Endocrine System

Front 1

Describe the major functions of the endocrine system.

Back 1

Production and secretion of hormones, chemical substances produced in the body that regulate the activity of cells or organs. These hormones regulate the body's growth, metabolism, sexual development and function.

Front 2

Define the terms; Hormone, Endocrine Gland, Endocrine Tissue (organ), and target cell.

Back 2

Hormone - chemical messengers that are transported by the bloodstream and stimulate physiological responses in cells of another tissue or organ.

Endocrine gland - a hormone source, such as the pituitary, thyroid, and adrenal glands.

Endocrine tissue - brain, heart, small intestine, bones, adipose tissue

Target cell - the cell that responds to the hormone.

Front 3

Compare and contrast how the nervous and endocrine systems control body function, with emphasis on the mechanisms by which the controlling signals are transferred through the body and the time course of the response(s) and action(s).

Back 3

They differ in their means of communication.

Nervous system: Electrical and chemical communication. Fast. Stops when stimulus ceases. Neurons quickly adapt and their reponses decline.

Endocrine system: Chemical. Slow. Trickle-down effect. Persistent responses.

Front 4

List the major chemical classes of hormones found in the human body.

Back 4

Steroid hormones- derived from cholesterol

Monoamines - synthesized from amino acids by the removal of COOH group, and retain a nitrogen (epinepherine, norepinephrine, dopamine, histamine, serotonin.)

Peptide hormones - (chains of 3-200+ amino chains)

Front 5

Describe how teach class is transported in the blood.

Back 5

Steroids: Hydrophobic, binds to hydrophilic transport proteins (albumins and globulins synthesized by the liver, and prolongs half-lives.)

Monomaines: Hydrophilic, mixes with blood plasma.

Peptides: Hydrophilic, mixes with blood plasma.

Front 6

Compare and contrast the types of receptors (cell membrane or intracellular) that each class binds to.

Back 6

G protein-coupled receptors:Epinephrine, norepinephrine and many peptide hormones; hypothalamic and hypophyseal control hormones, glucagon

Receptor tyrosine kinases:InsulinGrowth hormone and growth factors

Nuclear hormone receptors:Steroid hormonesThyroid hormone.

Front 7

Compare and contrast the mechanism of response that each class elicits (i.e. change in gene expression or change in an intracellular pathway via phosphorylation mechanism) and relate the response mechanism to the biochemical nature of the hormone molecule.

Back 7

Steroids: Receptor associates with the target gene, controls transcription. (estrogen and progesterone are good examples of steroid hormone actions)

Monoamines (thyroid hormone): acts on nuclear receptors. Enters target cells thru ATP dependent transport proteins.

Peptides and catecholamines: hydrophilic, stimulates tatrget indirectly. Binds to cell surface receptors, linked to second messenger systems, such as cAMP (cyclic adenosine monophosphate)

Front 8

Describe the roles of negative and positive feedback in controlling hormone release.

Back 8

Negative feedback (inhibitory) - increased target hormone levels inhibits the release of hormones.

Positive feedback (stimulatory) - a stimuli (stretching of uterus) increases release of hormone until completed (delivery)

Front 9

Describe the locations of and the anatomical relationships between the hypothalamus, anterior pituitary and posterior pituitary glands.

Back 9

The hypothalamus is shaped like a flattened funnel and forms the floor and walls of the third ventricle on the brain. The pituitary gland carries out many functions of the hypothalamus.

The anterior (adenohypophysis) pituitary has no nervous connection but is linked by a complex of blood vessels called the hypophyseal portal system.

The neurohypophysis is actually nervous tissue and not a true gland. It stores hormones made in the hypothalamic neurons until a nerve signal coming down the axon triggers their release.

Front 10

Define the terms releasing hormone, inhibiting hormone and tropic hormone.

Back 10

Releasing hormone: any of several hormones produced in the hypothalamus and carried by a vein to the anterior pituitary gland where they stimulate the release of anterior pituitary hormones.

Inhibiting hormone: Inhibiting hormones is where hormones from one gland or organ will inhibit the release of another structures' hormone. This process is called negative feedback.

Tropic hormone: a hormone that stimulates an endocrine gland to grow and secrete it's hormones, secreted by the adenohypophysis.

Front 11

Explain the role of the hypothalamus in the release of anterior pituitary hormones.

Back 11

The hypothalamus produces 8 hormones, and 6 regulate the anterior pituitary. They are releasing hormones if they stimulate pituitary cells to secrete hormones of their own, or inhibiting hormones in they suppress pituitary secretion. The effect is identified in their names.

Front 12

Explain the role of the hypothalamus in the production and release of posterior pituitary hormones.

Back 12

The hypothalamus releases OT and ADH which are stored and released by the posterior pituitary. OT comes mainly from neurons in the paraventricular nuclei, and ADH comes mainly from the supraoptic nuclei.

Front 13

T/F: Castration would raise a man's blood gonadotropin concentration.

Back 13

True

Front 14

T/F: Hormones in the glycoprotein class cannot have cytoplasmic or nuclear receptors in their target cells.

Back 14

True

Front 15

T/F: Epinephrine and thyroid hormone have the same effects on metabolic rate and blood pressure.

Back 15

True

Front 16

T/F: Tumors can lead to either hyposecretion or hypersection of various hormones.

Back 16

True

Front 17

T/F: All hormones are secreted by endocrine glands.

Back 17

False; hormones are also secreted by the heart, liver, kidneys, and other organs not generally regarded as glands.

Front 18

T/F: An atherosclerotic deposit that blocked blood flow in the hypophyseal portal system would cause the testes and ovaries to malfunction.

Back 18

True

Front 19

T/F: The pineal gland and thymus are larger in adults than in children.

Back 19

False; The pineal gland and thymus undergo involution with age.

Front 20

T/F: A deficiency of dietary iodine would lead to negative feedback inhibition of TSH synthesis.

Back 20

False; without iodine, there is no thyroid hormone (TH); without TH, there can be no negative feedback inhibition.

Front 21

T/F: The tissue at the center of the adrenal gland is called the zona reticularis.

Back 21

False; the tissue at the center is the adrenal medulla.

Front 22

T/F: Of the endocrine organs covered in this chapter, only the adrenal glands are paired; the rest are single.

Back 22

False; there are also two testes, two ovaries, and four parathyroid glands.

Front 23

CRH secretion would not raise the blood concentration of:

a. ACTH

b. thyroxine

c. cortisol

d. corticosterone

e. glucose

Back 23

b. thyroxine

Front 24

Which of the following hormones has the least in common with the others?

a. adrenocorticotropic hormone

b. follicle-stimulating hormone

c. thyrotropin

d. thyroxine

e. prolactin

Back 24

d. thyroxine

Front 25

Which hormone would no longer be secreted if the hypothalamohypophyseal tract were destroyed?

a. oxytocin

b. follicle stimulating hormone

c. growth hormone

d. adrendocorticotropic hormone

e. corticosterone

Back 25

a. oxytocin

Front 26

Which of the following is not a hormone?

a. prolactin

b. prolactin-inhibiting hormone

c. thyroxine-binding globulin

d. atrial natriuretic peptide

e. cortisol

Back 26

c. thyroxine-binding globulin

Front 27

Where are the receptors for insulin located?

a. in the pancreatic beta cells

b. in the blood plasma

c. on the target-cell membrane

d. in the target-cell cytoplasm

e. in the target-cell nucleus

Back 27

c. on the target-cell membrane

Front 28

What would be the consequence of defective ADH receptors?

a. diabetes mellitus

b. adrenogenital syndrome

c. dehydration

d. seasonal affective disorder

e. none of these

Back 28

c. dehydration

Front 29

Which of these has more exocrine than endocrine tissue?

a. the pineal gland

b. the adenohypophysis

c. the thyroid gland

d. the pancreas

e. the adrenal gland

Back 29

d. the pancreas

Front 30

Which of these cells stimulate bone deposition?

a. alpha cells

b. beta cells

c. C cells

d. G cells

e. T cells

Back 30

c. C cells

Front 31

Which of these hormones relies on cAMP as a second messenger?

a. ACTH

b. progesterone

c. thyroxine

d. testosterone

e. estrogen

Back 31

a. ACTH

Front 32

Prostaglandins are derived from

a. proopiomelanocortin

b. cyclooxygenase

c. leukotriene

d. lipoxygenase

e. arachidonic acid

Back 32

e. arachidonic acid

Front 33

The ___ develops from the hypophyseal pouch of the embryo.

Back 33

adenohypophysis

Front 34

Thyroxine (T4) is synthesized by combining two iodinated molecules of the amino acid ___.

Back 34

tyrosine

Front 35

Growth hormone hypersecretion in adulthood causes a disease called ___.

Back 35

acromegaly

Front 36

The dominant hormone in the stage of resistance of the stress reponse is ___.

Back 36

cortisol

Front 37

Adrenal steroids that regulate glucose metabolism are collectively called ___.

Back 37

glucocorticoids

Front 38

Testosterone is secreted by the ___ cells of the testis.

Back 38

interstitial

Front 39

Target cells can reduce pituitary secretion by a process called ___.

Back 39

negative feedback inhibition

Front 40

Hypothalamic releasing factors are delivered to the anterior pituitary by way of a network of blood vessels called the ___.

Back 40

hypophyseal portal system

Front 41

A hormone is said to have a/an ___ effect when it stimulates the target cell to develop receptors for other hormones to follow.

Back 41

permissive

Front 42

___ is a process in which a cell increases its number of receptors for a hormone.

Back 42

up-regulation

Front 43

medical meaning: adeno-

Back 43

gland (adenohypophysis)

Front 44

medical meaning: chole-

Back 44

bile (cholecystokinin)

Front 45

medical meaning: diabet-

Back 45

flow through (diabetes)

Front 46

medical meaning: eicosa-

Back 46

twenty (eicosanoid)

Front 47

medical meaning: luteo-

Back 47

yellow (luteinizing)

Front 48

medical meaning: -oid

Back 48

resembling (thyroid)

Front 49

medical meaning: -osa

Back 49

full of (glomerulosa)

Front 50

medical meaning: -pro

Back 50

favoring (progesterone)

Front 51

medical meaning: tropo-

Back 51

turn (gonadotropin)

Front 52

medical meaning: uri-

Back 52

urine (glycosuria)

Front 53

Which hormones are secreted by neuroendocrine cells?

Back 53

Oxytocin, epinephrine.

Front 54

Name 4 chemicals the function as both neutrotransmitters and hormones.

Back 54

norepinephrine, dopamine, thyrotropin releasing hormone (TRH), and antidiuretic hormone (arginine and vasopressin.)

Front 55

Local hormones are also known as

Back 55

Paracrines. They are secreted by one cell, diffuse to nearby cells in the same tissue, and stimulate their physiology.

Front 56

Which three monoamines are called catecholamines?

Back 56

Epinepherine, norepinephrine, dopamine.