Final Lab Exam: Digestive System

Question 1

Oral cavity

Answer 1

• mastication
• produces salivary amylase (strach) and lingual lipase (fat)
• saliva moistens food and bind it together into a soft mass (bolus) to aid in swallowing
• adults have 32 teeth; children have 20 teeth

Question 2

Parotid gland

Answer 2

• an extrinsic (major) salivary glands
• loacted beneath the skin anterior to the earlobe
• parotid duct passes over masseter, pierces buccinator, and open into mouth

Question 3

Pharynx

Answer 3

• muscular funnel connecting oral cavity to esophagus and nasal cavity to larynx
• pharyngeal constrictors: force food downward during swallowing
• upper esophageal sphincter: when not swallowing remains contracted to exclude air from the esophagus

Question 4

Esophagus

Answer 4

• straight muscular tube 25 to 30 cm long between pharynx and stomach
• extends from pharynx to cardiac orifice of stomach passing through esophageal hiatus in diaphragm
• lower esophageal sphincter: prevents stomach contents from regurgitating into the esophagus
  1. oral phase: the tongue forms a food bolus and pushes it into the laryngopharynx
  2. pharyngeal phase: the palate, tongue, vocal cords, epiglottis block the oral and nasal cavities and airway while pharyngeal constrictors push the bolus into the esophagus
  3. esophageal phase: peristalsis drives the bolus downward and relaxtion of the lower esophageal sphincter admits it into the stomach

Question 5

Stomach (fundus, body, pyloric)

Answer 5

• muscular sac in upper left abdominal cavity
• functions as a food storage organ
• liquifies the food and begins chemical digestion of proteins and fat
• results in chyme-acidic soupy mixture of semidigested food that passes on to the small intestine
• fundus: dome superior to the esophageal attachment
• body: makes up the greatest part distal to cardiac orifice
• pyloric: narrower pouch at the inferior end contains pyloric sphincter

Question 6

Pyloric sphincter

Answer 6

• ring of smooth muscle around pylorus
• regulates the passage of chyme into the duodenum

Question 7

Pancreas

Question 8

Gallbladder

Question 9

Duodenum

Question 10

Jejunum

Question 11

Ileum

Question 12

Ascending colon

Question 13

Transverse colon

Question 14

Descending colon

Question 15

Sigmoid colon

Question 16

Rectum