Digestive System – Chapter 26 (Fill-in-the-Blank Review)

A set of fill-in-the-blank flashcards covering core terminology, anatomy, physiology, and biochemistry of the digestive system to aid exam preparation.

The first of the six general functions of the digestive system is __.

ingestion

In the digestive system, coordinated muscular contractions that move material through the tract are called __.

motility (peristalsis and mixing)

The release of water, acid, buffers, and enzymes into the lumen of the GI tract is known as __.

secretion

The physical and chemical processes that break food into smaller molecules are collectively called __.

digestion

The movement of digested substances from the GI lumen into blood or lymph is __.

absorption

The elimination of indigestible residues from the body is termed __.

defecation (elimination)

The six organs that form the gastrointestinal (GI) tract are the oral cavity, pharynx, esophagus, stomach, __, and large intestine.

small intestine

The four tunics of the GI wall from deep to superficial are mucosa, __, muscularis, and serosa/adventitia.

submucosa

Peristalsis and segmentation are produced by the __ tunic of the GI tract.

muscularis

The nerve plexus located in the submucosa is the __ plexus.

submucosal (Meissner)

The myenteric plexus is located between the layers of the __ tunic.

muscularis

Organs that are completely surrounded by peritoneum and suspended by mesenteries are called __ organs.

intraperitoneal

Gastrin, secretin, and cholecystokinin (CCK) are three major __ that regulate digestion.

hormones

Mechanical digestion breaks food into smaller pieces, whereas __ digestion uses enzymes to break chemical bonds.

chemical

The anterior chamber of the upper GI tract that contains the tongue and teeth is the __.

oral cavity (mouth)

The three pairs of major salivary glands are the parotid, __, and sublingual glands.

submandibular

Chewing, or __, increases the surface area of food for enzymatic attack.

mastication

Primary (deciduous) teeth begin to erupt around __ months of age.

6

During swallowing, elevation of the soft palate and uvula blocks the __ to prevent food from entering the nasal cavity.

nasopharynx

The stomach cell that secretes hydrochloric acid and intrinsic factor is the __ cell.

parietal

An inactive digestive enzyme precursor is called a __.

zymogen (proenzyme)

Food in the stomach triggers the __ phase, a neural reflex that increases gastric motility and secretion.

gastric

The three regions of the small intestine from proximal to distal are the duodenum, __, and ileum.

jejunum

Brunner’s glands, found in the submucosa of the duodenum, secrete __ mucus.

alkaline (bicarbonate-rich)

Segmenting contractions in the small intestine that mix chyme with digestive juices are called __.

segmentation

The liver, gallbladder, and __ are the three accessory organs that empty secretions into the duodenum.

pancreas

Within a hepatic lobule, deoxygenated nutrient-rich blood from the portal vein mixes with oxygenated blood from the hepatic artery in the __.

hepatic sinusoids

The cecum, colon, and rectum are the three major regions of the __.

large intestine

Teniae coli, haustra, and abundant goblet cells are distinguishing histologic features of the __.

large intestine (colon)

Circular folds, villi, and __ are the three structures that greatly increase surface area in the small intestine.

microvilli

Stomach, jejunum, ileum, transverse colon, and sigmoid colon are examples of __ organs.

intraperitoneal

Pancreatic juice contains digestive enzymes and bicarbonate to __ acidic chyme entering the duodenum.

neutralize

Chyme passes from the ascending colon to the transverse colon at the __ colic flexure.

right (hepatic)

Glucose, gas production, and vitamin K synthesis in the colon are all results of __ action.

bacterial

Monosaccharides, disaccharides, and polysaccharides are the three major classes of __.

carbohydrates

Carbohydrate digestion begins in the mouth with the action of __ amylase.

salivary

In the small intestine, brush-border enzymes such as maltase and lactase complete the digestion of __ to monosaccharides.

disaccharides

The enzyme that initiates protein digestion in the stomach is __.

pepsin

Proteolytic enzymes are synthesized in inactive forms to prevent __ of the producing cells.

autodigestion (self-digestion)

Trypsin, chymotrypsin, and carboxypeptidase complete most protein digestion in the __ intestine.

small

Bile salts emulsify fats by forming tiny lipid droplets called __.

micelles

Inside enterocytes, absorbed fatty acids and monoglycerides are recombined to triglycerides and packaged into __.

chylomicrons

Pancreatic nucleases and brush-border enzymes break down DNA and RNA into nitrogenous bases, sugars, and __ groups.

phosphate

Short autonomic reflexes of the digestive tract that occur entirely within the enteric nervous system are called __ reflexes.

local (short)

Complete starch digestion requires salivary amylase, pancreatic amylase, and brush-border enzymes such as __.

maltase (also dextrinase, glucoamylase, sucrase, lactase)

Enterokinase (enteropeptidase) activates trypsinogen to trypsin, and trypsin then activates other pancreatic __.

zymogens (e.g., chymotrypsinogen, procarboxypeptidase)

The primary action of bile salts in lipid digestion is to __ large lipid droplets, increasing their surface area for enzyme attack.

emulsify