Digestive System

• The liver, stomach, salivary gland, buccal cavity, and all other organs are part of the digestive system.
• A great degree of absorption is occurring in the esophagus.
• The rectum, ileum, jejunum, duodenum, and all other parts of the small intestine are parts of the digestive system.
• The innermost layer of the mucosa of the small intestine is lined by simple squamous epithelium.
• Pseudostratified columnar epithelium is not a part of the innermost layer of the mucosa of the small intestine.
• Simple columnar epithelium is not a part of the innermost layer of the mucosa of the small intestine.
• Stratified columnar epithelium is not a part of the innermost layer of the mucosa of the small intestine.
• Organs have specific transport systems that enable the entry of these amino acids for metabolic purposes.
• Lipids/fatty acids should be broken down into smaller forms.
• Bile is needed to make these lipids amenable to be acted upon by enzymes such as lipase.
• Once broken down, lipids are absorbed and repackaged as lipoproteins (chylomicrons).
• In the liver, chylomicrons can be stored or transported to other places via lipoproteins (HDL and LDL).
• These chylomicrons exit the intestines and eventually will end up in the liver.
• Trypsin and chemicals break down proteins into simpler forms known as amino acids.
• These amino acids may be used by the organ to create more carbohydrates or proteins.
• Halzoun movement is a type of movement in the esophagus.
• The Pharynx, also known as the "Throat", connects the mouth to the esophagus and consists of the Nasopharynx, Oropharynx, and Laryngopharynx.
• The Esophagus has two sphincters on both ends: the Upper Sphincter, also known as the Cardiac Sphincter, and the Lower Sphincter.
• The Microscopic Anatomy of the Stomach includes Cells such as Surface Mucous Cells, which are found in the inner stomach and produce mucus.
• The main functions of the Digestive System are Ingestion and Mastication, Propulsion and Mixing, Digestion and Secretion, Absorption, and Elimination.
• Swallowing consists of a Voluntary Phase where the tongue pushes the food bolus against the hard palate, a Pharyngeal Phase that is largely a reflex, and an Esophageal Phase where peristalsis occurs.
• The Mucosa, Submucosa, Muscularis Propria, and Serosa/Adventitia are parts of the Digestive System's Microscopic Anatomy.
• The Oral Cavity consists of Lips, Cheeks, Tongue, Teeth.
• The Oral Cavity's main functions are Mastication and Preliminary Digestion.
• The Oral Cavity is associated with the Salivary Glands, Liver, and Pancreas.
• The Esophagus has skeletal muscle in the upper third, skeletal and smooth muscle in the middle third, and smooth muscle only in the lower third.
• The Esophagus is a muscular tube lined by stratified squamous epithelium (non-keratinizing) and propels the food bolus from the oral cavity to the stomach.
• The Peritoneum and Serous Membrane surrounding the visceral organs are associated with the Anatomy of the Digestive System.
• The Stomach consists of the Cardia, Fundus, Body, and Pyloric Area.
• Defecation is the process of eliminating the formed feces.
• The external anal sphincter is the one under voluntary control.
• The internal anal sphincter is not under voluntary control.
• The remaining chyme that was not reabsorbed is called feces.
• The large intestines have a mass movement pattern of contractions, in contrast to the peristaltic movement of the small intestines.
• The main goal is to break down these complex carbohydrates into simpler forms such as glucose and other monosaccharides.
• The defecation reflex is triggered when the feces reaches the rectum and anus area, causing the distention of these structures to send signals via the parasympathetic pathway for them to relax, resulting in the relaxation of the internal anal sphincter.
• All of these organs facilitate “digestion”, which includes mechanical digestion (chewing of food) and chemical digestion (enzymes and other chemicals breaking down food components into smaller absorbable compounds).
• Each mass movement contraction in the large intestines extends over 20 or more centimeters of the large intestine.
• Carbohydrates are broken down into their simpler forms such as glucose and other monosaccharides by the action of certain enzymes (e.g amylase).
• The body has transport systems to be able to absorb glucose for it to go to the target organs for energy metabolism.