What is the Endocrine System?
The Endocrine system facilitates the regulation and communication of the body through chemicals called hormones.
Endocrine glands secrete hormones, which travel through the body fluids such as the blood and act on specific target cells in various parts of the body to change their function
How does an Endocrine Gland deliver its hormones to its target cell?
Endocrine glands have no ducts, so they release hormones directly into the bloodstream where they are delivered to their target destination
What are the three main types of hormones?
What is a steroid hormone?
What is a Polypeptide hormone?
How do you calculate the mass of an amino acid residue?
110 D is the average weight of a single amino acid in all the naturally occurring amino acid residues based on their frequency.
Remember that H20 is lost in the formation of a peptide bond, this is taken into account in the averaging.
Take 110 D * the number of amino acids in the residue to get the approximate weight of the polypeptide.
Describe the hormone’s journey to the cell
The hormone is secreted from the endocrine gland into the blood stream.
The hormone travels through the blood to its target site
The hormone either binds to a receptor on the cell membrane if it’s H20 soluble, or it passes through the cell membrane and binds to a receptor within the cell either in the cytoplasm or the nucleus.
The hormone likely enters the nucleus regardless of solubility
In the nucleus, activation of mRNA synthesis occurs.
mRNA then goes into the cytoplasm to make proteins.
The whole receptor process is often called a biological cascade. This refers to a series of chemical reactions that occur from the binding of a hormone to a receptor.
Where do H20 soluble hormones bind on their target cell? What types of hormones are H20 soluble?
They bind to a receptor on the cell membrane and then are often brought into the nucleus.
Amine Hormones and some polypeptide hormones are H20 soluble
Where do lipid soluble hormones bind on their target cell? What types of hormones are lipid soluble?
Lipid soluble hormones pass through the cell membrane and bind to a receptor within the cytoplasm or within the nucleus. Most end up in the nucleus regardless of where they bind.
All Steroid hormones are lipid soluble, and some poplypeptide hormones (hydrophobic)
What is an Amine Hormone?
Describe the hypothalamus and what non-tropic hormones it makes?
What is Oxytocin?
Oxytocin is a hormone created in the hypothalamus and stored in the posterior pituitary gland.
Oxytocin stimulates milk secretion and stimulates contractions in the uterus. It also stimulates feelings of emotional connection.
What is ADH?
ADH (vasopressin) is a hormone created in the hypothalamus and stored in the posterior pituitary
It is an antidiuretic hormone. It is involved with H20 retention in the kidneys. This hormone helps maintain blood volume by retaining water if there is blood loss.
Describe the positive feedback loop of oxytocin
The more a baby sucks milk from the mammary glands, the more oxytocin is released to stimulate milk secretion.
What are tropic hormones?
Tropic hormones are hormones that stimulate other endocrine glands to release their hormones.
What are the hormones released from the Anterior Pituitary Gland?
Tropic Hormones
Non-Tropic Hormones
What is the function of Growth Hormone?
What is the function of FSH?
Follicle Stimulating Hormone
What is the function of LH?
Luteinizing hormone
What is the corpus luteum
What is the function of TSH?
Thyroid Stimulating Hormone
What is the function of ACTH?
Adrenocorticotropic Hormone
What is the adrenal cortex?
What is prolactin?