Topic 18 - Endocrine System Flashcards Preview

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Flashcards in Topic 18 - Endocrine System Deck (37):
1

Overview of the Endocrine System

  • ductless glands and endocrine tissues within other organs
  • secrete chemicals = hormones into blood
  • transported to target cells via circulation and act on target cells
  • target cell = cell with receptor specific for that hormone

2

Hormone Classes

List the classes of hormones

  1. Steroids
  2. Hormones derived from amino acids
  3. Peptide + Protein hormones

3

Hormone Classes

Steroids

  • synthesized from cholesterol (lipid soluble)
  • testosterone, estrogen, vitamin D

4

Hormone Classes

Hormones derived from amino acids

give example

and what kinds

  • e.g. derived from tyrosine 

2 kinds

  1. thyroxine/T4
  2. epinephrine + norepinephrine (catecholamines)

5

Hormone Classes ►Hormones derived from amino acids

Thyroxine/T4

what kind of hormone is it?

water or lipid soluble?

what does it do?

  • a thyroid hormone
  • lipid soluble
  • controls cellular metabolism

6

Hormone Classes ►Hormones derived from amino acids

epinephrine + norepinephrine (catecholamines)

what kind of hormone is it?

water or lipid soluble?

what does it do?

 

  • adrenal medulla hormones
  • water soluble
  • short term stress – part of the fight-or-flight response

7

Hormone classes

Peptide + Protein hormones

what is it?

water or lipid soluble?

name examples of these hormones

  • chains of amino acids
  • mainly water soluble
  • e.g. oxytocin, antidiuretic hormone (ADH), growth hormone (GH), insulin

8

Endocrine Glands

Name the types of glands

these glands have __ _____ ________.

 

Glands with no other function:

  1. Pituitary gland
  2. Thyroid gland
  3. Parathyroid gland
  4. Adrenal gland

9

Endocrine Glands 

Pituitary gland

how is it anatomically and functionally related to the _______. 

where is it located?

how many lobes?

  • suspended from hypothalamus
  • in sella turcica of sphenoid bone
  • 2 lobes

10

Endocrine glands ► Pituitary gland

what are the 2 lobes of the pituitary gland?

  1. Anterior pituitary
  2. Posterior pituitary

11

Endocrine gland ► Pituitary gland 

Anterior pituitary

  • what kind of tissue?
  • how is it regulated?
  • how many hormones?

 

 

  • epithelial tissue
  • anterior pituitary hormone secretion regulated by hormones released by the hypothalamus 
  • 3 metabolism hormones
  • 3 reproductive hormones

12

Endocrine gland ► Pituitary gland ► Anterior pituitary

What are 3 metabolism hormones of the anterior pituitary?

  1. Growth hormone
  2. Thyroid stimulating hormone (TSH)
  3. Adrenocorticotropic Hormone (ACTH) 

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Endocrine gland ► Pituitary gland ► Anterior pituitary ► Metabolism hormone

Growth hormone

what does it stimulate or promote?

promotes growth or metabolism

14

Endocrine gland ► Pituitary gland ► Anterior pituitary ► Metabolism hormones

Thyroid stimulating hormone (TSH)

what does it stimulate or promote?

 

stimulates secretion of thyroid

15

Endocrine gland ► Pituitary gland ► Anterior pituitary ► Metabolism hormone

Adrenocorticotropic Hormone (ACTH)

 

stimulates secretion of adrenal steroids

16

Endocrine gland ► Pituitary gland ► Anterior pituitary 

Name the reproductive hormones of the anterior pituitary

 

  1. Leutinizing Hormone (LH)
  2. Follicle Stimulating Hormone (FSH)
  3. Prolactin (PRL)
    • stimulates milk formation

17

Endocrine gland ► Pituitary gland

Posterior pituitary

what kind of tissue?

how is it anatomically and functionally related to the ______?

how does the hypothalamus affect the pituitary gland?

  • nervous tissue
  • extension of hypothalamus
  • hormones produced in hypothalamus, stored and secreted from the posterior pituitary:
    • Oxytocin
    • Antidiuretic Hormone (ADH) 

18

Endocrine gland ► Pituitary gland ► Posterior pituitary

Oxytocin 

what does it stimulate?

stimulates uterine contractions and milk ejection

 

19

Endocrine gland - Pituitary gland - Posterior pituitary

Antidiuretic Hormone (ADH) 

water reabsorption in kidney

20

Endocrine gland 

Thyroid gland 

where is it located?

what is it composed of?

fact

  • on anterior surface of the superior part of the trachea
  • butterfly shaped
  • Thyroid histology
    • follicles
    • parafollicular cells

21

Endocrine gland - Thyroid gland - Thyroid histology​

Follicles

what are the walls composed of?

what does it produce?

  • walls = epithelial cells (follicle cells)
  • produce T4

22

Endocrine gland - Thyroid gland - Thyroid histology

Parafollicular cells

where is it located?

what does it secrete?

  • between follicles
  • secrete calcitonin
    • increase  Ca++ uptake into bone (bone formation) which  lowers blood Ca++ bone matrix

23

Endocrine glands 

Parathyroid glands 

where is it located and how many?

what does it secrete?

 

  • 4 (usually) glands embedded in posterior thyroid
  • secrete parathyroid hormone (PTH)
    • increase blood Ca++ by breaking down bone matrix

24

Endocrine glands

Adrenal glands

where is it located?

what are the 2 parts?

  • superior surface of each kidney
  • 2 parts
    • adrenal cortex (outer)
    • adrenal medulla (inner)

25

Endocrine glands - Adrenal glands

Adrenal cortex (outer)

what tissue?

what does it secrete?

how many layers?

  • how many hormones are secreted by each layer?

  • epithelial tissue
  • secretes steroids only
  • 3 layers (1 hormone secreted by each):
    1. Zona Glomerulosa
    2. Zona Fasciculata  
    3. Zona reticularis   

26

Endocrine glands - Adrenal glands - Adrenal cortex

Zona glomerulosa

what does it secrete?

secretes mineralcorticoids (mainly aldosterone)

  • salt balance

27

Endocrine glands - Adrenal glands - Adrenal cortex

Zona fasciculata

 

what does it secrete?

  • example
  • what kind of hormone?

secretes glucocorticoids (e.g. cortisol)

  • long term stress hormone
  • carbohydrate metabolism

28

Endocrine glands - Adrenal glands - Adrenal cortex

Zona reticularis

what does it secrete?

secretes androgens + small amounts testosterone

  • some converted to estrogens in other tissues (especially fat)

29

endocrine gland - adrenal gland 

Adrenal medulla (inner)

what kind of tissue?

what hormones?

  • nervous tissue 
  • 2 main hormones:
    1. epinephrine (80%)
    2. norepinephrine (20%)

30

Endocrine tissues

name the 4

Endocrine function in organs that have other functions as well:

  1. Pancreatic Islets of Langerhans
  2. Hypothalamus
  3. Gonads
  4. Others

31

Endocrine tissues

Pancreatic islets of langerhans

  • 4 cell types (only covering 2 in this course)
    1. a-cells
    2. b-cells

32

a-cells

produce glucagon

-increases blood glucose

33

b-cells

produces insulin

-decreases blood glucose

34

Endocrine tissue

Hypothalamus

regulates anterior pituitary via:

  1. GHRH (growth hormone releasing hormone)
  2. GHIH (Growth hormone inhibiting hormone)
  3. HnRH (Gonadotropin releasing Hormone) - FSH + LH

35

Endocrine tissues

Gonads

  • Testes
    • leydig cells = testosterone
  • Ovaries
    • Cells of 1º and 2º follicles  = estrogen
    • corpus luteum = estrogen + progesterone

36

Endocrine Tissues

List the others

  • duodenum - secretin
  • kidney - renin
  • skin - vitamin D
  • heart - atrial natruiretic peptide (ANP)
  • etc.

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