Endocrine System Bookwork KEY

Multiple Choice:

2. B

5. A B C D

Short Answer:

1a. Nervous = fast (milliseconds to seconds)

Endocrine = slower (minutes to days), longer lasting

1b. NS = electrical stimulation

ES = chemical messengers (hormones)

1c. NS = short-term processes, such as stimulation of muscle contraction and glandular secretion.

ES = controls processes that go on for a longer period of time such as growth, development, metabolism and the functioning of the reproductive system.

3. Hormone—substances that arouse the body by altering cellular activity (such as raising or lowering normal metabolic processes). Steroids are lipid soluble, non-steroid are water soluble.

5. Negative feedback, the process by which the products of a chemical reaction “feedback” and inhibit their further synthesis, regulates the activity of all endocrine glands controlled by anterior-pituitary-tropic hormones, as well as those controlled by blood levels of nonhormonal substances. Most simply, when a hormone is at low levels in the blood, its synthesis is stimulated either by the release of an anterior-pituitary-tropic hormone (e.g., thyroxine production and release are stimulated by TSH) or by changing blood levels of certain substances (e.g., PTH production is stimulated by low book calcium levels and insulin release sis stimulated by high levels of blood glucose). As blood levels of the stimulated hormones increase, the stimulus substance is either turned off (in the case of tropic hormones) or ceases to exist (because hormonal action results in a “correction” of the blood levels of the trigger substances). Once there is no stimulus, the previously stimulated endocrine organ decrease its hormone output, and hormone levels drop once more. The cycle repeats again and again as hormone blood levels increase and decrease via the process of negative feedback.

9. Hypothalamus—received neuronal information and is directly upstream of pituitary in the bloodstream, secretes releasing and inhibiting hormones.

14. ADH and aldosterone. ADH is produced by the hypothalamus and released by the posterior pituitary; cause the kidney tubules to increase their uptake and retention of water (from the kidney filtrate). Aldosterone, an adrenal cortical hormone, regulates sodium ion (and secondarily, potassium ion) concentration in the blood. When sodium ion concentration is too low, aldosterone is released and causes the renal tubules to increase their reabsorption of sodium ions (and water follows by osmosis).

16. a. Lower estrogen = menopause, and they then become more susceptible to osteoporosis and arteriosclerosis.

b. general efficiency lowered = hypothyroid,

c. growth hormone low = muscle atrophy,

d. pineal gland calcifies = lower resistance to stress and infection

e. lower insulin production/malformation = type 2 diabetes

Clinic #2 and 3 or #4 and 6

2. Diagnosis is hyposecretion of GH. The prescription is commerciall pituitary GH. GH should stimulate bone growth as long as the epiphysial plates are still open.

3. Pitocin and oxytocin stimulate contraction of the smooth muscle of the uterus, thereby increase strength of uterine contractions

4. The catecholamines epinephrine and norepinephrine. The cause is usually a tumor. The catecholamines promote a rise in blood sugar (hyperglycemia) whereas thyroid hormones trigger glucose catabolism.

6. Cushing’s syndrome—hypersecretion of glucocorticoids from the middle region of the adrenal cortex