Signalling Processes Flashcards
What is cell signalling?
Complex system communication that:Governs basic cell activitiesCoordinates cell actionsThis ability is the basis of development, tissue repair, immunity and homeostasis
`List examples of what signalling is important for?
Development and growthMaintaining homeostasisFighting infectionsRepairing injured tissueInitiating and coordinating movementCognition
What diseases can be caused by cell signalling gone wrong?
CancerAutoimmune diseasesDiabetesMSParkinson’sSchizophreniaEpilepsyHuntington’sALS/ Motor neurone disease
How does signalling occur in the body?
Chemically or electrically, using a variety of messengers
What are the types of messengers involved in cell signalling?
IonsAmino acids, peptidesCytokinesNeurotransmittersHormonesNeurohormones
What is a hormone?
A messenger released by a cell/ gland that binds with specialised receptors on a target cell
What is a neurohormone?
Any hormone produced and released by neurons.
What does the signalling cell initially do?
Secretes a substance which acts as a chemical messenger
What is the role of the chemical messenger/ ligand in signalling?
Binds with specialised receptors on the target cell.
What part of the signalling process produces a response in the target cell?
Binding of the messenger to the receptor
What are the short-range signals?
Direct, Intracrine, Autocrine, Juxtacrine
What is a type of medium-range signal?
Paracrine
What is a type of long-range signal?
Endocrine
What are direct signals?
Substance passes freely between adjacent cells through channels
True or false? Direct signals are a type of juxtacrine signalling?
True
Give an example of a direct signal
Gap Junctions
What are intracrine signals?
The substance acts within the cell
Give an example of intracrine signals
Steroid hormones
What are autocrine signals?
Substance acts upon the cell that secreted it
What are examples of autocrine signals?
Growth factor hormonesImmune cells
What are juxtacrine signals?
Substance acts upon adjacent cells in direct contact with it
What are examples of juxtacrine signals?
Notch signallingGap Junctions
What are paracrine signals?
Substance acts upon cells nearby
What are examples of paracrine signals?
Clotting factorsAllergic responseNeurotransmitters
What is the difference between paracrine and direct/ juxtacrine signals?
Paracrine signals are medium-range while the others are short-range
What are endocrine signals?
Substance acts upon cells throughout the body (long-distance)
What is an example of an endocrine signal?
ADH
What is a nexus?
A gap junction (synonym)