cell signaling Flashcards
what are the three ways cells communicate?
- secreting chemical signals
- displaying molecules on their plasma membranes
- gap junctions
why do cells communicate with each other?
- regulate their development and organization to tissues
- control their growth and division
- coordinate other activities
how do cells send signals through chemical mediators that act locally?
- hormones travelling through the bloodstream via endocrine system
- neurotransmitters at synapses between two neurons
what communications do local chemical mediators act through?
- paracrine
- autocrine
- contact-dependent
what are the modes of secretion?
- merocrine
- holocrine
- apocrine
what is the type of secretion if the cell secretes signal by exocytosis without any damage to the cell itself?
merocrine
what are examples of merocrine secretion?
sweat glands
mammary glands
If the whole cell is expelled during the process of secretion and the ruptured cell becomes part of the secretory product, what kind of excretion is this?
holocrine
what is an example of holocrine secretion?
sebaceous glands
what is the secretion where only the apical part of the cell is shed in the secretory product?
apocrine
what is an example of apocrine secretion?
sweat glands in the armpit
what do all three cell signaling types (autocrine, paracrine, and endocrine) have in common?
involve secretion of some kind of chemical signal from a cell that binds to a receptor and causes downstream effect
what kind of cell signaling occurs when a cell releases a signal that acts on itself, binding to receptors on the plasma membrane and causing an effect within the same cell?
autocrine
what is an example of autocrine signaling?
release of cytokine IL-2 from T cells
how do cytokines protect our bodies through our immune system?
by promoting proliferation and differentiation of the same T cells
what cell signaling occurs when the cells releases a signal that acts on nearby cell and causes a downstream effect on target cells?
paracrine
where can paracrine signaling be seen?
neuromuscular junction
what cell signaling occurs when a cell releases a signal that must travel through the bloodstream to reach its target cells, which is often far away?
endocrine
what is an example of endocrine signaling?
hypothalamus releases GnRH that acts on the anterior pituitary to release LH that acts on Leydig cells in the testicle to produce testosterone
what type of signaling involves the chemical messages sent between two neurons at a synapse?
neurotransmitter
In order to deliver a message from one cell to another, the signal sent must be received by a ______
receptor
what are the two broad groups of cell receptors?
intracellular receptors
cell-surface receptors
where are intracellular receptors found?
within the cell, usually in the nucleus
what kind of substrates do intracellular receptors bind to?
substrates that can cross the plasma membrane , like steroid hormones