Oral Cavity, Pharynx, & Esophagus, Stomach

The oral cavity is also known as the:
A. Pharyngeal space
B. Buccal cavity
C. Nasal cavity
D. Gastrointestinal chamber

B. Buccal cavity

Which of the following is not a function of the oral cavity?
A. Ingestion
B. Filtration of blood
C. Mechanical digestion
D. Taste

B. Filtration of blood

Which structure allows for mechanical digestion in the oral cavity?
A. Salivary glands
B. Esophagus
C. Teeth during chewing
D. Soft palate

C. Teeth during chewing

What substance in the oral cavity contributes to chemical digestion?
A. Hydrochloric acid
B. Mucus from the large intestine
C. Bile
D. Saliva

D. Saliva

Before food can be swallowed, it must be:
A. Broken down in the stomach
B. Filtered by the lymph nodes
C. Mixed with bile and pancreatic juice
D. Chewed and combined with saliva to form a bolus

D. Chewed and combined with saliva to form a bolus

What is a bolus?
A. A digestive enzyme in the stomach
B. A muscular valve in the throat
C. Chewed food mixed with saliva, ready for swallowing
D. A region of the pharynx

C. Chewed food mixed with saliva, ready for swallowing

What type of epithelium lines most of the oral cavity?
A. Simple cuboidal
B. Transitional
C. Stratified squamous
D. Pseudostratified columnar

C. Stratified squamous

Which areas of the oral cavity are lined with keratinized stratified squamous epithelium for protection?
A. Tongue and uvula
B. Cheeks and soft palate
C. Hard palate and gums
D. Esophagus and pharynx

C. Hard palate and gums

What are the functions of the oral cavity?

• Ingestion

• Taste

• Mechanical Digestion

• Chemical digestion

• Swallowing

What is one of the primary functions of saliva in the oral cavity?
A. Increases blood pressure
B. Moistens the mouth for digestion
C. Triggers immune suppression
D. Neutralizes stomach acid

B. Moistens the mouth for digestion

Dental cavities are primarily caused by:
A. Enzyme overproduction in the stomach
B. Viral destruction of enamel
C. Acid produced by oral bacteria
D. Immune reactions to food particles

C. Acid produced by oral bacteria

Which enzyme found in saliva helps kill bacteria that produce acid in the mouth?
A. Amylase
B. Lysozyme
C. Lipase
D. Lactase

B. Lysozyme

Which antibody in saliva helps inhibit bacterial growth?
A. IgE
B. IgM
C. IgG
D. IgA

D. IgA

How does saliva help protect tooth enamel?
A. By providing a physical barrier
B. By increasing plaque formation
C. By buffering acids and promoting remineralization
D. By eroding dentin directly

C. By buffering acids and promoting remineralization

Saliva helps enhance taste perception by:
A. Producing insulin
B. Stimulating the olfactory receptors
C. Dissolving food molecules to activate taste buds
D. Blocking bitter taste receptors

C. Dissolving food molecules to activate taste buds

What is the function of salivary amylase?
A. Breaks down proteins into amino acids
B. Breaks down starches (carbohydrates) into simpler sugars
C. Digests fats in the stomach
D. Neutralizes stomach acid

B. Breaks down starches (carbohydrates) into simpler sugars

Which enzyme begins fat digestion and is activated by stomach acid?
A. Pepsin
B. Lingual lipase
C. Salivary amylase
D. Lactase

B. Lingual lipase

What are the functions of saliva?

• Moistens mouth

• Prevents cavities

• Dissolves food molecules to stimulate taste buds

• Begins chemical digestion

Which of the following is not one of the three major salivary glands?
A. Parotid
B. Submandibular
C. Sublingual
D. Pharyngeal

D. Pharyngeal

What so salivary glands secrete

saliva

how many large salivary glands are there?

3

How much saliva is typically produced by the human body per day?
A. 0.1–0.2 liters
B. 1–1.5 liters
C. 3–4 liters
D. 5–6 liters

B. 1–1.5 liters

Which part of the brain contains the salivatory nuclei that regulate salivation?
A. Cerebral cortex
B. Hypothalamus
C. Medulla oblongata and pons
D. Cerebellum

C. Medulla oblongata and pons

Which of the following stimuli can trigger salivation through the salivatory nuclei?
A. Tactile sensation from skin
B. Sound of thunder
C. Sight, smell, thought, or taste of food
D. Drop in blood pressure

C. Sight, smell, thought, or taste of food

Salivatory signals are transmitted through which two cranial nerves?
A. Trigeminal and vagus
B. Facial and glossopharyngeal
C. Accessory and hypoglossal
D. Oculomotor and trochlear

B. Facial and glossopharyngeal

What effect do parasympathetic signals have on salivation?
A. Inhibit all salivary gland activity
B. Stimulate saliva secretion
C. Stimulate only the parotid gland
D. Cause contraction of chewing muscles

B. Stimulate saliva secretion

What is the effect of sympathetic nervous system activation on saliva?
A. Completely shuts down saliva production
B. Increases secretion of watery saliva
C. Decreases secretion volume and increases mucus content
D. Stimulates salivary enzyme production only

C. Decreases secretion volume and increases mucus content

What is the primary role of the pharynx in the digestive system?
A. Site of nutrient absorption
B. Muscular funnel connecting the oral cavity to the esophagus
C. Organ that secretes digestive enzymes
D. Valve that prevents food from entering the lungs

B. Muscular funnel connecting the oral cavity to the esophagus

In addition to being part of the digestive system, the pharynx also functions as part of which other system?
A. Lymphatic system
B. Endocrine system
C. Respiratory system
D. Circulatory system

C. Respiratory system

What is the esophagus?
A. A gland that secretes digestive enzymes
B. A muscular valve controlling stomach entry
C. A muscular tube connecting the pharynx to the stomach
D. A sac that stores bile

C. A muscular tube connecting the pharynx to the stomach

What is peristalsis in the esophagus?
A. Voluntary movement of the diaphragm
B. Involuntary wave-like muscular contractions pushing food
C. A rhythmic heartbeat affecting digestion
D. The secretion of bile into the stomach

B. Involuntary wave-like muscular contractions pushing food

Which phase of swallowing is esophageal peristalsis considered?
A. Initial oral phase
B. Pharyngeal phase
C. Final phase of swallowing
D. Preparatory phase of chewing

C. Final phase of swallowing

Why is peristalsis important for food movement in the esophagus?
A. It relies on gravity to push food down
B. It prevents reflux into the oral cavity
C. It allows food to move toward the stomach even against gravity
D. It controls salivary secretion

C. It allows food to move toward the stomach even against gravity

What is the primary function of the stomach?
A. Absorb nutrients into the bloodstream
B. Produce red blood cells
C. Store food after ingestion
D. Synthesize glucose

C. Store food after ingestion

How much food can the stomach typically hold after a meal?
A. 100 mL
B. 500 mL
C. 1 liter
D. 5 liters

C. 1 liter

When very full, the stomach can expand to hold up to:
A. 1 liter
B. 2 liters
C. 3 liters
D. 4 liters

D. 4 liters

Which type of mechanical digestion occurs in the stomach?
A. Mastication
B. Peristalsis
C. Churning of food by muscular contractions
D. Grinding by teeth

C. Churning of food by muscular contractions

Which types of nutrients are primarily digested chemically in the stomach?
A. Carbohydrates and vitamins
B. Proteins and fats
C. Water and minerals
D. Fiber and glucose

B. Proteins and fats

What is chyme?
A. Undigested food in the large intestine
B. Fully digested nutrients ready for absorption
C. Semi-digested food mixture that goes into small intestine
D. Acidic secretions from the salivary glands

C. Semi-digested food mixture that goes into small intestine

Where does most digestion and nearly all absorption occur in the digestive tract?
A. Mouth
B. Stomach
C. Small intestine
D. Large intestine

C. Small intestine

What is unique about the muscularis externa of the stomach compared to other parts of the digestive tract?
A. It has skeletal muscle in all layers
B. It contains only one muscle layer
C. It has three layers of smooth muscle
D. It lacks any smooth muscle layers

C. It has three layers of smooth muscle

Which is the correct order of muscle layers in the stomach’s muscularis externa (from inner to outer)?
A. Circular, longitudinal, oblique
B. Oblique, circular, longitudinal
C. Longitudinal, circular, oblique
D. Circular, oblique, longitudinal

B. Oblique, circular, longitudinal

What type of epithelium lines the inner surface of the stomach?
A. Stratified squamous
B. Simple cuboidal
C. Transitional
D. Simple columnar

D. Simple columnar

What is the purpose of the mucus secreted by the stomach’s epithelial cells?
A. Aids in nutrient absorption
B. Protects the lining from stomach acid
C. Increases chyme production
D. Enhances blood flow

B. Protects the lining from stomach acid

What are gastric pits?
A. Folds in the muscularis externa
B. Depressions in the gastric mucosa that lead to glands
C. Openings for the bile duct
D. Regions of lymphatic tissue

B. Depressions in the gastric mucosa that lead to glands

What is located at the base of the gastric pits?
A. Peyer’s patches
B. Lymph nodes
C. Salivary glands
D. Stomach glands that produce digestive secretions

D. Stomach glands that produce digestive secretions

Which of the following statements about chief cells is true?
A. They are the least common cells in the stomach lining
B. They are only found in the esophagus
C. They are the most numerous cell type in the stomach
D. They secrete hydrochloric acid

C. They are the most numerous cell type in the stomach

Where are chief cells located?
A. Lining the esophagus
B. In the liver sinusoids
C. In the gastric glands of the stomach
D. In the pancreas

C. In the gastric glands of the stomach

What do chief cells secrete?
A. Mucus and bile
B. Gastric hormones and bicarbonate
C. Digestive enzymes like gastric lipase and pepsinogen
D. Insulin and glucagon

C. Digestive enzymes like gastric lipase and pepsinogen

What is the role of gastric lipase?
A. Neutralizes stomach acid
B. Initiates carbohydrate digestion
C. Breaks down fats into fatty acids and glycerol
D. Activates pepsinogen

C. Breaks down fats into fatty acids and glycerol

What is pepsinogen?
A. A hormone that stimulates acid production
B. A zymogen (inactive enzyme) secreted by chief cells
C. An alkaline buffer that coats the stomach
D. An active enzyme that digests fats

B. A zymogen (inactive enzyme) secreted by chief cells

How is pepsinogen converted into pepsin?
A. By mixing with bile in the duodenum
B. Through enzymatic breakdown by lipase
C. By exposure to hydrochloric acid (HCl) in the stomach
D. By amylase from the salivary glands

C. By exposure to hydrochloric acid (HCl) in the stomach

What is the main function of the enzyme pepsin?
A. Emulsifies fats
B. Breaks down starches
C. Chemically digests proteins into peptides
D. Activates pancreatic enzymes

C. Chemically digests proteins into peptides

How much gastric juice is typically produced by the stomach each day?
A. 0.5–1 L
B. 1–1.5 L
C. 2–3 L
D. 4–5 L

C. 2–3 L

Which of the following a component of gastric juice?

mixture water, HCL, pepsinogen, gastric lipase, intrinsic factor

Which cells secrete hydrochloric acid (HCl) in the stomach?
A. Chief cells
B. Mucous cells
C. G cells
D. Parietal cells

D. Parietal cells

What is one of the primary roles of HCl in the stomach?
A. Absorbs nutrients
B. Breaks up the bolus and liquefies it into chyme
C. Deactivates enzymes
D. Neutralizes acid in the stomach

B. Breaks up the bolus and liquefies it into chyme

How does HCl aid in protein digestion?
A. Absorbs amino acids directly
B. Converts proteins into DNA
C. Denatures proteins, making them easier to digest
D. Transports proteins to the intestines

C. Denatures proteins, making them easier to digest

What role does HCl play in enzyme activation?
A. Destroys all enzymes in the stomach
B. Converts pepsinogen to pepsin, the active enzyme
C. Inhibits lipase activity
D. Stimulates pancreatic enzyme secretion

B. Converts pepsinogen to pepsin, the active enzyme

What is pepsinogen?
A. A hormone secreted by the pancreas
B. An active enzyme that digests fats
C. A zymogen (inactive enzyme) secreted by chief cells
D. An alkaline buffer

C. A zymogen (inactive enzyme) secreted by chief cells

Which enzyme is activated by HCl but originally secreted in the oral cavity?
A. Gastric lipase
B. Amylase
C. Lingual lipase
D. Sucrase

C. Lingual lipase

How does HCl contribute to disease resistance in the stomach?
A. Triggers lymphocyte production
B. Stimulates the production of histamine
C. Destroys most ingested pathogens
D. Removes mucus from gastric lining

C. Destroys most ingested pathogens

Which stomach cells secrete intrinsic factor?
A. Chief cells
B. Mucous neck cells
C. G cells
D. Parietal cells

D. Parietal cells

What is the primary function of intrinsic factor?
A. Aids in fat digestion
B. Helps absorb vitamin B12 in the small intestine
C. Neutralizes stomach acid
D. Stimulates pepsinogen production

B. Helps absorb vitamin B12 in the small intestine

Intrinsic factor is essential because it:
A. Binds to vitamin B12, allowing for its absorption
B. Converts pepsinogen to pepsin
C. Stimulates secretion of bile
D. Breaks down proteins

A. Binds to vitamin B12, allowing for its absorption

Where is the vitamin B12–intrinsic factor complex absorbed?
A. Stomach lining
B. Liver sinusoids
C. Intestinal epithelial cells
D. Pancreatic ducts

C. Intestinal epithelial cells

Why is vitamin B12 important in the body?
A. It increases bile production
B. It supports digestion of starch
C. It is required for hemoglobin synthesis
D. It breaks down fatty acids

C. It is required for hemoglobin synthesis

What is the only indispensable function of the stomach?
A. Churning food into chyme
B. Secretion of pepsinogen
C. Storage of nutrients
D. Secretion of intrinsic factor

D. Secretion of intrinsic factor