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Part SplanchnologyⅡ
Alimentary system
Respiratory system
Urinary system
Genital system
VisceraMale Genital system
Female Genital system
But the viscera have some general features.
1.Lacations:within or near the important cavities.
2.Tube: each system has a tube with a opening
3.The main functions of the viscera are fulfill the metabolism and maintain the life of the species.
General structures of the viscera
Hollow organs
Solid organs: Hilum
腹股沟中点
anterior median line-
sternal line midclavicular line parasternal line
Ⅰ. The common used reference lines of the thorax
The reference lines of the thorax and abdomen regions
scapular line
paravertebral line
posterior median line
(midvertebral line)
upper right quadrant upper left quadrant
lower right quadrant lower left quadrant
Ⅱ.The abdominal regions
4 regions
9 regions
transtubercular plane
subcostal plane
midclavicular line
epigastric region
umbilical region
pubic region
hypochondrium
flank
groin
digestive canal
digestive glands
Chapter 5 The alimentary system (digestive system)
Composition
Digestive canal• Mouth• Pharynx• Esophagus • Stomach • Small intestine• Large intestine
Duodenum JejunumIleum
Digestive glands
Superior digestive canal
Inferior digestive canal
• Major salivary glands• Liver• Pancreas
Function: ingestion, digestion, absorption, egesting
Mouth Pharynx
Esophagus
Stomach
Duodenum
JejunumIleum
Large intestine
Liver
Pancreas
Major salivary glands
Section 1 The Oral Cavity
Consists of two parts• Oral vestibule : between cheeks and li
p and teeth• Oral cavity proper: within arch of teet
h Oral vestibule leads, by the space behi
nd the molar teeth, into the oral cavity proper
Boundaries• Anterior and lateral: gum and teeth• Posterior: oropharyngeal isthmus• Roof: palate • Floor: tongue, muscles and mucous m
embrane
• PalateTwo parts• Hard palate: anterior 2/3, formed
by the maxilla and palatine bone• Soft palate: posterior 1/3
– Uvula
– Palatoglossal arch
– Palatopharyngeal arch
Oropharyngeal isthmus superiorly formed by the soft palate, both sides of palatoglossal arches, and root of tongue inferiorly.
软腭
soft palate
hard palate
uvula
palatoglossal arch
palatopharyngeal arch
oropharyngeal isthmus※ ※
• Teeth
General features• Two sets:
– Deciduous– Permanent
• Classification: – Incisors– Canine– Premolars– Molars
Deciduous teeth: are 20 in number• Ten teeth in each mandibular and maxillary arch • Central incisor, lateral incisor, canine, first molar and second
molar in each quadrant
Upper jaw Ⅰ Ⅱ Ⅲ Ⅳ Ⅴ total 20
Lower jaw in. in. can. mol. mol.
• Eruption: stars at about 6 mouth of age and continues to beginning of two years
• Shedding: occurs between 6th and 12th years with replacement by permanent teeth
Permanent teeth (adult): are 32 in number • Sixteen in each mandibular and maxillary arch• Two incisors, one canine, two premolars, and thre
e molars in each quadrant
Upper jaw 1 2 3 4 5 6 7 8 total 32
Lower jaw • First permanent molar - appears at about 6 years• Third molars (wisdom teeth) - many erupt at any
time after 12 years of age or not at all (impaction).
General description• Each tooth consists of 3
parts:
– Crown
– Neck
– Root
• Dental cavity - contains connective tissue, blood vessels and nerves, and is continuous with the periodontal tissue through the root canal and apical foramen.
The types of the permanent teeth
incisors canine premolars molars
1 root of tooth 1-2 roots 2( below) or 3(above) roots
crown of tooth
root of tooth
neck of tooth
root canal
Gingivae (gums):oral mucosa that surround the teeth and cover adjacent regions of the alveolar bone.
Calcified tissues• Dentine - is a yellowish white
tissue, that forms the bulk of tooth.
• Enamel - is a head, brittle white tissue that covers the crown of the tooth
• Cement - is an unusual form of bone that covers the root of the tooth
Periodontal tissue• Periodontal membrane
• Alveolar bone
• Gum
• Tongue - muscular organ
Two parts: divided two parts by v-shaped terminal sulcus
• Body of tongue - ant 2/3 , apex of tongue - free rounded tip
• Root of tongue - post 1/3
At the apex of terminal sulcus is a small median pit, the foramen cecum of tongue
Lingual mucous membrane • Papillae of tongue
– filiform papillae
– fungiform papillae
– foliate papillae contain taste buds
– vallate papillae
• Lingual tonsil
- masses of submucosal lymphoid tissue on the root of tongue
lingual tonsil
vallate papillae
terminal sulcus
foliate papillae
fungiform papillae
filiform papillae
Inferior surface of tongue
• Frenulum of tongue - a midline fold of mucous membrane connecting tongue to floor of mouth
• Sublingual caruncle - small elevation
• Sublingual fold
frenulum of tongue
sublingual caruncle
sublingual fold
sublingual gland
Muscles of tongue• Intrinsic muscles of tongue
– Involved in changing shape of tongue
– Include longitudinal, transverse and vertical muscles of tongue
• Extrinsic muscles of tongue – Genioglossus Arises from mental spine of mand
ible and inserts into either side of midline of tongue
Action: acting together draw tongue forward and downward (depresses and protrudes tongue ); acting along making apex of tongue to opposite side
Intrinsic muscles
superior longitudinal muscle
inferior longitudinal muscle
transverse muscle
vertical muscle
Extrinsic muscles
※ genioglossus
• Major salivary glandsParotid gland• superficial part and deep part• triangular in shape, lies below
and in front of the external acoustic meatus, and partially covers the masseter.
• Parotid duct: arises front anterior border of gland, runs over the masseter a finger’s breadth below the zygomatic arch to pierce the buccinator and opens into the mouth cavity, opposite the upper second molar tooth
Submandibular gland • Position: lies in submandibular tri
angle, between anterior and posterior bellies of digastric
• Duct opens on to sublingual caruncle
Sublingual gland• Position: situated beneath the mu
cous membrane of the floor of mouth
• Ducts – Major sublingual duct - open
s onto the sublingual caruncle– Minor sublingual ducts - ope
n onto the sublingual fold
Section 2 The Pharynx
General features• A –fibromuscular tube, part
of digestive and respiratory systems
• Extends from base of skull to the inferior border of cricoid cartilage (lower border of C6 level)
• Three segments
soft palate
Inferior border of the vertebra C6
upper margin of the epiglottis
nasopharynx
oropharynx
laryngopharynx
torus tubariuspharyngeal recess
opening of the pharyngotympanic tube
pharyngeal tonsil
Nasopharynx - posterior to nasal cavities
• Extends from the base of skull to level of soft palate
• Structures– Opening of the pharyngoty
mpanic tube – Torus tubarius– Pharyngeal recess– Pharyngeal tonsil
Oropharynx - posterior to oral cavity
•Lies below soft palate, extends to upper border of epiglottis
•Palate tonsils
palate tonsil
Laryngopharynx
• Structures– Piriform fossae - lies
on each side of the inlet of larynx. piriform fo
ssa
Section 3 The Esophagus
• General features - a muscular tuber about 25cm long, connecting the pharynx at level of C6 vertebra, passes through the diaphragm at level of T10 vertebra and after 1~2 cm enters the stomach
• Division: Cervical part Thoracic part Abdominal part
Four constrictions • At its beginning, 15cm from in
cisors, lies at level of C6, is the narrowest part of the esophagus
• Where it is crossed by the arch of aorta
• Where it is crossed by left main bronchus, 25cm from incisors, lies at level of intervertebral disc between T4 and T5.
• Where it passes through the esophageal hiatus of diaphragm, 40cm from incisors, at level of T10
arch of aorta
left main bronchus
esophageal hiatus
junction
Section 4 The Stomach
• Position: in the epigastric,umbilical, and left hypochondrium regions.
• Shape-J-like shape• Two surface: anterior and posterior• Two openings
– Cardia– Pyloric orifice: Pyloric sphincter
• Four regions
• Cardia
• Fundus of stomach
• Body of stomach
• Pyloric part: Pyloric antrum and Pyloric canal
Cardia
Fundus of stomach
Body of stomach
Pyloric antrumPyloric canal
Pyloric part
• Two curvatures
• Lesser curvature : short, concave and directed to the right and upward, near its lower part is angular incisure
• Greater curvature : long, convex and directed to the left and downward, at the junction of left margin of esophagus and greater curvature is cardiac notch
pyloric orifice
lesser curvature
greater curvature
angular incisure
cardiac notch
cardiac orifice
pyloric sphincterpyloric valve
Section 5 The Small Intestine
• About 6-7m long, • Divided into
– Duodenum
– Jejunum
– Ilium
Duodenum
Jejunum Ilium
• Duodenum
Four parts • Superior part
– Duodenal cap – Superior duodenal flexure
• Descending part– Longitudinal fold of duo
denum– Major duodenal papilla– Minor duodenal papilla– Inferior duodenal flexure
• Inferior part• Ascending part
– duodenojejunal flexure
superior part
ampulla (duodenal cap )
pylorus
superior duodenal flexure
circular mucosal folds
descending part
major duodenal papilla
minor duodenal papilla
inferior duodenal flexure
• Suspensory muscle of duodenum (ligament of Treitz), a surgical landmark, descends from the right crus of diaphragm to duodenal termination.
• Jejunum and ileum
circular fold
aggregated lymphatic
follicles
solitary lymphatic
follicles
jejunum
ileum
Jejunum and ileum
Characteristics Jejunum Ileum
Position Upper 2/5 Lower 3/5
Diameter Greater Less
Wall Thicker Thin
Circular folds Larger, numerous and large villi
Fewer , smaller and less abundant villi
Vascularity Greater Less
Colour Deeper red Paler pink
Lymphatic follicles Solitary Aggregated
Fat in mesentery Less More
Section 6 Large Intestine
• Approximately 1.5m long, • Five parts:
– Cecum
– Vermiform appendix
– Colon
– Rectum
– Canal
Large Intestine Features• Larger• Taeniae coli• Haustra of colon• Omental appendice
taeniae coli
haustra of colon
omental appendices
• Cecum Blind sac, first part of larg
e intestine, with largest diameter and thinnest wall
• Lies in right iliac fossa• The ilium enters the cecu
m obliquely, and partially invaginates into it, forming the ileocecal valve - consists of two folds, probably delays flow of ileal contents into large intestine
ileum
ileocecal fold
ileocecal orifice
• Vermiform appendix
• Blind worm-like tube, 6 - 8cm long, about 0.5cm in diameter
• Opens into posteromedial aspect of cecum ,about 2 cm below ileoceal orifice
• The base at the appendix lies at the point of convergence of three colic bands (used as a guide to find the appendix during operation)
mesoappendix appendicular vessels
taeniae coli
• Surface marking of the base is at the so-called McBurney’s point which is at junction of lateral and middle thirds of line joining right anterior superior iliac spine and umbilicus
Mesentery of vermiform appendix• Triangular mesentery - extends fr
om terminal part of ileum to appendix
• Appendicular a. runs in free margin of the meseoappendix then along wall of appendix
Tip variable in position
• Preileal
• Pelvic
• Retrocecal
• Retroileal
• Subcecal
• Colon
• Ascending colon– right colic flexure
• Transverse colon– left colic flexure
• Descending colon descends almost vertically from left colic flexure to sigmoid colon at left iliac crest.
• Sigmoid colon - extends from descending colon to rectum at level of S3.
• Rectum
Position: within pelvic cavity, extends from S3 to pelvic diaphragm.
Curves• Sagittal plane
– Sacral flexure convex backward– Perineal flexure convex forward.
• Coronal plane– Upper and lower part - convex
to the right.– Middle part - convex to the left.
Lower part of rectum dilated, to form ampulla of rectum,three transverse folds of rectum
sacral flexure
perineal flexure
anal canal
ampulla
of rectum
• Anal canal• Anal columns - 6-11 in number, • Anal valves• Anal sinuses • Anorectal line• Pectinate line
– Above line, of endodermal origin– Below line, of ectodermal origin
• Anal pecten• White line (anocutaneous line) • Anus• Anal sphincters
– Sphincter ani internus– Sphincter ani externus
anal columns
anal valves
anal sinus
anal pecten
pectinate line white line
sphincter ani internus
sphincter ani externus
Comparison between the sites above and below the pectinate line
the site above the pectinate line the site below the pectinate line
epithelium simple cuboidal epithelium stratified squamous epithelium
aterial supply superior and inferior rectal artery anal artery
venous return hepatic portal vein internal iliac vein
lymph drainage lumbar lymph nodes superficial inguinal lymph nodes
innervation visceral nerves somatic nerves
• Position Most of liver lies in the right hyp
ochondrum and epigastric region, less part extending into the left hypochondrum.
Section 7 The Liver
• Shape• Two surfaces
– Diaphragmatic surface Convex and smooth
• Divided into right and left areas by falciform lig.
– Visceral surface
falciform ligment
ligamentum teres hepatis
right triangular ligament left triangular
ligament
Visceral surface - has a H-shaped fissures and grooves
• Left limb of H – Anteriorly: fissure for
ligamentum teres hepatis
– Posteriorly: fissure for ligamentum venosum
• Right limb of H – Anteriorly: fossa for g
allbladder– Posteriorly: sulcus for
vena cava
• Cross-bar of H is the porta hepatis: traversed by right and left hepatic ducts, left and right branches of proper hepatic artery and hepatic portal vein, nerves and lymphatic vessels. These structures which are surrounded by connective tissue called hepatic pedicle
• Four lobes: left, right, quadrate and caudate lobes
Inferior vena cava
fissure for
ligamentum teres
gallbladder
fissure for ligamentum venosum
Right lobe
Caudate lobe
Quadrate lobe
ligamentum teres hepatis
Left lobe
porta hepatis ※※
hepatic artery proper
portal
vein
common
hepatic
duct
Inferior border –thin and sharp
• Notch for ligamentum teres hepatis
• Notch for gallbladder
The segments of the liver• The segmentation of the liver, bases upon the principal divis
ions of the proper hepatic artery and accompanying hepatic ducts and hepatic portal vein - Glisson system.
• The hepatic veins, however do not follow the same pattern and vary: their main tributaries tend to run rather intersegmental.
Section 7 Extrahepatic Biliary Apparatus
Composition • Gallbladder
• Cystic duct
• Left and right hepatic ducts
• Common hepatic duct
• Bile duct
• GallbladderPosition :lies in fossa for gallbladd
er on visceral surface of liverFour parts• Fundus of gallbladder Surface projection: at the junctio
n of right midclavicular line and right costal arch
• Body of gallbladder• Neck of gallbladderFunction: receives,stores and con
centrates bile
fundus of gallbladder
body of gallbladder
neck of gallbladder
cystic duct
• Biliary duct system
• Right and left hepatic ducts unite outside of liver to form the common hepatic duct
• Cystic duct joins common hepatic duct to form bile duct
• Bile duct and pancreatic duct run obliquely through the wall of the descending part of duodenum where the two ducts usually unite to form the hepatopancreatic ampulla (ampulla of Vater), which rounded by sphincter of hepatopancreatic ampulla (sphincter of Oddi), each has an independent sphincteric mechanism for regulating flow, and opens at the major duodenal papilla
Bile is secreted by the liver cells
Common hepatic duct
when the fat enters the small intestine, the gallbladder contracts, the sphincter of hepatopancreatic ampulla relax
Bile duct
Major duodenal papilla
Biliary ductuli Right and left hepatic ducts
Cystic duct Gallbladder (store, concentrate)
left hepatic duct
common hepatic duct
cystic duct
bile duct
hepatopancreatic ampulla
(ampulla of Vater)
pancreatic duct
right hepatic duct
major duodenal papilla
Triangle of Calot• Boundaries: the common hepatic duct on the left, the cysti
c duct on the right, the liver, superiorily• Content: cystic artery
Sect ion 8 The Pancreas
• Shape and Position• A soft yellowish lobulat
ed gland• Lies behind the peritone
um on the posterior abdominal wall, roughly at the level of of L1~L2
• Five parts• Head - Flattened and locate
d in C-shaped curvatune of duodenum
• Uncinate process• Neck - constricted part• Body• Tail - runs in base of spleno
renal ligament to reach hilum of spleen
• Pancreatic duct• Main Pancreatic duct
– Begins at tail and throughout gland
– Joins common bile duct before entering descending part of duodenum at major duodenal papilla
• Accessory pancreatic duct– Opens 2cm above main
duct at minor duodenal papilla
• Pancreas Function
The pancreas is both an exocrine and an endocrine gland.
The exocrine portion of the gland produces a secretion that contains enzymes that are capable of hydrolyzing proteins, fats, and carbohydrates.
The endocrine portion of the gland-the pancreatic islet produces the hormones insulin that play a key role in carbohydrate metabolism.
Definition of superior and inferior alimentary canal. Structures of the soft palate. Definition of oropharyngeal isthmus. Structures of mucous membrane of tongue. Action of genioglossus. Names, position and openings of salivary glands. Classification of pharynx and structures of the nasopharynx. Constrictions of esophagus. Shape and structures of stomach and duodenum.
Highlights
Structures of descending part of duodenum.Position of caecum and vermiform appendix. Characteristic of cecum and colon. Position of ileocecal valve. Shape of rectum. Structures of anal canal. Shape and position of liver. Position and structure of porta hepatis. Boundaries and content of Triangle Calot. Formation of biliary ducts. Position and shape of pancreas.
Highlights