Download Science Grade (First 6 Weeks/3rd Trimester)

Endocrine Introduction Notes Answers
Ques 1: Describe the role of the endocrine system in the body.
Ans 1: The endocrine system is a system of control that uses
chemicals called hormones to affect the actions of cells throughout
the body.
Ques 2: Explain how the endocrine and autonomic nervous systems
work together to help maintain homeostasis.
Ans 2: The endocrine and autonomic nervous systems work together
to constantly monitor and adjust body conditions to maintain
homeostasis.
Examples:
-Calcium levels in the bones.
-Blood glucose levels.
-Electrolyte balance.
-”Fight or Flight”
Ques 3: Compare endocrine glands with exocrine glands.
Ans 3: Endocrine glands (like the pituitary) secrete hormones directly
into the blood while exocrine glands (like tear or lacrimal glands)
secrete their fluids through ducts.
Ques 4: What are prostaglandins and why are they called “local
hormones?”
Ans 4: Prostaglandins are fatty acid hormones that affect tissues in
close proximity (locally) to where they were released. Examples are
thromboxane and prostacylcin which have antagonist affects on blood
vessel wound repair. Thromboxane is made by the platelets allowing
them to clot and causes vasoconstriction. Prostacylcin is made by
blood vessel cells and does not allow for platelets to clump or clot
and causes vasodilation.
Ques 5: What are the advantages of having both a nervous system
and endocrine system?
Ans 5: The nervous system is incredibly quick and generally limits its
messages to specific cells and tissues on a short term basis. The
endocrine system is slower acting, with its affects longer term. Also,
the hormones have a broadcast effect where they influence many
different cells and tissues.
Ques 6: What is the difference between steroid and non-steroid
hormones?
Ans 6: Steroid hormones are lipids that are derived from cholesterol.
Testosterone and progesterone are examples. Non-steroid hormones
include amines (from amino acids), protein hormones, and peptide
hormones. Steroid hormones actually enter the target cell to affect
a change, while non-steroid hormones attach to the cell’s plasma
membrane. Non-steroid hormones affect their change on a cell by
binding with an active site on the surface of a cell’s membrane.