social cells 1- cell communication

Question 1

3 types of short distance communication

Answer 1

contact dependent (juxtacrine)

autocrine

paracrine

Question 2

2 types of long distance communication

Answer 2

synaptic

endocrine

Question 3

describe endocrine signalling

Answer 3

• long distance
• ligans are hormones
• very specific, can only influence cells with the right receptors
• very potent, small variations on hormone concentration can have a big effect

Question 4

diseases associated with hormonal deficiency

Answer 4

diabetes

osteoporosis

reproduction and infertility

growth retardation

Question 5

describe paracrine signalling

Answer 5

• short distance
• range of different ligands that can start it including growth factor and gases
• concentration of ligands is usually low and can be controlled in several different ways such as enzymes, ECM, antagonists, inhibitors

Question 6

diseases associated with defects in paracrine signalling include?

Answer 6

• inflammation
• allergies

Question 7

examples of paracrine ligand

Answer 7

histamine

thromboxane

leukotrienes

Question 8

describe autocrine signalling

Answer 8

• cell signalling to itself
• can decrease or promote signalling inisited by itself ( positive or negative feedback)

Question 9

ligands that promote autocrine signalling

Answer 9

• cytokines
• growth factors
  hormones

Question 10

what is juxtacrine/contact-dependent signaling?

Answer 10

signalling directly between 2 cells via direct contact

Question 11

what are the 3 forms of juxtacrine/ contact dependent signalling?

Answer 11

• membrane proteins on each cell interact
• membrane proteins interact with part of an extracellular matrix
• junctions link cells allowing small molecules to pass inbetween

Question 12

describe synaptic signalling

Answer 12

coordinates behaviour of cells far apart from each other

very specific - between neurons, between sensor and neuron or neuron and effector cell

Question 13

examples of local mediators

Answer 13

proteins, gases, sugars,

(paracrine)

Question 14

examples of neurotransmitters

Answer 14

adrenaline, dopamine, serotonin

Question 15

how is exrtracellular signal converted into a intracellular modification?

Answer 15

ligand binding with receptor causes a conformational change to receptor

Question 16

what are the 4 main types of receptors?

Answer 16

• ion channel coupled receptors (ionotropic receptors)
• G-protein- coupled receptors (metabotropic transmission)
• enzyme-coupled receptors- especially receptor tyrosine kinase (RTK)
• nuclear receptors (intracellular)