Endocrine

Question 1

Compare and contrast the endocrine and nervous systems as control systems of the body.

Answer 1

Endocrine:
-regulates growth development, reproduction & regulation of metabolism (usually long, slow processes)
- Longer amount of time for effector to respond to stimulus
-Longer duration of response
-Hormones are the chemicals used to communicate with target cells
Nervous:
-Regulates sensory perception, movements (usually rapid, short-lived processes)
-Shorter amount of time for effector to respond to stimulus
-Shorter duration of response
-Neurotransmitters are the chemicals used to communicate with target cells.

Question 2

Distinguish between exocrine and endocrine glands.

Answer 2

Exocrine:
-has glands that have ducts to carry away their secretions out of the body
Endocrine:
-has ductless glands
-does not have ducts/tubes to carry away it’s secretion (hormones pass directly into the bloodstream for distribution around the body)

Question 3

Describe how hormones are transported in the bloodstream (i.e., bound to a transport protein or unbound); how might this affect how long the hormones last in body fluids?

Answer 3

• hormones are transported via capillaries
• hydrophobic hormones bound to a transport protein
• hydrophobic hormone last longer in body fluids since they are “protected” by the transport protein
• hydrophilic hormone unbound to a transport protein
• hydrophilic hormone last shorter in the body fluids

Question 4

Compare and contrast membrane-bound (extracellular) hormone receptors and intracellular hormone receptors.

Answer 4

Extracellular receptors:

• extracellular hormone receptors are located on plasma membrane
• peptide hormones and catecholamines (not lipid soluble)
• Intracellular hormone receptors are within target cells

Question 5

Compare and contrast hydrophobic and hydrophilic hormones

Answer 5

Hydrophobic:
-examples: Aldosterone, testosterone and estrogen
-bounds to transport protein
-last longer in the body fluids(protected by transport protein)
-intracellular receptors
-directly affect gene activation
Hydrophilic:
-examples: Insulin, Thyroid stimulating hormone (TSH) and Luteinizing hormone
-Unbounds to transport protein
- Last shorter in body fluids 
-extracellular receptors
-Use a second messenger