Ch 19 Digestive System Flashcards
(136 cards)
How does the digestive system maintain homeostasis?
Maintains homeostasis by taking in food and water and then eliminating the waste products
Functions of the digestive system are carried out by the organs of the alimentarycanal or gastrointestinal tract (GI tract) and accessory organs
What are organs of the alimentary canal ?
Pharynx, esophagus, stomach, small intestine, large intestine, rectum, and anal canal
What are Accessory organs ?
Teeth, tongue, salivary glands, liver, gallbladder, and pancreas
What do salivary glands do?
Accessory organ
Secrete saliva, which contain enzymes that initiate breakdown of carbohydrates
What does mouth do?
alimentary canal
mechanical breakdown of food
chemical digestion of carbs begins
what does pharynx do ?
alimentary canal
connects mouth to esophagus
What does esophagus do?
alimentary canal
peristalsis pushes food to stomach
behind the trachea
What does stomach do?
alimentary canal
secretes acid and enzymes; mixes food with secretions to begin enzymatic digestion of proteins
What does small intestine do?
alimentary canal
mixes food with bile and pancreatic juice
final enzymatic breakdown of food molecules
main site of nutrient absorption
What does the large intestine do?
alimentary canal
absorbs water and electrolytes to form poop
What does rectum do?
alimentary canal
regulates elimination of poop
What is ingestion?
Function of digestive system
Eating and drinking
What is Secretion?
Function of digestive system
Saliva, water, acids, and enzymes enter the mouth and GI tract to help with the breakdown and absorption of foods.
What is Mixing and propulsion?
Function of digestive system
Move food along its way to the anal canal
What is Digestion?
Function of digestive system
Break down food into small molecules
Mechanical digestion begins in the mouth with the mastication of food.
Chemical digestion involves the further breakdown of food by the enzymes secreted by salivary glands, stomach, pancreas, and small intestine.
What is Absorption ?
Function of digestive system
Into the blood and lymph
takes place within the GI tract lumen by epithelial surface layer
What is Defecation
Function of digestive system
Elimination of wastes, indigestible substances, unabsorbed substances, water, some cells, and bacteria
Describe the mouth and its functions
Oral or buccal cavity
Takes in food and reduces its size through mastication
Starts the process of chemical digestion when saliva (has amylase) breaks down carbs
Boundaries are cheek, lips, hard/soft palate
What is the vestibule?
Space located between the lips and cheeks and the teeth
What is the oral cavity proper/
Space behind the teeth
What do the cheeks do?
Hold food in the mouth
Skin, adipose tissue, skeletal muscles, and an inner lining of moist nonkeratinized stratified squamous epithelium
What do lips do?
formed by Orbicularis muscle which closes the mouth
Fold of the mucous membrane called the labial frenulum that attaches the lips to the gingiva
What does the tongue do?
Made of skeletal muscle
Extrinsic muscles - attached to various bones such as the mandible and hyoid bone
Intrinsic muscles - change the shape and size of the tongue to assist with speech and swallowing
Held to the floor of the oral cavity by a fold of mucous membrane called the lingual frenulum (if too short - tongue tied or anklyoglossia)
On the dorsum (upper surface) of the tongue are many small projections called papillae (taste receptors and touch receptors)
Helps mix food and holds it between the teeth
Back of the tongue contains lymphatic tissue, called lingual tonsils, which destroy bacteria and viruses
What is the hard palate in the roof of the mouth?
Formed by the maxillary and palatine bones
Covered by a mucous membrane and stratified squamous epithelium