Learning goals
What are the different types of hormones?
Hormones are used to communicate by the endocrine system. They are chemical signals that
are secreted into the blood and distributed in the body.
Hormones are chemical messengers secreted by cells into extracellular fluids. They are
produced in the endocrine glands, such as pituitary, adrenal, pineal, thyroid and parathyroid
gland.
A final scheme divides hormones in three main chemical classes:
Peptide hormones: Composed of linked amino acids
Steroid hormones: All derived from cholesterol
Amino acid-derived hormones: Modifications of single amino acids
A hormone typically produces one or more of the following changes:
• Alter plasma membrane permeability or membrane potential, or both, by opening
and closing ion channels.
• Stimulates the synthesis of enzymes and other proteins within the cell.
• Activates or deactivates enzymes
• Induces secretory activity
• Stimulates mitosis
In general hormones act on receptors in 2 ways:
1. Water-soluble hormones (all amino-acid based hormones except for thyroid
hormone) act on receptor in the plasma membrane. These receptors are usually
coupled via regulatory molecules called G-proteins to one or more intracellular
second messengers which mediate the target cell’s response
Cyclic AMP signalling mechanism
PIP-calcium signalling mechanism
2. Lipid soluble hormones (steroids and thyroid hormone) act on receptors inside the
cell (either the nucleus or in the cytoplasm), which directly activate genes.
, Different signalling: Endocrine, autocrine, neuroendocrine, paracrine
What is the secretion and production place of hormones?
The primary production place of hormones are the posterior/anterior pituitary,
hypothalamus, thyroid gland, adrenal gland, pancreas, adipose tissue and the GI tract
Posterior pituitary/hypothalamus: Oxytocin and ADH
Anterior pituitary:
o Growth hormone(GH): growth promoting effects mediated indirectly by IGFs
o Thyroid stimulating hormone (TSH): stimulates thyroid gland to release
thyroid hormone
o Adrenocorticotropic hormone (ACTH): promotes release of glucocorticoids
and androgens
o Follicle stimulating hormone (FSH): in females stimulates ovarian follicle
maturation and oestrogen production; in males stimulates sperm production
o Luteinizing hormone (LH): in females triggers ovulation and stimulates
ovarian production of oestrogen and progesterone, in males promotes
testosterone production
o Prolactin (PRL): promotes lactation
Thyroid gland: Thyroxine and triiodothyronine
o Parathyroid hormone: Increases Ca absorption
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller emmavandergaag. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $3.74. You're not tied to anything after your purchase.