Endocrine intro

Question 1

What is the endocrine system involved with?

Answer 1

growth and development
sex differentiation
metabolism
adaptation (digestion, nutrient storage, electrolyte/water metabolism, reproductive functions)

Question 2

autocrine

Answer 2

into ECF and affect same cells that produce them

eg. insulin from pancreatic beta cells affects the same cells

Question 3

paracrine

Answer 3

secreted into ECF and affect nearby cells of a different type

eg. steroids on ovaries

Question 4

endocrine

Answer 4

hormone secreted into circulation that targets distant cells

Question 5

endocrine vs synaptic signalling

Answer 5

synaptic - NTs from one nerve to another nerve/muscle across a synapse
endocrine - hormone travels through bloodstream to target cell

Question 6

example of a single hormone exerting effect on different tissues

Answer 6

Estradiol
acts on ovarian follicle, maturation
uterus to stimulate growth and maintain cyclic changes
mammary gland, ductal growth
hypothalamic-pituitary system (gonadotropins and prolactins)
bone, skeletal integrity
general metabolic processes

Question 7

single function regulated by several hormones

Answer 7

lipolysis (release of fatty acid from adipose tissue)
catecholamines
insulin
glucagon
cytokines
tumor necrosis factor alpha

Question 8

Where are hormone receptors located?

Answer 8

surface of the cell

in the cell

Question 9

How do receptors on the surface of the cell act?

Answer 9

act through second-messenger mechanisms

Question 10

How do receptors located in the cell act?

Answer 10

they modulate the synthesis of enzymes, transport proteins or structural proteins

Question 11

categories of hormones

Answer 11

amines
peptides and proteins
steroids

Question 12

examples of amine hormones

Answer 12

adrenaline
noradrenaline
thyroid hormones T3 and T4

Question 13

examples of peptide and protein hormones

Answer 13

insulin

growth hormone

Question 14

examples of steroid hormones

Answer 14

cortisol
aldosterone
testosterone

Question 15

What gland do AD and NAD come from?

Answer 15

adrenal medulla

Question 16

gland for insulin?

Answer 16

Islets of Langerhans

Question 17

gland for growth hormone?

Answer 17

anterior pituitary

Question 18

gland for steroid hormones (cortisol, aldosterone, testosterone)?

Answer 18

adrenal cortex

Question 19

What hormones circulate unbound in blood?

Answer 19

peptide and protein

Question 20

What hormones circulate attached to transport carriers?

Answer 20

steroid and thyroid hormones

Question 21

How do hormones travel in the bloodstream?

Answer 21

free, unbound molecules

attached to transport carriers

Question 22

What factors affect the response of a target cell to a hormone?

Answer 22

number of receptors present (up and down regulation)

affinity of these receptors for hormones

Question 23

Are steroids hydrophilic or hydrophobic?

Answer 23

hydrophobic

Question 24

Can unbound or bound hormones diffuse into the cell?

Answer 24

unbound

Question 25

Where are steroid hormone receptors located?

Answer 25

in the nucleus or cytoplasm

Question 26

How do steroid hormone receptors work?

Answer 26

1. unbound hormone diffuses through target cell
2. receptor hormone complex binds to DNA and activates/represses one or more genes
3. activated genes create new mRNA (transcription) that moves to cytoplasm
4. translation produces new proteins
5. some hormones bind to membrane receptors that use 2nd messenger systems to create rapid responses

Question 27

What hormones use intracellular interaction?

Answer 27

oestrogens
testosterone
progesterone
adrenal cortical hormones
thyroid hormones

Question 28

What controls hormone levels?

Answer 28

• diurnal fluctuations within sleep-wake cycle
• regulated by feedback mechanisms that monitor glucose and water
• regulated by feedback mechanisms that involve hypothalamic-pituitary-target system

Question 29

what part of the brain is coordinating center for endocrine?

Answer 29

hypothalamus

Question 30

example of positive feedback

Answer 30

hypothalamus sends impulse to posterior pituitary
posterior pituitary releases oxytocin
produces milk
suckling stimulates nerves in breast to send impulse to hypothalamus

Question 31

negative feedback

Answer 31

1. inc glucose levels
beta cells release insulin
body/liver takes up more glucose
glucose declines
2. glucose declines
alpha cells release glucagon
liver breaks down glucagon and releases glucose
glucose rises

Question 32

endocrine disease classification?

Answer 32

hormone excess
hormone deficiency
hormone hypersensitivity
non-functioning tumours

Question 33

Measures for assessing hormone levels

Answer 33

blood tests
urine tests
stimulation and suppression tests
genetic tests
imaging
biopsy