Mastering A & P Chapter 17 Assignment 10

T or F: All endocrine glands secrete their hormones into the bloodstream.

- T

T or F: The endocrine cells of the pancreas are present in islets, whereas the exocrine cells are in acini.

- T

Compared to most other organs in the body, endocrine organs are: a. well vascularized b. have an average amount of vascularization c. poorly vascularized d. mainly epithelial cells

- a

Identify which one is a "master gland" that secretes at least 9 hormones. a. pituitary gland b. adrenal gland c. pancreas

- a

In a positive feedback loop, if concentrations of a specific hormone increase, what is the response of the effector organ? a. More of that hormone is secreted, which prompts further secretion of that hormone. b. The hormone level is always kept within a vary narrow range of "normal." c. A lesser concentration of that hormone is secreted until the hormone level reaches zero. d. Hormone secretion is immediately halted. e. Hormone secretion is halted once a maximum set point is reached.

- a

Pancreatic cell type that produces insulin: a. beta cells b. PP cells c. delta cells d. alpha cells e. gamma cells

- a

Which of the following statements concerning the endocrine glands is incorrect? a. The hormones they secrete travel more quickly than nerve impulses. b. The hormones they secrete regulate processes such as growth and metabolism. c. They are a group of ductless glands. d. They secrete messenger molecules called hormones.

- a

Identify the body structure where the pituitary gland is located: a. sell turcica of the sphenoid b. crista galli of the ethmoid c. posterior cranial fossa d. sphenoid sinus

- a - The sella turcica ("Turkish saddle") contains the hypophyseal fossa, a depression that holds the pituitary gland (or hypophysis). - It is an important endocrine organ that secretes at least nine major hormones that sits just inferior to the brain in the hypophyseal fossa, a depression in the sella turcica of the sphenoid bone.

Class of hormones secreted during chronic stress that depresses immune function is: a. mineralocorticoids b. glucocorticoids c. androgens d. gonadotrophins e. amino acid-based hormones

- b - Glucocorticoids depress the inflammatory response and inhibit the immune system when present in large quantities. They help the body deal with stressful situations such as fasting, anxiety, trauma, crowding, and infection. They keep blood glucose levels high enough to support the brain's activities while forcing most other body cells to switch to fats and amino acids as energy sources.

Which of these statements describing the effects of the parathyroid hormone on plasma calcium concentrations is false? a. It activates vitamin D, which stimulates Ca2+ uptake by the intestines. b. It increases secretion of Ca2+ by the kidney. c. It decreases calcium secretion of Ca2+ by the kidneys. d. It simulates osteoclasts to release more Ca2+ from bone.

- b - Parathyroid hormone is a small protein hormone secreted by the parathyroid cells that increases the blood concentration of calcium whenever it falls below some threshold value by stimulating osteoclasts to release more calcium from bone, decrease the excretion of calcium by the kidney, and activates vitamin D which stimulates the uptake of calcium by the intestine.

Steroid hormones are molecules that are derived from: a. proteins b. cholesterol c. peptides d. modified amino acids

- b - Steroid hormones are lipid molecules that are derived from cholesterol. The steroid-secreting cells have an extensive smooth endoplasmic reticulum which produces the steroid molecules, abundant lipid droplets, and the raw material from which steroids are made.

Pancreatic cell type that produces glucagon: a. delta cells b. PP cells c. alpha cells d. gamma cells e. beta cells

- c

Parathyroid hormone causes all of the following except: a. increase in plasma calcium b. activation of vitamin D c. inhibition of osteoclasts d. decreased secretion of calcium by the kidney

- c

The anatomical stalk of the pituitary is also known as: a. tuber cinerum b. neurohypophysis c. infundibulum d. pars tuberalis e. adenohypophysis

- c

The secretion of hormones by the anterior lobe of the pituitary is controlled by the: a. atria of the heart b. pars distalis c. hypothalamus d. pancreatic islets

- c

If a patient's basal metabolic rate (BMR) is always low, which hormone is not functioning correctly? a. cortisol b. norepinephrine c. thyroid hormone d. growth hormone e. glucagon

- c - Cortisol is the main type of glucocorticoids that stimulates metabolism of lipids and proteins and regulates sugar. They keep blood glucose levels high enough to support the brain's activities while forcing most other body cells to switch to fats and amino acids as energy sources. - Norepinephrine is in the adrenal medulla and is secreted into the flood to enhance the fight-or-flight response. - Thyroid hormone is secreted by the follicular cells of the thyroid gland and are constructed from a pair of amino acids and contains iodine. The main function is to increase basal metabolic rate which is the rate at which the body uses oxygen to transform nutrients into energy.

What do all adrenal cortex hormones have in common? a. Their secretion is dependent on stimulation by tropic hormones. b. They are all produced in a site remote from the adrenal gland. c. They are all steroidal hormones. d. They help people calm down after a stressful situation. e. They are also neurotransmitters.

- c - The adrenal cortex secretes a variety of hormones, all of which are lipid-based steroid hormones.

The adrenal medulla secretes: a. aldosterone b. cortisol c. epinephrine and norepinephrine d. glucocorticoids

- c - The adrenal gland has two parts: the adrenal cortex and the adrenal medulla. The adrenal medulla is the inner central core that secretes epinephrine and norepinephrine.

Which of the following is a major source of steroid hormones in the body? a. the pituitary b. the adrenal medulla c. the gonads d. the thyroid

- c - The gonads are the testes and ovaries. They produce steroid sex hormones.

Which gland secretes melatonin? a. pituitary gland b. corpus callosum c. pineal gland d. hypothalamus

- c - The pineal gland is a small, pinecone-shaped structure at the end of a short stalk on the roof of the diencephalone. It has pinealocytes, which are its endocrine cells that are arranged in both spherical clusters and branching cords. The cells themselves are star-shaped cells with long, branching processes. The brain signals the pinealocytes to secrete the hormone melatonin. Melatonin helps regulate circadian rhythms.

Which is an immune organ that also secretes endocrine hormones? a. pituitary gland b. thyroid gland c. thymus d. adrenal glands e. pancreas

- c - The thymus is located in the lower neck and anterior thorax and is lobulated. It is an important immune organ which has the site at which the white blood cells arise from precursor cells. - That transformation is stimulated by thymic hormones, which are secreted by the structure cells of the thymus - epithelial reticular cells.

Which of the following minerals is essential for the formation of thyroid hormone? a. iron b. copper c. iodine d. calcium

- c - Thyroid hormone is constructed from a pair of amino acids and contain iodine, which is essential to the function of the hormone.

The beta type of endocrine cells in the pancreatic islets secretes a hormone that: a. inhibits secretion by the exocrine pancreas b. raises blood sugar concentrations c. lowers blood sugar levels d. targets liver cells

- c The main cell types in the islets (the endocrine part of the pancreas) are alpha cells and beta cells. The alpha cells secrete glucagon, which is a protein hormone that signals liver cells to release glucose from their glycogen stores which raises blood sugar levels when they fall too low. Beta cells secrete insulin, which is a protein hormone that signals most of the cells of the body to take up glucose from the blood and promotes the storage of glucose as glycogen in the liver, thus lowering excessive blood sugar levels.

The thyroid gland is located: a. posterior to the sternum b. anterior to the aortic arch c. on the superior aspect of the kidneys d. immediately inferior to the larynx

- d

Which of the following is an example of a positive feedback loop? a. The only example in humans is preganglionic neurons of the sympathetic division of the ANS stimulating the cells of the adrenal medulla to release norepinephrine and epinephrine. b. The hypothalamus secretes gonadotropin-releasing hormone, which then prompts the adenohypophysis to secrete FSH, which then causese the production of androgens and stimulates sperm production in males. c. Hypothalamic neurons send axons to the neurohypophysis, which causes secretion of ADH, which then causes the kidneys to reclaim more water from urine. d. Oxytocin stimulates the uterus to contract, and contraction of the uterus stimulates further secretion of oxytocin.

- d

Class of hormones that regulates secretions of other endocrine glands. a. atrial naturetic peptide b. acidophilic c. renin d. basophilic e. tropic

- e

What is the function of glucagon? a. It prompts the secretion of steroid hormones from the adrenal medulla. b. It induces breast milk production during pregnancy. c. It decreases blood glucose (sugar) concentration. d. It inhibits the exocrine activity of the pancreas. e. It increases blood glucose (sugar) concentration.

- e

What secretes hormones that control blood sugar levels? a. pituitary gland b. thyroid gland c. thymus d. adrenal glands e. pancreas

- e

Largest purely endocrine gland in the body is: a. hypophysis b. adrenal gland c. pancreas d. thymus gland e. thyroid gland

- e - The thyroid gland is the largest purely endocrine gland in the body and has a copious blood supply from the superior and inferior thyroid arteries.