Chapter 18 - The Endocrine System

D. Produces electrolytes

E. down-regulation.

E. Both 1 and 2

A. Steroids

D. Both 1 and 2

C. Only water-soluble hormones use second messengers.

C. Antagonistic effect.

C. Mechanical stretching of the endocrine cell

C. Hormones released from the hypothalamus

A. Growth hormone

B. Prolactin

E. Adrenocorticotropic hormone

A. Luteinizing hormone

A. anterior pituitary gland

B. 7

C. Somatotrophs

C. Oxytocin and anti-diurectic hormone

A. blood osmotic pressure.

D. Calcitonin

D. Synthesis of calcitonin

A. Calcium

C. Dehydration

E. Increased production of all types of blood cells

A. Insulin

D. Thyroid hormone

C. Glucagon

C. Cortisol, hGH, Thyroid hormone

D. Increased digestive activities

Model Short Answer: Upon reaching their target cells, lipid-soluble hormones diffuse across the phospholipid bilayer of the target cell membrane and bind to receptors in the cytosol or nucleus. The activated receptor usually acts by turning transcription of genes either on or off, thus regulating synthesis of a protein. Water-soluble hormones bind to membrane receptors, which activate intracellular signaling pathways that lead to changes in the cell's metabolic activity.

Model Short Answer: The hypothalamus is the integrating center for much sensory input. It secretes releasing and inhibiting hormones which diffuse into the hypophyseal portal system to regulate secretion of all hormones from the anterior pituitary gland. The hypothalamus also contains receptors that monitor blood osmotic pressure and neural input from reproductive structures. Integration of this input leads to production of ADH and OT by neurosecretory cells of the hypothalamus. These hormones are then transported through the hypothalamohypophyseal tract to be secreted by exocytosis from the posterior pituitary gland in response to nerve impulses.

Model Short Answer: Vasopressin is also called antidiuretic hormone or ADH. In addition to its vasoconstrictive effects, ADH causes the kidneys to reabsorb more water. Someone who does not make enough ADH may not be able to contain all of the urine produced while they are sleeping. If they are not awakened by the pressure in their urinary bladder, they may wet the bed instead of getting up and going to the toilet. Since vasopressin helps the body reabsorb more water, a person's bladder should not get so full that they end up wetting the bed while sleeping.

Model Short Answer: A goiter is an enlarged thyroid gland. Hyposecretion goiters are usually due to insufficient iodide in the diet. Resulting low levels of thyroid hormones cause increased TRH and TSH until adequate thyroid activity is restored. Graves' disease causes hyperthyroidism by producing an antibody that mimics TSH. Thyroid enlargement occurs, and production of thyroid hormones increases. TRH and natural TSH remain low due to negative feedback, but TSH-mimicking antibody stimulates increased thyroid hormone production and secretion.

Model Short Answer: A starving person is lacking energy-providing nutrient sources, and so, must use structural components of the body as energy sources. The diabetic consumes adequate nutrients, but due to the lack of insulin, is unable to move glucose into cells, and so, cannot use the glucose as an energy source. In both cases, energy generation becomes dependent on non-glucose sources, such as fatty acids and amino acids. Mobilization and metabolism of fats and proteins for energy production purposes leads to ketoacidosis, weight loss, and hunger.

E. Myxedema

C. Goiter

C. Hirsutism

A. gynecomastia.

D. arachidonic acid.

A. placenta.

E. adipose tissue.

C. Ectoderm

B. Endoderm

C. Ectoderm

A. mesoderm.

D. Sebaceous gland

D. Its secretory products are carried in body fluids to distant target cells.

B. circulating hormone.

E. All the answer selections are correct.

E. follicle-stimulating hormone.

D. inhibin

C. parathyroid hormone

C. Epinephrine helps increase blood flow to exercising muscle.

It is not unusual to find them in other regions of the neck or even the thorax. The adjacent neck regions should be checked first.

Insulin should be administered because symptoms are indicative of diabetic shock.

(a) What hormone is being secreted in excess? The pituitary tumor is secreting out excessive amounts of the growth hormone. (b) What condition will Johnny exhibit if corrective measures are not taken? Johnny will exhibit structural abnormities, namely gigantism, if the proper corrective measures are not taken. (c) What is the probable cause of his headaches and visual problems? The probable cause of Johnny's headaches and visual problems is that the pituitary gland is protruding inferiorly and compressing the optic chiasma.

a. A likely possibility is that Sean has Addison's disease, which is a hyposecretory disorder of the adrenal cortex affecting secretion of both glucocorticoids and mineralocorticoids. The primary mineralocorticoid, aldosterone, is responsible for promoting Na+ absorption coupled to K+ secretion in the nephron. The resulting hyposecretion of aldosterone would be responsible for his elevated plasma K+. b. An ACTH stimulation test will allow the clinician to differentiate between a pituitary insufficiency of ACTH secretion, or an adrenal insensitivity or insufficiency. c. If ACTH does not cause a normal elevation of cortisol, then the problem originates from the adrenals, and is likely Addison's disease. d. If ACTH does cause an elevation of cortisol secretion, then likely a problem such as a tumor or malignancy exists within the anterior pituitary.

Mr. Proulx is suffering from Cushing's disease, brought on by high levels of his prednisone. His overall lousy feeling is due to muscle weakness and possible hyperglycemia, the swelling is due to water and salt retention, and the anti-inflammatory effect of the drug plays a role in suppression of immune-related defense mechanisms, increasing his susceptibility to colds.

A. Insulin

A. Calcium