Chapter 26 Quiz

Hormones are chemicals produced by the endocrine system that regulate a variety of body functions, such as metabolism. This means that hormones help to control the rate at which the body converts food into energy and how it uses that energy. By regulating metabolism, hormones play a crucial role in maintaining the body's overall functioning and balance. They ensure that essential processes like digestion, growth, and reproduction occur at the appropriate levels. Without hormone regulation, these body functions could become imbalanced and lead to various health issues. Therefore, the statement "regulate a variety of body functions, such as metabolism" accurately describes the role of hormones.

The nervous system has a faster response compared to the endocrine system because it uses electrical impulses to transmit signals. However, the signal does not last as long because it is quickly transmitted through neurons and synapses. This allows for rapid communication and coordination of bodily functions, but the effects of the signal may not be sustained over a long period of time.

Steroid hormones are lipids made from cholesterol. Cholesterol serves as the precursor molecule for the synthesis of steroid hormones in the body. These hormones are derived from cholesterol through a series of enzymatic reactions. Cholesterol is a type of lipid found in cell membranes and is also obtained from dietary sources. It is an essential molecule for the production of various steroid hormones such as cortisol, estrogen, and testosterone. Therefore, cholesterol is the correct answer as it is the main building block for the synthesis of steroid hormones.

The adrenal glands secrete hormones that enable the body to respond to stress. These hormones, such as cortisol and adrenaline, help the body react to stressful situations by increasing heart rate, blood pressure, and energy levels. The adrenal glands are located on top of the kidneys and play a crucial role in the body's stress response system.

The adrenal glands are located above the kidneys. They are responsible for producing hormones such as adrenaline and cortisol, which play a crucial role in regulating the body's response to stress, metabolism, and blood pressure. The ovaries are located in the lower abdomen, the pineal glands are located in the brain, and the pancreas is located in the abdominal cavity, none of which are nearest to the kidneys. Therefore, the correct answer is adrenal glands.

Steroid hormones and hormones derived from amino acids are the two main classes of molecules that function as hormones. Steroid hormones are derived from cholesterol and include hormones such as cortisol and estrogen. On the other hand, hormones derived from amino acids include hormones such as epinephrine and insulin. These hormones play crucial roles in regulating various physiological processes in the body, such as metabolism, growth, and stress response. Therefore, the correct answer is amino acids.

Some hormones must bind to a membrane receptor on a target cell's surface in order to activate it because they cannot cross cell membranes. Cell membranes are made up of a phospholipid bilayer that acts as a barrier, preventing the passage of certain molecules, including hormones. Therefore, for these hormones to exert their effects on target cells, they need to bind to specific receptors on the cell surface, which triggers a signaling cascade inside the cell. This allows the hormone to indirectly influence cellular processes without actually crossing the cell membrane.

The correct answer is an intracellular receptor protein that binds the hormone. This is because steroid hormones are lipid-soluble and can easily cross the cell membrane. Once inside the cell, the hormone binds to an intracellular receptor protein located in the cytoplasm or nucleus. This hormone-receptor complex then acts as a transcription factor, binding to specific DNA sequences and regulating gene expression. This ultimately leads to changes in the target cell's behavior or function.

Excessive secretion of parathyroid hormone can lead to the loss of calcium from the bone. Parathyroid hormone plays a crucial role in regulating calcium levels in the body. When there is an excess of parathyroid hormone, it stimulates the breakdown of bone tissue to release calcium into the bloodstream. This can result in a decrease in bone density and an increased risk of osteoporosis.

Insulin and glucagon are considered antagonistic hormones because they have opposite effects on blood sugar levels. Insulin is released by the pancreas in response to high blood sugar levels and helps to lower blood sugar by promoting the uptake and storage of glucose in cells. On the other hand, glucagon is released by the pancreas when blood sugar levels are low and helps to raise blood sugar by stimulating the breakdown of glycogen and the release of glucose into the bloodstream. Therefore, they have opposing actions on blood sugar regulation, making them antagonistic hormones.