Chapter 24 Digestive System Review

What are the major organs of the digestive system?

Oral Cavity - Ingestive with accessory organs (teeth, tongue)

Pharynx

Esophagus - Transport of material to stomach

Stomach - Chemical digestion of materials by acid and enzymes

Small intestine - Absorption of water, organic substrates, vitamins, ions

Large intestine - Dehydration and compaction of indigestible materials

What are the 6 intergrated processes of the digestive system?

Ingestion - Occurs when food enters body

Mechanical digestion and propulsion - Crushing & shearing food

Chemical digestion - breakdown of food into small organic fragments for absorption

Secretion - Release of water, acids, enzymes, buffers, salts

Absorption - Movement or of organic molecules, electrolytes, vitamins, minerals, and water

Defecation - Elimination of wastes from body

Define the Histology of the digestive tract, what are the major layers?

Mucosa

Submucosa

Muscular layer

Serosa

Where do the longitudinal folds in?

The empty stomach.

Where do the permanent transverse folds in?

The small intestine

What are the four functions of the Oral Cavity?

1. Sensory analysis

2. Mechanical Digestion (via teeth, tongue)

3. Lubrication (mixing with mucus and saliva)

4. Limited chemical digestion

What is the function of the Uvula?

Function of the Uvula is to prevent food from entering pharynx too soon

What is the tongue’s function (theres 4)

1. Mechanic digestion (compression, abrasion, distortion)

2. Manipulation to assist in chewing and to prepare food for swallowing

3. Sensory via touch, temperature, and taste

4. Secretion of mucins and lingual lipase

What is the function of Enamel in teeth?

Function of enamel is to cover the dentin.

What is the the cusp in teeth?

The cusp are the elevation.

What type of tooth is this?

What is its function?

Incisors

Used for clipping or cutting

What type of tooth is this?

What is its function?

Canines

Used for tearing or slashing

What type of tooth is this?

What is its function?

Premolars

Used to crush, mash, grind

What type of tooth is this?

What is its function?

Molars (two - three roots )

Used for crushing and grinding

What is another word for Deciduous teeth?

How many of them does a person have?

Baby teeth.

20 temporary teeth.

In terms of permanent teeth, how do they replace deciduous teeth?

How many permanent teeth do you have?

Via Eruption

32 Permanent teeth.

What salivary gland is this?

What is the function?

Parotid gland

Function is to produce secretions

What salivary gland is this?

What is the function?

Sublingual gland

Function is to produce mucus (acts a buffer)

What salivary gland is this?

What is the function?

Submandibular gland

Function is to secrete buffers, mucins, and salivary amylase

What percentage of water is saliva?

What is the remaining percentage consist of?

Saliva is 99.4% water

Remaining is electrolytes, buffers, antibodies, waste

What does saliva keep pH of mouth near?

7

Define Mastication

Chewing

(True or false) Tongue compacts chewed food into a bolus (rounded ball)

True

Define Deglutition, and can it be initaited voluntarily?

Deglutition is swallowing, can be initiated voluntarily, but proceeds automatically.

What are the major functions of the stomach?

Storage of ingested food

Mechanical digestion with muscular contractions

Chemical digestion of food with acid or enzymes

Define Chyme

Partially digested food mixed with acidic secretions of stomach.

(True or false) Nutrients are NOT absorbed in stomach.

True

What is the function of rugae?

Allow for expansion of gastric limen

How many mL of gastric juice does the gastric glands secrete?

1500mL

What do parietal cells secrete?

Hydrochloric acid.

What type of epithelium lines the stomac?

Simple columnar

What do chief cells secrete?

Pepsinogen

What do G cells release?

Somatostatin

What does the pancreatic lipase do?

Breaks down certain complex lipids.

What does the Nucleases do?

Breakdown of RNA or DNA

What are the 3 Proenzymes secreted by pancreas?

Trypsinogen

Chymotrypsin

Procarboxypeptidase

What is the liver divided into?

What does the liver secrete?

Left and right lobes

Caudate lobe

Quadrate lobe

Liver secretes bile.

(True or false) All blood leaving absorptive surfaces of digestive tract enters hepatic portal system.

True

(True or false) Liver removes and stores excess nutrients

True

What do the activities of the liver affect?

Carb metabolism

Lipid metabolism

Amino acid metabolism

Waste removal

Vitamin storage

(True or false) Liver recevives about 25 percent of cardiac output

(True or false) Liver is the largest blood reservoir in the body

True

True

What are the hematological regulation by the liver involve?

-              Synthesis of plasma proteins

-              Removal of circulating hormones

-              Removal of antibodies

-              Removal or storage of toxins

(True or false) Bile salts in bile break lipid apart emulsification in duodenum

(True or false) Gallbladder stores and concentrates bile prior to secretion

True

True

What are the 3 segments of the small intestine

Duodenum

Jejunum

Illeum

(True or false) Lacteal transports chylmicrons that are too large to enter blood capillaries

True

What are the major hormones of duodenum

-              Gastrin (contraction)

-              Secretin (activates)

-              GIP

-              CCK

-              VIP

-              Enterocrinin

What is the function of the Ileocecal valve

The Ileocecal valve is the connecting point between small intestine and large, open and closes to allow food to go one way

What are the 3 parts of the large intestine

Cecum

Colon

Rectum

What is the haustra

little folds

What are the four regions of the colon?

Ascending colon

Transverse colon

Descending colon

Sigmoid colon

(True or false) Large intestine lacks villi, and is dominated by goblet cells

True

Functionals or large intestine

Absorption or reaction of water nutrients bile salts and organic wastes

Compaction of feces, storage of fecal material

Why produces the “rotton egg” odor

Hydrogen sulfide

What is a balanced diet

-              Carbs

-              Lipids

-              Proteins

-              Vitamins

-              Minerals

-              Water

What are the water - soluble vitamins?

B’s and C’a

What are the fat - soluble vitamins

A

D

E
K