Digestive System Flashcards
What is the name given to the part of the digestive system containing the mouth and tongue?
Oral Cavity
Label these digestive system components
What are the two sections of the GI tract?
- Upper GI Tract
- Lower GI Tract
The digestive system can be divided into two groups, the ________ _______ and the ______ ______.
- Functional segments
- Accessory organs
What are the activities of the digestive system?
- Ingestion
- Digestion (mechanical breakdown)
- Propulsion
- Secretion
- Absorption
- Defecation
What does Ingestion refer to?
Taking the food in through oral cavity
What does propulsion refer to?
Swallowing, and the movement of food through the oesophagus to the stomach, small intestine and large intestine
What does Absorption refer to?
The taking in of nutrients into the blood and lymphatic vessels
What does defecation refer to?
The excretion of faeces through the anus
What are the Digestive juices?
- Saliva
- Gastric Juices
- Intestinal Juices
- Pancreatic Juices
- Bile
Label the missing parts marked in red
What is Peristalsis?
Alternate contractions of the Muscularis layer of the GI tract, to aid in propulsion of food through the tract
- The Tongue is a _____ muscle involved in _____, _____ and _____.
- Teeth ______ and _____ food. Adults have approximately ____ teeth.
- Salivary Glands:
- _______ - under the tongue
- ________ - under the angle of the jaw
- ______ - inside the cheek below the ears
- The tongue is a skeletal muscle involved in deglutition, speech and taste.
- Teeth tear and grind food. Adults have approximately 32 teeth by the age of 24.
- Salivary Glands:
Sublingual - under the tongue
Submandibular - under the angle of the jaw
Parotid - inside the cheek below the ears
What is deglutition?
Swallowing
What is mastication
Chewing
What is the first phase of deglutition?
- Oral/Buccal phase
- upper oesophageal sphincter contracts
- The tongue presses against the hard palate, forcing the bolus of the food into the pharynx
Complete the missing labels
What is the upper oesophageal sphincter also known as?
Pharyngoesophogeal Sphincter
What is Bolus?
Food that has been chewed and mixed with saliva in the mouth
What is the hard palate?
Roof of mouth
True or false: The first stage of deglutition is voluntary
True - you can choose to swallow
What is the second phase of deglutition?
- Pharyngeal phase
- Uvula and larynx rise to prevent bolus entering respiratory passageways
- The tongue blocks off the mouth. The upper oesophageal sphincter relaxes, allowing food to enter the oesophagus
True or false: the second phase of deglutition is Voluntary
False - the pharyngeal phase is involuntary
What is the third phase of deglutition?
- Oesophageal phase
- Pharynx contracts, forcing bolus into the oesophagus
- After food has entered the oesophagus, the upper oesophageal sphincter contracts again
True or false: The third phase of deglutition is voluntary
False - the oesophageal phase is involuntary
What occurs during the oesophageal phase to move bolus from the oesophagus through to the stomach?
Peristalsis
What is the average pH of stomach acids?
1-3
What is rugae?
Ripples in the lining of the stomach, to allow the stomach to stretch when more food is in
What are the four regions of the stomach?
- Fundus - Top
- Cardia - region just below the lower oesophageal sphincter
- Body - the main middle of the stomach
- Pylorus - lower region before the duodenum
What does bolus turn into in the stomach?
Chyme
What does the Pyloric sphincter control?
It allows Chyme to travel into the duodenum
Once digestion of the food bolus is complete, most of the nutrient absorption takes places from the _____.
Chyme
To help further breakdown the chyme, where does the duodenum receive secretions from?
- Gallbladder
- Pancreas
Which three parts make up the small intestine and how large are they?
Duodenum - 25cm
Jejunum - 2m
Ileum - 3m
Approximately how long is the large intestine?
1.5m
Why is it called the large intestine?
The lumen is larger than the small intestine
Where does the large intestine start and end?
Start - caecum
End - anus
What are the main functions of the large intestine?
- Absorption
- Microbial activity
- Mass transportation
What is another name for the large intestine?
Colon
Why is there more lymphoid tissue in the large intestine than in any other part of the GI tract?
So if any pathogens are found in the chyme an immune response can be initiated
Complete the missing labels on the large intestine
The liver is…
Largest _____
Largest _____
Makes and secretes _____
Located _______
Largest Gland
Largest Solid Organ
Makes and Secretes Bile
Located below the diaphragm
The liver is divisible into two lobes, seperated by the ________
Calciform ligament
The right lobe of the kidney is larger than the left lobe, causing what?
The right kidney to be lower than the left
Where is the gallbladder located?
In an indent, in the wall of the right lobe of the liver
Where does the liver receive its blood supply from?
- Hepatic artery - oxygenated blood
- Hepatic portal vein - deoxygenated blood, but nutrient rich
Which vein does the blood leave the liver by?
Hepatic vein
What is the pathway of bile?
- Bile leaves the liver through the right and left hepatic ducts (as there are two lobes to the liver)
- Right and left hepatic ducts fuse into the common hepatic duct
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