Endocrine System Ch 16

Front 1

What does the Endocrine system consists of two different types, what are they?

Back 1

The endocrine system consists of both ductless glands and some diffuse tissues.

Front 2

Endocrine tissues produce what, and what is their purpose?

Back 2

Endocrine tissues produce signaling proteins called hormones.

Front 3

How are hormones released into the body?

Back 3

Hormones are released from ductless glands and some diffuse tissues directly into the body.

Front 4

Describe the specificity of hormones function, and name and describe the cells they interact with.

Back 4

Hormones act with a specific function. They interact with their target cell by binding with the cells complementary recognition components.

Front 5

What are the important differences between hormonal and neural controls of body functioning?

Back 5

The endocrine and neural systems interact with each other, and work to coordinate the activity of the cells. The endocrine system regulates cellular metabolism by utilizing chemical messengers called hormones that are released into the blood. The nervous system affects muscles and glands by sending electrochemical impulses by way of neurons, causing the organs to respond within milliseconds.

Front 6

What does the prefix hormone mean?

Back 6

The prefix hormon means to excite.

Front 7

What are hormones, how do they work, and how does their method of delivery affect the speed in which their target cells?

Back 7

Hormones are chemical messengers that are released into and then travel through the blood where they attach to chemical receptors on their target cells. Compared to the delivery of signals sent from the nervous system, which cause an organ reaction in a matter of milliseconds, hormonal signals tend to have a lag period of a few seconds to a as long as a few days.

Front 8

Name the four endocrine system functions and briefly describe what they do.

Back 8

Homeostasis keeps levels at a constant, metabolism refers the speed of cellular activity, reproduction refers to mitosis (cell division), growth, and development.

Front 9

Briefly describe the structure and function of the plasma membrane.

Back 9

The plasma membrane is composed of a phospholipid bi-layer and contains proteins and cholesterol. It isolates the extracellular from the intracellular.

Front 10

Describe what receptor proteins are, and what they’re also known as.

Back 10

These are proteins or glycoproteins that protrude extracellularly and are sensitive to extracellular molecules.

Front 11

What binds to the receptor proteins and what are their function?

Back 11

Ligands are signaling chemicals that bond specifically to membrane proteins and their bond is called receptor-ligand binding, target cells work by binding to the specific cell that it is in search of. (?) Other proteins work as ID tags that communicate to the immune system whether they are friend or foe.

Front 12

What is happening with receptor regulation?

Back 12

Receptors are constantly being synthesized and broken down because there are approximately 2,000-100,000 receptors on a target cell for a particular hormone.

Front 13

What is the name for a decrease, and the name for an increase in the number of receptors, and how does this relate to hormone levels?

Back 13

A decrease in the number of receptors is called a down-regulation, and this happens when the hormone levels are high. An increase in the number of receptors is called an up-regulation, and this happens when the hormone levels are low.

Front 14

Give an example of a blocking hormone receptor, and briefly describe what this does.

Back 14

RU-486 binds to progesterone receptors and causes endometrial decidual degeneration, and eventually prohibits progesterone from regenerating. This can be used as a contraceptive.

Front 15

Describe what a neurotransmitter does.

Back 15

A neurotransmitter is a chemical messenger that may stimulate or inhibit effecter cells or neurons.

Front 16

What are some common biogenic amines, and what purpose do they serve?

Back 16

Epinephrine and norepinephrine are common biogenic amines that are neurotransmitters and are widely distributed in the brain. Some biogenic amines work as hormones.

Front 17

What are the two kind of mechanism of action, and describe their function, and name examples of these two.

Back 17

Neurotransmitters that bind to and open ion channels are called direct or ionotropic, and work cause rapid changes in postsynaptic cells by promoting changes in membrane potential. Neurotransmitters that promote wider, and sometimes longer lasting effects by acting through intracellular second-messenger molecules are called indirect or metabotropic (G proteins & 2nd messengers, e.g., cAMP).

Front 18

What are the two structures of hormones?

Back 18

Hormones are either water-soluble or lipid-soluble. Water soluble hormones aren’t able to get through the phospholipid bilayer, and thus they utilize the second messenger system. Lipid-soluble hormones are cholesterol and are able to get through the phospholipid bilayer, and thus they utilize the direct gene activation mechanism.

Front 19

What nervous system does the endocrine system work with?

Back 19

The endocrine system works with the autonomic system, which controls the release of some hormones.

Front 20

What are the four ways the endocrine system works to maintain internal control?

Back 20

The endocrine system coordinates body activities, like gamete production and release; it maintains homeostasis, like blood levels; it controls growth and development; it regulates metabolic processes, like the utilization of carbohydrates, lipids, and proteins.

Front 21

Does the endocrine system help the body to adjust to external change, if so then how?

Back 21

The endocrine system helps the body to adjust to external change that may cause trauma or stress.

Front 22

How are hormones able to affect nervous responses?

Back 22

Hormones like epinephrine and norepinephrine from the adrenal gland are able to stimulate or inhibit the nervous system by initiating nerve impulses or action potentials.

Front 23

Compared to the nervous system, what are the time differences of the endocrine systems effects?

Back 23

The endocrine systems effects are slower acting but longer lasting then the nervous system. The effects take place usually from 20 minutes to several hours.

Front 24

What is the difference between endocrine and exocrine?

Back 24

The exocrine system works by secreting it’s products (enzymes) into ducts, and the endocrine system works by secreting it’s products (hormones) into the blood stream.

Front 25

What are the nine major endocrine glands and organs that contain endocrine tissue?

Back 25

The nine major endocrine glands are the pituitary, thyroid, parathyroid, adrenal, pineal, thymus, hypothalamus (considered a neuroendocrine organ), pancreas, and gonads.

Front 26

What hormones does the stomach produce, and it’s trigger and purpose?

Back 26

The stomach produces gastrin, is secreted in response to food, and stimulates glands to release hydrochloric acid (HCl).

Front 27

What is the hormone the duodenum of the small intestine produces, and it’s trigger and purpose?

Back 27

The duodenum of the small intestine produces intestinal gastrin, is secreted in response to food, and stimulates the HCl secretion and GI tract motility.

Front 28

What are the two hormones the duodenum produces, their trigger, and purposes?

Back 28

The duodenum produces the hormones secretin and cholecystokinin (CCK), both of which are triggered in response to food. Secretin activates the pancreas and liver. CCK stimulates the pancreas.

Front 29

What hormones do the kidney produce, their triggers, and their purposes?

Back 29

The kidney produces erythropoietin, which is secreted in response to hypoxia, and stimulates red blood cell formation in bone marrow. The kidneys also produce renin in response to low blood pressure, and works to return blood pressure to normal.

Front 30

What hormone does skin produce, its trigger, and its purpose?

Back 30

Skin produces cholecalciferol (provitamin D3), is activated by the kidneys to activate vitamin D3, in response to parathyroid hormone, and works to stimulate active transport of dietary calcium across intestinal cell membranes.

Front 31

What hormones are produced by the heart (atria), its trigger, and its purpose?

Back 31

The heart produces the hormone atrial natriuretic peptide, is triggered by stretching of the atria (high blood pressure), and works with the kidney to inhibit sodium ion reabsorption and renin release to lower blood pressure.

Front 32

What are the two hormones released by adipose tissue, their triggers, and their purpose?

Back 32

Adipose tissue produces leptin in response to fat stores, is increased by nutrient uptake, and suppresses appetite and increases energy expenditure. Adipose tissue also produces resistin, the cause of which is unknown, and effects fat, muscle and liver by antagonizing insulin’s action on liver cells.

Front 33

Describe how gap junctions work?

Back 33

A Gap junctions function is to connect the intracellular space/cytoplasm of two adjoining animal cells. These are seen in single unit smooth muscle, cardiac muscle, and epithelia.

Front 34

What is an autocrine?

Back 34

An autocrine is a chemical that exerts their influence on the same cell that exerts them.

Front 35

What is a paracrine?

Back 35

A paracrine is a chemical that effects locally but only effects cells other than the one releasing it.

Front 36

What is an endocrine?

Back 36

And endocrine is secreted from a gland directly into the blood stream.

Front 37

What is a synapse?

Back 37

A synapse is a specialized junction where neurons communicate with each other, or with non-neural cells like muscles or glands.

Front 38

What are pheromones?

Back 38

Pheromones are air-borne chemicals that trigger a natural behavioral response between members within the same species.

Front 39

Describe the structure of amino acid-based hormones.

Back 39

Amino acid-based hormones are the most common type of hormones, and the sizes vary widely from simple amino acid derivatives, to peptides (short chains of amino acids), to proteins (long polymers of amino acids). These utilize the second messenger system.

Front 40

What are two different types of amino acid-based hormones and give two examples of each.

Back 40

One of the amino acid-based hormones is biogenic amines, which include epinephrine (E) and norepinephrine (NE). The other type of amino acid-based hormones is peptide hormones, which include antidiuretic hormone ((controls water balance through urine output and kidneys)) (ADH) and follicle-stimulating hormone (FSH) ((synthesized and produced in anterior pituitary by gonadotropes)).

Front 41

Describe the structure of steroids.

Back 41

Steroids are synthesized from cholesterol, and are only produced by the major endocrine organs as gonadal and adrenortical hormones.

Front 42

Give three examples of steroids and briefly describe their function.

Back 42

Estrogen is the primary female sex hormone, progesterone is involved with the female menstrual cycle and pregnancy, and testosterone is the primary male sex hormone and is an anabolic steroid.

Front 43

Describe the structure of Eicosanoids (anachidonic acid).

Back 43

These are signaling molecules made by oxygenation of twenty-carbon fatty-acid essential fatty acids (EFAs).

Front 44

Give two examples of eicosanoids and their purpose.

Back 44

Leukotrienes are both autocrine and paracrine signaling chemicals that mediate inflammation and some allergic reactions, and are involved in the making of histamine, and prostaglandins (PGs) are have multiple tagets and effects, including uterine contractions, blood clotting, pain, and inflammation.

Front 45

What are the two systems that target cells receive hormones through, their location, what structure of hormone works for which system, and which system is the fastest acting?

Back 45

Water-soluble hormones affect cells through the second messenger system because they are unable to pass through the phospholipid bilayer. Lipid-soluble hormones are able to pass through the phospholipid bilayer, and affect cells via the direct gene activation system. The second messenger system is the faster of the two.

Front 46

Name the five effects a hormone can have on a cell.

Back 46

A hormone can affect membrane permeability/potential, protein synthesis, enzymes, secretion, or mitosis (cell division).

Front 47

What method of delivery do steroid hormones utilize?

Back 47

Steroids are lipid-soluble and utilize direct gene activation.

Front 48

What method of delivery do amino acid-based hormones and eicosanoids utilize?

Back 48

Amino acid-based hormones and eicosanoids utilize the second messenger system.

Front 49

Describe the second messenger system.

Back 49

1.) The hormone, which acts as the first messenger, binds to the receptor.
2.) Next, the hormone binding causes the receptor to change shape, which allows it to bind to an inactive G protein.
3.) The G protein is activated as the GDP (GDP is like the light switch is off) bound to it is displaced by the high energy compound GTP (GTP is like the light switch is on).
4.) The activated G protein, moving along the membrane, binds to the effecter enzyme adenylate cyclase. Some G proteins stimulate adenylate cyclase, and others inhibit it. (Eventually GTP is hydrolyzed to GDP, and the G protein is inactive again.)
5.) If activated, adenylate cyclase generates the second messenger cAMP from ATP. cAMP triggers a cascade of chemical reactions beginning with the activation of protein kinase A (an enzyme that phosphorylates various proteins, many of which are proteins).

Front 50

Describe direct gene activation.

Back 50

1.) Steroid or thyroid hormones diffuse through the plasma membrane of the target cell and bind to a receptor-chaperonin complex in the nucleus.
2.) Once the hormone is bound, the chaperonin dissociates from the receptor and the hormone-receptor complex binds to a specific sequence on the DNA, which initiates transcription of a certain gene.
3.) The mRNA formed migrates into the cytoplasm, where it directs synthesis of a specific protein.

Front 51

What are nuclear hormone receptors?

Back 51

Nuclease hormone receptors form a class of ligand activated proteins that, when bound to specific sequences of DNA serve as on-off switches for transcription within the cell nucleus. These switches control the development and differentiation of skin, bone and behavioral centers in the brain, as well as the continual regulation of reproductive tissues.

Front 52

What is hormone-response element?

Back 52

A hormone-response element (HRE) is a specific DNA sequence that a receptor recognizes with markedly increased affinity and typically contains two consensus hexameric half-sites. The identity of a response element resides in three features: the sequence of the base pairs in the half-site, the number of base pairs between the half-sites and the relative orientation of the two half-sites. Thus each receptor protein dimmer that binds the DNA has to recognize the sequence, spacing and orientation of the half-sites within their response element.

Front 53

What are the three factors that affect target cell specificity?

Back 53

The three factors that affect target cell specificity are: blood levels of hormones, number of receptors (up- & down regulation), and the affinity of hormone and receptor.

Front 54

What is the general rule for a given level of hormone level in the blood?

Back 54

A high number of high-affinity receptors will produce a pronounced hormone effect, and a low number of low-affinity receptors will cause a low target cell response or an endocrine system dysfunction.

Front 55

What two ways do proteins travel in the blood stream?

Back 55

Proteins travel in the blood either free or bound to a protein carrier. Steroids and thyroid hormones tend to travel attached to a plasma protein.

Front 56

What two factors affect the concentration of hormones in the blood stream?

Back 56

Hormone concentration is dependent on the hormones rate of release, and the speed at which it’s inactivated and removed from body.

Front 57

Describe what a hormone’s half-life is.

Back 57

The length of time the blood level of a hormone is decreased in half, which varies from a fraction of a minute to a week.

Front 58

Describe the varying hormone onset times.

Back 58

Some hormones cause effects almost immediately, and some, especially steroids, take several hours to take effect. Some are secreted relatively inactive and must be activated by their target cells.

Front 59

Describe the duration of hormone effects.

Back 59

Hormone duration can last from ten seconds to several hours, depending on the hormone.

Front 60

Describe permissiveness of hormones.

Back 60

Permissiveness of hormones is one hormone needs another hormone(s) for its full effects to be exerted.

Front 61

Describe permissiveness of hormones.

Back 61

Synergism of hormones occurs when a hormones effects are amplified with the presence of other hormones.

Front 62

Describe antagonism of hormones.

Back 62

Antagonism of hormones is when one hormone’s effects opposes the effects of another hormone.

Front 63

Describe negative feedback.

Back 63

Negative feedback is when, as triggered by some internal or external stimuli, hormone levels rise until they affect their target organ, and then inhibit further hormone release.

Front 64

List and describe the three major ways that stimulate endocrine glands to manufacture and release hormones.

Back 64

Humoral stimuli is due to changing blood levels of certain critical ions and nutrients, neural stimuli is caused by nerve fibers, and hormonal stimuli is affected by the hormones released from other endocrine organs.

Front 65

Describe how the nervous system modifies the endocrine system.

Back 65

The nervous system is able to override the endocrine system controls to maintain homeostasis.

Front 66

What does hypo mean?

Back 66

Hypo means under. Hypothalamus = hypo = under + thalmos + inner chamber.

Front 67

How are the hypothalamic hormones distributed?

Back 67

Releasing and inhibiting hormones are sent to the anterior pituitary, and neurohormones are sent to the posterior pituitary.

Front 68

What does the prefix pituita mean?

Back 68

The prefix pituita means slime.

Front 69

What is the pituitary gland also known as?

Back 69

The pituitary gland is also known as the hypophysis (hypo = below + physis = growth).

Front 70

What connects the hypothalamus to the pituitary gland?

Back 70

The indundibulum, or stalk, connects the hypothalamus to the pituitary gland.

Front 71

What is the anterior pituitary gland made of, and what is it also known as?

Back 71

The anterior pituitary gland is made of epithelial tissue and is also known as the adenohypophysis.

Front 72

What is the posterior pituitary gland composed of, and what is it also known as?

Back 72

The posterior pituitary gland is not a true gland but rather is a mass of neuroglia, and the posterior pituitary gland is also known as the neurohypophysis.

Front 73

What is a tract?

Back 73

A tract is a collection of nerve cells.

Front 74

What is a portal system?

Back 74

A portal system is a short cut through the blood stream which goes from a capillary to a vein to a capillary.

Front 75

Describe the hypothalamic-hypophyseal tract.

Back 75

This tract lies in the infundibulum and carries oxytocin and antidiuretic hormones to be released in the capillary bed of the posterior pituitary gland (neurohypophysis) for distribution.

Front 76

Describe the hypophyseal portal system.

Back 76

The hypophyseal portal system connects the hypothalamus with the anterior lobe of the pituitary gland. This vascular connection the primary capillary plexus in the infundibulum communicates inferiorly the hypophyseal portal veins with the secondary capillary plexus. Releasing and inhibiting hormones are sent to the anterior lobe to regulate hormones produced there.

Front 77

What does the prefix somato mean?

Back 77

The prefix somato means body.

Front 78

What is GH, also known as, produced where, and what are its effects?

Back 78

Growth hormone stimulates growth and cell reproduction, is also known as somatotropin, and is produced in the adenohypophysis/anterior lobe.

Front 79

What is TSH, also known as, its effects, and where is it produced?

Back 79

Thyroid stimulating hormone is produced in the anterior lobe/adenohyphysis, works to stimulate the throid gland (which effects metabolism, growth and development, and secretes calcitonin.

Front 80

What is ACTH, where is it produced, and what are its effects?

Back 80

Adrenocorticotropic hormone is produced in the anterior lobe/adenohypophysis, and targets the adrenal gland. ACTH is related to enkephalin and endorphin, which act as the bodies pain regulators, and also to MSH (melanocyte stimulating hormone), which is involed appetite and sexual arousal.

Front 81

What are two hormones that are gonadotropins, where are they produced, and what are their effects?

Back 81

FSH (follicle-stimulating hormones) develop ovaries and have effects on men, and are produced in the anterior lobe/adenohypophysis. LH (luteninizing hormone) levels surge before ovulation, also have effects on men as ICSH (interstitial cell-stimulating hormone), and are produced in the anterior lobe/adenohypophysis.

Front 82

What are the effects of prolactin and where is this hormone produced?

Back 82

Prolactin stimulates milk production, and is produced in the anterior lobe/adenohypophysis.

Front 83

List the anterior lobe’s connection to the hypothalamus, six hormones produced, and stimulus for release of hormones.

Back 83

The anterior lobe connects to the hypothalamus through the hypophyseal portal system, hormones include: growth hormone (GH), follicle-stimulating hormone (FSH), luteinizing hormone (LH), thyroid-stimulating hormone (TSH), adrenocorticaltropin hormone (ACTH), and prolactin, and the stimulus for the release of these hormones is releasing and inhibiting hormones send via the hypophyseal portal system from the hypothalamus.

Front 84

Name two hormones released by the posterior lobe, and their effects.

Back 84

Oxytocin causes uterine contractions and is involved with milk let down. Antidiuretic hormone signals the kidneys to save water.

Front 85

What does the acronym SWEETHAT stand for?

Back 85

Hypothalamus functions:
S – leep
W – ake
E – motional
E – ndocrine
T – emperature
H – unger
A – utonomic
T – hirst

Front 86

List the posterior lobe’s connection to the hypothalamus, two hormones produced, and stimulus for release of hormones.

Back 86

The posterior lobe is collected to the hypothalamus via the hypothamamic-hypophyseal tract, releases oxytocin and anti-diuretic hormone, and action potentials are the stimulus for their release.