The Endocrine system

A G protein is?

A molecule that binds a guanine nucleotide and helps transduce a signal inside a target cell

Endocrine gland?

All choices are correct

Glucagon and insulin work _______ on blood glucose levels.

Antagonistically

Which is not a cell type found in the pancreatic islets?

C cell

Steroid homrones are lipids, derived from?

Cholesterol

Within the infundibulum, the axons from neurons extending into the posterior pituitary are known as the?

Hypothalamo-hypophyseal tract

Gluconeogenesis is?

Production of glucose from noncarbohydrate molecules, and it occurs when blood glucose is low

When the effects of water-soluble hormones on their target cells are considered, the hormone is considered?

The first messenger

The pars distalis is part of the adenohypophysis?

True

In which order would blood flow through these structures as it travels from the hypthalamus to the pituitary gland? A: Primary plexus B: Secondary plexus C: Hypophyseal portal veins

A - C - B

The term down-regualtion refers to the process by which?

A cell decreases the number of receptors it has or a hormone

Excessive secretion of GH in adults can cause?

Acromegaly

The release of hormones from the adrenal cortex is stimulated by?

Adrenocorticotrpoic hormone

Thyroid-stimulating hormone (TSH) is secreted by the?

Anteriod pituitary, and it targets follicular cells of the thyroid gland

Which lobe of the pituitary is larger and secretes more hormones?

Anterior pituitary

Eicosanoids are synthesized from?

Arachidonic acid

The hormones that come from the posterior pituitary?

Are synthesized in the hypothalamus and are released from the posterior pituitary when nerve signals arrive

Lipid-soluble hormones, such as progesterone exert their effects by forming hormone-receptor complexes that?

Bind to DNA and initiate transcription

Modified amino acids that act as hormones are referred to as ____ amines.

Biogenic

Thyroid hormone is somewhat unique in that it is a?

Biogenic amine that is lipid soluble

Aldosterone release can be triggered by the presence of the blood-borne messenger angiotension II or by low levels of sodium, and so its secretion regulation is said to be?

Both hormonal and humoral

Until thyroid hormone needs to be secreted, precursors to it are stored in a viscous, protein-rich fluid within the center thyroid follicles. This viscous fluid is known as _______.

Colloid

The hypothalamic hormone that triggers the release of adrenocorticotropic hormone (ACTH) is?

Corticotropin-releasing hormone (CRH)

The disease called _______ is caused by excessive secretion of glucocorticoids, and is characterized by redistribution of body fat to produce the features known as "moon face" and "buffalo hump".

Cushing syndrome

In most of its target cells, cortisol _______ glucose uptake and _______ protein metabolis.

Decreases, increases

Once a structure is fully grown and mature it will probably?

Down-regulate its receptors for growth hormone as it no longer needs to continue to grow at a fast rate

Intracellular signaling pathways within target cells are organized such that?

Each step allows fro amplification of the signal where one molecule can activate many

Although hormones influence activity in the neural and reproductive systems, they do not influence the digestive system.

False

Each of the body's blood-borne hormones comes from one of the major glands, namely, the pineal, thyroid, parathyroid, or adrenal glands.

False

Like all other hormone transport proteins, albumin is highly specific in terms of which hormone it carries through the blood.

False

Steroid, peptides, and nucleic acids are the three classes of hormones.

False

Which hormones are collectively called the gonadotropins?

Follicle-stimulating hormone and luteinizing hormone

Which is not correct regarding growth hormone (GH)?

GH stimulates the kidney to secrete somatomedin

The hormone that increases the rate of glycogen breakdown and glucose release by the liver is?

Gluagon

Generally, there are two main factors that determine the levels of a hormone in the blood.

Hormone synthesis is directly related to plasma hormone levels, and hormone elimination (by liver, kidneys, and target cell uptake) is inversely related to plasma hormone levels.

Parathyroid hormone release depends on blood levels of calcium. Such an endocrine reflex is said to be initiated by?

Humoral stimulation

The part of the brain that some consider to be a "master control center" of the endocrine system is the?

Hypothalamus

The thyroid gland is located?

Immediately anterior to the trachea

Damage to the liver might impair enzymatic degradation of some hormones. The levels of such hormones in the blood would therefor be expected to?

Increase

Thyroid hormone's effects are to?

Increase metabolic rate and body temperature by increasing protein synthesis in target cells

Which hormone is secreted by the beta cells of the pancreas?

Insulin

Lipophilic hormones bind to _____ receptors of target cells.

Intracellular

Cortisol binds to ______ receptors and has the effect of ______ blood glucose levels.

Intracellular, raising

Which is not correct regarding the pancreas?

It does not begin to secrete its hormones until puberty

Which is not true about the thyroid gland?

It has two lobes connected by a central portion called the commussure

The hormones and neurotransmitters releases by the endocrine and nervous system are chemical substances referred to as _____.

Ligands

Which type of hormone requires a carrier protein in the blood?

Lipid-soluble hormone

The process in which triglycerides are broken down into glycerol and fatty acids in known as?

Lipolysis

In response to high blood glucose, the pancreas releases insulin to enable glucose to enter body cells. When the blood glucose level returns to normal, insulin release stops. This is an example of regulation by?

Negative feedback

Which of the following is not considered to be a nutrient that cells oxidize to provide energy (in the form of ATP)?

Nucleic acids

Where are the target cells for follicle-stimulation hormone?

Ovaries and testes

The two hormones released from the posterior pituitary are?

Oxytocin and antidiuretc hormone

In addition to secreting hormones, the pancreas also produces?

Pancreatic juice

Two regions of the hypothalamus that are associated with the posterior pituitary are the?

Paraventricular nucleus and supraoptic nucleus

The three distinct areas of the anterior pituitary are the?

Pars distalis, pars intermedia, and pars tuberalis

When the activity of one hormone requires that of a second hormone, the interaction is said to be ______.

Permissive

In the signal transduction pathway that results in the formation of inositol triphosphate, the G protein directly activates?

Phospholipase C

The small, cone shaped gland that is in the epithalamus of the brain is the ____ gland.

Pineal

The parathyroid glands are located:

Posterior to the thyroid gland

The adrenal glands are located _____ to the parietal periotoneum and each has a cortex of a _____ color.

Posterior, yellow

Which is not a characteristic of the endocrine system?

Recovery time: Rapid, immediate return to prestimulation level

What is the function of the mineralocorticoids secreted by the adrenal glands?

Regulate electrolyte concentration in body fluids

When the effects of one hormone reinforce the activity of another hormone on the same target cell, the interaction is said to be?

Synergistic

Generally, the shorter the half-life of a hormone?

The more frequently it must be replaced

The release of hormones from adrenal medulla is stimulated by?

The sympathetic division of the autonomic nervous system

Thyroid hormone synthesis involves secretion of a glycoprotein called ______ by the follicular cells.

Thyroglobulin

Eicosanoids are a primary type of local hormone.

True

Increasing levels of cortisol inhibit the release of corticotropin-releasing hormone (CRH).

True

Reduced hormone concentration in the blood often causes target cells to?

Up-regulate receptors in order to increase cell sensitivity

Protein hormones are?

Water-soluble

Where is the pituitary gland located?

Within the sella turcia of the sphenoid bone

Which region of the adrenal cortex synthesizes glucocorticoids?

Zona Fasiculata

Which is not a tropic hormone?

Melanocyte-stimulationg hormone

Which hormone group is not secreted by the adrenal cortex?

No exceptions; all choices are secreted by the adrenal cortex

When a chemical messenger helps initiate an inflammatory response by causing cellular changes in neighboring cells, it is demonstrating ______ signaling.

Paracrine

Among their many functions, hormones regulate blood volume, cellular concentration, and number of platelets.

True

When follicular cells of the thyroid are stimulated to secrete TH they take up TH precursors from the inside of the follicle, transport and enzymatically modify them within a lysosome, and release TH to the blood.

True

When eicosanoids bring about cellular changes within the same cell from which they were formed, the process is called _____ stimulation.

Autocrine

Like proteins, eicosanoids are synthesized on ribosomes in a process that involves transcription and translation.

False

The function of each of the regulatory hormones of the hypothalamus is to trigger the release of a tropic hormone from the pituitary.

False

The reaction time for endocrine effects is generally measured in milliseconds.

False

Follicle-stimulation hormone is a?

Glycoprotein

You are "shadowing" and endocrinologist who is examining a patient complaining of weakness, weight loss, and hear intolerance. The doctor points out the patient's obvious exophthalmos and asks for your diagnosis. What would you speculate is the patient's problem?

Hypersecretion of thyroid hormone

Thyrotropin-releasing hormone is secreted by the?

Hypothalamus and it increases release of thyroid-stimulation hormone from the anterior pituitary

Exercise causes a(n) _______ in growth hormone (GH) levels; a rise in amino acid levels or decrease in glucose levels causes a(n) ______ in GH levels.

Increase, Increase

The pituitary gland is located _______ to the hypothalamus and is connected by the ______.

Inferior, Infundibulum

Oxytocin results in more forceful smooth muscle contractions in the uterus by causing target cells to increase production of?

Inositol triphosphate

Which hormone induces it's target cells to take up glucose, thereby lowering blood glucose levels?

Insulin

As someone starts to develop in puberty, most cells in their reproductive organs are probably starting to express?

More receptors for sex hormones

The hormone oxytocin is synthesized in the?

Paraventricular nucleus

The secretion of _______ by the anterior pituitary gland is not under the control of a hypothalamic regulatory hormone.

Prolactin

Within the adenylate cyclase signal transduction pathways of target cells, cAMP activates?

Protein kinase

Most hormones are made of chains of amino acids and are therefore?

Proteins

Growth hormone is secreted by _______ cells in the anterior pituitary?

Somatotropic

The primary function of ACTH is to?

Stimulate glucocorticoid release from the adrenal glands

The binding of a hormone and carrier protein is ____; a very _____ fraction of such a hormone in the blood is bound to a carrier at any one point in time.

Temporary, large

The half-life of a hormone is?

The time necessary to reduce the hormone concentration in the blood to half of what had been secreted

Fatty acids are organic molecules that cells an oxidize in order to have energy for the formation of ATP?

True

Growth hormone releasing hormone (GHRH) is one of the regulatory hormones released by the hypothalamus that acts on the pituitary.

True

The liver contains endocrine cells.

True