Chapter 8: 8.3 - Ingestion Flashcards
What does ingestion mean?
The taking in of nutrients (food)
What two parts are needed for digestion?
- Mechanical
2. Chemical
What is the mechanical part all about?
It is a physical digestion to grow the surface area (chewing)
What is the chemical part all about?
It’s when molecular bonds are broken and rearranged or reorganized.
What does Absorption mean?
The transfer of digested nutrients to the cells of the body.
It is also a passage of monomers through the mucous membrane of the intestine into blood and lymph.
What is Egestion?
- The removal of food waste from the body.
- It is also the release of indigestible wastes called feces.
What happens in the mouth?
- Chewing the food in the mouth breaks it down into smaller particles and increase the surface area = increases enzyme function
What is the salivary amylase?
It smashes down starches which are (complex carbohydrate) to simpler carbohydrates.
What is the Buffer?
biocarbonate (HCO3-)
What is it called when the trachea has a small flap like valve?
It’s called an epiglottis.
Things about Teeth
- It’s essential for physical digestion.
- Each tooth is surrounded by enamel.
- 8 chisel-shaped teeth or 8 sharp, dagger, shaped incisors
What are incisors used for?
They are used to cut food.
Things about Premolars
- They are broad and flattened.
- Specialized for grinding food.
Things about Molars
- They are wider, more flattened.
- They have cusps.
- They are made for crushing food.
Things about Wisdom Teeth
- It does not usually appear until 16 to 20 years of age.
Stuff about The Tongue
- Arranges food for chewing.
- Helps in mixing food and saliva.
- Moves bolus (ball) food to pharynx (back of throat)
Stuff about Taste
- Nerve cells on taste buds respond to particular flavors.
Stuff about Esophagus
- A muscular collapsible tube joined to the stomach.
- It pushes food into the stomach by the method of peristalsis.
- Small sphincter at the end (cardiac sphincter) directs the rate which food enters the stomach.
- The sphincter remains closed so gastric juice doesn’t splash against the esophagus.
What is Peristalsis?
They are rhythmic, wavelike contractions of muscle that move food along the gastrointestinal tract.
Stuff about the Stomach
- The inner surface is thrown into long folds known as the rugae in a J-shape.
- It can store about 1.5 L of food.
What are the 3 duties of the stomach?
- It stores and mixes food.
- Secretions (gastric juices) assist by breaking down/degrading food
- Directs passage of food to duodenum.
What does the pepsin do?
They break the long amino acid chains in proteins into shorter chains called polypeptides.
What are the 4 layers of the stomach?
- Mucus cells: They protect or preserve the stomach lining.
- Parietal cells: Hydrochloric acid (Hcl)
- Chief cells: Pepsinogen
- G Cells: Gastrin
Is pepsin active or inactive form? Also is pepsinogen active or inactive form?
Pepsin is active. Pepsinogen is inactive.
