Chapter 23: Digestive System Flashcards
What is the main function of the Digestive system?
To breakdown of food into smaller portions, to be absorbed as nutrients into the bloodstream, and transferred to the cells to produce energy, and aid in the elimination process.
The Digestive system is broken down into two parts, what are they:
*Alimentary Canal (GI tract) *Accessory digestive organs
The alimentary canal organs consists of:
mouth, pharynx, esophagus, stomach, small intestine, large intestine
The accessory organs consists of:
teeth, tongue, gallbladder, the salivary glands, liver and pancreas.
What is the difference between the alimentary canal and accessory organs?
Alimentary canal: digests food- breaks it down into smaller fragments and absorbs the digested fragments through its lining into the blood. Accessory organs: Food does not pass through these organs but helps with digestion.
Peristalsis:
Forward thrusting of food. No matter of the position of the body.
Segmentation:
Local mixing movement with the help of smooth muscle.
Name the four layers that compose the wall of the alimentary canal from innermost (lining lumen) to outermost.
Mucosa, Submucosa, muscularis externa and serosa.
Describe the overall structure and function of the mouth.
Mouth- mechanical breakdown of food- tounge, teeth, frenulum, styloid process, hyoid, taste buds, tonsils at base
What is the function of the epiglottis?
The epiglottis is a thin lid-like flap of cartilage tissue that is attached to the root of the tongue. It is situated in front behind the tongue and in front of the entrance to the larynx (voice box). When resting, the epiglottis allows air to pass through the larynx and into the rest of the respiratory system. When swallowing, it covers the entrance to the larynx to prevent food and drink from entering the windpipe. If both the air passage and the food passage were open when someone swallowed, air could enter the stomach and food could enter the lungs. The epiglottis is the way that this is prevented from happening, basically acting like a lid every time we swallow.
What is the function of the lingual frenulum?
is the attachment of tongue to he floor of the mouth, it prevents tongue from falling back and causing obstruction to our food and air passage.It also has a major role in speech, as a attachment of tongue.
What is the function of the uvula?
The main function of uvula is to prevent food going through the breathing passage while you swallow. The uvula function also involves, articulation of your voice to form sounds of speech. The uvula functions along with the back of the throat, palate, and air coming up from the lungs to produce a gruffy and other sounds.
Distinguish between mechanical digestion and chemical digestion.
Chemical digestion is where complex food molecules are broken down to the basic building blocks by enzymes. Mechanical digestion is chewing, churning and segmentation.
Compare and contrast the four layers of the alimentary canal wall (named above) in terms of their structure, function, and any distinguishing features.
Mucosa is moist epithelial that secretes mucus, digestive enzymes and hormones. The submucosa is moderately dense connective tissue containing blood vessels and nerve fibers. The muscularis externa is responsible for segmentation and peristalsis. Is made of smooth muscle cells. Sphincters form that act as valves to prevent backflow and control food passage from one organ to the next. Serosa is the protective outermost layer.
Name and locate the three sets of salivary glands in humans, name and describe the secretions from these glands, and name the two types of cells that compose these glands.
three sets of salivary glands: parotid = largest; lies over masseter, submandibular = floor of mouth; lateral, sublingual = floor of mouth, medial. The two types of cells that compose these glands are: mucous cells secretes mucus; serous cells secretes watery substance containing the enzyme salivary amylase.
Greater Omentum function and location:
Main functions: Prevent adhesions along peritoneal surfaces; to limit the spread of infection in the peritoneal cavity, and to store fat.
Location: It connects the inferior section of the stomach to the transverse colon. It hangs over the stomach like an apron. It extends to the colon and is suspended from the stomach to cover most of the small and large intestine.
Lesser Omentum functions and location:
Function: To prevent friction between organs and holding them together so that they aren’t flopping around
Location: Connects the stomach to the liver.
Sigmoid Mescolon function and location:
Location: Connects the sigmoid colon to the anterior abdominal cavity
function: To prevent friction between the organs, so they’re not moving around everywhere.
Define retroperitoneal organs.
Organs in the body found behind the membranes structure of the abdominal cavity known as the peritoneum.
