Endocrine System: Hormones, Regulation, and Cell Differentiation

What is the primary function of the endocrine system?

To regulate homeostasis and metabolism through hormones.

What are pluripotent stem cells?

Cells that can differentiate into various specialized cell types during development.

What role do transcription factors play in cell differentiation?

They influence gene expression, promoting or inhibiting differentiation.

How do epigenetic modifications affect cell differentiation?

They silence DNA, preventing transcription and maintaining cell specialization.

Why is differentiation important for hormone action?

Because most hormones do not act on all tissues; specific receptors are needed.

What is an example of a hormone that only stimulates specific cells?

Thyroid stimulating hormone (TSH) stimulates only thyroid cells.

What are the two broad categories of hormones?

Water soluble and lipid soluble hormones.

What type of hormones are made from amino acids?

Water soluble hormones, including single amino acids, peptides, and proteins.

What is the primary characteristic of lipid soluble hormones?

They can enter cells and bind to nuclear receptors.

What is the effect of water soluble hormones on enzymes?

They activate or deactivate premade enzymes inside the cell, leading to rapid effects.

How do lipid soluble hormones affect gene expression?

They bind to nuclear receptors, acting as transcription factors to stimulate new enzyme production.

What are the three ways hormone release is controlled?

Neuronal control, humoral control, and hormonal control.

What is the function of antidiuretic hormone (ADH)?

To increase water reabsorption in the kidneys.

What triggers the release of oxytocin?

Pressure on the uterus/cervix and nipple stimulation.

What is the overall function of growth hormone (GH)?

To promote growth and protein synthesis by activating lipid use.

What are the effects of growth hormone on the liver?

Stimulates gluconeogenesis and increases blood sugar levels.

What condition results from too little GH secretion in children?

Pituitary dwarfism.

What condition results from excess GH secretion in adults?

Acromegaly.

What is the primary function of prolactin?

To stimulate milk production in mammary glands.

What stimulates the secretion of prolactin?

A decrease in dopamine secretion by the hypothalamus and nipple stimulation.

What is the role of the posterior pituitary?

To release hormones produced in the hypothalamus, such as ADH and oxytocin.

What is the main target tissue for ADH?

The distal convoluted tubule and collecting duct of the nephron.

What is diabetes insipidus?

A condition characterized by excessive urination and thirst due to ADH deficiency.

What is the effect of the sympathetic nervous system on blood vessels in skeletal muscle?

Stimulates vasodilation.

Which endocrine gland is located in the hypophyseal fossa of the sella turcica?

Pituitary gland.

Which pancreatic cell type secretes insulin?

Beta cells.

Which division of the autonomic nervous system is active during a meal?

Parasympathetic division.