Digestive System Structures

Oral Cavity  First step in digestion  Teeth salivary glands  The oral cavity includes the lips, the inside lining of the lips and cheeks (buccal mucosa), the teeth, the gums, the front two-thirds of the tongue, the floor of the mouth below the tongue, and the bony roof of the mouth (hard palate).  First step in digestion  Teeth salivary glands  The oral cavity includes the lips, the inside lining of the lips and cheeks (buccal mucosa), the teeth, the gums, the front two-thirds of the tongue, the floor of the mouth below the tongue, and the bony roof of the mouth (hard palate).

oropharynx  Passageway that holds air and food  Contains the tonsils  The oropharynx is the middle part of the pharynx (throat) behind the mouth. It includes the following: Back one-third of the tongue. Soft palate. Side and back walls of the throat  Passageway that holds air and food  Contains the tonsils  The oropharynx is the middle part of the pharynx (throat) behind the mouth. It includes the following: Back one-third of the tongue. Soft palate. Side and back walls of the throat

Parotid Gland  Salivary lands In front of each ear  Largest salivary glad  Produces saliva  Salivary lands In front of each ear  Largest salivary glad  Produces saliva

Submandibular gland  Below lower jaw  Weigh 15grams  Contributes 67% of unstimulated saliva secretions  Below lower jaw  Weigh 15grams  Contributes 67% of unstimulated saliva secretions

Sublingual Gland  Smallest of the 3 salivary glands  Contributes only 3-5% of salivary volume  Located under the tongue  Smallest of the 3 salivary glands  Contributes only 3-5% of salivary volume  Located under the tongue

laryngopharynx  Both food and air passes  Exits and the back of the larynx  Both food and air passes  Exits and the back of the larynx

epiglottis  Located at the base of the tongue  Composed of cartilage  The tissue it is made of can swell or block your airway  Located at the base of the tongue  Composed of cartilage  The tissue it is made of can swell or block your airway

esophagus  Muscular tube connecting the throat to the stomach  Lined with mucosa  Lies behind the trachea  Muscular tube connecting the throat to the stomach  Lined with mucosa  Lies behind the trachea

Stomach  Organ located in left upper quadrant  Creates digestive enzymes  Receives food from the esophagus  Organ located in left upper quadrant  Creates digestive enzymes  Receives food from the esophagus

Pyloric Sphincter  The pyloric sphincter is a band of smooth muscle at the junction between the pylorus of the stomach and the duodenum of the small intestine. It plays an important role in digestion, where it acts as a valve to controls the flow of partially digested food from the stomach to the small intestine.

Duodenum  the first part of the small intestine immediately beyond the stomach, leading to the jejunum.  It receives partially digested food (known as chyme) from the stomach and plays a vital role in the chemical digestion of chyme in preparation for absorption in the small intestine.  inch (25-30 cm) long C-shaped, hollow tube.  the first part of the small intestine immediately beyond the stomach, leading to the jejunum.  It receives partially digested food (known as chyme) from the stomach and plays a vital role in the chemical digestion of chyme in preparation for absorption in the small intestine.  inch (25-30 cm) long C-shaped, hollow tube.

Jejunum  2 nd part of the small intestine  Absorption  Wavy and made of smooth muscle  2 nd part of the small intestine  Absorption  Wavy and made of smooth muscle

ilium  Thin wall  Last part of the small intestine  Contains the mesenteric fat  Thin wall  Last part of the small intestine  Contains the mesenteric fat

Caecum  Large intestine  Absorbs the remaining fluids and salts  Covered in mucous membrane  Large intestine  Absorbs the remaining fluids and salts  Covered in mucous membrane

Appendix  Junction of the small/large intestine  4 inches long  Lower right abdomen  Only exists in humans  Junction of the small/large intestine  4 inches long  Lower right abdomen  Only exists in humans

Ascending colon  Caries feces from the caecum to the rectum  First part of the colon  Connects to the transverse colon  Caries feces from the caecum to the rectum  First part of the colon  Connects to the transverse colon

Transverse colon  Lengthy part of the large intestine  Fermentation- process of breaking down food  The part of the colon that requires the most blood  Lengthy part of the large intestine  Fermentation- process of breaking down food  The part of the colon that requires the most blood

Descending colon  3 rd segment of the colon  Stores the remain of digestive foods  3 rd segment of the colon  Stores the remain of digestive foods

Sigmoid Colon  Final segment of the colon  S shaped  Final segment of the colon  S shaped

Rectum  Final section in the digestive tract  Many range from centimeters  Connects the sigmoid colon to the anus  Final section in the digestive tract  Many range from centimeters  Connects the sigmoid colon to the anus

Anus  External opening of the rectum  Has involuntary and voluntary sphincters  External opening of the rectum  Has involuntary and voluntary sphincters

Liver  Weighs about 3 pounds  Feels rubbery to the touch  Filters blood coming from the digestive tract  The only regenerating orgam  Weighs about 3 pounds  Feels rubbery to the touch  Filters blood coming from the digestive tract  The only regenerating orgam

Gall Bladder  Pear shaped, hollow  Under the liver on the right side  Stored and concentrates bile  Pear shaped, hollow  Under the liver on the right side  Stored and concentrates bile

Pancreas  Large gland  6 inches long  Behind the stomach  Produces enzymes, digestive juices, and insulin  Large gland  6 inches long  Behind the stomach  Produces enzymes, digestive juices, and insulin

Hepatic bile duct  6-8 inches  Connected to the gallbladder throught the cyctic duct  Tranports secreations from the liver and gallbladder to the intestine  6-8 inches  Connected to the gallbladder throught the cyctic duct  Tranports secreations from the liver and gallbladder to the intestine

Cystic bile duct  4cm  Bile stored in gall bladder travels through the cystic duct into the common bile duct  Lies next to the cystic artery  4cm  Bile stored in gall bladder travels through the cystic duct into the common bile duct  Lies next to the cystic artery

Common bile duct  Carries bile from the gallbladder to the duodenum  Between the stomach and the liver  Carries bile from the gallbladder to the duodenum  Between the stomach and the liver

Hepatopancreatic ampulla  Formed by the union of the pancreatic duct and the common bile duct  Located at the major duodenum papilla  Has various smooth muscle sphincters  Formed by the union of the pancreatic duct and the common bile duct  Located at the major duodenum papilla  Has various smooth muscle sphincters

Major duodenal papilla  Posteriorly in the descending part of the duodenum  Secretion of bile and other enzymes to facilitate digestion  Sometimes called papilla of vater  Posteriorly in the descending part of the duodenum  Secretion of bile and other enzymes to facilitate digestion  Sometimes called papilla of vater

Enteric nervous system  Operates from the brain and spinal cord  Controls the gastrointestinal system  Organs where enteric nervous system can be found in are :  Stomach  Small and large intestine  Pancreas  Gall bladder  Operates from the brain and spinal cord  Controls the gastrointestinal system  Organs where enteric nervous system can be found in are :  Stomach  Small and large intestine  Pancreas  Gall bladder

Parasympathetic nervous system  Branch of the autonomic nervous system  Active when the body is resting  Causes secretion of saliva, digestive enzymes, and insulin  Branch of the autonomic nervous system  Active when the body is resting  Causes secretion of saliva, digestive enzymes, and insulin

Vagus nerve  Begin in the soft palate  Travels farthest in the body than any cranial nerve  Recieves sensory information about taste  Begin in the soft palate  Travels farthest in the body than any cranial nerve  Recieves sensory information about taste

Abdominal aorta  Largest artery in the abdominal cavity  Supplies blood to much of the abdominal cavity  Largest artery in the abdominal cavity  Supplies blood to much of the abdominal cavity

Inferior vena cava  Carries oxygenated blood to the heart

Common iliac artery and vein  Large terminal branches of the aorta  Provides to the pelvis  Vein:  Come together  Large terminal branches of the aorta  Provides to the pelvis  Vein:  Come together

Internal iliac artery and vein  Smaller terminal branch  Also called the hypogastric artery  Drains blood from the pelvis and lower limbs into the inferior vena cava  Smaller terminal branch  Also called the hypogastric artery  Drains blood from the pelvis and lower limbs into the inferior vena cava

Celiac Trunk  Provides oxygenated blood to the Stomach, liver, spleen  Supplies Duodenum and pancreas  Main supplier to those organs  Provides oxygenated blood to the Stomach, liver, spleen  Supplies Duodenum and pancreas  Main supplier to those organs

Common hepatic artery  Supplies blood to the liver  Final branch of the celiac artery  Almost always located between the bile duct and the portal vein  Supplies blood to the liver  Final branch of the celiac artery  Almost always located between the bile duct and the portal vein

Left gastric Artery and Vein  Artery:  arises from the celiac artery and runs along the superior portion of the lesser curvature of the stomach  is the celiac trunk's narrowest branch  Vein:  carries blood low in oxygen, tributaries derived from both surfaces of the stomach  Artery:  arises from the celiac artery and runs along the superior portion of the lesser curvature of the stomach  is the celiac trunk's narrowest branch  Vein:  carries blood low in oxygen, tributaries derived from both surfaces of the stomach

Superior mesenteric artery and vein  Artery  Supplies blood from the gut which includes jejunum and ilium  Terminates and the illi8um  Vein lies to the right of the artery  Artery  Supplies blood from the gut which includes jejunum and ilium  Terminates and the illi8um  Vein lies to the right of the artery

Interior mesenteric artery and vein  Artery:  anterior branch of the abdominal aorta that supplies the hindgut  Vein:  a blood vessel that drains blood from the large intestine  Artery:  anterior branch of the abdominal aorta that supplies the hindgut  Vein:  a blood vessel that drains blood from the large intestine

Hepatic Portal Vein  Blood vessel that conducts blood from the GI tract and spleen to the liver  Filters toxins that may have been ingested from food  75% of total liver blood flow comes through this vein  Blood vessel that conducts blood from the GI tract and spleen to the liver  Filters toxins that may have been ingested from food  75% of total liver blood flow comes through this vein

Hepatic Vein  Drains the deoxygenated blood from the liver into the inferior vena cava.  Divided into upper and lower  Separated the liver into segments  Leads to liver damage if it is blocked  Drains the deoxygenated blood from the liver into the inferior vena cava.  Divided into upper and lower  Separated the liver into segments  Leads to liver damage if it is blocked