Term
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Definition
| Breakdown of food into component nutrients small enough to enter cells |
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Term
Describe the two types of digestion |
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Definition
1. Mechanical. Breaks food into smaller pieces to increase surface area for enzymes. Occurs in the mouth and stomach
2. Chemical. Breaks food down by use of enzymes, bonds are broken. Occurs in the mouth, stomach, and small intestine. |
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Term
| Describe how the mouth's structre is suited to its function. |
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Definition
The mouth recieves food and holds the food in preperation for swollowing.
- Lips: keep fluids in mouth
- Tongue: pushes food between teeth, mixes food with saliva and prepares food bolus.
- Teeth: chew food, mechanical digestion.
- Salivary glands: 3 pairs (parotid, sublingual, sumandibular) which all produce and release saliva. |
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Term
| What properties does saliva have that makes it suited for its function? |
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Definition
1. Water: Lubricates the mouth to aid in swollowing
2. Salivar amylase: Responsible for the chemical digestion in the mouth. Enzyme that breaks starch into maltose (sugar)
3. Others: like mucus and antibodies. |
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Term
Describe the location of swollowing. |
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Definition
The Pharynx is the location of swollowing. It is a chamber at the back of the mouth (between the mouth and esophagus)
- Common passageway for food and air
- Splits into thachea and esophagus |
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Term
| Describe the process of swollowing |
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Definition
Reflex action that results from the contractions of muscles that line the pharynx.
1. Tongue pushes bolus to the back of mouth
2. Soft palate at back of mouth moves back to cover the opening of the nasal cavity.
3. Epiglottis covers trachea.
4. Food bolus passes into espohagus. |
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Term
What is the role of the espohagus? |
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Definition
Brings food bolus from pharynx to the stomach.
Food is pushed along by peristalsis: rythmic contractions of the muscles ling the esophagus.
Reverse peristalsis can occur; vomiting or heartburn. |
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Term
Describe the Cardiact Spincter |
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Definition
A ring of muscle that regulates the flow of material into and out of the stomach.
When relaxed = open
When contracted = closed |
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Term
| What are some features of the stomach that make it well suited for its function? (list 6) |
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Definition
1. 3 layers of muscle to churn food (mechanical digestion)
2. Can expand to store partially digested food
3. Has a layer of mucus to protect wall from stomach acids
4. Folds to increase surface area - for gastic acid
5. Presence of food stimulates release of Gastrin (a hormone which causes the release of gastric juice)
6. Contains gastric juice which contains water [hydrolisis], hydrocloric acid [kill bacteria] and pepsingen [chemical digestion of proteins]. |
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Term
| What is the function of the Pyloric Sphicter? |
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Definition
- Controls the amount of chyme (runny food) entering the duodenum of the small intestine.
- Repeatedly opens and closes allowing chyme to pass through in small squirts only. |
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Term
| Describe how the structure of the small intestine is suited to its function. |
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Definition
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