Endocrine System

1. What is the difference between endocrine and nervous system?

• Endocrine  has more  general effects than nervous system

1. Which of the following statements concerning membrane-bound receptors is true?

• Chemical signals that are large, water-soluble molecules normally bind to membrane bound receptors

1.  Membrane-bound receptors can

1. Open  or close membrane channels
2. Activate G-proteins
3. Activate enzymes attached to the cell membrane
4. Produce a cascade effect by activating many enzymes inside the cell
5. Do all of these things

1. Endocrine glands

1. Include the salivary glands
2. Secrete chemical signals called hormones
3. Secrete their chemical signals into the blood
4. Secrete their products into ducts
5. Have both secrete chemical signals called hormones and  secrete their chemical signals into the  blood

1. Hormones

1. Are produced in large quantities by most cells
2. Usually affect  cells close to those that produces hormones
3. Bind only to cells that have receptors  for that specific hormone
4. Are either lipid or polysaccharide molecules
5. Have all these characteristics

1. Which of these types  of hormone molecules are NOT correctly matched with  the example or description

1. Protein hormone→anterior pituitary hormones
2. Protein hormone→ prostaglandin-like hormone
3. Lipid hormone→ steroids
4. Peptide hormone→ posterior pituitary hormone
5. Lipid hormone→  hormones that diffuses through the cell membrane

1. Hormone action

1. Most  protein and peptide hormone bind to receptors on the surface of the cell membrane
2. The combination of a hormone with its receptor may alter the permeability of the cell  membrane
3. A hormone that combines with a receptor in the cell membrane may act as a first messenger
4. Cyclic AMP (cAMP) functions  as a second messenger
5. All of these are true

1. Which of the following statements concerning regulation of hormone secretion is NOT true?

1. The secretion rate for some hormones is directly controlled by the blood levels of chemicals
2. The secretion rate for some hormones is directly controlled by another hormones
3. The secretion of hormones is controlled by positive-feedback mechanisms that keep the body within a narrow range of values
4. The secretion rate for some hormones  is controlled by the nervous system
5. All of these statements are true

1.  Endocrine system glands

1. Secrete hormones into ducts
2. Usually have a poor blood supply
3. May  have functions in addition to producing hormones
4. Have all these properties
5. Have secrete hormones into ducts and usually have poor blood supply

1. The pituitary gland

1.  Is  a small  gland that rests  in  the sella turcica of the sphenoid bone
2. Is also called the hypothalamus
3. Has a superior lobe above the hypothalamus, and an inferior  lobe below the hypothalamus
4. Is connected to  the optic chiasma by the infundibulum
5. Has all these characteristics

1. The anterior pituitary

1. Is made up of nerve cells connected to the hypothalamus
2. Is controlled by releasing hormones produced in the hypothalamus
3. Controls the functions of other glands such as the  ovaries,  testes and thyroid glands
4. Has all of these characteristics
5. Has only characteristics controlled by the releasing hormones produced in the hypothalamus and controls the  functions  of other glands such  as ovaries,  testes  and thyroid glands

1.   The hypothalamic-pituitary portal system

1. Is a collection of nerves that  connect the hypothalamus and  posterior pituitary
2. Includes capillary beds and veins that transport releasing  hormones
3. Allows the anterior pituitary to control the cerebrum and hypothalamus
4. Connects the hypothalamus  to the midbrain
5. Carries blood directly to the posterior  pituitary

1.  Growth hormone

1.  Stimulates  fat synthesis
2. Favors protein breakdown
3. Deficiency in an adult can produce dwarfism
4. Excess after growth  is complete produces acromegaly
5. Produces all of these effects

1.  Gonadotropins

1.  Are secreted by the   posterior pituitary
2. Regulate  growth,  development  and functions  of ovaries and testes
3. Include both TSH and ACTH
4. Are controlled by the releasing hormones from the thyroid gland
5. Directly promote water retention by the kidneys

1. ACTH stimulates the

1.  Thyroid gland
2. Ovaries and testes
3. Hypothalamus
4. Adrenal cortex
5. Posterior pituitary

1. Prolactin

1. Helps development of, and production of milk in the breast
2. Causes  “milk letdown” from the breasts of lactating women
3. Causes contraction of the muscle of the uterus
4. Stimulates development of sperm cells in males
5. Does  both causes milk letdown from the breasts of lactating women and causes contraction of the muscle of the uterus

1.  The hormone from the posterior pituitary that increases water reabsorption in the kidney tubules is  

1. ADH
2. Prolactin
3. MSH
4. Oxytocin
5. FSH

1. ADH is

1. Sometimes called oxytocin
2. Can  cause blood vessels to constrict when present in the blood in large amounts
3. Causes “milk letdown” from  the breasts of lactating women
4. Stimulates melanocytes and causes them to synthesize melanin
5. Has both is sometimes called oxytocin and Can  cause blood vessels to constrict when present in the blood in large amounts

1. Which of these statements concerning thyroid glands is NOT true?

1. Thyroid hormones include T3 and T4 (thyroxine)
2. Are produced in thyroid follicles
3. Thyroid hormone secretion is stimulated by TSH
4. Insufficient  iodine in the diet causes thyroid gland to decrease in size
5. Increased thyroid hormone secretion causes a decrease in  TSH

1.  Hyperthyroidism

1. Can  cause cretinism in infants
2. Results in an   elevated rate of metabolism
3. Can cause  extreme  nervousness and chronic fatigue
4. Would  cause an increase in  TSH secretion
5. Does both results in an elevated metabolism and cause an extreme nervousness and chronic fatigue

1. Calcitonin

1. Is secreted by  the parathyroid glands
2. Increases the amount of calcium absorbed by the intestine
3. Is synthesized by parafollicular cells of the thyroid gland
4. Increases calcium release from bone
5. Secreted when blood calcium levels drop too low

1. Parathyroid hormones (PTH)

1. Increases calcium level in the blood
2. Inhibits the formation of active vitamin D in the kidneys
3. Decreases the rate of bone breakdown
4. Has an effect similar to that of calcitonin
5. Has all these characteristics

1. The adrenal medulla  

1. Is stimulated by the sympathetic nervous system
2. Produces epinephrine and  norepinephrine
3. Is stimulated when a person is physically excited
4. Produces the “fight or flight” response
5. Has all these properties

1.  Which of these would  NOT be a major effect of hormones released from the adrenal medulla

1.  Increased heart rate
2. Breakdown of glycogen to glucose
3. Decreased blood flow through  skeletal  muscles
4. Dilation of bronchioles
5. Release of  fatty acids from fat cells

1. Cortisol

1.  Is  classified as a glucocorticoid
2. Initiates the breakdown of protein fat
3. Reduces the inflammatory effect (when in pharmacological doses)
4. Secretion is stimulated  by ACTH
5. Has all of these properties

1. Aldosterone

1. Causes potassium ions to be retained in the  body
2. Secretion is stimulated primarily by the  ACTH
3. Secretion increases when blood potassium levels increase
4. Causes increased retention of sodium ions and water by the body
5. Has both secretion increases when blood potassium levels increase and causes increased retention of sodium ions and water by the body

1. Which of these statements concerning aldosterone secretion is NOT true?

1. Low blood pressure stimulates the release of renin from the kidney
2. Renin causes angiotensinogen to be converted to angiotensin I.
3. Angiotensin  II  acts on  the adrenal cortex to increase aldosterone secretion
4. Aldosterone causes increased potassium retention
5. Angiotensin II constricts blood vessels

1. Adrenal Androgens

1.   Are produced in the adrenal medulla
2. Stimulate the development of male sexual characteristics
3. Reduce inflammatory response as  primary  effect
4. Cause reabsorption  of potassium and water
5. Have all  of  these properties

1. The endocrine portion of the pancreas

1.  Consists of pancreatic islets dispersed among exocrine portion  of  pancreas
2. Secretes insulin and glucagon
3. Produces androgens
4. Has all of these characteristics
5. Has characteristics consists of pancreatic islets dispersed among exocrine portion  of  pancreas and  secretes insulin and glucagon only

1. If blood glucose decreases below normal  

1.   The  nervous system will  malfunction
2. The   increased breakdown of  fats  tends to produce metabolic alkalosis
3. Large volumes  of urine will be produced
4. The heart rate will decrease
5. All of those events will  occur

1. Insulin is secreted in response to

1. Increased blood glucose levels
2. Decreased parasympathetic  stimulation
3. Decreased  blood levels  of amino acids
4. All of these characteristics

1.  In persons with diabetes mellitus

1. The  blood glucose levels become very high
2. Tissues cannot take up glucose effectively
3. Proteins are broken down to provide energy for metabolism
4. Acidosis  may result from rapid fat breakdown
5. All  of these events  are more  likely than in a healthy individual

1. Symptoms of diabetes mellitus include

1. Increased appetite
2. Weight gain
3. High energy  level
4. Limited urine   output
5. All of these

1. Which of these statements about Insulin Shock is NOT true?

1. Insulin shock results from too much glucose in the blood
2. Insulin  shock may result from too  much insulin, or from not eating after being injected with insulin
3. Insulin shock causes the brain to malfunction
4. Insulin shock can result in disorientation, convulsions and loss of…

1. Secretion of which  of these hormones would increase shortly after a meal

1.  Glucagon
2. Growth hormone
3. Epinephrine
4. Glucocorticoids
5. Insulin

1. The major target tissue for  glucagon is

1.  Heart
2. Brain
3. Liver
4. Skeletal muscle
5. Smooth muscle

1. Which of these hormones increases blood glucose and increases lipid breakdown but slows down protein breakdown?

1. Glucagon
2. Epinephrine
3. Insulin
4. Glucocorticoid
5. Growth hormone

1. Testosterone

1. Is secreted by the hypothalamus
2. Stimulates the adrenal cortex to  produce adrenal androgens
3. Secretion is  secreted by the hormone from  posterior pituitary
4. Has a negative feedback effect on the hypothalamus and anterior pituitary
5. Has all  of  these effects

1. The thymus gland

1. Becomes smaller with increasing age
2. Is important in the function of the immune system
3. Secretes thymosin
4. Is found in the upper part of the thoracic cavity above the heart
5. Has  all of these characteristics

1. Melatonin

1. Is secreted by the thymus gland
2. Is thought  to increase the secretion of releasing hormone from the hypothalamus
3. Increases FSH and LH
4. May be controlled by changes in day length
5. Has all of  these properties

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