Digestive system Flashcards
What are the six digestive system processes?
- Motility
- Secretion
- Digestion
- Absorption
- Elimination
- Ingestion
Name the four layers of the digestive tract.
- Mucosa
- Submucosa
- Muscularis
- Serosa
What are the primary organs of the digestive system?
- Mouth
- Pharynx
- Oesophagus
- Stomach
- Small Intestine
- Large Intestine
What are the accessory organs of the digestive system?
- Teeth
- Tongue
- Gallbladder
- Salivary glands
- Liver
- Pancreas
What is the function of saliva?
- Soften food
- Moisten food
- Dissolve food
- Clean mouth and teeth
What is chyme?
A creamy paste formed in the stomach after food is mixed with gastric juices.
What is the pH of the stomach?
2
True or False: The mucosa of the stomach has longitudinal folds called rugae.
True
What are the three layers of muscle in the stomach responsible for?
Compressing, kneading, and mixing food.
Fill in the blank: The stomach secretes _______ to protect its wall from gastric acid.
Mucus
What is the primary role of the small intestine?
Most digestion and absorption occurs here.
Name the three portions of the small intestine.
- Duodenum
- Jejunum
- Ileum
What are the four structural features of the small intestine that increase surface area?
- Circular folds
- Villi
- Microvilli
- Length of the small intestine
What is peritonitis?
Acute inflammation and infection of the peritoneum.
What causes dental caries?
Plaque laid down by bacteria.
What is the function of the large intestine?
- Formation of faeces
- Absorption of water, ions, and vitamins
- Movement of contents to the rectum
What is appendicitis?
Acute inflammation of the appendix due to blockage.
What is the role of the gallbladder in digestion?
Stores and concentrates bile.
Fill in the blank: _______ is the process of moving digested nutrients through the gastrointestinal mucosa.
Absorption
What are the two key membrane types found in the body?
- Mucous membranes
- Serous membranes
What is the function of the peritoneum?
Covers organs within the abdominal cavity and reduces friction.
True or False: The oesophagus has the same mucous barrier as the stomach.
False
What happens during vomiting?
Forcible expulsion of contents from the stomach.
What is the role of salivary amylase?
Digests starch to maltose.
What are taste buds responsible for?
Detecting different tastes: sweet, sour, bitter, salty, umami.
What is halitosis?
Bad breath.
What is dysphagia?
Difficulty swallowing.
What is the main cause of peptic ulcer disease?
Gastric acid erosion of the mucous membrane.
Fill in the blank: The _______ sphincter controls the passage of chyme from the stomach to the small intestine.
Pyloric
What is the role of hormones in the digestive system?
Digestive secretions and motility are controlled and coordinated by at least 13 hormones activated by the presence of food in an organ.
Hormones stimulate production of digestive secretions and motility, with negative feedback mechanisms shutting down secretion once digestion is complete.
What hormone is produced in response to fatty acids and amino acids in the duodenum?
Cholecystokinin
This hormone stimulates the gallbladder to contract and release bile to emulsify fats.
What system controls gastric secretions and motility alongside hormonal control?
Enteric nervous system
It can be overridden by the sympathetic and parasympathetic control of the autonomic nervous system.
Which nerve supplies parasympathetic fibers to most of the GI tract?
Vagus nerve (CN X)
It stimulates digestive secretions and motility.
What triggers the gastroileal reflex?
Distension of the stomach
It intensifies peristalsis in the small intestine, moving chyme into the caecum.
What does the gastrocolic reflex stimulate?
Mass peristalsis in the colon
This reflex occurs during or after a meal and drives feces into the rectum.
What is the defecation reflex?
A reflex action aided by voluntary contractions of the diaphragm and abdominal muscles
It allows for the elimination of feces.
What initiates the defecation reflex?
Distension of the rectum
This stimulates stretch receptors in the rectal wall.
Where is the control center for the defecation reflex located?
Sacral spinal cord
This center coordinates the reflex action for elimination of feces.
What are the effects of aging on the digestive system?
- Decreased gustation and olfaction
- Altered dental function
- Decreased secretion of digestive enzymes
- Decreased motility and loss of smooth muscle tone
- Increased risk of constipation
- Altered voluntary control of external anal sphincter
- Decreased neural and hormonal control
These changes can lead to reduced appetite, delayed passage of chyme and feces, and fecal incontinence.
True or False: The external anal sphincter is under voluntary control.
True
This control allows for postponing defecation, except in infants.
Fill in the blank: The _______ reflex stimulates mass peristalsis in the colon.
Gastrocolic
This reflex is initiated when the stomach is distended.
What happens if there is insufficient bulk or lack of feces during the defecation reflex?
The reflex will not occur
This can lead to complications in elimination.
