A & P Test V

Which of the following is NOT one of the six general functions of the digestive system?

Filtration of blood for waste

Which organ is considered part of the gastrointestinal (GI) tract rather than an accessory organ?

Esophagus

The process of moving substances through the GI tract via muscle contractions is called:

Motility

Which type of receptor in the GI tract detects the presence of specific chemicals within
the lumen?

Chemoreceptors

"Long reflexes" in the digestive system are coordinated by the:

Central nervous system (CNS)

The enteric nervous system consists of which two plexuses?

Submucosal and Myenteric

Which tunic of the GI tract wall is composed of an epithelium, lamina propria, and a thin
layer of smooth muscle?

Mucosa

The thin layer of smooth muscle that creates folds in the mucosa to increase surface area is the:

Muscularis mucosae

Most nutrients are absorbed into the blood capillaries, but large lipids and lipid-soluble vitamins are absorbed into:

Lymphatic capillaries (lacteals)

The nerve plexus located between the inner circular and outer longitudinal layers of the
muscularis is the:

Myenteric plexus

Which hormone is primarily released by the stomach to regulate digestive processes?

Gastrin

Organs that are completely surrounded by visceral peritoneum are called:

Intraperitoneal

The double layer of peritoneum that supports, suspends, and stabilizes the GI tract organs is the:

Mesentery

Which of the following is a function of saliva?

Moistens food to form a bolus, initiates chemical breakdown of starch, Inhibits bacterial growth with lysozyme

What is the name of the most anterior teeth used for slicing or cutting food?

Incisors

During the pharyngeal phase of swallowing, which structure rises to block the nasopharynx?

Soft palate and uvula

Which phase of swallowing is the only one that is voluntary?

Voluntary phase

Reflux esophagitis, commonly known as heartburn, is caused by:

Acidic chyme refluxing into the esophagus

Chronic GERD (Gastroesophageal Reflux Disease) can lead to a tissue change where stratified squamous epithelium is replaced by:

Columnar secretory epithelium

The "short reflexes" of the digestive system are unique because they:

Are mediated entirely within the enteric nervous system

Which region of the stomach is located immediately adjacent to the opening of the esophagus?

Cardia

The internal folds of the stomach lining that allow it to expand when filled are called:

Rugae (Gastric folds)

Which layer of the stomach's muscularis is unique compared to the rest of the GI tract?

Oblique layer

Which cell type in the gastric gland is responsible for secreting hydrochloric acid (HCl)?

Parietal cell

What is the function of intrinsic factor, secreted by parietal cells?

Vitamin B12 absorption in the ileum

In the stomach, pepsinogen is converted into the active enzyme pepsin by:

Hydrochloric acid (HCl)

The "pacemaker cells" of the stomach are responsible for:

Establishing the basic rhythm of muscular contraction

Which phase of gastric regulation is initiated by the thought, smell, or sight of food?

Cephalic phase

The hormone gastrin, secreted by G-cells, has what effect on the stomach?

Stimulates stomach secretions and motility

What is the name of the "back-and-forward" motion in the small intestine that mixes chyme with secretions?

Segmentation

Which segment of the small intestine is the primary region for chemical digestion and nutrient absorption?

Jejunum

The fingerlike projections of the small intestine mucosa that increase surface area for absorption are:

Villi

What specialized lymphatic capillary within a villus is responsible for absorbing lipids?

Lacteal

The structural and functional units of the liver are called:

Hepatic lobules

In a liver lobule, where do oxygenated blood from the hepatic artery and nutrient-rich blood from the hepatic portal vein first mix?

Hepatic sinusoids

What substance is produced by the liver to mechanically digest lipids through emulsification?

Bile

Which structure stores, concentrates, and releases bile?

Gallbladder

The portal triad at the periphery of a liver lobule consists of:

Hepatic artery, portal vein, and bile ductule

Which condition involves the replacement of healthy hepatocytes with fibrous scar tissue, often due to chronic alcoholism or hepatitis?

Cirrhosis

The gastroileal reflex causes:

Movement of contents from the ileum to the cecum in response to food in the stomach

Which of the following is the primary function of the gallbladder?

To store, concentrate, and release bile produced by the liver

The pancreas is considered a retroperitoneal organ that has both endocrine and exocrine
functions. Which cells are responsible for its exocrine function?

Acinar cells

Which pancreatic cell type is specifically responsible for secreting alkaline, HCO3-rich fluid to neutralize acidic chyme?

Duct cells

Pancreatic juice contains all of the following EXCEPT:

Bile salts

Which hormone is released from the small intestine in response to fatty chyme and stimulates the gallbladder to contract?

Cholecystokinin (CCK)

What is the primary stimulus for the release of Secretin from the small intestine?

Increased acidity of chyme

Which structure in the large intestine consists of thin longitudinal bundles of smooth muscle that bunch the intestine into sacs called haustra?

Teniae coli

In the large intestine, the process of compacting watery chyme into feces and storing it occurs between which two points?

Ileocecal junction to the anus

Histologically, how does the mucosa of the large intestine differ from that of the small intestine?

It lacks villi and has numerous goblet cells

What is a key role of the indigenous microbiota (normal bacterial flora) in the large intestine?

To synthesize B vitamins and vitamin

Which reflex is initiated by stomach distension and causes a powerful "mass movement" in the large intestine?

Gastrocolic reflex

During the defecation reflex, which muscle is under voluntary (somatic) control?

External anal sphincter

Where does the chemical digestion of carbohydrates begin, and which enzyme is
responsible?

Oral cavity; Salivary amylase

Which of the following is a "brush border enzyme" required to finish the breakdown of starch
into individual glucose molecules?

Dextrinase

Which brush border enzyme is specifically responsible for digesting milk sugar (lactose)?

Lactase

In protein digestion, which enzyme is responsible for activating trypsinogen into active
trypsin?

Enteropeptidase

Why are proteolytic enzymes (like trypsin and chymotrypsin) released from the pancreas in an inactive form?

To prevent the enzymes from digesting the proteins within the pancreatic cells themselves

What is the function of bile salts in lipid digestion?

They emulsify lipids into smaller droplets (micelles) to increase surface area for lipase

Once lipids are reassembled into triglycerides within epithelial cells, they are wrapped in protein to form __________, which then enter the __________.

Chylomicrons; lacteals

Which enzymes, released by the pancreas, break the phosphodiester bonds between
nucleotides in DNA and RNA?

Deoxyribonuclease and ribonuclease

Which of the following is NOT considered a major nutrient biomolecule required in the diet?

Nucleic acids

A "complete protein" is defined as a protein that:

Supplies all the essential amino acids

Which group of vitamins are fat-soluble and can lead to an overdose if stored in excess in the body?

Vitamins A, D, E, and K

Which vitamin is a precursor for the formation of the visual pigment retinal?

Vitamin A

How do major minerals differ from trace minerals?

Major minerals are required in amounts > 100 mg daily; trace minerals are < 100 mg daily

Iron deficiency is one of the most common mineral deficiencies. What is the primary role of iron in the body?

Component of hemoglobin to bind oxygen

Which lipid is a component of all animal-based products and serves as a precursor for steroid hormones and bile salts?

Cholesterol

The USDA's "MyPlate" visual representation includes which five food categories?

Grains, Vegetables, Fruits, Protein, and Dairy

The "Absorptive State" typically lasts about four hours after a meal. What is the primary
hormone regulating this state?

Insulin

During the absorptive state, the liver responds to insulin by:

Increasing glycogenesis (synthesizing glycogen from glucose)

Which state occurs between meals when the body relies on stored nutrients to maintain homeostatic blood glucose levels?

Postabsorptive state

What is the primary function of Very-Low-Density Lipoproteins (VLDLs)?

Transport triglycerides from the liver to peripheral tissues (adipose)

Which lipoprotein is often called "good cholesterol" because it transports lipids from the arterial walls back to the liver?

HDL

The process in the liver where the amine group is removed from an amino acid is called:

Deamination

Which liver process involves joining fatty acids with glycerol to form triglycerides for
storage?

Lipogenesis

What is the liver's response to an increase in dietary cholesterol intake?

It decreases its own synthesis of cholesterol

"Basal Metabolic Rate" (BMR) is defined as the energy used:

At rest (individual has not eaten for 12 hours and is relaxed)

Which method of measuring BMR is considered "indirect" because it measures oxygen
consumption rather than heat production?

Respirometer

What is the most important variable influencing a person's Basal Metabolic Rate?

Body surface area

Total Metabolic Rate (TMR) is calculated as:

BMR plus metabolism associated with physical activity