Introduction Of Splanchnology And Digestive Canal-ruan-2015.pptx

03-31-2015

Introduction:  Splanchnology is the scientific study of the viscera and its organs. Including :  Alimentary (Digestive) system 

Respiratory system,



Urinary system



Genital system.

General structures of viscera 1. Tubular organs  Center part – lumen  Peripheral part- wall (four layers) ① ② ③

④

Mucosa Submucosa Muscular layer Serosa or adventitia

2. Parenchymatous organs  Fibrous capsule  Lobules  Hilum or porta

Composition:  Digestive canal  Digestive glands

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Functions: ①Ingestion – taking food into the digestive tract ②Propulsion – swallowing and

peristalsis (waves of contraction and relaxation of muscles in the organ walls)

③Mechanical digestion – chewing, mixing, and churning food 5

Functions: ④Chemical digestion – catabolic breakdown of food

⑤Absorption – movement of nutrients from the GI tract to the blood or lymph ⑥Defecation – elimination of indigestible solid wastes.

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Components: 1. 2. 3. 4. 5. 6. 7.

Mouth Pharynx Esophagus Stomach Small Intestine Large intestine Anus

1. Mouth (Oral Cavity)  Oral cavity is divided into two parts: Vestibule –the space between lips externally and teeth and gums internally Oral cavity proper – the area behind the teeth  lateral wall - teeth  Roof : Hard palate (anterior) and Soft palate (posterior)  Floor: the area of the oral cavity beneath the tongue covered by muscles(mylohyoid)

Mouth (Oral Cavity)- roof and floor

1. Mouth (Oral Cavity)

(1) Palate Hard palate: anterior 2/3 Soft palate: posterior 1/3 Uvula: the little piece of flesh that hangs down from the rear portion of the soft palate.

(2) Isthmus of fauces  the constricted and short space that establishes the connection between the cavity of the mouth and the oropharynx, bounded anteriorly by the palatoglossal folds and posteriorly by the palatopharyngeal folds; the lateral wall is the tonsillar fossa (contains palatine tonsil).  These two folds are formed by the palatoglossus muscles and the palatopharyngeus muscle respectively, covered with mucous membrane.

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(3) Palatine tonsil on the left and right sides at the

tonsillar fossa. 

Tonsillitis is an inflammation of the tonsils and will often cause a sore throat and fever.



In chronic cases tonsillectomy

may be indicated.

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

A muscle on the floor of the mouth



Functions:



① Digestive organ -manipulates food and secretes saliva for chewing and swallowing.



② Taste organ - the upper surface of the tongue is covered

in papillae and taste buds. 

③Pronounce organ - speech.



④ Teeth cleaner

Division: 

Root( posterior to terminal sulcus)



Body(anterior to terminal sulcus



Apex

Two surfaces:  Dorsum or superior surface ① Papillae: 

Circumvallate papillae



Fungiform papillae



Filiform papillae

②Lingual tonsil: 

•

Rounded masses of lymphatic tissue that cover the posterior region of the tongue.

 Ventral or inferior surface ①Frenulum of tongue(f)

f

②sublingual caruncle (SC) at which the submandibular gland empties into the oral cavity.

SC

③sublingual fold (arrows)  It extends from the posterolateral aspect of the floor of the oral cavity to the sublingual papilla (sp)beside the base of the frenulum of the tongue at the midline anteriorly.

SC

sp

①Intrinsic muscles  Longitudinal  Transverse  Vertical ②Extrinsic muscles  Genioglossus  styloglossus  hyoglossus

①Division:  crown of tooth  Neck  root of tooth  Dental pulp cavity  Dental pulp  Root canal of tooth ②Dental tissues  Enamel  Cementum  Dentin ③Periodontal structure  Gums  Alveolar bone  Periodontal ligament

Neck

Gums Alveolar bone

Root canal

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④Two sets of teeth





Deciduous (milk):20



permanent: 28~32

Arrangement of the teeth

(from the midline to the lateral) 

Incisors(2)



Canine(1)



Premolars(2)



Molars(3)



The part of throat situated immediately posterior to the mouth and nasal cavity, superior

to the esophagus, larynx. 

Subdivisions: ①Nasopharynx ②Oropharynx ③Laryngolpharynx

Location:  the space behind the oral cavity, btw nasopharyx and laryngopharyx

② Nasopharynx Location: 

The space between the soft palate and the base of the skull, superior to the oral cavity, and posterior to nasal cavity through posterior nasal apertures.

② Nasopharynx Structures Features: Pharyngeal opening of auditory tube Tubal torus Pharyngeal recess Pharyngeal tonsil (Adenoid)  Waldeyer's tonsillar ring : an lymphoid tissue ring located in the pharynx and to the back of the oral cavity. 

 Formed by :

   

Pharyngeal tonsil(Adenoid) Tubal tonsil Palatine tonsils Lingual tonsils

Waldeyer's tonsillar ring

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Location: 

the portion of the pharynx below the upper edge of the epiglottis, opening into the larynx and esophagus.

Feature: 

Piriform recess ( piriform sinus)



the laryngeal orifice.

Function of Pharynx: 

Serves as a passageway for air and food

 An organ consists of a muscular tube through which food passes from the pharynx (C6) to the stomach (about 25-30cm long).  Subdivisions:  Cervical part  Thoracic part  Abdominal part Function:  conducts food from the mouth to the stomach by peristalsis (slow rhythmic squeezing)

 Three constrictions ①Pharyngoesophageal constriction - at its commencement, 15cm from the incisor ②Thoracic constriction crossed by left principal bronchus, 25cm

③Diaphragmatic constriction - passes through the diaphragm,40cm





 • • • •

•

A muscular, hollow, dilated part of the alimentary canal.

Location: between the esophagus and the small intestine. Anatomy of the Stomach Cardiac orifice(opening) Pyloric orifice (opening) Greater curvature Lesser curvature Angular incisure

Intermediate groove



Anatomy of the Stomach



The angular incisure 



used as separation point between the right and left portions of the stomach. An imaginary line drawn perpendicular to the lesser curvature of the stomach through the angular incisure makes up the boundary between the body of the stomach and pylorus.

Intermediate groove

Anatomy of the Stomach Divisions： ①Cardia-Where the contents of the esophagus empty into the stomach. ②Fundus-Formed by the upper curvature of the organ. ③Body or Corpus -The main, central region. ④Pylorus-The lower section of the organ that facilitates emptying the contents into the small intestine. 

Intermediate groove

Pylorus is divided into pyloric antrum and pyloric cannal by intermediate groove.

 Functions

of the Stomach

①Mix food ②Reservoir (the second phase of digestion ) ③mastication (chewing) ④Start digestion of (Protein, Nucleic acids and Fats) ⑤Activates some enzymes ⑥Destroy some bacteria ⑦Makes intrinsic factor – B 12 absorption

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The part of the gastrointestinal tract (gut) btw the stomach and the large intestine. Subdivisions:  Duodenum- attached to the stomach, curves around the head of the pancreas 

•

Jejunum- attaches anteriorly to the duodenum. Ileum - extends from jejunum to large intestine



The first section of the small intestine, a hollow jointed tube about 25-30 cm long connecting

the stomach to the jejunum. 

Subdivision:  1)Superior part: 3cm  2)Descending part: 8-10cm  3)Horizontal part: 10cm  4)Ascending part: 3 cm

Descending part:  Major duodenal papilla  Minor duodenal papilla  Hepatopancreatic ampulla 35

Comparison: • • • • • • •

Jejunum Ileum Location: ULQ LRQ Length 2/5 3/5 Calibre large small Circular fold more and higher lesser and lower Lymphatic Follicles solitary aggregated Arterial arcades one or two three or four

Jejunum and ileum Location: Length:

ULQ 2/5 LRQ

3/5 39

Jejunum and ileum Circular fold more and higher Lymphatic Follicles solitary Arterial arcades one or two

lesser and lower aggregated three or four

①Digestion: 

Source of enzymes that are mixed with chyme



Bile enters from the gall bladder

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② Absorption: 80% ingested water Electrolytes Vitamins Minerals Carbonates Active/facilitated transport Monosaccharides Proteins •Di-/tripeptides •Amino acids 

Lipids • • • •

Monoglycerides Fatty acids Micelles Chylomicrons

Division： Cecum

Vermiform appendix Colon 

Ascending



Transverse



Descending



sigmoid

Rectum Anal canal

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Cecum – saclike first part of the large intestine Location -right iliac fossa Features ： Ileocecal valves ileocecal sphinctor







is a blind-ended worm shaped tube connected to the cecum. Root Hangs from the posteromedial wall of the caecum. Tip Positions (varied) :  Below or behind the caecum (subcaecal or retrocaecal).  Below the brim of the lesser pelvis (pelvic).  Behind or in front of the terminal part of the ileum .

McBurney’ point  is the name given to the point over the right side of the abdomen that is one-third of the distance from the ASIS (anterior superior iliac spine) to the umbilicus (the belly button).  This point roughly corresponds to the most common location of the base of the appendix where it is attached to the cecum.

Division:  Ascending colon  Right colic flexure  Transverse colon  Left colic flexure  Descending colon  Sigmoid colon Features:  Colic bands – three bands of smooth muscle  Haustra – bulges caused by contraction of taeniae coli  Epiploic appendages – small fat accumulations on the viscera

 Continuous with sigmoid colon at S3 ①External feature:  Sacral flexure - The anteroposterior curve with concavity anteriorward of the first portion of the rectum.  Perineal flexure -The anteroposterior curve with convexity anteriorward of the last portion of the rectum.  Ampulla of rectum (lower part)- the dilated section of the rectum where feces are stored until they are eliminated via the anal canal.

②Internal structure: Transverse folds (Houston valve)  superior (left) 11 cm to anus  middle (right) 9 cm to anus  inferior (left) 7 cm to anus

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About 3.8 cm long

①Internal structure ▪Anal columns ▪Anal valves [fissure in ano 肛裂] ▪Anal sinuses  [anal fistula 肛瘘] ▪Dentate line ▪Anal pecten (transitional zone btw mucous and skin, ▪White line ▪(intersphincter sulcus)

▪anus

② Muscles 1) sphincter ani internus 2) sphincter ani externus a. subcutaneous part b. superficial part

c. deep part [fecal incontinence 大便失禁]

intersphincter sulcus

White line

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 Functions of the Large Intestine 

Absorption of water



Eliminates indigestible food from the body as feces



Does not participate in digestion of food



Goblet cells produce mucus to act as a lubricant