Hormones control out body Flashcards
(41 cards)
What is homeostasis?
Maintaining a stable and continuous internal environment
What do exocrine glands do?
Secrete into ducts that carry the secretions to the body surface or to one of the body’s cavities
Examples of exocrine glands? (3)
Sweat glands, salivary glands, mucous glands
What are endocrine glands?
Secrete hormones into extracellular fluid that surrounds the cell that makes up a gland
What are hormones?
Chemicals that are secreted by endocrine glands. They change the function of cells by changing the types, activities, or quantities of proteins produced
What are steroid hormones?
Steroid hormones are lipid soluble, meaning they can diffuse a cell membrane.
How do steroid hormones work?
They are released into the blood stream, when they reach the target cell the hormone detaches from the transport protein, this enables them to travel through the cell membrane, inside the cell, the hormone combines with a receptor protein in the cytoplasm or nucleus
What are 4 examples of steroid hormones?
Oestrogen, progesterone, cortisol, and aldosterone
What are protein or amine hormones?
Water soluble, this means that the hormone cant diffuse through the cell membrane
How do amine hormones work?
Attaches to a receptor protein in the membrane of the target cell. This combination causing a secondary messenger substance to diffuse through the cell and active particular enzymes.
What are hormone receptors?
Specific, will only bind to one specific molecule. Limited numbers of receptors in each cell membrane.
What is enzyme amplification
One hormone doesn’t cause the manufacture of only one enzyme.
How does enzyme amplification work?
The one hormone triggers a cascading effect, in which the number of reacting molecules involved are increased my thousands of times for each step along the metabolic pathway. One hormone molecule could trigger the production of a billion enzyme molecules.
What is hormone clearance?
Once the desired/ required effect is achieved, the hormone must be turned off.
How does hormone clearance work?
By breaking down the hormone molecule. Although, some are broken down in target cell, and some are broken down in the liver or the kidneys. The hormones are usually excreted in the urine or bile.
What is control of hormone secretion?
An over or underproduction disrupts homeostasis and the function. So the secretion of hormones is regulated by feedback loops
What does the hypothalamus regulate?
Temperature, water balance, and heart rate, as well as the increase and decrease of the hormonal secretion.
What is the hypothalamus?
Part of the nervous and endocrine gland, secretes inhibiting factors, and releasing factors
What are inhibiting factors?
Factors that slow down the secretion of a hormone
How do these factors travel?
They travel through blood vessels to the anterior pituitary gland affecting the secretion of the anterior pituitary glands. Other hormones travel via nerve fibers to the posterior pituitary gland where they will be released.
What are releasing factors?
Factors that stimulate the release of a hormone
What are the two lobes of the pituitary gland?
Anterior lobe (L) and the pituitary lobe (R)
What is the secretions of anterior pituitary gland controlled by?
The release of these hormones are controlled by the releasing of the inhibiting factors.
In regards to the posterior pituitary gland where are the hormones produced?
The hormones are produced in special cells, which are located in the hypothalamus, they have long extensions that reach the gland through the infundibulum. the hormones travel down the extension and are stored in the blood stream.
