Endocrine System Chp. 17 - A&P ii

True or False: An agonist is a drug that will bind to the hormone receptor and inhibit it.

False

Tropic hormones provide this type of stimuli.

Hormonal

What type of stimuli involves blood levels of certain chemicals?

Humoral

Which of the following types of actions of hormones is one where the hormone acts on the cell that secretes it?

Autocrine

Which of the following patterns of hormone secretion is where the hormone is stimulated to increase and decrease in the blood at a relative consistent time

Episodic hormone secretion

This type of chemical messenger acts on neighboring cells.

Paracrine

This type of hormone interactions involves on hormone needing another hormone as a helper.

Permissive

This type of hormone has a receptor in the nucleus.

Steriod

This type of chemical messenger is delivered to a target cell by the blood.

Endocrine

This type of hormone has a short half life

Protein

What type of hormone protein or lipid needs a protein carrier in the blood and binds to an internal cell receptor?

Steroids (cortisol, testosterone, estrogen, aldosterone) & Thyroid hormones due to being lipid soluble & unable to dissolve in blood plasma

• binds to the nucleus with receptors

Hormones release negative feedback or positive feedback, which is more common?

Negative feedback

example - thyroid hormones inhibit the secretion of their
releasing hormones from the hypothalamus and their tropic
hormone from the anterior pituitary.

If two hormones are needed together to cause the effect, this is called

Synergistic Interaction

What do all hormones need in order to work

Receptors

How are lipid vs protein based delivered while in the bloodstream

Proteins/ peptides
▪ are water-soluble and therefore transported easily as free hormones in the
blood stream
▪ Receptors are present in the cell membrane of target cells

Lipids/ amino acid derivatives/ fatty acid derivatives
▪ are not transported as easily and need a binding protein to be transported in
the bloodstream
▪ enter into cells and bind to receptors in the cytoplasm or nucleus

Which of the following patterns of hormone secretion is where the concentration of the hormone is relatively stable and circulates in the blood for up to weeks?

Chronic hormone secretion

example - thyroid hormones

Which of the following patterns of hormone secretion is where the concentration of the hormone rapidly increases in response to a stimuli for a short amount of time/can be irregular?

Acute hormone secretion

example - insulin after meals, epinephrine

Down-Regulation vs Up-Regulation

Down-Regulation

• Less sensitivity (receptors) so the hormone has less of an effect

Examples of Down-Regulation:

• When there is chronic exposure of insulin to target cells there is a down-regulation of insulin receptors in those cells. This occurs in type 2 diabetes.
  • Drug abuse may result in the down-regulation of dopamine receptors in target cells, which in turn would require more drug to achieve the same effect

Up-Regulation

• More sensitivity so the hormone effect is enhanced

Examples of up-regulation:
• Oxytocin receptors - During pregnancy, the uterus needs to become more responsive to oxytocin to initiate and maintain labor. Upregulation of oxytocin receptors on the uterine smooth muscle cells.
• When ovulation needs to occur to release the oocyte from the ovary, there is an upregulation of receptors for luteinizing hormone in ovarian cells. A surge of LH ensures the oocyte is released

A drug with similar structure of a specific hormone that can bind to a hormone receptor
and activate it

Agonist

example: drugs in asthma inhalers mimic epinephrine to cause smooth muscles in the lung to relax

What type of feedback occurs when the hormone’s secretion is stimulated by the hormone itself (“self-perpeturating”)

Positive Feedback (giving birth, blood clotting, lactation)