AP II Lab Quiz 7 Digestive System
The organs of the digestive system are separated into into 2 major groups:
(1) Alimentary Canal/Gastrointestinal canal (2) Accessory digestive organs
The walls of the pharynx consist largely of two layers of skeletal muscles:
(1) an inner layer of longitudinal muscle (2) outer layer of circular constrictor muscles. *Together these initiate wavelike contractions that propel food inferiorly into the esophagus.
The Esophagus extends from the laryngopharynx through the diaphragm to the gastroesophageal sphincter in the superior aspect of the stomach. Approximately _______ cm long in humans.
25 sm long It is a food passageway that conducts food to the stomach in a wavelike peristaltic motion. The walls at its superior end contain SKELETAL MUSCLE, which is replaced by SMOOTH MUSCLE in the areas nearing the stomach.
digestion
Breakdown of food substances into simpler forms that can be absorbed and used.
In the small intestine, enzymes from two sources complete the digestion process:
Brush Border enzymes: which are hydrolytic enzymes bound to the microvilli of the columnar epithelial cells; and more important.
The small intestion has three subdivisions:
Duodenum Jejunum Ileum
pyloric part of stomach
Funnel-shaped pouch that forms the distal stomach. Pyloric antrum: wide superior portion of the pyloric part. Pyloric canal: narrow tubelike portion of the pyloric part. Pylorus: distal end of the pyloric part that is continuous w/ the small intestine. Pyloric sphincter: valve that controls the emptying of the stomach into the small intestine.
The _____ ________, a slight thickening of the smooth layer at the esophagus-stomach junction, controls food passage into the stomach.
Gastroesophageal Sphincter
The stomach is made up of several regions:
Greater Omentum Lesser Omentum Lesser Curvature Greater Curvature
There are two mesenteries in the stomach:
Greater omentum and Lesser omentum connect to the stomach. -The greater omentum extends from the greater curvature of the stomach, and reflects downward, and covers most of the abdominal organs in an apron-like fashion.
At the duodenum, the ducts join to form the bulblike _____ __________ and empty their products into the duodenal lumen through the ________ __________:
Hepatopancreatic ampulla Major duodenal papilla
Very often in young children, the _________ tonsils become inflamed and enlarge, partially blocking the entrance to the pharynx posteriorly and making swallowing difficult and painful.
Palatine
The three pairs of salivary glands that secrete into the oral cavity include:
Parotid Gland, Sublingual gland, Submandibular gland.
The amount of lymphoid tissue in the submucosa of the small intestine are called_________ increases along the length of the small intestine and is very apparent in the ileum.
Peyer's Patches
When the tongue initiates swallowing, the food passes posteriorly into the ________, a common passageway for food, fluid, and air.
Pharynx
The mucosa of the oropharynx and laryngopharynx, like that of the oral cavity, contains a protective ___________ __________ _________:
Protective Stratified Squamous Epithelium
Most digestive activity occurs in the __________ part of the stomach.
Pyloric
The __________ is primarily located in the upper left quadrant of the abdominopelvic cavity and is nearly hidden by the liver of the diaphragm.
Stomach
Muscularis Externa:
Subdivision of layer: Circular layer, Longitudinal Layer Tissue type: inner layer of smooth muscle, outer layer of smooth muscle. Function: segmentation and peristalsis of digested food along the tract are regulated by the myenteric nerve plexus.
Serosa (visceral peritoneum):
Subdivision of layer: Connective Tissue, Epithelium (mesothelium) Tissue type: Areolar connective tissue, Simple Squamous epithelium. Function: Reduces friction as the digestive organs slide across one another.
Submucosa
Subdivision of the layer: N/A Tissue Type: Areolar and dense irregular connective tissue containing blood vessels, lymphatic vessels, and nerve fibers (submucosal plexus). Function: Blood vessels absorb and transport nutrients. Elastic fibers help maintain the shape of each organ.
In the large intestine, the longitudinal muscle layer of the muscularis externa is reduced to three longitudinal muscle bands called the____:
Teniae coli
palatoglossal arch
The posterior border of the oral cavity.
absorption
The process by which nutrient molecules pass through the wall of the digestive system into the blood.
The anal canal has two sphincters:
Voluntary external anal sphincter composed of skeletal muscle. Involuntary internal anal sphincter composed of smooth muscle. *the sphincters are usually closed except during defecation*
Mesentery
a general term that refers to a double layer of the peritoneum: a sheet of two serous membranes fused together that extends from the digestive organs to the body wall.
Lingual Tonsils:
a mass of lymphoid tissue, which covers the base of the tongue posterior to the oral cavity proper.
Large intestine:
about 1.5 m "(5 ft) long and extends from the ileocecal valve to the anus. It encircles the small intestine on three sides.
Pancreatic juice is very ____________. Its high concentration of bicarbonate ion (HCO3) neutralizes the acidic chyme entering the duodenum from the stomach.
alkaline
The anal canal terminates in the ________, the opening to the exterior of the body.
anus
Cardia (cardial part)
area surrounding the cardial orifice through which food enters the stomach.
Oral cavity proper:
area that lies within the teeth and gums.
The colon is divided into several distinct regions. The _____________ travels up the right side of the abdominal cavity and makes a turn at the right colic (hepatic) flexure to cross the abdominal cavity as the transverse colon.
ascending colon
The mechanical and chemical breakdown of food begins ________ the food has left the oral cavity.
before
The liver performs many metabolic roles, but its digestive function is to produce ________, which leaves the liver through the common hepatic duct, then enters the duodenum through the bile duct.
bile
The __________ run between adjacent cells toward the bile duct branches in the triad regions, where the bile eventually leaves the liver.
bile canaliculi
premolars (bicuspids)
broad crowns with rounded cusps used to grind or crush.
Subdivisions of the Large Intestine:
cecum, appendix, colon, rectum, anal canal.
The sinusoids empty into the ____, and the blood ultimately drains from the liver via the ____.
central vein, hepatic veins
Incisors:
chisel shaped and exert a shearing action used in biting.
After the food is processed in the stomach, it resembles a creamy mass called ______, which enters the small intestine through the pyloric sphincter.
chyme
A condition in which the liver is severely damaged and becomes hard and fibrous.
cirrhosis
Canines (eye teeth, cuspids):
cone-shaped teeth used for tearing food.
3 major funtions of the large intestine:
consolidate and propel the unusable fecal matter toward the anus and eliminate it from the body. While it does this task it : (1) provides a site where intestinal bacteria manufacture vitamins B and K; and (2) reclaims most of the remaining water from undigested food, thus conserving body water.
Jejunum:
continuous with the duodenum, extends for 2.5 m (about 8 feet). Most of the jejunum occupies the umbilical region of the abdominal cavity.
WHEN DIGESTIVE ACTIVITY IS NOT OCCURRING IN THE DIGESTIVE TRACT, BILES BACKS UP INTO THE _______________ AND THEN ENTERS THE GALLBLADDER.
cystic duct
Circular folds:
deep, permanent folds of the mucosa and submucosa layers that force chyme to spiral through the intestine, mixing it and slowing its progress. These structural modifications decrease in frequency and size toward the end of the small intestine.
Palatine Tonsils:
each side of the mouth at posterior end, are masses of lymphoid tissue.
Duodenum:
extends from the pyloric sphincter for about 25 cm (10 inches) and curves around the head of the pancreas; most of the duodenum lies in a retroperitoneal position.
palatopharyngeal arch:
extends from the soft palate to the pharyngeal wall.
The human liver has four lobes and is suspended from the diaphragm and anterior abdominal wall by the __________.
falciform ligament
Epiploic appendages:
fat-filled pouches of visceral peritoneum that hang from the colon's surface.
The posterior soft palate is:
fibromuscular structure that is unsupported by bone.
Villi:
fingerlike projections of the mucosa tunic that give it a velvety appearance and texture.
Uvula:
fingerlike projections of the soft palate extend inferiorly from its posterior margin.
The alimentary canal wall has four basic layers or tunics:
from the lumen outward are the: mucosa, submucosa, muscularis externa, and either a serosa or adventitia. *each of these layers has a predominant tissue type and specific function in the digestive process.
small green sac on the inferior surface of the liver where bile is stored.
gall bladder
Within the mucous membrane-lined cavity are the:
gums, teeth, tongue, and openings of the ducts of the salivary glands.
The anterior portion of the hard palate is referred to as the ________ because the palatine process of the maxillae and horizontal plates of the palatine bones underlie it.
hard palate
Stellate macrophages, special phagocytic cells also called ________, line the sinusoids and remove debris such as bacteria from the blood as it flows past, while the hepatocytes pick up oxygen and nutrients.
hepatic macrophages
Inflammation of the liver:
hepatitis
Bile is continuously being made by the _______.
hepatocytes
Each lobule is basically a hexagonal structure consisting of cordlike arrays of _______ which radiate outward from a central vein running upward in the longitudinal axis of the lobule.
hepatocytes (liver cells).
The major duodenal papilla, an orfice controlled by a muscular valve called the _________ _________:
hepatopancreatic sphincter
The pancreas exocrine secretion includes many ________ enzymes produced by the acinar cells and is secreted into the duodenum through the pancreatic ducts.
hydrolytic
Any residue remaining undigested and unabsorbed at the terminus of the small intestine enters the large intestine through the ___________ __________.
iliocecal valve
Teeth are classified as:
incisors, canines (cuspids), premolars (bicuspids), molars.
Blockage of the ducts is one cause of ________.
jaundice
The ascending colon turns at the _______ ____ ______ _____ and continues down the left side of the abdominal cavity as the descending colon.
left colic (splenic) flexure
The ________, the largest gland in the body, is located inferior to the diaphragm, more to the right than the left side of the body.
liver
Bile is formed in the ___________ and stored in the ___________.
liver, gallbladder
The liver is very important to the initial processing of the nutrient-rich blood draining the digestive organs. Its structural and functional units are called _______.
lobules
Enzymes produced by the pancreas are ducted into the duodenum largely via the _______ ______ ________.
main pancreatic duct
Lingual frenulum:
membrane that secures the inferior midline of the tongue to the floor of the mouth.
Microvilli:
microscopic projections of the surface plasma membrane of the columnar epithelial lining cells of the mucosa.
body of stomach
midportion of the stomach and largest region.
Alimentary canal consist of:
mouth, pharynx, esophagus, stomach, and small and large intestines.
The floor of the oral cavity is occupied by the ________, which is largely supported by the __________, and attaches the hyoid bone, mandible, styloid processes, and pharaynx.
muscular tongue; mylohyoid muscle
The pharynx is divided into 3 parts:
nasopharynx: behind nasal cavity oropharynx: behind oral cavity extending from soft palate to epiglottis. laryngopharynx: behind the larynx extending from epiglottis to base of larynx.
Food enters the digestive tract through the _________?
oral cavity or mouth.
The _______ is a soft triangular gland that extends horizontally across the posterior abdominal wall from the spleen to the duodenum. Like the duodenum it is a retroperitoneal organ.
pancreas
The sigmoid colon, rectum, and anal canal lie in the ___________ anterior to the sacrum and thus are not considered abdominal cavity structures.
pelvis
The small intestine is suspended by a double layer of ______________, the fan-shaped mesentery, from the posterior abdominal wall.
peritoneum
At each of the six corners of the lobule is a _________, so named because three basic structures are always present there: a portal arteriole (a branch of the hepatic artery, the functional blood supply of the liver), a portal venue (a branch of the hepatic portal vein carrying nutrient-rich blood from the digestive viscera).
portal triad
Lips (labia) funtion:
protect the anterior opening, the oral orifice.
digestive system
provides the body with nutrients, water, and electrolytes essential for health. These organs serve to ingest, digest, and absorb food and eliminate the remains.
The small intestine extends from the __________ to the ileocecal valve.
pyloric sphincter
Except for the transverse and sigmoid colons, the colon is ___________________.
retroperitoneal
One component of saliva, ________________, begins the digestion of starchy foods within the oral cavity.
salivary amylase
Gastric Glands of the mucosa:
secrete hydrochloric acid (HCI) and hydrolytic enzymes.
It takes an S-shaped course as the ____________ colon.
sigmoid
BETWEEN THE LIVER CELLS ARE BLOOD FILLED SPACES, ____________ THROUGH WHICH BLOOD FROM THE HEPATIC PORTAL VEIN AND HEPATIC ARTERY PERCOLATES
sinusoids
Nearly all nutrient absorption occurs in the _______. Where three structural modifications increase the absorptive surface of the muscosa: Microvilli, Villi, Ciruclar Folds.
small intestine
The ________ _________ is a convoluted tube 6 to 7 meters (about 20 ft long) in a cadaver, but only about. 2 m (6 ft) long during life because of its muscle tone.
small intestine
Haustra:
small pocketlike sacs.
The stomach contains a third (innermost) layer obliquely oriented layer of _________ in its muscularis externa that allows it to churn, mix, and pummel food into smaller fragments.
smooth muscle
Oral vestibule:
space between teeth and cheeks
The stomach is a temporary ________ region for food as well as a site for ______ and ___________ breakdown of food.
storage mechanical chemical
Alimentary Canal Wall Layers: Mucuosa (3) subdivision of layer
subdivision of the layer: (1) Epithelium Tissue Type: Stratified squamous epithelium in mouth, oropharynx,laryngopharynx, esophagus,and anus; Simple Columnar Epithelium in the remainder of the canal. Function: secretion of mucous, digestive enzymes, and hormones; absorption of end products into the blood, protection against infectious disease. (2) Lamina propria Tissue type: areolar connective tissue w/ blood vessels. mainly lymphoid follicles. (3) Muscularis Mucosae: a thin layer of smooth muscle.
Accessory structures include:
teeth: physically break down food. salivary glands, gallbladder, liver, and pancreas (which secret their products into the alimentary canal.
fundus of stomach
the dome-shaped area that is located superior and lateral to the cardia.
The cheeks form:
the mouths lateral walls, and its palate (roof).
Ileum:
the terminal portion of the small intestine is about 3.6 m ( 12 ft long) and joins the large intestine at the ileocecal valve. It is located inferiorly and somewhat to the right in the abdominal cavity, but its major portion lies in the pubic region.
The mucosal glands also secrete a __________ mucous that helps prevent the stomach itself from being digested by the proteolytic enzymes.
viscous
Diarrhea
watery stool.
