Pearson Questions BIOL 2302 FINAL

What are chemical substances secreted by cells that regulate metabolic functions of other cells?

Hormones

Which of the following is NOT a typical result of a long-term stress response?

Decreased production of glucocorticoids

What is the primary function of hormones?

Act as chemical messengers that regulate the metabolic function of cells in the body

How are glands that secrete their products into surrounding tissue fluids classified?

Endocrine glands

How are glands that secrete onto a membrane surface classified?

Exocrine glands

Which of the following statements is true of amino acid-based hormones?

They require a receptor in the plasma membrane.

What do virtually all amino acid-based hormones exert their signaling effects through?

Second messengers

Which hormone can act on receptors inside the target cell that directly activate specific genes?

Testosterone

Which of the following is NOT a change that may be caused by hormonal stimulus?

Direct control of the nervous system

What does the ability of a specific tissue or organ to respond to a hormone depend on?

The presence of the appropriate receptors on the cells of the target tissue or organ

How do steroid hormones exert their action?

Entering the nucleus of a cell and initiating or altering the expression of a gene

How does the second-messenger mechanism of hormone action operate?

Binding to specific receptors and employing the services of G proteins and cAMP

Thyroid hormone enters target cells in a manner similar to what?

Steroid hormones, because both diffuse easily into target cells

Which of the following is NOT a component of the cyclic AMP signaling mechanism?

Steroid

What property of a hormone allows it to pass unassisted through a plasma membrane?

Lipid solubility

What are chemical substances secreted by cells that regulate metabolic functions in the body?

Hormones

How are glands that secrete products into surrounding tissue classified?

Endocrine glands

Which hormone can act on receptors inside the target cell to activate specific genes?

Testosterone

How does thyroid hormone enter target cells?

In a manner similar to steroid hormones, because both diffuse easily into target cells.

What is a characteristic of lipid-soluble hormones?

They can pass through cell membranes.

What describes the mechanism that directly responds to changing blood levels of ions and nutrients?

Humoral stimulation

What type of stimulus do the parathyroid glands respond to?

Humoral

What determines whether a particular cell can respond to a hormone?

The presence of a specific hormone receptor

What does the hypothalamic-hypophyseal tract do?

Runs through the infundibulum

What is a key function of oxytocin?

Release is an example of a positive feedback control mechanism

What system transports hormones from the hypothalamus to the anterior pituitary gland?

Hypophyseal portal system

What hormone does the anterior pituitary release in response to stress?

ACTH

Which hormone helps the body avoid dehydration?

Antidiuretic hormone

Which hormone is synthesized by the posterior pituitary?

ADH

Where is thyrotropin-releasing hormone (TRH) made?

Hypothalamus

What is the target of thyroid hormones?

Various tissues throughout the body

What do thyroid hormones inhibit?

Component 'A' and component B.

What triggers the release of parathyroid hormone (PTH)?

A drop in blood calcium levels.

What is a physiological response to PTH release?

Increased osteoclast activity in bone.

What does PTH increase in the kidneys?

Calcium reabsorption.

What does PTH activate in the kidneys?

Vitamin D.

What type of stimulation controls parathyroid release?

Humoral.

What happens if parathyroids respond properly to low blood calcium?

Less calcium will be excreted in the urine by the kidneys.

What is gluconeogenesis?

The formation of glucose from fats and proteins.

What hormone is responsible for gluconeogenesis?

Cortisol.

What does aldosterone do?

Increases sodium reabsorption.

Which hormone is essential for maintaining fluid levels?

Aldosterone.

Which hormone helps prevent a drop in blood sugar levels?

Insulin.

Which cells secrete insulin when blood glucose levels rise?

Beta cells.

Which cells secrete glucagon during stress?

Alpha cells.

What are the receiving chambers of the heart?

Right and left atria

What is the layer of the heart that actually contracts?

Myocardium

Which chambers of the heart contain oxygenated blood?

Left atrium and ventricle

Which statement is correct regarding the ventricles?

The right ventricle empties into the pulmonary trunk.

Which heart chamber receives oxygenated blood from the lungs?

Left atrium

What prevents backflow of blood from the right ventricle?

Right tricuspid valve

What forms the bulk of the heart?

Fibrous cardiac skeleton

What aids in the conduction of the action potential in the heart wall?

Connective tissue

What are the chambers of the heart that contain deoxygenated blood?

Right atrium and ventricle

What is the function of the left ventricle?

Pumps oxygenated blood to the body

What is the function of the right ventricle?

Pumps deoxygenated blood to the lungs

What separates the left atrium from the left ventricle?

Mitral valve

What separates the right atrium from the right ventricle?

Tricuspid valve

What is the role of the pulmonary valves?

Prevent backflow from the pulmonary artery

What is the role of the aortic valve?

Prevent backflow from the aorta

What are the two types of heart valves?

Atrioventricular and semilunar valves

What is the function of the endocardium?

Lines the heart chambers

What is the function of the epicardium?

Outer layer of the heart

What is the role of the coronary arteries?

Supply blood to the heart muscle

What is the function of the heart's septum?

Divides the left and right sides of the heart

What is the primary function of the heart?

Pumps blood throughout the body

What does the aortic valve do?

It closes the opening between the left ventricle and the aorta.

Which valve is located between the right atrium and the right ventricle?

Tricuspid valve

What is the effect of an incompetent tricuspid valve?

Reduced efficiency in the delivery of blood to the lungs.

Why is the left ventricular wall thicker than the right wall?

To pump blood with greater pressure.

Which of the following does NOT deliver oxygen-poor blood to the heart?

Pulmonary veins

Into which chamber of the heart do the superior vena cava, inferior vena cava, and coronary sinus return deoxygenated blood?

Right atrium

What is the function of the pulmonary semilunar valve?

It is located between the right ventricle and the pulmonary trunk.

What is the function of the mitral valve?

It is located between the left atrium and the left ventricle.

What is the role of the coronary sinus?

It returns deoxygenated blood from the heart muscle to the right atrium.

What is the role of the superior vena cava?

It carries deoxygenated blood from the upper body to the right atrium.

What is the role of the inferior vena cava?

It carries deoxygenated blood from the lower body to the right atrium.

What is the purpose of the pulmonary arteries?

They carry oxygen-poor blood from the right ventricle to the lungs.

What is the main function of the left atrium?

To receive oxygen-rich blood from the lungs.

What is the main function of the right ventricle?

To pump deoxygenated blood to the lungs.

What is the main function of the left ventricle?

To pump oxygen-rich blood to the body.

What is the primary role of heart valves?

To prevent backflow of blood.

What does the term 'incompetent valve' refer to?

A valve that does not close properly, allowing backflow of blood.

What is the significance of the thicker left ventricular wall?

It generates higher pressure to circulate blood throughout the body.

What is the function of the aortic semilunar valve?

It prevents backflow of blood from the aorta into the left ventricle.

What moves through pulmonary capillaries?

Blood

What is the function of the left atrium?

Receives oxygenated blood from the lungs.

What is the function of the right atrium?

Receives deoxygenated blood from the body.

How does cardiac muscle differ from skeletal muscle?

Cardiac muscle has more nuclei per cell.

What allows cardiac muscle to act as a functional syncytium?

Gap junctions.

What is a characteristic of cardiac muscle cells compared to skeletal muscle cells?

Cardiac muscle cells are larger than skeletal muscle cells.

What are the specialized junctions between cardiac muscle cells called?

Intercalated discs.

Which structure is NOT part of the intrinsic conduction system of the heart?

Atrioventricular (AV) valve.

What does the plateau phase of an action potential in cardiac muscle cells result from?

Influx of Ca2+ through slow Ca2+ channels.

What happens to the SA node if a chemical blocker reduces Na+ transport into pacemaker cells?

The SA node would depolarize more slowly, reducing the heart rate.

What sequence do electrical impulses pass through the conduction system of the heart?

SA node, AV node, AV bundle, bundle branches, and subendocardial conducting network.

What does the P wave on an electrocardiogram represent?

Atrial depolarization.

What does the QRS wave of the electrocardiogram represent?

Ventricular depolarization.

What happens if the SA node is not functioning?

An ECG will show no P waves with a heart rate between 40-60 bpm.

What is a difference between cardiac and skeletal muscle regarding oxygen deficiency?

Cardiac muscle cells quickly die in the absence of oxygen; skeletal muscle cells adapt better.