Human Digestive System and Nutrition Practice Flashcards

A set of 30 flashcards in Question and Answer style covering the anatomy, processes, and nutrient composition related to the human digestive system.

What is metabolism defined as in the context of digestion?

The process on how the cells use the energy that they obtained from food during digestion.

Which nerve is prompted by the stimulus of smell when food is detected by the nose?

The olfactory nerves.

What are the three pairs of major salivary glands?

1. Parotid, 2. Sublingual, 3. Submandibular.

Where are the parotid glands located?

On the inside of the cheeks, below and in front of each ear canal.

How many teeth do human adults and children typically have?

Adults have $32$ teeth, while children have $20$ primary teeth.

What are the functions of incisors and canines compared to premolars and molars?

Incisors and canines are used for tearing and biting food, while premolars and molars are ideal for chewing due to their large surfaces.

What is a bolus?

A starchy ball of food softened by enzymes in saliva; the rounded soft mass of chewed food.

What are the five basic taste sensations detected by taste buds?

Sweet, sour, salty, bitter, and umami (savory).

What is the function of the epiglottis?

It is a flap that closes the windpipe (trachea) upon swallowing to prevent the food bolus from entering the lungs.

What is peristalsis?

The series of involuntary, wavelike muscular contractions that occur in the digestive tract to push food down.

What is the lower esophageal sphincter (LES)?

A muscular valve that relaxes to allow food to pass from the esophagus into the stomach.

What is the composition and pH of the gastric juice in the stomach?

It is composed of hydrochloric acid (HCl) and pepsin, with a pH level between $1$ and $2$.

What are rugae and what is their purpose?

Ridges of muscle tissue in the stomach that help expand its surface area to accommodate up to $0.9\,liter$ of food.

What is chyme?

A thick, semi-liquid food mass formed by the churning and mixing of bolus with gastric juices.

Which muscular valve acts as the exit from the stomach into the small intestine?

The pyloric sphincter.

What percentage of chemical digestion and nutrient absorption occurs in the small intestine?

$90\%$.

What are the names and lengths of the three segments of the small intestine?

1. Duodenum ($25\,cm$), 2. Jejunum ($2.5\,m$), and 3. Ileum ($3.6\,m$).

What are the fingerlike projections on the folded surfaces of the small intestine?

Villi, which are further covered by microvilli.

Name the three accessory organs of the digestive system.

1. Pancreas, 2. Liver, and 3. Gallbladder.

What are the three enzymes found in pancreatic juice?

1. Pancreatic amylase, 2. Trypsin (proteolytic enzyme), and 3. Lipase.

How is sucrose (table sugar) broken down, and what are its components?

It is broken down by the enzyme sucrase into glucose and fructose.

What is the largest organ of the body in terms of mass, and what does it produce?

The liver; it produces bile.

What is emulsification?

The process where large lipid globules are broken down into several small lipid globules.

What are the four parts of the large intestine?

1. Ascending colon, 2. Transverse colon, 3. Descending colon, and 4. Sigmoid colon.

What are the six processes of the digestive system?

1. Ingestion, 2. Propulsion, 3. Digestion, 4. Absorption, 5. Assimilation, and 6. Defecation.

How many calories per gram are provided by carbohydrates, proteins, and fats?

Carbohydrates provide $4\,calories/gram$, proteins provide $4\,calories/gram$, and fats provide $9\,calories/gram$.

List the nine essential amino acids that must come from food.

Histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine.

What is the difference between Marasmus and Kwashiorkor?

Marasmus is a severe lack of both protein and energy (extreme weight loss), while Kwashiorkor is a severe protein deficiency (swollen limbs and bulging abdomen).

What is the difference between saturated and unsaturated fats?

Saturated fats are solid at room temperature and increase bad cholesterol, while unsaturated fats are liquid at room temperature and help lower bad cholesterol.

What are Trans Fats, and why are they considered harmful?

Processed fats from hydrogenated oils that increase bad cholesterol and risk of heart disease; many are banned by the FDA.