Gastrointestinal system Flashcards
What are the primary organs of the gastrointestinal tract
Oral/Buccal cavity, pharynx, esophagus, stomach, small intestine, large intestine and anus
Functions of the digestive tract and accessory organs
Ingestion of food
Mechanical processing - breaking of food into smaller particles by mastication
Secretion of enzymes and acids
Digestion - chemical breakdown of foods into small organic fragments via secretion of enzymes and acids
Absorption of nutrients and water
Excretion of waste products
What are the accessory digestive organs
Liver, Gallbladder and Pancreas
Where is bile produced?
The liver
Where is bile stored and concentrated/
The gall bladder
Function of bile
Convert fats in food into fatty acids for absorption into the gut
What are the roles of the pancreas?
Endocrine system: Secretion of hormones, including blood sugar-regulating hormones: insulin and glucagon
Exocrine system: Secretion of enzymes into the digestive tract through duct in duodenum
What are the cavities found in the trunk
Thoracic cavity
Abdominal cavity
Pelvic cavity
4 Quadrants of the abdomen
Right upper quadrant
Left upper quadrant
Right lower quadrant
Left lower quadrant
9 regions of the abdomen
Right hypochondria
Epigastric
Left hypochondria
Right lumbar
Umbilical
Left lumbar
Right iliac
Hypogastric
Left iliac
What organs are found in the right hypochondria
region
Right lobe of the liver
Gallbladder
Hepatic duct
Right Colic Angle
What organs are found in the epigastric region
Esophagus
Stomach
Liver
Spleen
Pancreas
Right and Left kidneys
Right and Left ureters
Left supradrenal gland
Small Intestine
Transverse colon
What organs are found in the left hypochondria region
Spleen
Left kidney
Tail end of pancreas
Parts of Small intestine
Left Colic Angle
What organs found in the right lumbar region
Ascending colon
Small intestine
Right Kidney
What organs are found in the umbilical region
Small intestine (ileum)
Transverse colon
Left and Right Kidney
What organs are found in the left lumbar region
Descending colon
Left Kidney
Spleen
What organs are found in the right iliac
Appendix
Ovary
Cecum
What organs are found in the hypogastric region
Small intestine
Sigmoid colon
Rectum
Anus
Urinary bladder,Ureter
Uterus, ovaries (in female)
Prostate (in male)
What organs are found in the left iliac region
Descending colon
Sigmoid colon
Ovary
Loin to groin pain caused by
Ureteric stones are being pushed from Kidney towards urinary bladder
Gallstones - Pain will arise in
Right hypochondria
Liver disorders - Pain arises in
Right hypochondria
Stomach ulcers - Pain arises in
Epigastric, umbilical and left hypochondria
Heartburn - Pain arises in
Epigastric
Spleen disorders - Pain arises in
Left hypochondria
Pancreatitis - Pain arises in
Umbilical, Left hypochondria
Kidney stones - Pain arises in
Right lumbar, Left lumbar
Urine infection - Pain arises in
Hypogastric, Left and Right lumbar
Constipation - Pain arises in
Right lumbar, Left lumbar, Right iliac
Early appendicitis/Appendicitis - Pain arises in
Umbilical, Right iliac
Inflammatory bowel - Pain arises in
Umbilical, Left lumbar
Small bowel disease - Pain arises in
Umbilical
Umbilical hernia - Pain arises in
Umbilical
Pelvic pain (Gynae) - Pain arises in
Right and left iliac, Hypogastric
Groin pain (Inguinal Hernia) - Pain arises in
Right and left iliac
Urine infection - Pain arises in
Hypogastric
Oral cavity lined by
Non-keratinised stratified squamous epithelium
Roof of the oral cavity formed by
Hard and soft palates
The floor of the oral cavity is dominated by
the tongue
Hard palate of the oral roof made of
Bones
Soft palate of the oral cavity made of
Muscle
Uvula is part of the
soft palate
What are the 4 basic types of tissue
Connective tissue, Epithelial tissue, muscle tissue and nervous tissue
3 principle shapes of epithelial cells
Squamous, columnar and cuboidal
Squamous epithelial cells protect against
Physical and chemical wear and tear
Shape of squamous cells
Thin, flat cells that look like fish scales
Where are squamous epithelial cells found
Surface of the skin and some lining of the digestive tracts
Characteristics of stratified squamous keratinised epithelium
Flat
Absence of nucleus and organelles
Presence of keratin - which makes the skin waterproof
What lines the outer surface of the lip
Thin skin. Presence of keratinised squamous stratified epithelium, Hair follicles, Sebaceous gland, Sweat glands.
What lines the inner surface of the lip
Mucosa. Non-keratinised squamous stratified epithelium.
Circumvallate papillae is found along the
Sulcus terminalis
What is the depression on the tongue called
Median sulcus
What are the 4 types of papillae on the tongue
Circumvallate, Fungiform, Filiform, Foliate
The tongue is made of
Interlacing bundles of mainly skeletal muscles
The tongue is lined by
Non-keratinised squamous epithelium
Types of salivary glands
Parotid, Submandibular, Sublingual glands
Function of saliva
Helps in the lubrication of food
Dissolves chemicals to stimulate taste buds
Contains salivary amylase to break down carbohydrate
Composition of saliva
Water 99.4%
Ions, glycoprotein, antibody and enzymes 0.6%
70% of saliva is produced by
Submandibular gland
Rank the amount of saliva produced by salivary glands
1) Submandibular gland
2) Parotid gland
3) Sublingual gland
What is the fold of mucus membrane found under the tongue
Lingual Frenulum
Where does the duct of the parotid gland open into?
The second upper molar tooth
Location of the parotid gland
Largest gland
Situated below the ear
Location of the submandibular gland
Found in the floor of the mouth
Location of the sublingual gland
Situated in the floor of the mouth below the tongue
Type of saliva secretion by parotid gland
Serous, watery secretion
Type of saliva secretion by submandibular gland
Mixed serous and mucosa secretion
Type of saliva secretion by sublingual gland
Mucosa secretion
3 Segments of the pharynx
Nasopharynx, Oropharynx, Laryngopharynx
Oropharynx is a common passageway for
air, food and liquids
Where does the oropharynx end
Epiglotis
Function of the esophagus
Hollow 25 cm muscular tube that transports food and liquids from the laryngopharynx to the stomach
Extent/Location of the esophagus
Neck
Passes through the posterior part of Thoracic cavity
Enters the Abdominal cavity via an opening in the diaphragm
Organs surrounding the esophagus
Neck and upper thoracic cavity: Trachea
Lower thoracic cavity: Heart, aorta
4 Layers of the gastrointestinal tract
Inner most: Mucosa
Submucosa
Muscularis Propria
Outer most: Adventita
Epithelial lining of the esophagus is
Stratified squamous epithelium
Components of the muscularis externa of esophagus
Upper third region: Skeletal muscle
Middle third: Skeletal and smooth muscle
Lower third: Smooth muscle
Stomach is found in these regions
Umbilical, Epigastric, Left Hypochondria
Shape of the stomach
J-shaped distensible muscle bag
Rugae is formed when
Stomach is empty, mucosa of stomach is thrown into folds
What are the orifices and curvatures of the stomach
Orifices:
Cardiac orifice
Pyloric orifice
Curvatures:
Lesser curvature
Greater curvature
Dome-shaped section at the top of the stomach is known as
The fundus
Parts of the stomach
Fundus, Cardiac, Body, Pylorus
Pyloric sphincter is found in which region
Pylorus region
What are the 2 omentums
Lesser omentum and greater omentum
Where is the lesser omentum found
Extends from the liver to the lesser curvature of the stomach
Where is the greater omentum found
Hangs down from the greater curvature of the stomach
Structure of the lesser omentum
Double layer of peritoneum
Function of the greater omentum
Fat deposition - having varying amounts of adipose tissue
Immune contribution - having milky spots of macrophage collections
Infection and wound infection - may physically limit the spread of intraperitoneal infections. Can be found wrapped around areas of infection and trauma.
Peritoneum cavity is?
Potential space between the parietal and visceral layers of the peritoneum
Peritoneum cavity is filled with? Which is secreted by?
Serous peritoneal fluid which is secreted by the mesothelial cells lining the peritoneum
Intraperitoneal organs vs retroperitoneal organs
Intraperitoneal organs are enveloped by visceral peritoneum which covers the organ both anteriorly and posteriorly.
Retroperitoneal organs are only covered in parietal peritoneum which covers the anterior region of the organ
Organs that are only covered by parietal peritoneum are known as
Retroperitoneal organs
Stomach blood supply from
Celiac artery
Stomach venous drainage by
Portal vein
Functions of the stomach
Storage of ingested food
Mechanical breakdown of food
Disruption of chemical bonds via acids and enzymes
Chyme leaves the stomach
What is Chyme
Soupy mixture that leaves the stomach
What lines the mucous membrane in the stomach?
Simple columnar epithelium
Type of cells found in the epithelium in the stomach
Columnar epithelial cells
Characteristic of columnar epithelial cells in the stomach
Nuclei are elongated and usually located near the base of cells.
Elongated, column-shaped and a height of at least four times their width
Cells that make up the gastric gland in the stomach
Mucosal cells
Parietal/Oxyntic cells
Chief cells
Neuroendocrine cells
Function of mucosal cells in the gastric gland
Secretion of thick viscous fluid, which protects the stomach from acidic effects of gastric juice
Function of parietal/oxyntic cells in the gastric gland
Secretion of hydrochloric acid and Intrinstic factor
Intrinsic factor is required for absorption in the terminal ileum
Function of Chief cells in the gastric gland
Secretion of pepsinogen which is needed to breakdown proteins into polypeptides
Function of neuroendocrine cells in the gastric gland
Secretion of serotonin
What is gastritis?
Inflammation of gastric stomach
What is gastric ulcer?
Erosion of stomach lining. Full-thickness loss of the gastric mucosa.
What are the 4 stomach-related diseases?
Gastritis, gastric ulcer, stomach cancer and gastroesophageal reflux disease
What is gastric erosion?
Partial loss of stomach mucosa with the preservation of the muscularis mucosa
What is gastroscopy?
Viewing the stomach through an illuminated tube
Significance of barium meal?
Diagnostic test used to detect abnormalities of the esophagus, stomach and small intestine using x-ray imaging.
Barium sulfate lines the lining of the gastrointestinal tract allowing for accurate x-ray imaging
What is gastroesophageal reflux disease?
A condition where the acidic gastric fluid flows backwards into the esophagus resulting in heartburn
Regions of the small intestine
Duodenum, Jejuneum, Ileum
Location of the small intestine
Lies between the stomach and the large intestine
Length of the small intestine
6-7m long
What does the mesentery consist of?
What is the function of the mesentery?
2 layers of peritoneum
Provides a passageway for blood vessels, lymphatic vessels and nerves to reach viscera.
Allows for communication between body wall and internal organs
Common bile duct and main pancreatic duct open into the
Middle of 2nd part of the duodenum
Bile and pancreatic juice is secreted into the
Middle of the second part of the duodenum
What are Plica circulares?
Numerous permanent circular folds of mucous membrane
Where are Plica Circulares located?
In the lower part of the duodenum and the jejunum
Function of the Plica Circulares
Slows down the passage of food along the intestine
Increases the surface area of absorption
Compare and contrast between the jejunum and ileum
Arterial arcades: Jejunum has less complex arterial arcades whereas ileum has more complex arterial arcades
Vesa recta: Jejunum has longer vesa recta, ileum has shorter vesa recta
Plica circulares: Jejunum has more, thicker and more highly folded plica circulares while ileum has less, thinner and less folded plica circulares
Fat present in mesentery: Jejunum has less fat present, ileum has more fat present
Coeliac arterial supply to
From esophagus to middle of second part of duodenum
(esophagus, stomach, upper part of duodenum)
Superior Mesenteric arterial supply to
From middle of second part of duodenum to the anterior 2/3 of the transverse colon
(lower part of duodenum, jejunum, ileum, ascending colon, 2/3 of transverse colon)
Inferior Mesenteric arterial supply to
From anterior 2/3 of transverse colon onwards
(1/3 of transverse colon, descending colon, rectum, anus)
Function of the small intestine
Enzymatic digestion by maltase, lactase and sucrase enzyme which act on sugars and exopeptidase which act on peptides.
Absorption - Presence of plica circulares and mucosa of intestine which has villi and microvilli
Secretion of cholecystokin hormone - which stimulates contraction of gall bladder and production of enzymes by pancreas and secretin.
Secretin neutralises the pH of chyme upon entering the small intestine
What are the enzymes present in the small intestine
Maltase lactase sucrase exopeptidase
What are enzymes present in the stomach and produced by
Pepsinogen, chief cells
Enzymes in the small intestine produced by
Enterocytes
Villi of the small intestine consists of which cells
Enterocytes and goblet cells
Structure of the mucosa of the small intestine
Numerous finger-like projections
Presence of intestinal glands found in between villi
Function of goblet cells in small intestine
Produce mucin
Glands present in the submucosal layer of small intestine
Brunner’s gland, Peyer’s patches
Brunner’s gland present in
Submucosal layer of Duodenum
Peyer’s patches present in
Submucosal layer of ileum
Function of Brunner’s gland
Production of alkaline mucus which prevents erosion or ulceration of duodenum mucosa by acidic gastric contents
Venous drainage of small intestine into
the portal vein
Structure of the large intestine:
-Horse shoe shaped
Parts of the large intestine:
- Cecum/Appendix
- Ascending colon
- Transverse colon
- Descending colon
- Sigmoid colon
- Rectum
- Anal canal
length
Location
Function
