Endocrine

What are the signaling mechanisms of the endocrine and nervous systems?

Endocrine system uses chemical signaling; nervous system uses chemical and electrical signaling.

What is the primary chemical signal of the endocrine system?

Hormones.

How does the response time of the endocrine system compare to the nervous system?

Endocrine responses can be fast or slow, while nervous responses are always fast (1-10 ms).

What type of responses does the endocrine system produce?

Widespread responses.

What is the primary function of the endocrine glands?

To secrete hormones directly into surrounding fluid.

How is the endocrine system involved in maintaining homeostasis?

It works together with the autonomic nervous system.

Which embryonic layer develops glands producing steroid hormones?

Mesoderm.

Name some glands that produce amine, peptide, and protein hormones.

Pituitary and pineal glands, adrenal medulla (ectoderm), and thyroid & parathyroid glands, pancreas, thymus (endoderm).

What structure in the hypothalamus regulates hormone release?

The hypothalamic hormones.

Which hormones are considered tropic hormones from the anterior pituitary?

FSH, LH, ACTH, TSH.

What is the role of Gonadotropins (FSH and LH)?

Regulate the function of ovaries and testes.

What does Prolactin primarily stimulate in females?

Breast development and milk production.

How is Growth hormone (GH) primarily controlled?

By the release of GHRH and GHIH (somatostatin).

What hormone triggers the adrenal cortex to release corticosteroids?

Adrenocorticotropic hormone (ACTH).

What is the major mineralocorticoid secreted by the zona glomerulosa?

Aldosterone.

What do glucocorticoids like cortisol primarily regulate?

Glucose metabolism.

What type of hormones are produced in the adrenal medulla?

Adrenaline and noradrenaline.

What is the primary effect of thyroid hormones such as T3 and T4?

Influence basal metabolic rate.

What is calcitonin's function in the body?

Reduce blood calcium levels.

What activates parathyroid hormone (PTH) release?

Low blood calcium levels.

What does oxytocin do during childbirth?

Stimulates uterine contractions and dilation of the cervix.

What do pancreatic islets secrete?

Glucagon, insulin, somatostatin, and pancreatic polypeptide.

How does insulin regulate blood glucose levels?

Facilitates glucose uptake from the blood and stimulates glycogenesis.

What is the function of leptin produced by adipose tissue?

Produces a feeling of satiety after a meal.

How does the adrenal medulla respond to stress?

Secretes adrenaline and noradrenaline as part of the fight-or-flight response.

What is the difference between acute and chronic stress responses?

Acute stress leads to immediate hormone release for fight-or-flight, while chronic stress results in prolonged hormonal elevation.

What are the major hormones produced by the adrenal cortex?

Mineralocorticoids, glucocorticoids, and androgens.

What triggers insulin release?

High blood glucose levels.

Which hormone inhibits the release of glucagon and insulin?

Somatostatin.

What is the function of the hypothalamus in the endocrine system?

Acts as the command center, controlling hormone release.

What role does calcitriol play in the kidneys?

Regulates blood calcium levels.

What is the role of erythropoietin (EPO) produced by the kidneys?

Stimulates production of red blood cells.

What regulates the production of melatonin in the pineal gland?

Light levels; inhibited by daylight, increased in darkness.

What compounds are thyroid hormones synthesized from?

Iodine and thyroglobulin.

What is the structure of the pituitary gland?

It is a 2-lobed organ suspended from the hypothalamus.

What hormones are secreted by the posterior pituitary?

Oxytocin and ADH (antidiuretic hormone).

What is the second messenger commonly used in the hormone signaling cascade?

cAMP (cyclic adenosine monophosphate).

What are the effects of adrenaline during the fight-or-flight response?

Increases blood glucose, heart rate, and blood pressure; dilates airways.

How does aldosterone affect sodium and potassium levels?

Increases Na+ retention and affects K+ levels, important for fluid balance.

What is the pathway of hormone release from the hypothalamus to the anterior pituitary?

Hypophyseal portal system.

Which types of hormones cannot pass through cell membranes?

Water-soluble hormones.

What feedback mechanism regulates blood calcium levels?

Negative feedback loop involving PTH and calcitonin.

What does the term 'hydrophilic hormones' refer to?

Hormones unable to diffuse through the lipid bilayer of cell membranes.

What stimulates the release of glucagon?

Low blood glucose levels.

What is the role of follicle-stimulating hormone (FSH)?

Stimulates gamete production.

What does the zona reticularis of the adrenal cortex produce?

Small amounts of androgens.

What influences the release of antidiuretic hormone (ADH)?

Increases in plasma osmolarity.

What role does the liver play in hormone regulation?

Releases hormones and non-hormonal products into blood.

What is the primary function of the messages sent from the autonomic nervous system?

To control involuntary responses.

What is the primary mechanism by which peptide hormones exert their effects?

They act via receptor-mediated signaling cascades.

What does the term 'primordial hormones' refer to?

Hormones that come from the primitive digestive tract.

What is the effect of insulin on lipogenesis?

Promotes triglyceride synthesis.

How do water-soluble hormones interact with their target cells?

They bind to cell membrane receptors, initiating a signaling cascade.