HUMAN ANATOMY & PHYSIOLOGY - ENDOCRINE SYSTEM TEST BANK
CONTAINS REAL EXAM QUESTIONS AND CORRECT DETAILED
ANSWERS WITH RATIONALES|ALREADY GRADED A+||
Structure of the pancreatic islets - CORRECT ANSWERS-1. Alpha cells (A cells) secrete
glucagon
2. Beta cells (B cells) secrete insulin
Alpha cells (A cells) - CORRECT ANSWERS-1. secrete glucagon
2. Glucagon: produced by A cells; tends to increase blood glucose levels by glycogenolysis +
gluconeogenesis (liver)
Beta cells (B cells) - CORRECT ANSWERS-1. secrete insulin
2. Insulin: produced by B cells; lowers blood concentration of glucose, amino acids, and fatty acids and
promotes their metabolism by tissue cells
Regulation of Blood Glucose Levels - CORRECT ANSWERS-
The classical endocrine hormones - CORRECT ANSWERS-have a "global" effect in the body
since they can travel throughout the blood stream
Classification by chemical structure - CORRECT ANSWERS-1. Steroid hormones
2. Nonsteroid hormones
Steroid hormones
Examples: cortisol, aldosterone, estrogen, progesterone, testosterone - CORRECT ANSWERS-
1. Synthesized from cholesterol (Figure 16-5)
2. Lipid soluble; easily pass through the phospholipid plasma membrane of target cell
, Nonsteroid hormones - CORRECT ANSWERS-1. Synthesized primarily from amino acids
2. *Protein hormones*: long, folded chains of amino acids (e.g., insulin, parathyroid hormone)
3. *Peptide hormones*: smaller than protein hormones; short chain of amino acids (e.g., oxytocin,
antidiuretic hormone)
4. *Amino acid derivative hormones*: each derived from a single amino acid molecule
Target Cell Concept: Lock and Key Model - CORRECT ANSWERS-
Mechanism of steroid hormone action - CORRECT ANSWERS-1. Steroid hormones are lipid
soluble; their receptors are normally found in the target cell's cytosol
2. After a steroid hormone molecule has diffused into the target cell, it binds to a receptor molecule to
form a hormone-receptor complex
3. Activates a certain gene sequence to begin transcription of mRNA
4. Newly formed mRNA molecules move into the cytosol, associate with ribosomes, and begin
synthesizing protein molecules that produce the effects of the hormone
Mechanism of steroid hormone action diagram - CORRECT ANSWERS-
Mechanisms of nonsteroid hormone action - CORRECT ANSWERS-1. The second messenger
mechanism: also known as the fixed membrane receptor model
2. A nonsteroid hormone molecule acts as a "first messenger" and delivers its chemical message to fixed
receptors in the target cell's plasma membrane
3. The "message" is then passed by way of a protein into the cell where a "second messenger" triggers
the appropriate cellular changes
The second messenger mechanism diagram - CORRECT ANSWERS-
Endocrine gland secretion may also be regulated by a hormone produced by another gland -
CORRECT ANSWERS-
CONTAINS REAL EXAM QUESTIONS AND CORRECT DETAILED
ANSWERS WITH RATIONALES|ALREADY GRADED A+||
Structure of the pancreatic islets - CORRECT ANSWERS-1. Alpha cells (A cells) secrete
glucagon
2. Beta cells (B cells) secrete insulin
Alpha cells (A cells) - CORRECT ANSWERS-1. secrete glucagon
2. Glucagon: produced by A cells; tends to increase blood glucose levels by glycogenolysis +
gluconeogenesis (liver)
Beta cells (B cells) - CORRECT ANSWERS-1. secrete insulin
2. Insulin: produced by B cells; lowers blood concentration of glucose, amino acids, and fatty acids and
promotes their metabolism by tissue cells
Regulation of Blood Glucose Levels - CORRECT ANSWERS-
The classical endocrine hormones - CORRECT ANSWERS-have a "global" effect in the body
since they can travel throughout the blood stream
Classification by chemical structure - CORRECT ANSWERS-1. Steroid hormones
2. Nonsteroid hormones
Steroid hormones
Examples: cortisol, aldosterone, estrogen, progesterone, testosterone - CORRECT ANSWERS-
1. Synthesized from cholesterol (Figure 16-5)
2. Lipid soluble; easily pass through the phospholipid plasma membrane of target cell
, Nonsteroid hormones - CORRECT ANSWERS-1. Synthesized primarily from amino acids
2. *Protein hormones*: long, folded chains of amino acids (e.g., insulin, parathyroid hormone)
3. *Peptide hormones*: smaller than protein hormones; short chain of amino acids (e.g., oxytocin,
antidiuretic hormone)
4. *Amino acid derivative hormones*: each derived from a single amino acid molecule
Target Cell Concept: Lock and Key Model - CORRECT ANSWERS-
Mechanism of steroid hormone action - CORRECT ANSWERS-1. Steroid hormones are lipid
soluble; their receptors are normally found in the target cell's cytosol
2. After a steroid hormone molecule has diffused into the target cell, it binds to a receptor molecule to
form a hormone-receptor complex
3. Activates a certain gene sequence to begin transcription of mRNA
4. Newly formed mRNA molecules move into the cytosol, associate with ribosomes, and begin
synthesizing protein molecules that produce the effects of the hormone
Mechanism of steroid hormone action diagram - CORRECT ANSWERS-
Mechanisms of nonsteroid hormone action - CORRECT ANSWERS-1. The second messenger
mechanism: also known as the fixed membrane receptor model
2. A nonsteroid hormone molecule acts as a "first messenger" and delivers its chemical message to fixed
receptors in the target cell's plasma membrane
3. The "message" is then passed by way of a protein into the cell where a "second messenger" triggers
the appropriate cellular changes
The second messenger mechanism diagram - CORRECT ANSWERS-
Endocrine gland secretion may also be regulated by a hormone produced by another gland -
CORRECT ANSWERS-
