Hormones and Receptors

Front

What is a juxtacrine signaling mechanism?

Back

A sender and target cell and right next to one another, receptor on the target cell binds to a macromolecule on the sender cell and a message is communicated

Front

What is a endocrine signaling mechanism?

Back

A sender cell creates a hormone, which enters the bloodstream. Within the bloodstream, a receptor either binds to the hormone and carries it, or it binds directly with a receptor attached to the target cell

Front

What is paracine signaling?

Back

A sender cells secretes hormones that travel to receptors on target cells, very localized within a tissue

Front

What is synaptic signaling?

Back

A neuron sends an electrical signal down its axon, releasing neurotransmitters that travel across its synapse to receptors on the target cell (very fast)

Front

What major hormones do pancreatic alpha cells and pancreatic beta cells synthesize?

Back

Alpha: polypeptide glucagon

Beta: polypeptide insulin

Front

What major hormones do the adrenal cortex and adrenal medulla synthesize?

Back

Cortex: steroid cortisol

Medulla: catecholamine epinephrine

Front

What major hormone does the thyroid create?

Back

Thyroxine

Front

What are the 3 different relationships that hormones and receptors can have?

Back

Some cells have receptors for more than one hormone, some hormones have receptors present in only one tissue, and some hormones have receptors in more than one tissue

Front

What is the dissociation constant (KD)?

Back

Ligand concentration needed to occupy half of the total number of hormone receptors on a cell/tissue, only fraction of receptors must bind to a ligand in order for a maximum response to be achieved (KD inversely proportional to the affinity that a ligand has for a receptor)

Front

How does a typical intracellular receptor work?

Back

A HYDROPHOBIC hormone often bound to a carrier protein enters a cell and binds to a intracellular receptor, where it enters the nucleus of the cell. Then the hormone outputs mRNA with a new gene transcription that includes the hormone.