AAPC-CPC Certified Professional Coder - Set 1 - Part 3

Correct Answer: Chemical messengers acting over minutes, hours, or weeks

The endocrine system acts through chemical messengers called hormones, and its action is measured in minutes, hours, or weeks and is more generalized. The nervous system instead acts in seconds and is localized. Option a is incorrect because describes nervous system action, which uses electrical impulses and neurotransmitters and produces short-duration, localized effects rather than the generalized, slower effects of hormones. Option c is incorrect because neurotransmitters are the primary chemical signal of the nervous system, which is listed as always traveling a short distance, while hormones travel long or short. Option d is incorrect because ducts belong to exocrine glands, a gland category; endocrine glands are ductless and release hormones directly into the blood.

Correct Answer: Calcitonin

Calcitonin is secreted by the parafollicular cells of the thyroid gland. It opposes the parathyroid glands by reducing blood calcium, and it is released when blood calcium becomes too high. Option a is incorrect because it is secreted by the parathyroid glands in response to low blood calcium, and its effect is to raise calcium rather than lower it. Option b is incorrect because it is produced in the thyroid follicles and requires iodine for its synthesis, so it does not come from the parafollicular cells. Option c is incorrect because it comes from the anterior pituitary and prompts the thyroid to enlarge when iodine is lacking, not the parafollicular cells.

Correct Answer: Closure of the valves

Heart sounds associated with the heartbeat are due to vibrations in the tissues and blood caused by closure of the valves. Abnormal heart sounds are called murmurs, which differ from these normal sounds. Option a is incorrect because myocardial contraction is systole, a phase of the cardiac cycle; the sounds come from vibrations after valves close, not from the contraction itself. Option b is incorrect because the sinoatrial node is the pacemaker that initiates impulses to set the heartbeat rhythm, but it does not produce the sounds heard during auscultation. Option d is incorrect because the coronary sinus collects most cardiac veins and opens into the right atrium; it is part of coronary drainage, not a sound source.

Correct Answer: Visceral pericardium

The visceral pericardium, also called the epicardium, is the inner layer of the serous pericardium. It is fused to the heart and forms the outer layer of the heart wall. Option b is incorrect because forms the inner layer of the heart wall, lining the chambers and serving as the main component of the valves. Option c is incorrect because lies in the outer serous layer and is fused to the fibrous pericardium, not to the heart itself. Option d is incorrect because is the sturdy outer sublayer of dense connective tissue that protects the heart and holds it in position; it is not fused to the heart.

Correct Answer: Blood vessels

The lymphatic system consists of lymph, lymphatic vessels, and organs containing lymphoid tissue. Blood vessels belong to the circulatory system; lymphatic vessels are described as differing from them, so they are not a component. Option a is incorrect because these are the transport component, running from the lymph capillaries through the trunks to the ducts, and they carry fluid only away from tissues. Option b is incorrect because it is the fluid component, derived from blood plasma and named lymph once interstitial fluid enters the lymph capillaries. Option d is incorrect because the lymphatic system is defined as including organs with lymphoid tissue, such as lymph nodes, which filter lymph and hold lymphocytes.

Correct Answer: Natural passive immunity

Passive immunity is the transfer of antibodies from an immune person to a nonimmune person. Trans-placental antibodies and maternal antibodies in breast milk are the natural examples, and they last only a limited time before degrading. Option b is incorrect because this form comes from vaccination, which prompts the recipient's own immune response and memory, rather than transferring finished antibodies from the mother. Option c is incorrect because this form is delivered by immunoglobulin injections taken from previously exposed animals, which is a different route from placental transfer or breast milk. Option d is incorrect because active immunity rests on memory cells formed during the individual's own adaptive immune response to a pathogen, not on antibodies received from the mother.

Correct Answer: laryngopharynx

The pharynx is divided into three major regions: the nasopharynx, the oropharynx, and the laryngopharynx. The laryngopharynx is therefore the third region that completes the list. Option a is incorrect because the trachea, the windpipe, is the main airway to the lungs and belongs to the lower respiratory tract, not the pharynx. Option c is incorrect because the larynx is named in the upper respiratory tract as a structure separate from the pharynx, so it is not one of the pharyngeal regions. Option d is incorrect because the nasal cavity is a separate space that opens into the pharynx, as the location of the pharyngeal tonsils shows.

Correct Answer: Secretin and cholecystokinin

Pancreatic secretions are controlled by the hormones secretin and cholecystokinin. The other pairs are endocrine products of the islets, a gastric hormone, or digestive enzymes produced by the pancreas itself. Option a is incorrect because these are hormones the islets of Langerhans secrete into the blood as the endocrine product, not the regulators of pancreatic secretions. Option b is incorrect because these are pancreatic enzymes released by the exocrine acinar cells, meaning they are products of the gland rather than hormones controlling it. Option d is incorrect because gastrin regulates gastric activity in the stomach, so pairing it with secretin does not describe the control of pancreatic secretions.

Correct Answer: Liver

The urinary system consists of the kidneys, ureters, urinary bladder, and urethra. The liver is not among them; it is a different excretory organ that excretes bile pigments from the destruction of hemoglobin. Option a is incorrect because the urethra is a tubular component of the system that carries urine from the urinary bladder to the outside. Option c is incorrect because the ureters are listed as a component of the urinary system and carry urine from the kidneys to the urinary bladder. Option d is incorrect because the urinary bladder is a named component of the system, serving as a temporary reservoir for urine.

Correct Answer: Corpus spongiosum

The corpus spongiosum is the single, midline ventral column of erectile tissue in the penis. It surrounds the urethra and expands at its distal end to form the glans penis. Option a is incorrect because are the two dorsal columns of erectile tissue in the penis, not the single midline ventral column that surrounds the urethra. Option b is incorrect because is the loose fold of skin, also called the foreskin, that covers the glans penis; it is not erectile tissue. Option c is incorrect because is the expanded distal end formed by the corpus spongiosum, so it is a part of that column rather than the column itself.