the endocrine system

Question 1

what is endocrine signalling

Answer 1

hormones are secreted into the circulatory system to act on distant target cells

Question 2

what is intracrine signalling

Answer 2

signalling molecules released act within the same cell, are never releaed outside the cell

Question 2

what is autocrine signalling

Answer 2

signalling molecules released by the cell act on the same cell, but are released externally

Question 3

how many major endocrine glands are there in mammals

Answer 3

9

Question 4

how many hormones are there in mammals

Answer 4

> 70

Question 5

what are the 4 types of hormone, which are amines, and are they hydrophillic or phobic

Answer 5

peptides - hydrophilic
catecholamines (amine) - hydrophilic,
thyroid hormone (amine) - hydrophobic,
steroids - hydrophobic

Question 6

how are peptides transported and what is their receptor

Answer 6

transport - none, free hormone
receptor - target cell surface

Question 7

how are catecholamines transported and what is their receptor

Answer 7

transport - partly bound to plasma proteins
receptor - target cell surface

Question 8

how are thyroid hormones transported and what is their receptor

Answer 8

transport - mostly bound to plasma proteins
receptor - intracellular target

Question 9

how are steroids transported and what is their receptor

Answer 9

transport - mostly bound to plasma protein
receptor - intracellular target

Question 9

what are peptide proteins and what is their lifecycle

Answer 9

large precursor proteins
synthesised, processed, and packaged into secretory granules by golgi complex
stored and then exocytosis

Question 10

what are amine hormones derived from

Answer 10

tyrosine

Question 11

where are catecholamines stored

Answer 11

chromaffin granules

Question 12

what is the life cycle of thyroid hormone

Answer 12

thyroglobulin synthesised and secreted in to extracellular colloid
combined with iodine, reabsorbed by endocytosis and secreted

Question 12

what are steroids derived from and how

Answer 12

cholesterol precursor via enzymatic reactions

Question 16

when are steroids secreted and how

Answer 16

immediately by diffusion

Question 16

can hormones be secreted by multiple glands

Answer 16

yes

Question 17

can glands secrete multiple hormones

Answer 17

yes

Question 18

what is the importance of hormone receptors

Answer 18

ensure specificity of target and effect,
amplify hormone response

Question 19

what hormones use membrane receptors

Answer 19

peptides and catecholamines

Question 20

what is activated by a membrane receptor

Answer 20

second-messenger systems to activate or inhibit existing proteins

Question 21

what hormones use nuclear receptors

Answer 21

steroids and thyroid

Question 22

what are nuclear receptors

Answer 22

transcription factors

Question 23

where are nuclear receptors bound

Answer 23

hormone response elements in promoter of target cells

Question 24

3 things that modulate hormone effects (effects are proportional to:)

Answer 24

number of receptors,
post binding regulation (transcriptional / post-transcriptional regulation),
hormone concentration

Question 25

3 types of control secretion rates can be under

Answer 25

negative feedback control,
response to stimulus,
biological rhythms

Question 26

what is permissiveness and give an example

Answer 26

presence of one hormone increases activity of another
thyroid hormone increases epinephrine receptors

Question 26

what is antagonism and give an example

Answer 26

one hormone opposes the actions of another
insulin and glucagon have opposing effects on glucose

Question 27

what is the ‘command centre’ in vertebrates

Answer 27

hypothalamus-pituitary complex

Question 27

what is the posterior pituitary made of

Answer 27

nervous tissue

Question 27

what is synergism and give an example

Answer 27

complementary actions so that their combined activities are greater than separate activities
glucagon and epinephrine increase glucose levels

Question 28

what is the anterior pituitary made of

Answer 28

glandular tissue

Question 29

name 2 hormones secreted by the posterior pituitary and 2 areas they can act

Answer 29

vasopressin - acts on nephrons in the kidneys increasing permeability, also act on arterioles causing vasoconstriction
oxytocin - acts on uterus stimulating contractions, also acts on mammary glands stimulating milk ejection

Question 30

5 hormones released by anterior pituitary and what they do

Answer 30

thyrotropes - act on thyroid gland,
somatotropes - inhibit / release of growth hormone,
gonadotropes - LH and FSH release
lactotropes - prolactin releasing hormone for breast milk,
corticotropes - act on adrenal glands to release cortisol

Question 30

what happens if growth hormone is stimulated

Answer 30

bone and soft tissue growth, increase in cell number and size

Question 30

what is the role of thyroid hormones

Answer 30

regulate metabolism,
growth and development,
metamorphosis