of mouth (just lateral to lingual frenulum)
Mucous Cells
Secrete mucin - froms mucus
Serous Cells
Secrete watery fluid containing ions, lysozyme, amylase
Parasympathetic Innervation of submandibular and sublingual glands
CN VII (facial)
Parasympathetic Innervation of parotid glands
CN IX (glossopharyngeal)
Intraperitoneal organs
Stomach, jejunum, ileum, cecum, appendix, transvers, sigmoid colons
Retroperitoneal organs
Lie directly against posterior abdominal wall (not within peritoneum). Duodenum, pancreas, ascending, descending colons, rectum
Mesenteries
Folds of peritoneum that support/ stabilize intraperitoneal GI tract organs. Vessels and nerves travel within these folds
Greater Omentum
Mesentery extending inferiorly from greater curvature of stomach. Covers most abdominal organs
Lesser Omentum
Mesentery connecting lesser curvature of stomach to liver
Mesentery Proper
Mesentery that suspends jejunum and ileum
Mesocolon
Mesentery of transverse and sigmoid colons
Falciform Ligament
Peritoneal fold that attaches liver to anterior internal abdominal wall.
Histology of Esophagus
Stratified squamous epithelium; thick submucosa
Histology of Stomach
No goblet cells; mucosa contains gastric pits (with gastric glands); Has an inner oblique and middle circular layer of muscularis
Histology of Small Intestine (General)
Mucosa has villi
Histology of duodenum
Submucosal glands (Brunner glands)
Histology of jejunum
Most prominent circular folds and largest villi (Compared to duodenum and ileum)
Histology of ileum
Most goblet cells and Peyer’s patches (compared to duodenum and ileum)
Hormones produced by pineal gland
Melatonin
Histology of Large Intestine
Mucosa contains intestinal glands
Hormones produced by hypothalamus
Oxytocin, ADH
Hormones produced by anterior pituitary gland
ACTH, TSH, GH, PRL, FSH, LH, MSH
Hormones produced by posterior pituitary gland
Trick question!relese of oxytocin and ADH
Hormones produced by parathyroid gland
Parathyroid hormone
Hormones produced by thyroid
T4, T3, Calcitonin
Hormones produced my adrenal glands (Medulla)
Epinephrine and norepinephrine
Hormones produced by adrenal glands (Cortex)
Aldosterone, androgens, cortisol, corticosterone, cortisone
Hormones produced by pancreas
Insulin and glucagon
Adenohypophysis
Anterior Pituitary Gland
Neurohypophysis
Posterior Pituitary Gland