lecture 2

Whats the function of the endocrine system?

Its the slow control system

What are the major organs of the endocrine system?

Pancreas, thymus, testis, and ovaries

What are the major glands of the endocrine system?

Pineal gland, pituitary gland, thyroid gland, and adrenal glands

What is the study of hormones, the glands that produce them and the tissues that are affected by them

Endocrinology

What are the functions of the endocrine system?

Glands secrete hormones that regulate:
➢ Homeostasis
➢ Growth
➢ Reproduction
➢ Metabolism

what is the goal of cell to cell signaling?

to elicit a response in the target cell

What is cell to cell signaling characterized by?

1) The chemical messenger is produced by the signaling cell
2) The chemical messenger conveys specific information
3) The chemical messenger has an intended recipient, the target cell

What are the types of cell to cell signaling?

direct contact, extracellular diffusion, and through the blood

In what volume are chemical messengers transmitted in?

low concentrations (10^-10M)

What type of cell to cell signalling requires direct contact between the signaling and receiving cell?

Juxtacrine signaling

What can signals diffuse through?

Gap junctions

What are the two types of extracellular diffusion of chemical messengers?

Paracrine and autocrine

What type of extracellular diffusion sees the chemical messenger affects another cell?

Paracrine

What type of extracellular diffusion sees the chemical messenger affects itself?

autocrine

What is the definition of a hormone?

Chemical messengers released from endocrine cells that travel through the blood to affect distant target cells

What releases neurohormones into the blood?

Neurosecretory Neuron

What are chemicals that are released into the environment that affect members of the same species?

Pheromones

What are chemicals that are released into the environment that affect members of different species?

Allelomones

What are the five types of hormones?

Peptides and proteins, Modified amino acids, Steroids, Thyroid hormones

What is an example of peptide and protein hormones?

Growth hormone

What are the two highlighted types of modified amino acids?

Tyrosine (Dopamine) , and Tryptophan (Melatonin)

What are steroid hormones derived from?

Cholesterol

What is an example of a steroid hormone

Testerone

What are thyroid hormones derived from?

tyrosine, iodinated

What type of hormone needs salts?

thyroid hormone uses iodine which needs salt

What are Eicosanoids?

small lipids derived from arachidonic acid

What is an example of an eicosanoids hormone?

Prostaglandins

Whats needed for chemical messaging?

A proper receptor for each chemical messenger

What determines cell response to chemical messengers?

The type of receptor that the messenger binds to. The same messenger can bind to multiple types of receptors

Where can receptors be?

They can be intercellular, or on the cell membrane

What can can diffuse through the cell membrane and bind to the intracellular receptors

Nonpolar ligands, steroids, and lipids (steroids are lipids)

What can’t diffuse through the cell membrane and bind to the extracellular portion of membrane receptors?

Polar and charged ligands

Can steroids bind to intracellular receptors?

Yes

Where do activated steroids that bind to intracellular receptors go?

They move to enter the nucleus

What can activated receptor steroid complex can affect?

Transcription of DNA and mRNA