Endocrine System: Hormone Types, Mechanisms, and Regulation

What are the two main control systems of the body?

The nervous system and the endocrine system.

What is the primary function of hormones?

To act as chemical messengers produced by endocrine glands that travel through the bloodstream to target cells.

What type of feedback mechanism do hormones typically operate under?

Negative feedback control.

What is the difference between autocrine and paracrine signaling?

Autocrine signaling affects the same cell type, while paracrine signaling affects nearby cells.

What are tropic hormones?

Hormones that stimulate other glands to release their hormones.

What is the difference between endocrine and exocrine glands?

Endocrine glands are ductless and release hormones directly into the bloodstream, while exocrine glands have ducts and secrete substances outside the body or into the digestive system.

What are the types of intracellular messengers?

Neurotransmitters, hormones, neurohormones, neuromodulators, paracrines, autocrines, and pheromones.

What are the main chemical natures of hormones?

Hormones can be proteins, amino acid derivatives, or steroids.

What is the half-life of a hormone?

The length of time it takes for half a dose of a substance to be eliminated from the circulatory system.

What is down-regulation in hormone receptors?

The process where a cell removes receptors to become less sensitive to a hormone.

What is up-regulation in hormone receptors?

The increase in the number of receptors on a cell, making it more sensitive to a hormone.

How can the half-life of a hormone be prolonged?

By binding to plasma proteins or adding a carbohydrate group.

What are the two types of hormone receptors?

Membrane-bound receptors for protein hormones and intracellular receptors for steroid hormones.

What is the role of G proteins in hormone signaling?

G proteins act as molecular switches that transmit signals from activated receptors to target proteins inside the cell.

What is the difference between acute and chronic hormone secretion patterns?

Acute secretion is episodic and occurs in response to specific stimuli, while chronic secretion is more stable and continuous.

What is humoral stimuli in hormone release?

The release of hormones in response to changes in the composition of the extracellular fluid.

What is neural stimuli in hormone release?

The direct stimulation of hormone release by the nervous system.

What is the latent period in hormone action?

The time it takes for a hormone to bind to its receptor and initiate a response, which can take minutes to days.

What is the role of cyclic AMP (cAMP) in hormone signaling?

cAMP acts as a second messenger that mediates the effects of hormones binding to membrane-bound receptors.

What happens when epinephrine binds to its receptors in the heart?

It increases calcium permeability, leading to an increase in the force and rate of cardiac contractions.

What is the function of protein kinases in hormone signaling?

Protein kinases activate enzymes that facilitate cellular responses to hormones.

What is the significance of hormone transport in the bloodstream?

Hormones can be transported freely or bound to plasma proteins, affecting their availability and half-life.