Hormone Activity Flashcards
What is the role of “Hormone Receptors”?
Only the target cells of a given hormone have the receptor that bind and recognize that hormone.
What is the effect of “Down Regulation”?
This is a result of too many of a certain type of Hormone present.
This may result in the target cell receptors decreasing in number.
“Down Regulation” makes the target cells less sensitive to a hormone.
What happens when a hormone is deficient?
The number of receptors for that hormone may increase to make the target cell more sensitive to a hormone.
This is known as “Up Regulation”.
What is the difference between Local and Circulatory Hormones?
Most endocrine Hormones are “Circulatory Hormones”.
They pass from secretory cells - IF - Circulatory system.
Other Hormones called “Local Hormones”.
They act locally on neighbouring cells or on the same cell that secreted them without entering the blood stream.
What are Local hormones that act on the neighbouring cells?
The local hormones that act on neighbouring cells are called “Paracrines”.
What are Local Hormones that act on the same cell it was secreted from?
These cells would be called “Autocrines”.
What Type of Hormones deactivate quickly?
The Hormones that would deactivate quickly and not linger are “Local Hormones”.
How do circulating Hormones get deactivated?
In time they get deactivated by the Liver & Excreted by the kidneys.
How long do Circulating hormones last in the blood stream?
They can last from minutes to Hours occasionally.
There are Chemical classes to Hormones, what are they?
The types of Chemical Classes of hormones include:
Lipid Soluble and Water Soluble.
What are the types of Lipid Soluble Hormones?
Steroid, Thyroid & Nitric Oxide.
What are the types of Water Soluble Hormones?
Amine Hormones, Peptide Hormones, Protein Hormones, Etcosanoid Hormones.
What is involved in Hormone transport in the blood?
Transport proteins Synthesized in the liver help transport hormones in the blood stream.
There is 3 functions to doing this:
Helps make Lipid soluble hormones temporally water soluble.
Helps the hormones not get filtered by the kidneys as fast.
It helps provide a reserve of hormones in the blood to be used.
What is the mechanism of hormone action definition?
The response of a hormone depends on both the Hormone and the target cell. (Various target cells respond differently to the same hormone).
Within the Mechanism of hormone action, Hormonal Effects include what?
It includes changing the permeability of the Plasma membrane, Stimulating transport of a substance into or out of the Target cells, Altering the rate fo a metabolic reactions, or causing contraction of smooth cardiac mm.
Where are receptors for Lipid-soluble hormones?
They are located inside target cells.
Receptors for Water soluble hormones are found in the plasma membrane of the target cell.
In relation to Hormone Interactions, What does the responceivness of a target cell depend on?
3 things:
Hormones concentration in blood.
Abundance of target cell receptors.
Influences excepted by other hormones.
What does it mean for a hormone to have a “Permissive effect”?
This is a referring to the actions of some hormones on target cells require a simultaneous or recent exposure to a second hormone.
When the effect of 2 hormones acting together s stronger than if they were acting by themselves, What is this called?
This is called having a “Synergist effect”.
What is it called when one hormones opposes the effects of another one?
This would be called “Antagonistic Effects”.
What is an Example of “Antagonistic Effects” of Hormones?
Insulin promotes the synthesis of glycogen by the liver cells.
And Glucagon, witch stimulates the breakdown of glycogen in the liver.
What is involved in the Control of Hormone Secretion?
The release of most hormones occurs in sort burst with little or no secretion between burst.
What is hormone secretion regulated by?
Signals from the nervous system, Chemical changes in the blood, and other hormones.
How is the Hypothalamus related to hormone secretion?
Hypothalamus is the major link between the Nervous system and the endocrine system.
How is the Pituitary gland related to the release of hormones?
It is a pea shaped structure attach to the Hypothalamus by a stalk, The “Infundibulum”.
What are the Portions of the Infundibulum and Pituitary gland?
Anterior & Posterior.
What are the functions of the Anterior Pituitary Gland?
It secretes hormones to regulate a wide range of bodily activities, from growing too reproduction.
What is the other name for the Anterior Pituitary gland?
It is AKA Adenohypophysis.
When does the Anterior Pituitary gland release hormones?
The release of Anterior Pituitary hormones is Stimulated by Releasing hormones from the Hypothalamus.
What is the “Hypophyseal Portal System”?
This is how the Hormones released by the Hypothalamus reach the anterior pituitary.
In this portal system, blood flows from capillaries in the hypothalamus into portal veins that carry out blood to capillaries of the Anterior pituitary.
What are the types pituitary cells?
The types of cells include: Somatotrophs, Thyrotrophs, Gonadotrophs, Lactotrophs, Corticotrophs.
What are the Hormones that the Anterior Pituitary Gland release?
There is 7 kinds: HGH TSH (thyroid stimulating hormone) FSH (follicle stimulating hormone) LH (Luteinizing Hormone) MSH (Melanocyte-stimulating Hormone) Prolactin Adrenocorticotropic Hormone
What does the Posterior Pituitary Gland consist of?
After Oxytocin and Antidireutic are created they are packaged and stored in the posterior pituitary gland until they’re are stimulated to be released.
What is the Other name for the Posterior Pituitary gland?
It is AKA Neurohypophysis.
What is the function of the Posterior Pituitary Gland?
It does not Synthesis hormones, but it does store 2 types of hormones.
What Creates Oxytocin?
The cell bodies of the Paraventricular nucleus.
What creates Antidireutic?
The cell bodies of the Supraoptic nucleus.
What is Oxytocin?
During delivery of the baby the stretching of the cervix stimulates the release of Oxytocin, this enhances contraction of smooth mm cells in the walls of the uterus.
What is Antidireutic?
Decreases Urine production causing more water to be returned to the blood.
This decreases Urine Volume.
What does the Thyroid gland consist of?
It has Microscopic sac called “Thyroid Follicles”. The walls of each follicle are made up of cells called “Follicular Cells”.
Where is the Thyroid gland located?
Found just inferior to the Larynx composed of R and L lobes.
What are Thyroid Follicles?
They make up the wall of the Thyroid Gland and the wall of each follicle contains
What do the Follicular Cells of the Thyroid Gland produce?
They produce (T4) Thyroxine & (T3) Triiodothyronine. They are known as Thyroid Hormones.
What are the Actions of the Thyroid Hormones?
Most body cells have receptors for thyroid hormones, They will exert their effects throughout the body.
They increase basal metabolic rate.
Stimulate synthesis of additional Sodium-Potassium pumps.
Stim protein synthesis & Increase the use of glucose and fatty acids for ATP production.
Enhances Norepinephrine and Epinephrin.
Along with HGH and Insulin, thyroid hormones help grow the body skeletal and nervous system.