Digestive System Part 1 Flashcards
The abdomen is enclosed by the…
Abdominal wall and the inner large peritoneal cavity
What are the 3 main functions of the abdominal cavity
→ protects+ contains the major organs
→ breathing- abdominal wall relaxes to allow thoracic cavity to expand-contract
→ increasing abdominal pressure, assists in defecation and childbirth
What are the 4 quadrants of the abdomen.
4 quadrants
• Median sagittal plane
• Axia plane at the level of the
umbilicus and L3/4
-right upper quadrant
Left upper quadrant
Right lower quadrant
Left lower quadrant
What are the 9 regions of the abdomen
Right hypochondrium
Epigastric region
Left hypochondrium
Right flank
Umbilical region
Left flank
Right groin / iliac
Left groin / iliac
Pubic region
How is the abdomen divided for clinical purposes?
4 quadrants: Median sagittal and axial plane (L3/L4)
9 regions: Mid-clavicular planes, subcostal plane (L3), intertubercular plane (L5)
What structures are found in the right hypochondrium?
Liver, gallbladder, right kidney, small intestine
What structures are found in the epigastric region?
Stomach, liver, pancreas, duodenum, adrenal glands, transverse colon
What are the five layers of the abdominal wall?
Skin, subcutaneous tissue, muscle and fascia, extra-peritoneal fat, parietal peritoneum
What are the major muscles of the abdominal wall?
External oblique, internal oblique, transversus abdominis, rectus abdominis, pyramidalis
What is the peritoneum and its functions?
A continuous serous membrane that lines the abdominal cavity and covers organs
Reduces friction, allows movement, and provides pathways for vessels and nerves
What is the function of mesenteries?
Suspend organs in place, allow limited movement, provide a conduit for blood vessels, nerves, and lymphatics
What is the greater omentum and its function?
A large peritoneal fold extending from the stomach over the intestines
Fat storage, immune response, limits infection spread
hat is the function of the lesser omentum?
Connects the lesser curvature of the stomach to the liver
What organs are intraperitoneal?
Stomach, small intestine, transverse colon, liver, spleen, tail of pancreas
What organs are retroperitoneal?
Kidneys, adrenal glands, ureters, aorta, inferior vena cava, parts of the colon and pancreas
What is the function of the digestive system?
Converts food into energy, absorbs nutrients, eliminates waste
What are the main parts of the GI tract?
Mouth, pharynx, esophagus, stomach, small intestine, large intestine, rectum, anus
What are the four main tissue layers of the GI tract?
Mucosa- inner epithelium, contains blood and lymph
submucosa- loose connective tissue to bind mucosa to the muscle layer. contains neuromuscular and lymph structures
muscularis- muscle layer, helps churn and mass movements
serosa- fibrous outer layer in the thorax. single serous layer membrane in the peritoneum
What is the mucosa layer responsible for?
Protection, secretion, absorption
mucous membrane
lamina proproa
muscular mucosa
What are the two layers of muscle in the GI tract?
Inner circular and outer longitudinal muscles
What is the function of peristalsis?
Moves food through the digestive system via coordinated muscle contractions
What is the function of the autonomic nervous system in digestion?
Parasympathetic: Increases secretion and motility
Sympathetic: Decreases secretion and motility
What is the arterial blood supply to the digestive system?
Coeliac artery (liver, spleen, stomach)
Superior mesenteric artery (small intestine, pancreas)
Inferior mesenteric artery (colon, rectum)
What is the main venous drainage of the digestive system?
Hepatic portal system in the liver
What are the main functions of digestion?
Mechanical and chemical breakdown of food for absorption
- What are the major digestive enzymes and their functions?
Amylase: Carbohydrate digestion
Proteases: Protein digestion
Lipases: Fat digestion
What are the three main parts of the mouth?
Oral cavity, vestibule, tongue
. What are the main functions of the tongue?
Mastication, swallowing, speech
What are the three major salivary glands?
Parotid- opens into mouth just below ears, digestive carbs
submandibular - lower jaw, lubrication
sublingual- lubrication, makes it easier to swallow
aids in dissolving food particles, has antimicrobial agents, washes away any remaining food particles.
what are the main functions of saliva
-lubrication
-digestion
-antimicrobial protection
What are the three stages of swallowing (deglutition)?
Oral stage (voluntary)- mouth closed, bolus forced posteriorly by voluntary muscles of tongue/ cheek.
Pharyngeal stage (involuntary reflex)- involuntary contraction of muscles to propel bolus into oesophagus.
Esophageal stage (peristalsis)- peristalsis only starts when stimulated when food in pharynx. propels food to stomach, lubrication by mucous.
What is the role of the esophagus in digestion?
Transports food from mouth to stomach via peristalsis
What are the functions of the liver in digestion?
Produces bile, processes nutrients, detoxifies blood
What is the function of the gallbladder?
Stores and concentrates bile
How does the pancreas aid digestion?
Produces digestive enzymes and bicarbonate
What is the function of the ileocecal valve?
Controls flow from small to large intestine
What is the role of the appendix?
May contribute to immune function
what is the function of the rectum
stores and expels feces
What are the primary components of feces?
Water, bacteria, undigested food, waste products
What is the role of fiber in digestion?
Aids in bowel movement, prevents constipation
What are common digestive disorders?
GERD, IBS, Crohn’s disease, ulcers
What is the significance of gut microbiota?
Assists digestion, produces vitamins, supports immunity
How does the nervous system regulate digestion?
Enteric nervous system controls gut function
What hormones regulate digestion?
Gastrin, secretin, cholecystokinin
What is the function of gastric mucus?
Protects stomach lining from acid
What is the role of bicarbonate in digestion?
Neutralizes stomach acid
What is the function of the pyloric sphincter?
Controls release of stomach contents to small intestine
- What is chyme?
Partially digested food mixed with digestive secretions
What is the function of the lacteals in the intestine?
absorbs dietary fats
what are haustra
pouches in the colon aiding in movement of contents
what triggers defecation?
stretching of rectum initiates reflex.
