Model Building - Digestive System Organs



Unit 13 Notes: The Digestive System

Use the diagrams in the PPT and textbook to label the digestive system structures below. Look closely to see which line is pointing to each structure.

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1. Our only digestive decisions are:

a.Whether or not to eat

b.What to eat

c. After that, all processes are involuntary.

2. What are the 2 main groups of organs and their functions? List the organs involved.

a.

b.

3. Describe/define the 6 essential activities of the digestive process.

a. The process of taking food into the digestive tract by mouth is known as ____________________________________.

b. __________________________________ constitutes the processes that move food through the alimentary canal. The major means of propelling food through the digestive tract is known as ______________________________________. This process involves alternate waves of __________________________________ & ____________________________________ of muscles in the organ walls.

i. In the process of segmentation, _______________________________segments of the intestine alternately contract and relax. This results in the _____________________________ of food since the food is moved forward and then backward.

ii. Review: Explain how peristalsis is different from segmentation: (describe & purpose)

c. __________________________ digestion physically prepares food for chemical digestion. Examples of these physical processes include:

1.

2.

3.

d. Chemical digestion is a(n) catabolic process in which large food molecules are broken down by ______________________ .

e. Absorption is the transport of digested end products from the lumen of the ____________________________________ (organ) to the ______________________.

f. Defecation: _______________________________________________________

Structures of the Digestive System

I. Mouth

A. Why is the epithelium on the gums, hard palate, and dorsal surface of tongue keratinized?

B. Lips and cheeks

1. keep food between teeth when we chew

2. play a role in _____________________________

C. Palate

1. hard palate & soft palate

2. Reminder: What happens during swallowing so that we do not aspirate food into the lungs or into the nose?

II. Tongue

A. Functions

1. speech movements

2. mixes food with _____________________

3. forms food bolus: Use glossary to define bolus - _________________________________________________________________________

B. Internet: What are the specific functions of the intrinsic & of the extrinsic muscles of the tongue?

C. Lingual Frenulum

1. secures tongue to floor of mouth

2. limits _________________________ movements

3. tongue tied: _________________________________________________________ _________________________________________________________________________________________________________________________

D. Papillae: give specific location on tongue (see picture)

1. filiform: give tongue ___________ so you can lick ice cream off of a cone (cats have lots of these so tongues are rough) Located: ____________________________

The next 3 types are taste buds:

2. fungiform: Located: ______________________________________________

3. (circum)vallate: Located:____________________________________________

4. foliate: Located: ___________________________________________________

III. Salivary Glands

A. 4 functions of saliva

1. The mucous cells produce ________________________________________________________

2. The clear serous fluid portion contains an enzyme _________________________ (produced by the serous cells) which begins the chemical digestion of _________________________________________________

B. Salivary Glands: know the location & type of secretion

IV. Pharynx

A. 2 muscular layers (circular & longitudinal) cause ________________ waves to move food

B. Oropharynx and laryngopharynx are common passageways for ________________, ________________ & ____________________.

C. Nasopharynx has no _________________________ role (unless you laugh so hard that you blow your soda through your nose !!!)

V. Esophagus

A. ________________ inches long

B. epiglottis routes food into it

C. goes through the diaphragm to join stomach at ___________________________ sphincter

End of Quiz #1 Material– Includes diagram on front page

VI. Stomach

A. Function: site of mechanical & chemical breakdown

B. ~ 10 inches long on ____________________ side of abdomen and can hold _______________________ L of food when filled

C. __________________ sphincter: controls stomach emptying into small intestine

D. _____________________ – large longitudinal folds that help mix food in stomach

E. The parietal cells of the stomach produce ___________________________ factor that is needed for the absorption of _____________________________________________________. A deficit of either of the above substances can cause ________________________________ anemia

F. It takes the stomach about _______________ hours to empty.

G. What do the mucus neck cells produce & why is this mucosal barrier so very important?

H. What are the 3 main components of the gastric mucosal barrier?

I. Briefly describe the 3 phases of gastric secretion.

|Phase |Action |

| | |

| | |

| | |

J. define chyme: ___________________________________________________________

K. Gastric/Peptic Ulcer

a. Define:

b. Most ulcers are caused by bacteria ______________________________________.

c. Aggravated by:

d. Dangers:

VII. Small Intestine: Body’s major digestive organ

_____ meters long (~21 feet) but only ___ inch in diameter

B. suspended by ______________ (membrane) in the abdominal cavity

C. List & describe the 3 sections of the small intestine & give their approx. length

a.

b.

c.

D. Function: ________________________________________________________________ – huge surface area due to length and modifications

E. List & define the 3 structural modifications in the SI that increase SA

a.

b.

c.

F. What do Peyer’s patches do and why is this important?

Liver

A. many metabolic & regulatory functions

B. Only digestive function: produce _____________ for export to duodenum. Bile is used to ____________ fats – distributes fat in solution to be accessible to digestive enzymes.

C. _____ lobes - Largest gland – weights _______ lbs - Very vascular

Gallbladder

______ inches long

A. thin walled, greenish sac

B. store & concentrate __________________________

Pancreas

A. principal ____________________ producing organ of digestive system

B. the acinar cells secrete _______________________________ for digestion

C. The Islets of Langerhans produce two hormones _____________________ & ________________ to regulate ________________________.

Sketch the Negative Feedback Mechanism for Blood Glucose Regulation

Large Intestine (Colon)

A. _______ feet long

A. What are the major functions of the large intestine?

B. List the subdivisions of the LI.

| |Soluble fiber |Insoluble fiber |

|Define | | |

|What it does | | |

|examples | | |

C. List the 6 benefits of dietary fiber.

D. Why is the appendix a trouble spot?

E. What is the difference in functions of the internal and external anal sphincters?

End of Quiz #2 Material – includes diagrams of stomach & liver

Complete Summary of Enzymes Chart

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Anus

Appendix

Ascending colon

Descending colon

Duodenum

Esophagus

Gall bladder

Ilium

Jejunum

Liver

Oral cavity

Pancreas

Parotid gland

Pharynx

Rectum

Sigmoid colon

Spleen

Stomach

Sublingual gland

Submandibular gland

Tongue

Transverse colon

Uvula/soft palate

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a. The four paired extrinsic muscles ________________, _____________, ________________, and ___________ the tongue.

b. The four paired intrinsic muscles alter the shape of the tongue by: _____________ and ______________ it, ____________ and ___________________ its apex and edges, and ____________________ and ______________________ its surface.

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1. What happens when the cardioesophageal sphincter fails to close tightly?

2. Why can this damage the esophagus?

3. What are some complications of GERD?

4.

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Note the different regions

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Cardioesophageal sphincter

Fundus

Greater curvature

Lesser curvature

Pyloric sphincter

Body

Rugae

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Folds are called ___________________

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Falciform ligament

Liver (lobes)

Gall bladder

Common bile duct

Common hepatic duct

Cystic duct

Pancreatic duct

Pancreas

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Add sigmoid flexure and cecum to diagram

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