Body Systems Flashcards
What is the gland that releases hormones in response to the messages sent by the control centre?
Pituitary gland
Why is it important to maintain good glucose levels?
So cellular respiration can occur
What is the role of the digestive system?
Break down ingested foods and liquids into substances that the body can absorb and use for tissue repair, energy and growth. Removes waste products (maintaining homeostasis)
What is the first organ of the digestive system?
Mouth
What is the main purpose of the mouth?
Mechanical digestion of food, through mastication and the movement of the tongue. This increase the SA:V ratio of the food. Mastication also combines saliva from the salivary glands with the food, which digests foods
Where are the salivary glands located?
Lining of the mouth
How does the mouth break down the food?
Mastication and movement of the tongue
What does saliva contain?
Salivary amylase, water, mucus
What are the tissues of the mouth?
Lips, hard and soft palate, uvula and tossils, tongue, gums, teeth, cheeks
What is the oesophagus?
A muscular tube that connects the pharynx to the stomach
How does the oesophagus move food forwards?
Peristalsis
How does peristalsis work?
Muscles in the oesophagus wall contract behind the bolus and relax in front of the bolus, in wave-like movements
What is the LES?
Lower oesophageal sphincter
What is the purpose of the LES?
Prevent food from reentering the oesophagus
What is the stomach?
A J-shaped organ that mixes food with enzymes that chemically digest
What happens when food enters the stomach?
The stomach walls begin to contract (mechanical digestion)
What is the first section of the small intestine called?
Duodenum.
What organs empty into the duodenum?
Digestive juices (from the pancreas) and bile (from the gallbladder).
What substances are secreted by the small intestine walls into the duodenum?
Digestive enzymes.
What is further broken down in the small intestine?
Starches, proteins, lipids
What is the second section of the digestive system called?
Jejunum
What happens to food as it travels along the small intestine?
Nutrients get absorbed by villi and microvilli
How is food moved into the jejunum?
Peristalsis
What are the structures that absorb nutrients in the small intestine?
Villi and microvilli.
What are villi?
Small projections that line the small intestine and increase surface area.
What are microvilli?
Even smaller projections that further increase surface area.
What nutrients are absorbed by the ileum?
Vitamin B12 and bile acids.
What are the connections of villi to the circulatory system?
Connected to many capillaries that circulate nutrients around the bloodstream.
What are the components of what is left in the small intestine?
Dead cells, electrolytes, and waste products.
What are the layers of tissue that make up the small intestine?
Mucosa, submucosa, muscularis externa, and serosa.
What has happened by the end of the small intestine?
Nutrients have been absorbed
What does the pancreas do?
Produce pancreatic juices
What is the liver’s function in relation to digestion?
Produceand secrete bile (digestive enzyme)