Lecture 16: Endocrine System and Hormone Signaling

These flashcards cover essential concepts related to the endocrine system and hormone signaling, helping to prepare for the exam.

What are the two types of hormones based on their structure?

Amino acid-based hormones and steroids.

How are amino acid-based hormones released from endocrine cells?

They are stored in secretory vesicles and released via exocytosis.

What distinguishes steroid hormones from amino acid-based hormones in terms of storage?

Steroid hormones are made when needed and are not stored.

What type of receptor do steroid hormones bind to?

Intracellular receptors in the cytosol or nucleus.

What is the function of the Growth Hormone Releasing Hormone (GHRH)?

Stimulates the release of growth hormone from the anterior pituitary.

What hormone is secreted by the parathyroid glands in response to low blood calcium levels?

Parathyroid hormone (PTH).

What triggers the release of cortisol from the adrenal cortex?

Adrenocorticotropic hormone (ACTH) from the anterior pituitary.

What is the role of antidiuretic hormone (ADH)?

Regulates water balance by preventing urine formation.

What triggers the release of oxytocin?

Distension of the cervix during labor and suckling during breastfeeding.

How does the hypothalamus influence the anterior pituitary?

By secreting tropic hormones that stimulate the anterior pituitary to release its hormones.

What condition results from excess growth hormone after closure of growth plates?

Acromegaly.

What type of feedback mechanism is primarily used to control hormone release in the endocrine system?

Negative feedback.

What is the primary effect of insulin-like growth factors (IGFs)?

Mediates growth and promotes the uptake of nutrients and collagen-building.

How does the endocrine system differ from the nervous system in terms of signaling speed?

The endocrine system is slower and has longer-lasting effects.

What is the role of G-protein coupled receptors in hormonal signaling?

They activate intracellular signaling pathways, such as the cAMP cascade.

What is diabetes insipidus related to in terms of hormone secretion?

A deficiency of antidiuretic hormone (ADH).