All High School Biology Resources
Example Question #47 : Organs And Organ Systems
Which hormone type always attaches to a membrane-bound receptor in order to affect a target cell?
All hormone types attach to membrane-bound receptors
Steroid hormones and tyrosine derivatives are largely nonpolar, and can enter the nucleus of target cells. Peptide hormones are unable to cross the cell membrane, and must attach to membrane-bound receptors in order to affect target cells. Remember that the membrane is only permeable to small, nonpolar molecules. Peptide hormones are proteins, meaning they are usually large and polar. In order to affect the cell, these hormones cannot cross the membrane, and must instead bind to a receptor at the surface.
Steroid hormones include testosterone, estrogen, and aldosterone. Tyrosine derivatives include the thyroid hormones (T3 and T4) and epinephrine. Most other hormones are peptide hormones.
Example Question #48 : Organs And Organ Systems
What type of hormone is insulin?
Insulin is an example of an endocrine hormone because it is secreted into the blood and transported to distant areas of the body. Insulin is released from the pancreas, but acts on numerous regions of the body, including the liver and muscle cells.
Autocrine and paracrine signaling involve signaling close to the cell that secreted the hormone. In paracrine signaling, molecules are secreted by one cell and bind to receptors on an adjacent cell to elicit a response. In autocrine signaling, the secreted compounds bind to receptors on the surface of the same cell from which they were released, eliciting a response from the same cell. Exocrine secretions are released into ducts designed to connect outside of the body, such as the digestive tract or sweat glands. This is in contrast to endocrine secretions, which enter the blood or interstitium.
Example Question #1 : Understanding Types Of Hormones
Which of the following hormones is responsible for setting the basal metabolic rate?
The thyroid gland is responsible for secreting thyroid hormones (T3 and T4), which are responsible for setting the basal metabolic rate (BMR). The concentrations of these hormones are what tell the cells which metabolic pathways to undergo. Since body heat is a byproduct of metabolism, thyroid hormone also determines body temperature.
Example Question #2 : Understanding Types Of Hormones
Which of the following hormones is secreted by the adrenal medulla?
The adrenal medulla secretes epinephrine (adrenaline), which is involved in the body's "fight of flight" response. Epinephrine is released in response to direct neural stimulation during periods of short-term stress and acts to stimulate the sympathetic nervous system.
Example Question #3 : Understanding Types Of Hormones
Which organ is known as the "master" endocrine gland?
The pituitary gland is known as the "master" endocrine gland because it secretes several hormones that control other endocrine glands. These are known as tropic hormones. Adrenocorticotropic hormone, thyroid-stimulating hormone, and follicle-stimulating hormone are some examples of pituitary tropic hormones.
Example Question #4 : Understanding Types Of Hormones
Which structural class of hormone is derived from cholesterol and can be identified by its four ring molecular structure?
Steroid hormones are the only ones derived from cholesterol and are always characterized by a four ring molecular structure. Some examples include sex hormones such as androgens and estrogens as well as some adrenal hormones like cortisol (a glucocorticoid) and aldosterone (a mineralocorticoid).
Example Question #765 : High School Biology
Aldosterone is a hormone that is activated by the renin-angiotension pathway. It plays an important role in regulating the body sodium levels and plasma volume levels. What is another factor regulating aldosterone in the body?
Increased potassium levels will stimulate aldosterone to increase potassium secretion. The main regulators of aldosterone are potassium and the renin-angiotensin pathway.