8.2 Endocrine Organs and Hormones Flashcards

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1
Q

How much glucose does the body requires?

A

Body cells require a regular supply of glucose for cellular respiration; brain cells, in particular, could die quickly when deprived of glucose.

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2
Q

What should happen to blood glucose levels?

A

Maintained above a specific value.

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3
Q

What happens when the blood glucose level is high?

A

It has several harmful effects, such as damaging blood vessels.

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4
Q

What helps in keeping the blood glucose level within a specific range?

A

The endocrine portion of the pancreas with the help of the liver play a significant role in this regulation.

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5
Q

What is the pancreas made up of? Describe what happens there.

A

Most of the pancreas is composed of exocrine cells that secrete pancreatic juice into special ducts that eventually reach the small intestine.

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6
Q

Define the islets of Langerhans.

A

The endocrine cells of the pancreas are scattered throughout the tissue of this organ, in groups called the islets of Langerhans.

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7
Q

What does the islets of Langerhans produce?

A

2 hormones: insulin and glucagon.

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8
Q

What do insulin and glucagon do?

A

Regulate blood glucose levels.

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9
Q

What’s the function of insulin?

A

It causes a decrease in blood glucose levels.

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10
Q

What’s the function of glucagon?

A

It causes an increase in blood glucose levels.

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11
Q

What can you conclude about glucagon and insulin?

A

They have opposite effects on blood glucose levels.

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12
Q

What happens to the human body after a meal rich in carbohydrates?

A

The amount of glucose in the blood rises above normal levels.

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13
Q

What does the islets of Langerhans do after the blood glucose level had risen?

A

The islets of Langerhans cells in the pancreas detect the increase in blood glucose and secrete insulin into the blood.

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14
Q

What happens after the insulin had been released?

A

The liver and the muscle cells, 2 major target organs of insulin, respond by absorbing glucose from the blood, which will be used in cellular respiration or stored in the form of glycogen.

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15
Q

What happens once the glucose had been taken care of?

A

It lowers blood glucose levels and helps bring them back to normal values.

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16
Q

What happens to the islets of Langerhans when blood glucose levels drop below normal levels whilst fasting?

A

The islets cells secrete glucagon into the blood.

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17
Q

What does the glucagon do?

A

It stimulates the liver to break down glycogen into glucose for release into the blood, which raises blood glucose levels.

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18
Q

Define diabetes.

A

Diabetes mellitus, or simply diabetes, is a disease that occurs when the body fails to regulate blood glucose levels.

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19
Q

How many types of diabetes mellitus?

A

2 main types of diabetes mellitus: type 1 and type 2

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20
Q

When does Type 1 diabetes usually occur?

A

Typically appears early in life, during childhood or adolescence.

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21
Q

Describe Type 1 diabetes.

A

It’s an autoimmune disease that results when the beta cells of the islets of Langerhans are attacked and destroyed by the bidi’s immune system.

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22
Q

What are beta cells?

A

They are responsible for the production of insulin.

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23
Q

What do people with type 1 diabetes lack?

A

They lack sufficient insulin for glucose regulation.

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24
Q

What happens to people with type 1 diabetes after a mean rich in carbohydrates?

A

Since people with type 1 diabetes produce little or no insulin, blood glucose levels cannot be reduced to normal values, and a condition knows as hyperglycemia will occur.

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25
Q

Define hyperglycemia.

A

An excess of glucose in the bloodstream.

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26
Q

What are symptoms of hyperglycemia?

A

Blurred vision, increased thirst, and frequent urination.

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27
Q

What can hyperglycemia cause glucose to do?

A

Be excreted in urine.

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28
Q

Does urine usually contain glucose? Explain why.

A

Urine normally does not contain significant amounts of glucose because this nutrient is fully reabsorbed into the blood from the filtrate in the kidneys.

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29
Q

Will all the glucose be reabsorbed into the blood?

A

Only a certain amount of glucose can be reabsorbed by the kidneys; thus, high concentrations of glucose in the blood will result in some glucose being excreted in the urine.

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30
Q

What do individuals with diabetes have a hard time doing?

A

They have difficulty raising their blood glucose levels to normal values during periods of fasting or inadequate food intake.

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31
Q

What does insulin and glucagon normally do?

A

Insulin stimulates the liver to store glucose in the form of glycogen, forming reserves in the body for periods of limited glucose intake, and glucagon triggers the breakdown of these reserves into glucose to be released into the blood, bringing glucose levels back to normal.

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32
Q

What happens, as a result, in people with type 1 diabetes?

A

Since little or no insulin is secreted in individuals with type 1 diabetes, glycogen is not formed.

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33
Q

What are people with type 1 diabetes at the hight risk of?

A

Diabetic patients are at a high risk of developing a condition known as hypoglycemia.

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34
Q

Define hypoglycemia.

A

A deficiency of glucose in the bloodstream.

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35
Q

What are symptoms of hypoglycemia?

A

Confusion, shakiness, sweating, hunger, and weakness.

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36
Q

What can extreme fluctuations in blood glucose levels lead to?

A

Organ damage, coma, and even death.

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37
Q

How can individuals with type 1 diabetes be protected from extreme fluctuations in blood glucose levels?

A

By taking insulin injections, eating regularly, and avoiding meals rich in carbohydrates.

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38
Q

How can type 1 diabetic people monitor their blood glucose level at home?

A

Using a simple device, they can also test for presence of sugar in their urine using glucose test strips.

39
Q

How is type 2 diabetes characterized?

A

It is characterized by a reduction in the ability of cells to respond to insulin.

40
Q

What happens to insulin in type 2 diabetes?

A

It gradually loses its ability to manage blood glucose levels.

41
Q

How does the pancreas respond to the inability of insulin to work?

A

It responds by producing greater and greater amounts of insulin, which exhausts the pancreas and eventually may damage it.

42
Q

Why do people with type 2 diabetes have difficulties in regulating blood glucose levels?

A

Mainly due to the decreased effectiveness of insulin on body cells, not the absence of insulin.

43
Q

When does type 2 diabetes occur?

A

Adulthood.

44
Q

Why does type 2 occur?

A

Certain lifestyle factors (e.g. inactivity and unhealthy diet) and genetic factors increase the risk of developing type 2 diabetes.

45
Q

What are symptoms of type 2 diabetes?

A

Frequent urination, glucose in the urine, abnormal thirst, and unexplained weight loss.

46
Q

How can individuals with type 2 diabetes manage their blood glucose levels?

A

Through lifestyle changes, such as diet, weight control, and regular exercise.

47
Q

What drug can be taken by type 2 diabetic patients?

A

Hypoglycemic drugs (other than insulin).

48
Q

How can type 2 diabetic patients monitor blood glucose levels help?

A

Urine glucose levels help regulate blood sugar levels and thus prevent extreme fluctuations, thereby avoiding complications of diabetes, such as heart disease and kidney failure.

49
Q

Describe the shape of adrenal gland.

A

Pyramid-shaped endocrine glands.

50
Q

Where are adrenal glands located?

A

On top of each kidney.

51
Q

What is part of the adrenal gland stimulated by?

A

The nervous system to release a hormone called adrenaline.

52
Q

What is the hormone adrenaline involved in?

A

Fight-or-fight response.

53
Q

Explain the fight-or-flight response.

A

It’s a physiological response to a perceived threat or danger.

54
Q

When is the adrenaline released?

A

When you are frightened or excited, such as when taking an exam or participating in a competition, the brain sends a nerve impulse to the adrenal glands, along a specific nerve, stimulating the secretion of adrenaline into the blood.

55
Q

What affects does adrenaline have?

A

It increases heart rate and blood pressure, supplying more blood to the organs needed in the fight-or-flight response, namely the skeletal muscles and the brain.

56
Q

What happens to the digestive organs during an adrenaline rush?

A

Digestive organs aren’t required for the fight-or-flight response, so adrenaline causes the blood vessels that supply the digestive system to constrict, temporarily diverting blood away from digestive organs. This is what causes the fluttery feeling in the stomach referred to as “butterflies”.

57
Q

What’s another effect of adrenaline?

A

Is the relaxation of the muscles of the digestive organs and tensing and more forceful contraction of the skeletal muscles.

58
Q

What happens to the blood vessels in the skin?

A

They become constricted by the action of adrenaline, which is why most people become pale when frightened or faced with danger.

59
Q

What do other actions of adrenaline include?

A

Expanding the air passages of the lungs, causing the breathing rate to increase to supply more oxygen to the actively respiring body organs involved in the fight-or-flight response.

60
Q

What happens to the pupils under the effect of adrenaline?

A

They dilate, this allows more light into the eyes, improving visual clarity for detecting nearby threats.

61
Q

What does adrenaline do to the liver?

A

It stimulates the liver to break down glycogen down into glucose, which is then released into the blood.

62
Q

What happens when glycogen is broken down?

A

This provides a rapid supply of fuel to the brain, the contracting skeletal muscles, and other organs to meet their high energy needs due to vigorous action.

63
Q

What are ovaries?

A

The female reproductive organs responsible for the production of the female gametes, also called eggs, or ova.

64
Q

What is the ovaries endocrine function?

A

They secrete the hormones estrogen and progesterone.

65
Q

What do estrogen and progesterone do?

A

They regulate the activity of the female reproductive organs and are responsible for the development of secondary female sexual characteristics at puberty.

66
Q

Are the levels of these hormones kept constant in a female human?

A

No, they’re not maintained at a constant value in the blood; their levels fluctuate over a repeated monthly cycle celled the menstrual cycle.

67
Q

What are the causes for disruptions in the cycle?

A

Disruptions in the cyclic fluctuations of estrogen and progesterone levels in the blood can lead to problems with the menstrual cycle, such as fertility problems.

68
Q

What is the testes?

A

It’s the male reproductive organ that produces the male gametes, also called sperm.

69
Q

What is the testes’s endocrine function?

A

They secrete the primary male sex hormone testosterone.

70
Q

What does testosterone do?

A

Play a central role in the development of male reproductive organs and in the production of sperm.

71
Q

What happens when there’s an increase in the testosterone levels at puberty?

A

It stimulates the development of secondary male sexual characteristics.

72
Q

What are role does that hormone play?

A

Plays a role in regulating bone density and muscle size and strength.

73
Q

What happens when there is a deficiency on testosterone?

A

It can lead to infertility problems, among other health problems.

74
Q

What is the thyroid?

A

An endocrine gland.

75
Q

Where is the thyroid located?

A

In the neck.

76
Q

What are the 2 hormones secreted by the thyroid gland?

A

Triiodothyronine (T₃) and thyroxine (T₄).

77
Q

What are the functions of T₃ and T₄?

A

They regulate body temperature, metabolism, heart rate, growth, and development, as well as various other physiological processes.

78
Q

What happens when there’s an excess or deficiency in these hormones?

A

It can lead to health problems.

79
Q

Describe graves’ disease.

A

It’s characterized by the secretion of excess T₃ and T₄ hormones which causes symptoms such as irregular heartbeat, excessive sweating, wand weight loss.

80
Q

What is pituitary?

A

It’s an endocrine gland.

81
Q

Where is pituitary found?

A

At the base of the brain.

82
Q

What do the hormones secreted by pituitary gland do?

A

They regulate the activity of other endocrine glands and endocrine tissues.

83
Q

Give an example of pituitary gland production.

A

It produces 2 hormones that regulate the production of estrogen and progesterone by the ovaries.

84
Q

What are these 2 hormones called?

A

Luteinizing hormone (LH) and follicle-stimulating hormone (FSH).

85
Q

What controls the release of T₃ and T₄?

A

It is released by the thyroid glands which is regulated by the thyroid-stimulating hormone (TSH) which is another hormone secreted by pituitary gland.

86
Q

What other hormones are secreted by pituitary glands?

A

Growth hormone (GH), which helps regulate growth and development in the body.

87
Q

What is one of the most well-known effects of GH?

A

It’s stimulating increases in height throughout childhood and adolescence.

88
Q

Is GH meant to work on one endocrine tissue or gland?

A

Unlike other pituitary hormones, GH is not known to act on a particular endocrine gland or tissue to regulate the release of another hormone; target organs of GH are not endocrine glands.

89
Q

What is referred to as “the master gland”? Why?

A

The pituitary gland because of its role in coordinating the activity of many other glands.

90
Q

Why is that term no longer used?

A

Because it was discovered that the pituitary gland itself is controlled largely by the hypothalamus.

91
Q

Where is the hypothalamus located?

A

It’s a region of the brain located near the pituitary gland.

92
Q

What does the hypothalamus release?

A

It releases hormones that regulate the production and release of hormones by the pituitary gland.

93
Q

What hormone does the hypothalamus release?

A

A hormone called gonadotropin-releasing hormone (GnRH), which stimulates the release of FSH and LH from pituitary gland.

94
Q

What’s another hormone the hypothalamus releases?

A

It’s the growth-hormone-releasing (GHRH), which stimulates the release of GH from the pituitary gland.