A&P: Lab E Quiz

Digestive Tract

Is a continous tube within the body

• also know as the alimentary canal

• major divisions: oral cavity, pharynx, esophagus, stomach, small intestine, and large intestine

Gastrointestinal tract (GI)

subset of the digestive tract that has portions that process nutrients and absorb water

• stomach, small intestine, large intestine

• lined by simple columnar epithelium

Accessory digestive organs

the liver and pancrease

Oral cavity and pharynx

Where food and water pass when swallowed

• lined with stratified squamous epithelium for abrasive food

oropharynx

stratified squamous epithelium

laryngopharynx

stratified squamous epithelium

upper esophageal sphincter

circularly arranged skeletal muscle of the lower pharynx

• upper esophagus is only open during swallowing and is usually closed to exclude air from digestive tract

Esophagus and GI tract layers

Mucose, submucosa, muscularis externa, outer layer of serosa of adventitia

Mucosa

mucosa: epithelium, lamina propria, musclaris mucosa

Lamina propria

areolar connective tissue

Submucosa

areolar connective tissue and dense irregular connective tissue

muscularis muscosa/muscularis externa

smooth muscle

Plexuses of the gut

the nervous structures associated with stimulating or inhibiting glandular secretions and smooth muscles

myentric plexus

found within the muscularis externa

submucosal plexus

found between submucosa and muscularis mucosa

Esophagus

transport food from pharynx TO THE stomach

• passes thru the diaphragm

• made of non-keratinized squamous epithelium

• posterior to the trachea, above the diaphragm

• bolus causes expansion of esophogus with the incomplete C-rings of the trachea

• has two layers of muscularis externa: inner circular and outer longitudinal layer

• covered by adventitiia within mediastinum and serosa within the peritoneum

• esophageal glands is a good indicator to identify this structure

Superior esophagus

retroperitoneal and has adventitia

inferior esophagus

is intraperitoneal and has a serosa

abdominal cavity

contains organs of the gastrointestinal tract

• including, stomach, small intestine, majority of large intestine, liver and pancreas

Pelvic cavity

contains the rectum

rectum

retroperitoneal and intrapelvic

• covered by adventitia

• simple columnar epithelium

Spleen

Part of the abdominal cavity but NOT an organ of the digestive syste,

• has a venous drainage

• intraperitoneal organ

  • covered by visceral peritoneum

parietal peritoneum

lines interal wall of the abdomen

• composed of simple squamous epithelium

visceral peritoneum

covers individual organs that are in the peritoneum (intraperitoneal) also know as a serosa

• composed of simple squamous epithelium

stomach

intraperitoneal organ

• visceral peritoneum = serosa

four regions

• cardiac region, fundic region, bod, pykoric region

has an additional muscularis exteerna

• inner oblique layer, inner circular layer, and outer longitudinal layer

lamina propria of the stomach

where you can find the lymphatic tissue

transverse colon

intraperitoneal organ

• visceral peritoneum

kidneys

retroperitoneal

• covered by adventitia

proximal duodenum

intraperitoneal organ

• visceral peritoneum = serosa

• 0.25 m

• low goblet cell #

jejunum

intraperitoneal organ

• visceral peritoneum

• 2.5 m

• moderate # of goblet cells

• no glands

ileum

intraperitoneal organ

• visceral peritoneum

• 3.6 m

• goblet cells more prominent

• no glands

• but has lymphatic tissue in submucosa

transverse colon

intraperitoneal organ

• visceral peritoneum

cecum

intraperitoneal organ

• visceral peritoneum

sigmoid colon

intraperitoneal organ

• visceral peritoneum

pancrease

retroperitoneal organ

• covered by adventitia

Distal part of the duodenum

retroperitoneal organ

• covered by adventitia

• 0.25 m

• low goblet cell #

ascending colon

retroperitoneal organ

• covered by adventitia

ascending colon

retroperitoneal organ

• covered by adventitia

major organs

• stomach

• small intestine

• large intestine

cardiac sphincter

smooth muscle

• seperates esophagus from the stomach

pyloric sphincter

composed of smooth muscle

• sseperates stomach from small intestine

gastric rugae

inner folds within the stomach

gastric glands

in the stomach and produce gastric secretions

intestinal villi

finger like projections of the mucosa into the lumen

Intestinal crypts

invaginations originating at the base of the villia

• analgous to gastric pits

microvilli

found on absorptive cell

Plicae circulares

macroscopic folds of the intestinal wall

Duodenal glands

exocrine glands

Large intestine

regions include cecum, ascending colon, transverse colon, ascending colon, sigmoid colon, and the rectum

anal canal

non-keratinized stratified squamous epithelium

Liver

located beneath the diaphrag and has 4 lobes

• left

• quadrate

• caudate

• supported by falciform ligament: separartes right and left lobe

• intraperitoneal

lined by a thick hepatic capsule composed of dense irregular connective tissue

Branch of Hepatic portal vein

simple squamois epithelium

Branch of Hepatic artery

simple squamous epithelium

Branch of common Hepatic duct

simple cuboidal epithelium

skeletal muscle sphincters

upper esophageal and the external anal sphincter

smooth muscle sphincter

cardiac sphincter, pyloric sphincter, ileocecal sphincter, internal anal sphincter, hepatopancreatic sphincter

• all are thickened portions of the inner circular layer

mesentry

associated with small intestine

mescolon

associated with the colon

celiac trunk

branch includes common hepatic artey, left gastric artery, and splenic artery

common hepatic artery

branches to form hepatic artery proper, right gastric artery, and gastroduodenal artery

superior mesentric artery

supplies blood to distal duodenum, the jejunum, ileum, cecum, ascending colon, and right transverse colon

Inferior mesentric artery

provides blood supply to left transverse colon, descending colon, sigmoid colon, and rectum

Pancreatic blood supply

gets blood from the splenic artery, gastroduodenal artery, and superior mesentric artery

Hepatic portal vein

receives blood from capillaries of all gastrointestinal tract and the spleen

• this blood is depleted of O2 and high in CO2

• unique: has wo capillary beds

Hepatic artery proper

carries systemic arterial blood with high O2 levels and low CO2 levels to liver tissue

Internal and external anal sphincters

smooth muscle