AP1-Ch.13 Practice Guide

Growth hormone signals the release of IGF-1 from the __________.

liver

A hormone with an effect that lasts for days would have a __________.

long half-life

Compared to the nervous system, the endocrine system __________.

may have a longer lasting effect

A hormone is a __________ and the target cell is __________.

molecule that has a metabolic effect on another cell; a cell that has receptors for specific hormones

A person under stress may have a lowered resistance to infection.

True

With age, levels of GH _________ and levels of ADH __________.

decrease; increase

A hormone has a half-life of 20 minutes. After an hour, __________ percent of the original number of molecules remains.

12.5

What is the cause infantile hypothyroidism?

A deficiency of thyroid hormones at birth

What is the cause of Type 1 diabetes mellitus?

A disorder of the immune system

Along with insulin, amylin is a hormone that a diabetic pancreas fails to produce. It is comprised of a long chain of amino acids. It cannot cross the cell membrane, so it binds to a receptor on the cell surface to elicit an action. Which hormone class is amylin?

A protein hormone

What is the most common cause of hyperparathyroidism?

A tumor

Diabetes insipidus is caused by __________.

ADH deficiency

Hyposecretion of hormones from the adrenal cortex leads to __________.

Addison disease

What stimulates the release of hormones from the adrenal cortex?

Adrenocorticotropic hormone

What is a cause of Type 2 diabetes mellitus?

An insensitivity of cells to insulin?

Where are the target cells for hypothalamic releasing hormones located?

Anterior pituitary gland

Where is the thyroid gland located?

Anterior to the trachea

What do nerve fibers in the posterior lobe of the pituitary gland secrete?

Antidiuretic hormone

Where is the pineal gland located?

Attached to the thalamus

A 78-year-old male takes human growth hormone supplements to regain the strength of his youth. Why might he be disappointed with the results?

Because GH decreases fat and increases muscle mass, but does not improve strength.

How can a hormone have effects on some cells but not on other cells?

Because target cell receptors are unique for each hormone.

What primarily controls the secretion of parathyroid hormone?

Blood calcium concentration

Which of the following will increase as a result to stress?

Blood pressure

What hormone stimulates calcium deposition into bone?

Calcitonin

How does a nonsteroid hormone effect change in a target cell?

By causing synthesis of a second messenger

In response to high blood calcium levels, the thyroid gland releases a hormone that works to lower blood calcium. This is an example of which endocrine control method?

Changing plasma levels of a substance stimulate a gland directly.

Kristin discovers a lump in her neck. Upon examination, her physician determines it's a tumor of the thyroid and performs a complete removal. Which of the following is a hormone Kristin will need to be supplemented with?

Cholecalciferol

What is the primary control for the secretion of parathyroid hormone?

Concentration of blood calcium

Why is cortisol useful in controlling inflammatory reactions?

Cortisol decreases the permeability of capillaries.

Cells of the adrenal medulla are closely associated with preganglionic fibers of the parasympathetic division of the autonomic nervous system.

False

What is a result of Addison disease?

Decreased blood sodium levels

What is the action of insulin?

Decreases concentration of blood glucose

The use of erythropoietin (EPO) is banned for use by Olympic and professional ahtletes. Why would an athlete what to take EPO?

EPO increases the number of red blood cells.

When comparing the nervous system to the endocrine system, which of the following applies to the endocrine system?

Endocrine system has more widespread and long-lasting effects.

What is an action of growth hormone?

Enhances the movement of amino acids into cells

Which of the following is a hormone secreted by the adrenal medulla?

Epinephrine

Estradiol is a type of estrogen whose hormone effects promote female sex characteristics. Its structure consists of various carbon-hydrogen rings and it is a lipid, but not a prostaglandin. Knowing the structure, how would you expect this hormone to cause a response in a target cell?

Estradiol will enter the target cell and bind to an intercellular receptor, causing a change in gene expression.

How do exocrine glands differ from endocrine glands?

Exocrine glands secrete through ducts or tubes to a free surface.

A tropic hormone prevents endocrine glands from releasing their hormones, thereby maintaining homeostasis.

False

Human growth hormone is secreted by the pituitary gland and travels via the bloodstream to affect target cells all throughout the body. Thus, it is an autocrine secretion.

False

Oxytocin stimulates the kidneys to conserve water.

False

Parathyroid hormone stimulates the activity of bone-resorbing osteoblasts.

False

The nervous system releases hormones at synapses and the endocrine system releases neurotransmitters into the bloodstream.

False

The thalamus controls the secretion of pituitary hormones.

False

Diane has type 1 diabetes mellitus. Which of the following describes physiological effects she that might develop?

Fatty acids and ketone bodies will accumulate in her blood if she forgets/refuses her treatment.

A female patient is experiencing a hormonal imbalance that results in low estrogen production, causing her to skip menstrual periods and not to ovulate. Which of the following is most likely the imbalanced hormone?

Follicle-stimulating hormone

What is a common symptom of Graves' Disease?

Goiter

Dave has diabetes mellitus. If untreated, which of the following describes how the disease affects his bodily fluids?

His urine has high osmotic pressure.

What are tropic hormones?

Hormones that stimulate other endocrine glands to secrete hormones

Maxwell has a very high metabolic rate, is skinny, and has protruding eyes. These are symptoms of what condition?

Hyperthyroidism

Where are hormones secreted by the posterior pituitary synthesized?

Hypothalamus

Growth hormone stimulates the release of __________.

IGF-1

What is the action of glucagon?

Increased blood glucose concentration

Concentration of growth hormone is not constant throughout life. When do fluctuations in blood levels occur?

Increases at puberty and levels off after adolescence

What does "endocrine" mean?

Internal secretion

What is the effect of a steroid hormone binding to a receptor in a target cell?

It directly causes protein synthesis.

Jerry drinks a few beers and soon has to urinate. What effect did alcohol have on the hormonal control of urination?

It inhibited secretion of ADH.

What hormone is produced in response to the absence of light in the environment and is associated with circadian rhythms?

Melatonin

What hormone is secreted by the pineal gland?

Melatonin

In addition to a drop in blood calcium concentration, identify another symptom of hypoparathyroidism.

Muscle cramps

What controls most hormone concentrations?

Negative feedback

Which of the following has both endocrine and exocrine functions?

Pancreas

Choose the example that demonstrates a positive feedback loop of hormonal control.

Pressure receptors sense the movement of a baby against and through the cervix during labor. They stimulate the hypothalamus to release a hormone that causes uterine contractions. This causes more pressure receptor stimulation, leading to larger releases of the hormone and stronger, more frequent contractions. Hormone release ceases after pressure sensations cease.

Which of the following hormones requires a releasing hormone from the hypothalamus for its secretion?

Prolactin

What can cause upregulation of a target cell's receptors?

Prolonged decreased concentration of a hormone

What can cause down regulation of a target cell?

Prolonged elevated concentration of a hormone

How do the hormones T3 and T4 differ?

T4 is converted to T3 in peripheral tissues

The opposing roles of the thyroid and parathyroid hormones maintain the balance of calcium and phosphate ions in the blood. What will happen if the parathyroid gland develops a defect that prevents PTH secretion?

The amount of calcium ions and phosphate ions in the blood will decrease.

Which control pathway was responsible for the adrenaline release Goldilocks experienced when she woke up surrounded by three bears?

The nervous system directly stimulated an endocrine gland.

A patient develops a cyst in the pars intermedia as a child which grows over time. The resulting shape of the cyst puts significant pressure only on the posterior lobe of the pituitary gland and causes defective hormonal production and secretion. Which of the following symptoms would you predict?

The patient will have abnormal/high risk labors and may be forced to undergo C-sections instead of vaginal labor due to weak uterine contractions.

Which of the following is true for steroid hormones?

They are soluble in lipids.

Removal of the anterior pituitary gland would affect the functioning of which gland(s) or structure(s)?

Thyroid gland

What endocrine gland secretes triiodothyronine?

Thyroid gland

What is an action of the thyroid hormone?

To enhance the rate at which proteins are synthesized

What is a function of hormones?

To stimulate growth, reproduction, and development

What is the action of cortisol?

To stimulate the production of glucose from noncarbohydrates

Why is oxytocin administered to women during childbirth?

To stimulate uterine contractions

A hormone is a molecule secreted into the bloodstream that acts on target cells that have the specific receptors for that hormone.

True

Cushing syndrome is caused by hypersecretion of cortical hormones.

True

If an abnormal thyroid gland were to develop without extrafollicular cells, secretion of calcitonin would be severely diminshed.

True

If the adrenal medulla were to lose the ability to secrete hormones, blood pressure, heart rate, and breathing rate would be affected.

True

Nonsteroid hormones include peptides, proteins, glycoproteins, and amines.

True

Norepinephrine and epinephrine are amines.

True

Steroid hormones diffuse through cell membranes and bind to intracellular receptors, whereas nonsteroid hormones bind to receptors on the target cell membrane.

True

The hormones secreted by the adrenal medulla are amines.

True

The sex hormones from the adrenal cortex are primarily androgens.

True

The target cells of hypothalamic releasing hormones are in the anterior pituitary gland.

True

What is another name for antidiuretic hormone?

Vasopressin

Nonsteroid hormones cause __________ in their target cells.

activation of adenylate cyclase

Graves' disease, the most common form of hyperthyroidism, is caused by __________.

an autoimmune disorder

Molecules that are produced within one tissue that then regulate another tissue within the same organ are called _________ secretions.

autocrine

A night-shift worker experiences extreme difficulty falling asleep due to being exposed to bright lights during both night and day. The unusual pattern of light exposure is disturbing their __________, which is controlled by the hormone __________.

circadian rhythm; melatonin

Aldosterone promotes the homeostasis of ions by causing the kidneys to __________.

conserve sodium and excrete potassium

A sweat gland is an example of a(n) __________ gland.

exocrine

When comparing levels of ACTH in the blood, ACTH levels during times of stress would be _________ during times of relaxation.

higher than

Dopamine, released from the __________, inhibits secretion of prolactin.

hypothalamus

As a result of the general stress response, blood concentrations of epinephrine __________ and blood concentrations of cortisol _________.

increase; increase

Melanocyte-stimulating hormone, which regulates the formation of melanin, is produced by the _________.

intermediate lobe of the pituitary gland

ADH and oxytocin are secreted by __________.

neurosecretory cells

During early embryonic development, a protein called sonic hedgehog is released from a cell and travels through the interstitial fluid to nearby cells. This helps to establish the path and direction of development for the nervous system and limbs. Knowing this, sonic hedgehog must be a(n) __________ signal.

paracrine

Secretions that affect only nearby cells are termed _________.

paracrine

An upregulated cell has an increase in __________.

the number of receptors available for binding

What do all hormones have in common?

they are organic compounds

The thymus gland secretes hormones called __________ that __________.

thymosins; control production and differentiation of white blood cells