SCIT 1408 Applied Human Anatomy and Physiology II - Digestive System Chapter 23 A

8/18/2019 SCIT 1408 Applied Human Anatomy and Physiology II - Digestive System Chapter 23 A

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Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings

Digestive System Functions:

Digestion & Absorption

Alimentary canal Mouth

Pharynx

Esophagus

Stomach

Small intestine

Large intestine

Accessory digestive organs Teeth

Tongue

Gallbladder

Salivary glands

Liver

Pancreas


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Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Figure 23.1

1.

.

!.

".#.

$.

The %igestive Tract


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Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Figure 23.2

Ta&ing 'ood in

(ontraction)relaxation

(atabolic

rxns

movement o' nutrients 'rom the

G* tract to the blood or lymph

+aste

elimination InterActive Physiology®:

Motility, pages 3-5


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Peristalsis and Segmentation

Figure 23.3

Peristalsis , pushes 'ood thru in

1 directionSegmentation- bac&

'orth/ mixing propulsion


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Intrinsic!"trinsic #ontrol o$ t%e I 'ract

Figure 23.(

InterActive Physiology®:

Control of the Digestive System,

pages 3-8


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Peritoneum and Peritoneal #avity

Figure 23.)a

smaller


7/33Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings

Peritoneum and Peritoneal #avity

Figure 23.)b



*lood Supply: Splanc%nic #irculation

Arteries0

epatic2 splenic2 le't gastric

*n'erior and superior

mesenteric

3rgans served0

Spleen2 liver2 stomach

Small and large intestines

epatic portal circulation0

(ollects nutrient rich venous blood 'romdigestive visera delivers it to liver 'or

metabolism



+istology o$ t%e Alimentary #anal

Figure 23.,



-ayers o$ Alimentary #anal: ucosa

Stuctures:

1.Epithelium- Simple columnar epithelium2 goblet cells

$. Lamina propria- areolar2 lymphoid

#. Muscularis mucosae- local movements o' mucosa

Functions:

1. Secretion o' mucus-Protects organs 'rom auto digestion

$. Absorption o' end products o' digestion

#. Protection against in'ectious disease



-ayers o$ Alimentary #anal:

Sumucosa , dense connective tissue/

Elastic 'ibers

4lood2 lymphatic vessels2 lymph nodes2 nerves

Muscularis e!terna , circular2 longitudinal muscle

Segmentation

Peristalsis

Serosa , protective visceral peritoneum 5eplaced by the 'ibrous adventitia in the esophagus

5etroperitoneal organs have both an adventitia and serosa



!nteric /ervous System

$ intrinsic nerve plexuses0

Submucosal nerve plexus , regulates glands and

smooth muscle in the mucosa

Myenteric nerve plexus , Ma6or nerve supply thatcontrols G* tract mobility

Segmentation and peristalsis are largely automatic

involving local re'lex arcs

Lin&ed to the (7S via long autonomic re'lex arc

P-A0P-A0 InterActive Physiology :

#ontrol o$ t%e Digestive System page )


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out%

3ral or buccal cavity0

lips2 chee&s2 palate2 tongue

strati'ied s8uamous epithelium

gums2 hard palate2 dorsum o' tongue &eratini9ed

P-A0P-A0 InterActive Physiology :

Anatomy evie4 page (


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Anatomy o$ t%e 5ral #avity: out%

Figure 23.6a


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5ral #avity and P%aryn": Anterior 7ie4

Figure 23.6b

:Tongue tied;


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'ongue

s position

Lingual 'renulum- secures the tongue to the 'looro' the mouth/ short? tongue tied/ surgical repair


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'ongue

Superior sur'ace bears three types o' papillae


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'ongue

Figure 23.8


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Salivary lands

Produce and secrete saliva that0

(leanses the mouth

Moistens and dissolves 'ood chemicals

Aids in bolus 'ormation

(ontains en9ymes that brea& do=n starch Extrinsics0 Parotid2 Submandibular2 Sublingual/ digestion

*ntrinsic0 Throughout the oral mucosa/ moisture

Serous cells- ma&e saliva Mucus cells- ma&e mucus

Strong sympathetic stimulus" #ry mouth

InterActive Physiology®:

Secretion, pages 3-5


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Salivary lands

Figure 23.9a

1.

#.

$.

MCMPS


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Saliva: Source and #omposition

D-DD.!F =ater2 hypo-osmotic2 slightly acidic

solution containing

Electrolytes , 7aG2 H G2 (l , 2 P3"$, 2 (3# ,

%igestive en9yme , salivary amylase Proteins , mucin2 lyso9yme2 de'ensins2 and *gA

Metabolic =astes , urea and uric acid


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'eet%

Primary and permanent dentitions have 'ormed by

age $1

Primary , $I deciduous teeth that erupt at intervals bet=een and $" months

Permanent , enlarge and develop causing the rooto' deciduous teeth to be resorbed and 'all out bet=een the ages o' and 1$ years

All but the third molars have erupted by the end o'adolescence

Csually #$ permanent teeth


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Deciduous 'eet%

Figure 23.1.1


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Permanent 'eet%

Figure 23.1.2


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$* 1( $PM #M

J $ @#$ teeth$* 1( $PM #M

Dental Formula: Permanent 'eet%

A shorthand =ay o' indicating the number and

relative position o' teeth

+ritten as ratio o' upper to lo=er teeth 'or the

mouth

Primary0 $* @incisors2 1( @canine2 $M @molars

Permanent0 $*2 1(2 $PM @premolars2 #M


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'oot% Structure

T=o main regions , cro=n and the root

(ro=n , exposed part o' the tooth above thegingiva

Enamel , acellular2 brittle material composed o'calcium salts and hydroxyapatite crystals/ thehardest substance in the body

Encapsules the cro=n o' the tooth

5oot , portion o' the tooth embedded in the 6a=bone


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'oot% Structure

7ec& , constriction =here the cro=n and root

come together

(ementum , calci'ied connective tissue

(overs the root Attaches it to the periodontal ligament


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'oot% Structure

Periodontal ligament

Anchors the tooth in the alveolus o' the 6a=


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'oot% Structure

%entin , boneli&e material deep to the enamel cap

that 'orms the bul& o' the tooth

Pulp cavity , cavity surrounded by dentin that

contains pulp

Pulp , connective tissue2 blood vessels2 and nerves


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'oot% Structure

5oot canal , portion o' the pulp cavity that extends

into the root

Apical 'oramen , proximal opening to the root

canal

3dontoblasts , secrete and maintain dentin

throughout li'e


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'oot% Structure

Figure 23.11


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'oot% and um Disease

%ental caries , gradual deminerali9ation o' enamel

and dentin by bacterial action

%ental pla8ue2 a 'ilm o' sugar2 bacteria2 and mouth

debris2 adheres to teeth

Acid produced by the bacteria in the pla8ue

dissolves calcium salts

+ithout these salts2 organic matter is digested by

proteolytic en9ymes

%aily 'lossing and brushing help prevent caries by

removing 'orming pla8ue


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'oot% and um Disease: Periodontitis Gingivitis , as pla8ue accumulates2 it calci'ies and

'orms calculus2 or tartar Accumulation o' calculus0

%isrupts the seal bet=een the gingivae and the

teeth Puts the gums at ris& 'or in'ection

Periodontitis , serious gum disease resulting 'rom

an immune response *mmune system attac&s intruders as =ell as body

tissues2 carving poc&ets around the teeth anddissolving bone

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SCIT 1408 Applied Human Anatomy and Physiology II - Digestive System Chapter 23 A