_____________ digestion occurs within the cell, usually in membrane-bound vesicles.
Intracellular digestion
______________ digestion refers to the digestive process that occurs outside the cell, within a lumen or tract.
Extracellular digestion
Mammals have a one-way digestive tract known as the ________________.
Alimentary canal
Path of human digestive tract
1. oral cavity2. pharynx3. esophagus 4. stomach5. small intestine6. large intestine7. anus *OP ESSLA**
The ________________ is where mechanical and chemical digestion of food begins.
oral cavity
_____________ digestion is the breakdown of large food particles into smaller particles through the biting and chewing action (mastication).
mechanical digestion
While _____________ digestion does not lead to changes in the molecular composition of food, the total surface area of the food is increased, allowing for faster and more efficient enzymatic action
mechanical digestion
_____________ digestion refers to the enzymatic breakdown of macromolecules into smaller molecules, and begins in the mouth when the salivary glands secrete saliva.
Chemical
_________ lubricates food to facilitate swallowing, and provides a solvent for food particles.
Saliva
___________ is secreted in response to a nervous reflex triggered by the presence of food in the oral cavity.
Saliva
Saliva contains the enzyme ________________ (ptyalin) which hydrolyzes starch into simple sugars.
salivary amylase
The tongue manipulates the food during chewing, rolling it into a ball called a ___________, and pushes it into the pharynx.
Bolus
Chemical rxn of salivary amylase:
salivary amylasestarch + H2O --------------------> maltose
The digestive and respiratory passages come together in the _____________.
Pharynx
Food is moved down the esophagus by rhythmic waves of involuntary muscular contractions called _________________.
Peristalsis
When a wave of peristalsis spreads down the esophagus, a specialized ring of muscle in the lower esophagus opens, allowing food to enter the stomach. Following the peristaltic wave, this muscle, called the lower ________________, returns to its normal closed state, thus preventing the regurgitation of stomach contents into the esophagus.
lower esophageal sphincter or cardiac sphincter
The walls of the stomach are lined with a thick gastric mucosa containing 2 glands: _________________, _______________.
Gastric glandsPyloric glands
The _____________ glands of the stomach are stimulated by nervous impulses from the brain, which responds to the sight, taste, and/or smell of food.
Gastric glands
The _____________ glands are composed of 3 types of secretory cells: mucous cells, chief cells, and parietal cells.
Gastric glands
____________ cells secrete mucus, which protects the stomach lining from the harshly acidic juices present in the stomach.
Mucous cells
______________ is composed of the secretions of the chief cells and the parietal cells.
Gastric juice
___________ cells secrete pepsinogen, the zymogen of the protein-hydrolyzing enzyme, pepsin.
Chief
__________ is the zymogen of the protein-hydrolyzing enzyme, pepsin.
Pepsinogen
Parietal cells secrete _____________.
HCl
______________ facilitates the conversion of pepsinogen to pepsin.
HCl
In the stomach, _________ hydrolyzes specific peptide bonds to yield polypeptide fragments.
pepsin
The ___________ glands secrete the hormone gastrin in response to the presence of certain substances in food.
Pyloric glands
In the stomach, __________ stimulates gastric glands to secrete more HCl, and also stimulates muscular contractions of the stomach, which in turn churn food.
gastrin
The low pH of the stomach stops the activity of _______________, which functions optimally at a near neutral pH of saliva.
salivary amylase
In the stomach, ___________ is a hydrolytic enzyme that acts on protein to produce peptides. ?protein +H2O --------------> peptides
Pepsin
In the stomach, the churning produces an acidic, semi-fluid mixture of partially digested food known as _____________.
Chyme
At the junction of the stomach and the small intestine is the muscular ________________.
pyloric sphincter
The _________________ regulates the passage of chyme from the stomach into the small intestine via alternating contractions and relaxations.
pyloric sphincter
Although nutrient absorption occurs in the small intestine, alcohol and certain drugs (ex: aspirin) can be directly absorbed into the systemic circulation through capillaries in the stomach wall. A. TrueB. FalseTrue False
TRUE
The small intestine is divided into 3 sections in the following order:
duodenum, jejunum, and ileum.
Most digestion in the small intestine occurs in the ________________, where the secretions of the intestinal glands, pancreas, liver, and gall bladder mix together with the acidic chyme entering from the stomach.
duodenum
The presence of chyme triggers hormonal release, which in turn stimulates and regulates the secretions of the small intestine and its accessory organs. A. TrueB. FalseTrue False
TRUE
The majority of nutrient absorption occurs across the walls of the _____________.
Jejunum and the ileum.
The ___________ is a vestigial structure containing lymphoid tissue that is often surgically removed if it becomes infected.
Appendix
Protein digestion begins in the ____________.
Stomach
Lipid digestion begins in the _______________.
Small intestine
What is the main function of the large intestine?
reabsorption of water form solid feces/wastes.
In addition to hormonal regulation, the digestive processes are also stimulated by the _______________, and inhibited by the ________________.
stimulated by the parasympathetic nervous systeminhibited by the sympathetic nervous system