Endocrine

Question 1

Endocrine signalling

Answer 1

Secreted by glands into capillary and has target organs reached by blood

Question 2

Neuroendocrine signalling

Answer 2

Secreted by nerves into capillary and has target organ reached by blood

Question 3

Neurotransmitters

Answer 3

Released by axon terminals of neurons into synaptic junctions, act locally

Question 4

Paracrine signalling

Answer 4

Secreted by cells into Extracellular fluid and effects neighbouring cells of a different type

Question 5

Autocrine signalling

Answer 5

Secreted by cells into Extracellular fluid and affect function of same cells that produce them

Question 6

Proteins & polypeptide endocrine molecule structure

Answer 6

Contains 2 amino acids and stored in secretory vesicles until needed

Question 7

Protein & polypeptide endocrine molecule function by…

Answer 7

• Bind to cell surface receptors and work through G reactive type proteins
• about 75% of SMAs transduced with G-protein coupled receptors

Question 8

Steroid endocrine molecule structure

Answer 8

• Made from cholesterol, lipid soluble
• needs transport plasma protein to travel through the blood

Question 9

Steroid endocrine hormones are produced and secreted from…

Answer 9

Adrenal cortex, ovaries, testes, placenta

Question 10

Steroid hormones function

Answer 10

Signalling occurs through binding to cytoplasmic or nuclear receptors

Question 11

Derivatives of tyrosine are made in…

Answer 11

Thyroid and adrenal medulla

Question 12

Thyroid hormones are secreted by the ____

Answer 12

Thyroid

Question 13

T4 is ____

Answer 13

Thyroxine

Question 14

T3 is ____

Answer 14

Triiodothyronine

Question 15

T4 comprises ____ of thyroid hormones

Answer 15

97%

Question 16

T3 comprises ____ of thyroid hormones

Answer 16

3%

Question 17

T4 is active/inactive?

Answer 17

Inactive

Question 18

T3 is active/inactive?

Answer 18

Active

Question 19

Biochemically, amino acid derivatives function like ____

Answer 19

Steroid

Question 20

Tyrosine derivatives made in the adrenal medulla are termed ____

Answer 20

Catecholamines

Question 21

Name the catecholamines

Answer 21

Dopamine, norepinephrine, epinephrine

Question 22

Catecholamines function like ____

Answer 22

Polypeptide hormones

Question 23

Name the steps of G-Reactive protein function

Answer 23

1. Opens a membrane channel for a specific ion
2. Activates cAMP or cGMP
3. Activates enzymes
4. Activates gene transcription

Question 24

What happens when G-reactive proteins open an ion-specific channel?

Answer 24

Keeps it open for a longer period of time than is generally seen with a typical ligand-gated channel

Question 25

What happens when cAMP or cGMP is activated?

Answer 25

Stimulates specific metabolic machinery in the neuron

Question 26

What happens when enzymes are activated?

Answer 26

Initiates biochemical reactions in target cell

Question 27

What happens when gene transcription is activated?

Answer 27

Gene transcription & protein synthesis May alter metabolism or morphology of cell

Question 28

Types of polypeptide growth factors

Answer 28

Mitogens Trophic factors Chemoattractants

Question 29

Function of mitogens

Answer 29

Stimulate cell proliferation (mitosis)

Question 30

Function of trophic factors

Answer 30

Growth & survival

Question 31

Function of chemoattractants

Answer 31

Gradient for mobile (WBC) cells (inflammation)

Question 32

Histamine and nitric oxide are ____

Answer 32

Amines

Question 33

Histamine location

Answer 33

- made by mast cells with IgE molecules on surface - located in CT of bronchi & intestines

Question 34

How does histamine work?

Answer 34

1. Allergen causes cross links to form between IgE molecules, Ca enters cell —> histamine released 2. Binds to either H1 or H2 receptor

Question 35

What happens when H1 histamine receptor is activated?

Answer 35

A. Causes venules to vasodilate —> increases tissue swelling & WBC infiltration into tissue B. Causes release of hypothalamic releasing factors —> increase release of anterior pituitary hormone

Question 36

What happens when H2 histamine receptor is activated?

Answer 36

Causes release of stomach acid from parietal cells in stomach

Question 37

Nitric Oxide (NO) works as a…

Answer 37

Localized negative feedback to vasoconstriction

Question 38

Describe how Nitric Oxide (NO) works

Answer 38

1. Arteriole constricts due to E or NE 2. Causes release of ACh by endothelial cells, increases Ca influx to endothelial cells 3. Turns on enzyme: NO-synthase, converts arginine to citrulline and releases NO 4. NO diffuses to smooth muscle cells 5. Stimulates smooth muscle light chain phosphatase —> vasodilation