Internal Communication: Nervous and Endocrine Systems

Flashcards covering the comparison between the nervous and endocrine systems, hormone types, and gland characteristics.

What is the definition of a hormone according to the notes?

A hormone is a molecule synthesized by the cells of an endocrine structure that, when released, travels via the bloodstream and binds only to specific receptors on target cells.

What are two key physical characteristics of endocrine glands?

They are very vascular (containing many capillaries/blood vessels for transport) and consist of glandular epithelial tissue which is secretory.

How do tropic hormones differ from nontropic hormones?

Tropic hormones stimulate the production and secretion of hormones by other endocrine glands, whereas nontropic hormones stimulate cellular growth, metabolism, or other functions.

Provide an example of a tropic hormone and a nontropic hormone.

An example of a tropic hormone is TSH; an example of a nontropic hormone is thyroxine ($T_3$, $T_4$).

According to the transcript, which organ functions as both an endocrine and exocrine gland?

Pancreas

What are the characteristics of exocrine secretions and their delivery method?

Exocrine secretions are less specific (e.g., saliva, enzymes, prostatic fluid, breast milk), utilize a duct, and may be a measurable volume.

Compare the speed of action between the nervous system and the endocrine system.

The nervous system is very rapid, while the endocrine system is relatively slow, with signaling that may take minutes, hours, or days to generate an effect.

Compare the nature of the message used by the nervous system versus the endocrine system.

The nervous system uses electrical impulses traveling along nerves, while the endocrine system uses chemical messages traveling in the bloodstream.

How does the area of response differ between the nervous and endocrine systems?

The nervous system response is localized (often confined to one area of the body), whereas the endocrine system response is widespread (usually noticed in many organs).

Compare the duration of response between the nervous and endocrine systems.

Nervous system responses are short acting and usually completed within seconds; endocrine system responses can be prolonged and may take years before being completed.

What are examples of processes controlled by the nervous system?

Reflexes such as blinking and movement of the limbs.

What are examples of processes controlled by the endocrine system?

Growth and development of the reproductive system.