Endocrine, Paracrine, Autocrine, Intracrine Regulatory Factors

Question 1

What do cell expressions array?

Answer 1

Sensing proteins or receptors to recognised specific stimuli

Question 2

What are the 3 main routes for receptor based signals?

Answer 2

Nervous system, endocrine system and locally produced factors

Question 3

What is autocrine signalling?

Answer 3

Cell targets itself

Question 4

What is gap junction signals?

Answer 4

A cell targets a cell connected by gap junctions

Question 5

What is paracrine signalling?

Answer 5

A cell targets a nearby cell

Question 6

What is endocrine signalling?

Answer 6

A cell targets a distant cell through the bloodstream

Question 7

What does the endocrine system do?

Answer 7

Secrete endocrine cells a long way from target cells, hormones released into bloodstream to travel to cell

Question 8

What types of cells can respond to hormones?

Answer 8

cells with specific receptors

Question 9

What types of receptors are there?

Answer 9

Intracellular and extracellular

Question 10

what is the rate of hormones?

Answer 10

Slow acting

Question 11

What do hormones regulate?

Answer 11

Homeostatis and gradual changes

Question 12

What are hormones produced by?

Answer 12

Endocrine cells, some nerves and non-endocrine cells e.g insulin

Question 13

What is an example of simple endocrine pathway?

Answer 13

Low blood glucose to secrete glucagon goes to liver for glycogen breakdown

Question 14

What is an example of simple neurohormone pathway?

Answer 14

Suckling, posterior pituitary secretes oxytocin smooth muslce in breast releases milk

Question 15

What is a simple neuroendocrine pathway example?

Answer 15

Sensory nueron signals, hypothalamus secretes prolactin hormon ant pituitary secretes prolact mammary gland then milk production

Question 16

What does 1/2 main type of hormone do?

Answer 16

Enter cell and bind to intracellular receptors e.g steroid hormones like oestrogens

Question 17

What does 2/2 main type of hormone do?

Answer 17

Bind to receptors on PM e.g insulin and cant enter cell, act via secondary messenger

Question 18

What type of signals to cells detect?

Answer 18

Chemical and physical

Question 19

What do physical signals do?

Answer 19

Converted to chemical at level of receptor

Question 20

What type of signalling does physical follow?

Answer 20

Rhodopsin signallinh

Question 21

When are secondary messengers produced?

Answer 21

When hormone binds a cell surface receptor

Question 22

What are the 2 main types of secondary messengers?

Answer 22

cAMP and Ca

Question 23

How is cAMP formed?

Answer 23

Increase activity of adenyl cyclase which converts ATP to cAMP

Question 24

What does cAMP activate?

Answer 24

Series of enzyme reactions, through cascade effect and amplification

Question 25

What bacteria is cholera caused by?

Answer 25

Vibrio chloerae

Question 26

What clinical feature does cholera cause?

Answer 26

Severe diarrhoea

Question 27

What is produced by the cholera toxin and where does it enter?

Answer 27

Cholera toxin enters gut cells, binds covalently to g protein that controls adenyl cyclase

Question 28

How does increased adenyl cyclase cause death with cholera?

Answer 28

Increased AC activity, increase cAMP , increase active transport of ions by intestinal cells, increase sodium and water in gut

Question 29

When does paracrine signalling occur?

Answer 29

When a cell releases signalling molecule into its immediate enviroment and molecule bound by effects

Question 30

What is an e.g of paracrine signalling?

Answer 30

Somatostatin acts on nieghbour cells and inhibits insulin secretion

Question 31

When does autocrine signalling occur?

Answer 31

cell releases a regulatory molecule which is bound by its own receptors

Question 32

What does autocrine signalling act on?

Answer 32

cell which released it, positive feedback IGF

Question 33

What is intracrine signalling?

Answer 33

Intracellular signalling - between different parts of same cell e.g nucleus and organelles

Question 34

What happens in intracrine signalling?

Answer 34

Molecules dont leave cell

Question 35

What are steroid hormones?

Answer 35

non-polar lipid soluble structure that can cross PM to a steroid receptor

Question 36

What does steroid hormones affect?

Answer 36

Regulation of gene expression

Question 37

What blocks the receptor from binding to dna till hormones present?

Answer 37

Inhibitor

Question 38

What are the 3 functional domains of a steroid receptor?

Answer 38

Hormone binding domain, DNA binding domain, domain that interacts with coactivators to affect gene expression

Question 39

What are 3 types of membrane receptors?

Answer 39

Channel linked, enzymatic and g protein receptors

Question 40

What are channel linked receptors?

Answer 40

Ion channel that opens in response to ligand

Question 41

What are enzymatic receptors?

Answer 41

Receptor is enzyme activated by ligand

Question 42

What is g protein couples receptors?

Answer 42

G protein bound to gtp assist in transmitting signal

Question 43

What are receptor tyrosine kinases?

Answer 43

Membrane receptors, activated by dimerization and autophosphorylation when bound by ligand, activates receptor adds a phosphate to tyrosine on response protein e.g insulin

Question 44

What happens in the kinase cascade?

Answer 44

Series of protein kinases that phosphorylate in sucession, amplifies signal of few signal molecules illiciting large cell response

Question 45

What at MAP kinases activated by?

Answer 45

Kinase cascades

Question 46

What are Gprotein receptors?

Answer 46

bind to g proteins, switch on by receptor activates effector proteins enzyme

Question 47

What does effector protein activate?

Answer 47

Second messenger which generates cellular response to original signal

Question 48

What happens with the nervous system?

Answer 48

Stimulation at dendrites alters electrical properties in PM and releases stores neurotransmitters sucy as ACH which bind to receptor on cell surface