Semester on Energy and metabolism Flashcards
What is the liver?
- A large four lobed gland located in right upper quadrant
- Liver is the body’s metabolising organ
- The liver has various functions including producing bile
How is blood circulated through the liver?
Hepatic portal circulation
- Blood from the intestines, pancreas and spleen goes to the hepatic portal vein
- Hepatic portal vein divides and re-divides into 2 capillary beds in the liver and drains between them
- After this blood is filtered by the liver, it joins the rest of the circulating blood and travels to the heart
What is the peritoneum?
A series of membranes that covers the organs found in the abdominopelvic cavity.
Between the layers is the peritoneal cavity containing fluid that allows membranes to slide over one another.
What is the function of the peritoneum?
To protect and support the organs of the abdominopelvic cavity, ensuring a pathway of blood and lymph
What are the four layers of the gastrointestinal tract?
- Mucosa - innermost layer of epithelium along a layer of smooth muscle
- Submucosa - connective tissue, contains blood vessels, nerve endings, lymph
- Muscularis Externa - layers of smooth muscle that move food along via contractions
- Serosa - visceral peritoneum and connective tissue
What are the structures of the oral cavity?
Mouth, teeth (32 permanent), gums and buccal regions, tongue, lips and salivary glands
How does the tongue aid digestion?
Mixes food with saliva and aids with swallowing
What is the epiglottis and it’s function?
- a flap that closes over the trachea
- prevents food from entering the lungs (aspiration)
What is the tube-like structure that transports food to the stomach?
The oesophagus
What is the structure of the stomach?
- C-shaped storage area containing HCl
- Has mucosa layer that protects stomach wall
- Connects to oesophagus at cardio-esophageal sphincter
- Connects to small intestine at pyloric sphincter
What are the sections of the small intestine?
The duodenum, the jejunum and the ileum
What structures in the small intestine ensure nutrients from food are absorbed?
Villi, microvilli and circular folds
What accessory organ of the digestive system produces enzymes and secretes them into the duodenum?
The pancreas
Where is bile stored?
The gallbladder, located in the inferior surface of the liver
What is the role of the nervous system in digestion?
Responsible for the movement of food along the gastrointestinal tract by controlling sphincters and other smooth muscles
What cranial nerve serves the digest system?
Cranial nerve no. 10 - the vagus nerve
Where is the pharynx and what does it do?
- At the back of the throat
- Prepares food for swallowing
What is a cell of the liver called?
A hepatocyte
What cells in the liver clear bacteria and toxins from the blood?
Kupffer cells
What are the six digestive processes?
Ingestion – taking food into the mouth
Secretion – release of fluids, enzymes, etc
Motility – involves the movement of food, includes peristalsis & segmentation;
Digestion – breaking food down into smaller products through chemical or mechanical processes
Absorption – moves food particles from the small intestine into the blood and lymph
Elimination – disposal of waste
What is an enzyme?
A protein catalyst that increases or decreases the rate of chemical reactions
What are hormones?
- Chemical messengers produced in endocrine glands
- Hormones travel in blood to various organs and effect many processes including metabolism of foods
