A&P II Ch 15 Digestion and Nutrition

-------tonsils are lymphatic tissues located on the roof of the tongue.

Lingual

Submandibular Glands

Located in the floor of the mouth, on the inside surface of the lower jaw. The secretory cells of these glands or about equally serous and mucus, and secrete a more viscous fluid.

Parotid Glands

Lying in front of the ear, are the largest of the major salivary glands; they secrete a clear watery fluid (serous) rich in salivary amylase.

Submucosa

Made up of loose connective tissue as well as glands,blood blood vessels, lymphatic vessels and nerves. It's vessels nourish surrounding tissues and carry away absorbed materials.

Regulation of small intestinal secretions:

Mechanical and chemical stimulation from chyme causes goblet cells to secrete mucus. Distention of the intestinal wall stimulates parasympathetic reflexes that stimulate secretions from the small intestine.

Mucus

Mucous cells secrete a thick liquid, which binds food particles and acts as a lubricant during swallowing.

Mixing movements

Occurs when smooth muscles in small segments of the tube contract rhythmically

Pharyngeal Tonsils

Other masses of lymphatic tissue or adenoids are on the posterior wall of the pharynx above the border of the soft palate.

Pancreatic Duct

Pancreatic Acinar cells cluster around tiny tubes that merge to form larger ones, and then give rise to the ---------- ----.

What are these enzymes?

Peptidases, intestinal lipase, sucrase, Maltase, lactase

Mucous Cells

Produce thick fluid (mucus)that protects the stomach lining.

Mucous Cells

Produce thick fluid that protects the stomach lining.

Inactive form (Zymogen granules)

Protein digesting enzymes are released in an -------- ---- and are activated upon reaching the small intestine.

What types of macromolecules are digested by the enzymes found in pancreatic juice?

Proteins, starch, and glycogen, triglycerides and nucleus acids

Muscular layer

Provides movements of the tube consist of two coats of smooth muscle tissue. The fibers of the inner coat encircle the tube. When the circular fibers contract the tubes diameter decreases. The fibers of the outer muscular coat run lengthwise. Wendy's longitudinal fibers contract, the tube shortens.

Digestion

Refers to the mechanical and chemical breakdown of foods so that nutrients can be absorbed by cells.

Laryngopharynx

(Bottom portion) just inferior to the Oropharynx is a passageway to the esophagus.

Primary teeth

(Decidous teeth) usually erupt through the gums (gingiva) at regular intervals between the ages of six months and 2 to 4 years old. There are 20 decidous teeth, 10 in each jaw. They usually shed in the same way they erupted.

Oropharynx

(Middle portion) is posterior to the soft palate and inferior to the Nasopharynx it is a passageway for food moving downward from the mouth and for air moving to and from the nasal cavity.

Secondary teeth

(Permanent teeth) push the primary teeth out of their sockets. Consists of 32 teeth 16 in each Jaw. Usually begin to erupt at six years but the set me not be complete until the third molars emerge between 17 to 25 years old.

Nasopharynx

(Top portion) communicates with the nasal cavity and provides a passageway for air during breathing.

Cholecystokinin

--------------- from the wall of the small intestine stimulates the release of pancreatic juice with abundant digestive enzymes.

Accessory organs of the digestive system

Salivary glands liver gallbladder, pancreas

Parietal Cells

Secrete hydrochloric acid.

Chief Cells

Secrete pepsinogen which is activated when it comes in contact with hydrochloric acid becoming pepsin.

Chief Cells

Secrete pepsinogen, which is activated when it comes in contact with hydrochloric acid. The active form of Pepsinogen is pepsin.

Salivary Glands

Secrete saliva which moistens and dissolves food particles, binds them together, allows tasting, helps to cleanse the mouth and teeth, and begins carbohydrate digestion.

Common Hepatic Duct

Secretions from hepatic cells are collected in bile canals that converge to become hepatic ducts and finally form the ------ ------- ----.

The Mesenteries

Support blood vessels, nerves, and lymphatics that serve the intestinal wall.

The digestive system consist of

The alimentary canal through which the food passes and the accessory organs that aid in digestion

Pancreatic Acinar Cells

The cells that produce pancreatic juice, and make up the bulk of the pancreas.

The small intestine consists of what three parts?

The duodenum, jejunum, and ileum

Mouth

The first portion of the alimentary canal, it functions to receive food and begins mechanical digestion by mastication. The oral cavity is the chamber between the pallet and tongue. The narrow space between the teeth, cheeks, and lips is called the vestibule.

Secretin

The hormone -------- from the duodenum stimulates the release of pancreatic juice with a high bicarbonate ion concentration, but few digestive enzymes.

Mucosa or mucous membrane

The inner layer which is lined with epithelium attached to connective tissue. It protects tissues of the canal and carries on secretion and absorption. In some regions the mucosa is folded with tiny projections that extend into the passageway or lumen of the digestive tube.

Structure of the Small Intestinal Wall:

The inner wall of the small intestine is lined with fingerlike intestinal villi, which greatly increase the surface area available for absorption and aid in mixing actions. Each villus contains a core of connective tissue housing blood capillaries and a lymphatic capillary called a lacteal. Between the bases of adjacent villi are tubular intestinal glands.

Serosa or serous layer

The layer of epithelium on the outside and the connective tissue beneath compose the serous layer or outer covering of the tube also called the visceral peritoneum. The cells of the serosa protect underlying tissues and secrete serous fluid, which moistens and lubricates the tubes outer surface so that organs within the abdominal cavity slide freely against one another.

Liver Structure:

The liver is divided into right and left lobes and is enclosed by a fibrous capsule. Each lobe is separated into hepatic lobules consisting of hepatic cells radiating from a central vein. Hepatic sinusoids separate groups of hepatic cells.

Liver Functions:

The liver is responsible for the metabolism of many chemicals such as carbohydrates, lipids, and proteins. The liver also stores glycogen, vitamins A, D and B 12, iron and blood. The liver filters the blood, removing damaged red blood cells and foreign substances, and removes toxins. The livers role in digestion is to secrete bile.

3 stages of Swallowing:

1) food is mixed with saliva forming a bolus, and voluntarily forced into the Oropharynx with the tongue 2) sensory receptors in the pharynx sense food, which triggers swallowing reflex. 3) peristalsis transports the food in the esophagus to the stomach.

Fats may be in the stomach for? Proteins and carbohydrates?

3-6 hours, proteins and carbohydrates pass through quickly.

Pharynx

A cavity lying behind the mouth. It functions in both the digestive and respiratory systems. It connects the nasal and oral cavities with the larynx and esophagus. It has three parts.

Uvula

A muscular arch of the soft palate extends posteriorly and downward as a cone-shaped projection. It's function is to close off the nasal cavity during swallowing.

Gallbladder

A pear-shaped sac lying on the interior surface of the liver. It is connected to the cystic duct, which joins the hepatic duct, these two ducts merge to form the common bile duct leading to the duodenum. A sphincter muscle controls the release of bile from the common bile duct. Stores bile between meals and reabsorbs water to concentrate the bile. Contraction releases bile into the duodenum.

Liver

A reddish-brown organ located in the upper right quadrant of the abdominal cavity is the body's largest internal organ.

Tongue

A thick muscular organ covered by a mucous membrane with taste buds located on rough projections called Pappillae which provides friction and helps handle food. It is attached to the floor of the mouth by the lingual frenulum.

Salivary Amylase

A watery fluid produced by serous cells. This enzyme splits starch and glycogen molecules into disaccharides, the first step in the chemical digestion of carbohydrates.

Bile

A yellowish green liquid that hepatic cells secrete it includes water, bile salts, bile pigments, cholesterol, and electrolytes. Bile pigments are breakdown products from red blood cells. Only the bile salts have a digestive function.

Small intestine

About 20 ft receives secretions from the Pancreas and liver, completed digestion of the nutrients in chyme absorbs the products of digestion, and transports the remaining residues to the large intestine.

Large Intestine:

Absorbs water and electrolytes and forms and stores feces.

List the pancreatic enzymes

Amylase, lipase, proteases, nucleases

Intrinsic Factor

Another component of gastric juice, helps the small intestine absorb vitamin B12.

Intrinsic Factor

Another component of gastric juice, required for vitamin B12 absorption from the small intestine.

Intestinal Glands

At the bases of the villi secrete large amounts of watery fluid that carry digestive products into the villi.

Ileocecal Sphincter

At the distal end of the small intestine, joins the small intestines ilium to the large intestines cecum. Usually remains closed unless a Gastroileal reflex is elicited after a meal.

Teeth

Begin mechanical digestion by breaking pieces of food into smaller pieces. This action increases the surface area of food particles, allowing more digestive enzymes access to the food molecules.

Function and Regulation of the Gallbladder:

Bile does not normally enter the duodenum until cholecystokinin stimulates the gallbladder to contract. The hepatopancreatic sphincter remains contracted unless a peristaltic waves approaches it, at which time it relaxes and a squirt of bile enters the duodenum. Bile salts emulsify fats into smaller droplets, and aid in the absorption of fatty acids, cholesterol, and certain vitamins.

Incisor

Bite off pieces of food

Chemical digestion

Breaks food into simpler chemicals

Mechanical digestion

Breaks large pieces into smaller ones without altering their chemical composition

Hepatic Portal Vein

Carries blood rich in absorbed nutrients to the liver.

Kupffer Cells

Carry on phagocytosis in the liver.

Goblet Cells

Cells that secrete mucus in the small intestine, which are abundant throughout the mucosa.

Pyloric Sphincter

Controls release of food from the stomach into the small intestine.

Pyloric sphincter

Controls release of food from the stomach into the small intestine.

Great Omentum

Draped over the intestine

Microvilli

Epithelial cells of the mucosa have embedded digestive enzymes on their tiny hair like______.

Alimentary canal

Extends from the mouth to the anus and several accessory organs which secrete substances into the canal used in digestion. Includes the mouth pharynx esophagus stomach small intestine large intestine and rectum and anus.

What factors regulate the rate of stomach emptying?

Fluidity of chyme and type of food

Mixing and Emptying Actions

Following a meal, mixing actions of the stomach turn the food into chyme and pass it toward the pyloric region using peristaltic waves

Cheeks

Form the lateral walls of the mouth, consist of outer layers of skin, pads of subcutaneous fat, mussels associated with expression and chewing and interlinings of Moist stratified squamous epithelium.

Palate

Forms the roof of the oral cavity and consist of a bony anterior part (hard palate) and a muscular posterior part (soft palate)

Together products of mucous cells, chief cells, and parietal cells form-----.

Gastric Juice

Gastrin

Gastric secretions are enhanced by parasympathetic impulses and the hormone -------, which is released from gastric glands.

Gastrin

Gastric secretions are enhanced by parasympathetic impulses and this hormone, which is released from gastric glands.

Canine

Grasp and tear food

Premolars/Molar

Grind food particles

Pancreas

Has an exocrine function of producing pancreatic juice that aids digestion and is closely associated with the small intestine

Lower Esophageal Sphincter

Helps to prevent regurgitation of the stomach contents into the esophagus.

Lips

Highly mobile structures that surround the mouth opening. They contain skeletal muscles and sensory receptors useful in judging the temperature and texture of foods.

Palatine Tonsils

In the back of the mouth. On either side of the tongue and closely associated with the palate are masses of lymphatic tissue these structures lie beneath the epithelial lining of the mouth and like other lymphatic tissues, help protect the body against infection.

Segmentation

In the small intestine, aids mixing by alternately contracting and relaxing the smooth muscle in nonadjacent segments of the organ. Because segmentation follows a back and forth pattern, materials are not moved along the tract in one direction.

Propelling movements

Include a wavelike motion called Peristalsis, which is caused by contraction behind a mass of food as relaxation allows the mouse to enter the next segment of the tube.

Sublingual Glands

Inferior to the tongue the smallest of the major salivary glands. Their secretory cells are primarily the mucous type, making their secretions thick and stringy.

Stomach

Is A J shaped muscular organ in the upper left abdominal quadrant that uses gastric juices to begin protein digestion.

The Stomach

Is a J shaped muscular organ that uses gastric juices to begin protein digestion.

Esophagus

Is a food passageway from the pharynx to the stomach. Mucous glands are scattered throughout the walls and produce mucus to moisten and lubricate the inner lining of the tube.

The Duodenum

Is the shortest and most fixed portion of the small intestine; the rest is mobile and lies free in the peritoneal cavity.

Regulation of Pancreatic Secretion:

The nervous and endocrine systems regulate release of pancreatic juice.

Hepatopancreatic Sphincter

The pancreatic and bile ducts join and empty into the small intestine which is regulated by the ---------------- ---------.

Cholecystokinin

The presence of fats and proteins in the upper small intestine causes the release of ------------- from the intestinal wall, which also decreases gastric motility

Movements of the small intestine:

The small intestine carries on segmentation and peristaltic waves. Movements are slow taking 3 to 10 hours to travel it's length.

Mesentery

The small intestine is suspended from the posterior abdominal wall by a double layered fold of peritoneum called ______.

Gastric Absorption

The stomach absorbs only small quantities of water and certain salts, alcohol, and some lipid soluble drugs.

Gastric Glands

Within the mucosa of the stomach open as gastric pits. These glands generally contain three types of secretory cells.

Gastric glands

Within the mucosa of the stomach open as gastric pits. These glands generally contain three types of secretory cells.