(PSY 450) Chapter 2: The Endocrine System


Terms in this set (...)

Define: Endocrine
Affect target cells via bloodstream
Define: Exocrine
Products secreted into ducts that carry them to environment external to the gland. (e.g. salivary glands)
Define: Ectocrine
Affect other organisms
Define: Intracrine
Intercellular chemical mediation
Define: Autocrine
Feedback regulation of source cells
Define: Paracrine
Affect neighboring cell
(True or False): The secretion of hormones is regulated by the nervous system through the feed back effect
(True or False): Hormones usually cause long term effects like change in behavior, growth, etc
(True or False): The hormones function is to stimulate or inhibit the target organs.
What are the two main classes of hormones?
Protein & steroid
What are the main functions of the following steroid hormones? (1) Progesterone (2) Testosterone
(1) Uterine and mammary development, pregnancy
(2) Spermatogenesis
How do protein and steroid hormones differ in their interaction with their receptors and subsequent effects/mechanisms of action in the cell?
Protein hormones: Transmembrane receptors
-Protein hormones are hydrophilic, meaning they can travel through the bloodstream freely but cannot enter a cell (because of the hydrophobic hydrocarbon chains that are a component of the phospholipid bilayer).

Steroid hormones: Intracellular receptors
-Affects gene expression at transcription and translation stages
-Steroid hormones are hydrophobic, meaning they can diffuse passively across its membrane.
Give two examples of how hormone levels may be regulated in the body. Why is regulation so important?
When glucagon levels rise, insulin is secreted by the pancreas, lowing blood glucose levels. When glucose levels fall, glucagon is secreted by the pancreas, which increases blood glucose levels.

Regulation is important in order to maintain homeostasis.