Endocrine system 1

Question 1

Communication is critical for:

Answer 1

survival and function

Question 2

2 major communication systems:

Answer 2

nervous and endocrine systems

Question 3

4 Types of Chemical Messengers:

Answer 3

Autocrine/paracrine, neurotransmitters, neurohormones, hormones

Question 4

What is autocrine/paracrine ?

Answer 4

Acts on itself - autocrine
Acts on another cell nearby - paracrine

Question 5

Neurohormones?

Answer 5

Released from synaptic vesicles by neuron, released into blood and acts in manner similar to hormones

Question 6

Hormones

Answer 6

endocrine system messengers, transported in blood, target cell expresses specific receptors and released from endocrine gland DIRECTLY into blood

Question 7

Differences between hormones and neurotransmitters: hint 2

Answer 7

Neural messages can only travel along existing nerve tracts; hormonal messages can travel in the circulatory system; thus any cell receiving blood is potentially able to receive a message.

Neural messages are all-or-none events that have rapid onset and offset; neural signals can take place in milliseconds; plus, electrical signal can travel along myelinated axons at speeds up to 100 meters per sec
Whereas Hormonal messages are graded events that can take seconds, minutes or hours to occur

Question 8

4 types of hormones:

Answer 8

Peptide and catecholamines - Hydrophilic
Steroid and thyroid - Lipophilic

Question 9

How are hormones categorised?

Answer 9

BY solubility

Question 10

What are steroid hormones derived from?

Answer 10

Cholesterol

Question 11

What are steroid hormones?

Answer 11

Small lipid soluble molecules that diffuse via cell membrane, receptor is intracellular

Question 12

2 types of receptors:

Answer 12

Surface and nuclear

Question 13

Surface receptors:

Answer 13

Bind peptides and catecholamines at cell membrane

Question 14

Nuclear receptors:

Answer 14

Bind thyroid and steroid hormones, inside the cell

Question 15

How are cells exposed to hormones?

Answer 15

Via circulation

Question 16

What does receptor activation alter?

Answer 16

Channel function and 2nd messenger systems

Question 17

What does extracellular chemical (hormone) bind to?

Answer 17

Surface receptor

Question 18

What cells can respond?

Answer 18

Only cells with receptors for hormone

Question 19

Where are endocrine glands derived from?

Answer 19

Epithelial tissue

Question 20

What are endocrine glands composed of?

Answer 20

Endocrine glands are composed of clumps of secretory cells

Question 21

Endocrine glands surrounded by…

Answer 21

Endocrine glands are surrounded by capillaries (fenestrated)

Question 22

Do endocrine glands have ducts?

Answer 22

NO - no duct system

Question 23

What system has ducts?

Answer 23

Exocrine glands

Question 24

Main function of primary endocrine organs?

Answer 24

Hormone release

Question 25

E.gs primary endocrine organs

Answer 25

pituitary, thyroid, parathyroid, adrenal and pineal glands

Question 26

Primary endocrine organs...

Answer 26

Discrete organs

Question 27

Secondary endocrine organs...

Answer 27

dispersed in organs

Question 28

E.gs of 2ndary endocrine organs?

Answer 28

heart, kidney, liver, etc

Question 29

neuro-endocrinology?

Answer 29

nervous and endocrine systems co-regulate many physiological functions - study of this is called Neuro-Endocrinology This studies how the brain regulates Pituitary hormone secretion

Question 30

What do neuroendocrine cells release? where is this found?

Answer 30

Neurohormones Found in, for example: adrenal medulla, thyroid, Pancreas / islet of Langerhans, pituitary cells, renin-secreting cells, gastro-intestinal tract, lower respiratory tract

Question 31

Endocrine gland secretion triggered by:

Answer 31

Hormones, neurotransmitters and metabolic factors

Question 32

2 types of feedback loops:

Answer 32

Long-loop and short-loop

Question 33

Feedback can be?

Answer 33

Excitatory / inhibitory

Question 34

Positive feedback

Answer 34

activation

Question 35

Negative feedback

Answer 35

inhibition

Question 36

Trophic hormones?

Answer 36

Regulate secretion of other hormones either releasing or inhibitory

Question 37

Examples of Trophic hormones: TSH what happens?

Answer 37

thyroid-stimulating hormone (TSH) secreted from anterior pituitary stimulates thyroid hormone secretion from thyroid gland and maintains structural integrity of thyroid gland

Question 38

Example of Trophic hormone pathway

Answer 38

anterior pituitary -> TSH -> Thyroid gland -> T3.T4 Thyroid hormone

Question 39

Primary Hyposecretion what is it and what causes it?

Answer 39

abnormality within gland - cannot secrete enough Causes: genetic, dietary (eg lack of iodine), chemical or toxic, immunologic (autoimmune diseases), cancer, surgery (removal / Iatrogenic) and idiopathic (unknown)

Question 40

2ndary hyposecretion is...

Answer 40

Deficiency of trophic hormone - not able to make it

Question 41

General causes of hypersecretion:

Answer 41

Immune factors, tumours continuously secrete hormone

Question 42

Primary hypersecretion?

Answer 42

Too much hormone secreted due to abnormality within gland

Question 43

2ndary hypersecretion?

Answer 43

excessive stimulation of gland causes oversecretion