Anatomy 18 - The Endocrine System Flashcards Preview

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Flashcards in Anatomy 18 - The Endocrine System Deck (76)
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1
Q

What is the endocrine system

A

A system of ductless glands that regulate bodily function via hormones

2
Q

What are the main functions of the endocrine system

A

It maintains homeostasis, it helps the body react to stress, it is a major regulator of growth and development and it controls physical and behavioural activities

3
Q

How does it maintain homeostasis

A

By regulating activities such as the concentration of chemicals in body fluids and the metabolism of proteins, lipids and carbohydrates

4
Q

What are the tissues/glands within the endocrine system known as

A

Endocrine glands

5
Q

What do endocrine glands do

A

They secrete chemicals into extracellular space

6
Q

What are the chemicals secreted by the glands called

A

Hormones

7
Q

How is it determined which cells are acted on by specific hormones

A

Only cells with the compatible receptors will be affected by specific hormones

8
Q

What are the three ways in which endocrine glands are stimulated

A

Hormonal, humoral and neural

9
Q

What is hormonal stimulation

A

When the stimulation of a gland occurs through hormones being secreted from somewhere else e.g. the pituitary stimulating the thyroid

10
Q

What is humoral stimulation

A

The stimulation of a target gland through the presence of a molecule within the bloodstream

11
Q

What is neural stimulation

A

Stimulation of a gland via direct signals from the nervous system

12
Q

What are the central glands of the endocrine system

A

The pineal and pituitary glands

13
Q

What are the peripheral glands of the endocrine system

A

The thyroid, parathyroid, thymus, adrenal/suprarenal glands and the pancreas

14
Q

Where is the pineal gland situated

A

In the roof of the 3rd ventricle

15
Q

What are the cells within the pineal gland called

A

Pinealocytes

16
Q

What is the major secretory product of the pineal gland

A

Melatonin

17
Q

What is melatonin involved in

A

Regulating sleep

18
Q

What is the pituitary gland split into

A

The anterior and posterior pituitary

19
Q

What is the pineal gland involved in regulating

A

Day/night cycles

20
Q

What is the anterior pituitary composed of

A

Glandular tissue

21
Q

Function of the anterior pituitary

A

To manufacture and release hormones

22
Q

Hormones released from where control secretion of hormones from the anterior pituitary

A

The ventral hypothalamus

23
Q

Through what system is the secretion of hormones from the anterior pituitary controlled

A

The hypophyseal portal system

24
Q

What is the posterior pituitary composed of

A

Neural tissue

25
Q

Function of posterior pituitary

A

Acts as a storage area and releases neurohormones

26
Q

Where are the neurohormones released by the posterior pituitary made

A

The hypothalamus

27
Q

Where is the pituitary located

A

In the hypophyseal fossa of the sella turcia of the sphenoid bone

28
Q

What takes up hormones released by the pituitary

A

The bloodstream

29
Q

What hormones are secreted by the anterior pituitary

A

Growth hormone, thyroid stimulating hormone, adrenocorticotrophic hormone, follicle stimulating hormone, luteinising hormone and prolactin

30
Q

What regulates growth hormone

A

Growth hormone releasing hormone and growth hormone inhibiting hormone

31
Q

What does growth hormone target

A

The liver, muscle, bone and cartilage

32
Q

What regulates thyroid stimulating hormone

A

Thyroid releasing hormone and feedback

33
Q

What is thyroid regulating hormone involved in regulating

A

Metabolism

34
Q

What regulated follicle stimulating hormone

A

Gonadotrophin-releasing hormone and feedback

35
Q

What does follicle stimulating hormone target

A

The testes/ovaries

36
Q

What does follicle stimulating hormone regulate

A

The development, growth, maturation and reproductive processes of the body

37
Q

What occurs due to a lack of follicle stimulating hormone

A

Failure of sexual maturation

38
Q

What is adrenocorticotrophic hormone regulated by

A

Corticotrophin-releasing hormone and feedback

39
Q

What does adrenocorticotrophic hormone act on

A

The adrenal cortex

40
Q

What causes the production of adrenocorticotrophic hormone

A

Stress

41
Q

What does the release of adrenocorticotrophic hormone cause increased production of

A

Corticosteroids

42
Q

What is luteinising hormone regulated by

A

GnRH and feedback

43
Q

Where does luteinising hormone target

A

The ovaries/testes

44
Q

What does luteinising hormone stimulate the production of

A

Testosterone, the development of the corpus luteum and causes ovulation

45
Q

What does a lack of luteinising hormone cause

A

Failure of sexual maturation

46
Q

What is prolactin regulated by

A

Prolactin releasing hormone and prolactin inhibiting hormone

47
Q

Where does prolactin target

A

The mammary glands

48
Q

What hormones does the posterior pituitary release

A

Oxytocin and antidiuretic hormone

49
Q

What regulates oxytocin

A

The hypothalamus and also by uterine stretching and suckling

50
Q

Where does oxytocin target

A

The uterus and breasts

51
Q

What does oxytocin stimulate

A

Birth and milk production

52
Q

What regulates ADH

A

The hypothalamus by the blood osmolarity and volume

53
Q

Where does ADH target

A

The kidneys

54
Q

What causes a release of ADH

A

The body being dehydrated

55
Q

What secretes thyroid hormone

A

Follicle cells

56
Q

Where does thyroid hormone effect

A

All cells except the brain, sleep, uterus and thyroid

57
Q

What is the thyroid hormone involved in

A

The metabolism of carbohydrates, proteins and lipids

58
Q

What do parafollicular cells secrete

A

Calcitonin

59
Q

What is the function of calcitonin

A

To lower the level of Ca++ in the blood

60
Q

What is the function of parathyroid hormone

A

To increase the level of Ca++ in the blood

61
Q

What does the thymus secrete and what is it essential for

A

Peptide hormones and for normal development of T lymphocytes and the immune response

62
Q

What is involved in the short term stress response

A

The adrenal medulla

63
Q

What does the adrenal medulla cause

A

An increase in heart rate and blood pressure, it causes the liver to convert glycogen to glucose, causes the dilation of the bronchioles, causes an increase in alertness and metabolism

64
Q

What does the pancreatic islets produce

A

Glucagon and insulin

65
Q

What is glucagon involve in

A

The synthesis of alpha cells

66
Q

What is insulin involve in

A

The synthesis of beta cells

67
Q

What do beta cells cause

A

The blood sugar levels to be lowered

68
Q

What do alpha cells cause

A

The blood sugar level to increase

69
Q

What does the adrenal cortex synthesise

A

Corticosteroids

70
Q

How many corticosteroids are produced by the adrenal cortex

A

24

71
Q

What are corticosteroids synthesised from

A

Cholesterol

72
Q

What are the three categories of corticosteroids

A

Mineralocorticoids, glucocorticoids and sex steroids

73
Q

Function of mineralocorticoids

A

Control electrolyte balance

74
Q

Function of glucocorticoids

A

Stimulate fat and protein catabolism and release fatty acids and glucose into the blood

75
Q

What stimulates the secretion of glucocorticoids

A

Adrenocorticotropic hormone

76
Q

What is involved in the long term stress response

A

The adrenal cortex