Ch 45 Endocrine System Flashcards Preview

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Flashcards in Ch 45 Endocrine System Deck (81):
1

Hormones

Chemical signals

2

Where are hormones secreted into?

The circulatory system

3

Hormones serve what purpose?

Communicating regulatory messages within the body

4

What allows hormones only to effect target cells?

Receptors on those target cells for the specific hormone

5

What two systems coordinate internal communication?

1) Endocrine system

2) Nervous system

6

Endocrine system

Secretes hormones that coordinate slower, but longer-acting responses

7

Nervous system

Conveys high-speed electrical signals along neurons

8

What do signals within the nervous system do?

Regulate other cells

9

Neurons

Specialized cells of the nervous system

10

Endocrine signaling maintains what?

Homeostasis

11

Endocrine signaling mediates what?

Responses to stimuli

12

Endocrine signaling regulates what?

Growth and development

13

Local regulators

Molecules that act over short distances

14

How do local regulators reach target cells?

Solely by diffusion

15

Two types of signaling that produces local regulators

1) Paracrine signaling

2) Autocrine signaling

16

Paracrine signaling

Target cells lie near the secreting cells

Act locally by diffusing to nearby target cells

17

Autocrine signaling

Target cell is also the secreting cell

Have regulatory action on the cell that produces them

18

Endocrine glands

Small, ductless glands that release hormones into blood vessels

19

Synapses

Specialized junction formed between neurons and target cells

20

Neurons secrete what?

Neurotransmitters

21

Neurotransmitters

Molecules that diffuse short distances and bind to receptors on target cells

22

Neurosecretory cells

Specialized nerves in the brain that secrete neurohormones into the circulatory system

23

Three major classes of molecules that function as hormones

1) Polypeptides

2) Amines

3) Steroids

24

What two major classes of molecules that function as hormones are also water soluble?

1) Polypeptides

2) Amines

25

What major class of molecules that function as hormones are also lipid soluble?

Steroids

26

Water soluble hormones freely diffuse into what?

The blood

27

Water soluble hormones bind to what?

Signal receptor proteins in cell membranes

28

How do lipid soluble hormones enter the circulatory system?

Bound to transport proteins

29

Once in the circulatory system, how do lipid soluble hormones reach their target cells?

Freely diffusing through cell membranes

30

Hormones binding to membrane receptor proteins activate what?

Second-messengers within the cell

31

Second-messengers serve what purpose?

They are used in multiple reactions

32

Second-messenger activation amplifies what?

The hormone's signal and activates kinases

33

Kinases

Molecules that regulate enzymes

34

Steroids hormones (estrogen, testosterone) bind to proteins located where?

In the cytoplasm

35

What happens after steroid hormones bind to proteins in the cytoplasm?

The hormone-receptor complex enters the cell nucleus and activates/inhibits transcription of specific genes

36

Genetic code leaves the nucleus in what form?

Messenger RNA

37

Ribosomes

Translate mRNA into polypeptides

38

How do members of the same animal species sometimes communicate?

With pheremones

39

Pheremones

Chemicals that are released into the environment

40

Functions of pheremones

1) Marking trails leading to food

2) Defining territories

3) Warning of predators

4) Attracting potential mates

41

The same hormones may have different effects on target cells that have different...

1) Receptors for the hormone

2) Signal pathways

3) Proteins for carrying out the response

42

Can a hormone have different effects in different species?

Yes

43

Epinephrine has multiple effects in mediating what?

The body's response to short-term stress

44

Epinephrine binds to receptors on the plasma membrane of what?

Liver cells

45

Binding of epinephrine and liver cells triggers what?

The release of messenger molecules that activate enzymes and result in the release of glucose into the bloodstream

46

Simple hormonal negative feedback loops

The product of the hormonal response has a negative effect on the stimulation of further hormone release

47

Antagonistic hormones

Have opposite effects and forms a homeostatic system of negative feedback loops

48

Insulin

Reduces blood glucose by promoting uptake of glucose by cells and production of glycogen by the liver

49

Glucagon

Increases blood glucose by stimulating breakdown of glygogen to glucose

50

Type 1 diabetes mellitus (insulin-dependent)

Autoimmune disorder in which the immune system destroys pancreatic beta cells

51

Type 2 diabetes mellitus (non-insulin-dependent)

Involves insulin deficiency or reduced response of target cells due to change in insulin receptors

52

Major endocrine glands

1) Hypothalamus
2) Pineal gland
3) Pituitary gland
4) Thyroid gland
5) Parathroid glands
6) Adrenal glands
7) Pancreas
8) Kidney
9) Ovaries
10) Testes (males)

53

Organs containing endocrine cells

1) Thymus
2) Heart
3) Liver
4) Stomach
5) Kidney
6) Small intestine

54

Hypothalamus

Receives information from the nervous system and initiates responses through the endocrine system

55

What is attached to the hypothalamus?

Pituitary gland

56

What two structures compose the pituitary gland?

1) Posterior pituitary

2) Anterior pituitary

57

Posterior pituitary

Stores and secretes hormones that are made in the hypothalamus

58

Anterior pituitary

Makes and releases hormones under regulation of the hypothalamus

59

Tropic hormones effect what?

The release of other hormones

60

Growth Hormone (GH)

Secreted by the anterior pituitary gland and has tropic and nontropic actions and diverse metabolic effects

61

Growth hormone stimulates the production of what?

Growth factors

62

What causes gigantism?

An excess of growth hormone

63

What causes dwarfism?

Lack of growth hormone

64

Hormone cascade pathway

A hormone can stimulate the release of a series of other hormones, the last of which activates a nonendocrine target cell

65

Do hormone cascade pathways typically involve negative or positive feedback?

Negative feedback

66

The release of thyroid hormone to increase metabolism results from what?

A hormone cascade pathway involve the hypothalamus, anterior pituitary, and thyroid gland

67

Adrenal gland

Releases hormones that regulate the stress response

68

Where is the adrenal gland located?

On top of the kidney's

69

Two glands that make up the adrenal gland

1) Adrenal medulla

2) Adrenal cortex

70

Adrenal medulla

Inner portion of adrenal gland

Rapid response

71

Adrenal cortex

Outer portion of adrenal gland

Long-term response

72

Three sex hormones

1) Androgens

2) Estrogens

3) Progestrins

73

Are all three sex hormones found in males, females, or both?

Found in both males and females, but in different proportions

74

Testes primarily synthesize what sex hormones?

Androgens

Primarily testosterone

75

Testosterone

Stimulates development and maintenance of the male reprodcutive system

76

Estrogens

Responsible for maintenance of the female reproductive system and the development of female secondary sex characteristics

77

What is the most important estrogen?

Estradiol

78

Progestins serve what purpose in mammals?

Primarily involved in preparing and maintaining the uterus

79

Pineal gland

Secretes melatonin

Located in the brain

80

What controls the release of melatonin?

Light and dark cycles

81

The primary functions of melatonin appear to relate to what?

Biological rhythms associated with reproduction