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Pathophysiology Module 9 – BIOL 331/ BIOL331 (Latest
2026/2027) | Verified Q&A | Portage Learning | Grade A
Performance
Define endocrine, paracrine, and autocrine.
Endocrine: Hormones are released to circulation to act on a target organ (i.e. TSH,
ADH) Paracrine: Hormones act locally on cells close to where they are released (i.e.
estrogen and testosterone) Autocrine: Hormones produce a biologic action on the cell
that released them (i.e. insulin)
What are the different structural types of hormones?
(1) amines and amino acids; (2) peptides and proteins; and (3) steroids, which are made
from cholesterol
What is the function of the hypothalamus?
The hypothalamus serves to link the nervous system to the endocrine system. It
regulates homeostasis, body temperature, hunger, behavior, emotion, and pain. The
hypothalamus produces releasing hormones, which stimulate the pituitary to release
stimulating hormones.
What is the role of the pituitary gland?
The pituitary gland is known as the "master gland," since it stimulates target organs to
secrete their hormones.
Explain the concept of negative feedback and give an example:
Negative feedback is how the body maintains homeostasis, or equilibrium. The brain is
constantly monitoring hormone levels to keep levels within its certain range or set-
point. Negative feedback prevents over-secretion of any hormone. The action of ADH,
which dilutes the blood, is one example. Once the blood is dilute, the hypothalamus
detects the dilute levels and stops releasing ADH.
Explain the concept of positive feedback and give an example:
Positive feedback enhances or increases the amount of the hormone that is released.
One example is oxytocin, a hormone that causes the uterus to contract. The action of the
uterus contracting causes more oxytocin to be released.
Explain the ways in which hormones can be over-secreted:
Increased hormone secretion can occur from any of the following reasons: (1) the target
gland over-secretes due to pathology; (2) the pituitary or hypothalamus over-stimulates
the target gland; (3) hormones are being produced from a different site (i.e. hormone
producing tumor); (4) hyperactive genetic mutation of the target hormone receptors.
, How does decreased hormone secretion occur?
Decreased hormone secretion can occur from any of the following reasons: (1) a
congenital or acquired disorder of the target gland; (2) the pituitary does not secrete
enough stimulating hormone; (3) the hypothalamus does not secrete enough releasing
hormone; (4) the hormone is defective; (5) the receptors of the target organ do not
respond.
Adrenal insufficiency can be caused by what ways?
(1) Primary adrenal insufficiency, or Addison's disease, due to dysfunction in the
adrenal glands. (2) Decreased ACTH stimulation from the pituitary, or secondary
adrenal insufficiency. (3) Decreased CRH from the hypothalamus, or tertiary adrenal
insufficiency.
With Addison's disease, what hormones and lab values will be altered?
With Addison's disease, both cortisol and aldosterone secretion are decreased and
ACTH levels are elevated. With low aldosterone, there will be low sodium, and increased
potassium. Low sodium will also cause hypotension.
What can cause Cushing syndrome?
(1) Iatrogenic, from long-term treatment with steroids (2) Over-secretion by one or both
adrenal glands (due to adrenal adenoma or carcinoma) (3) Over-stimulation of the
adrenal glands by an ACTH-secreting tumor in the pituitary (this is know as Cushing's
disease.) (4) Over-stimulation of the adrenal glands by an ectopic ACTH producing
tumor (most common being small cell lung cancer)
What are the signs and symptoms of Cushing syndrome?
Cushing syndrome can present with a buffalo hump (fat pads) in the back, abdominal
obesity, moon (round) face, muscle weakness, easy bruising, thin skin, edema, purple
striae, osteoporosis and/or osteonecrosis, acne, hirsutism, virilization,
immunosuppression, diabetes, and cognitive changes, including mood changes to
psychosis.
What lab values will be altered in primary and secondary hyperthyroidism?
With primary hyperthyroidism, TSH will be low, since the thyroid is secreting a lot of
the hormone without being told by the pituitary. With secondary hyperthyroidism, the
TSH will be high, since the pituitary is over-secreting it. In both cases, T4 and T3 will be
elevated, since this is what differentiates hyper- from hypo- thyroidism.
What are signs and symptoms of hypothyroidism?
Signs and symptoms of hypothyroidism include weight gain, fatigue, weakness,
bradycardia, hypoventilation, cold intolerance, constipation, arthralgias, myalgias,
and/or anemia. Goiter may be present.
What are the roles of insulin and glucagon?
Insulin moves glucose into cells to reduce blood sugar levels. Glucagon causes a release
of glucose into the blood when levels are low. These hormones work together to
Pathophysiology Module 9 – BIOL 331/ BIOL331 (Latest
2026/2027) | Verified Q&A | Portage Learning | Grade A
Performance
Define endocrine, paracrine, and autocrine.
Endocrine: Hormones are released to circulation to act on a target organ (i.e. TSH,
ADH) Paracrine: Hormones act locally on cells close to where they are released (i.e.
estrogen and testosterone) Autocrine: Hormones produce a biologic action on the cell
that released them (i.e. insulin)
What are the different structural types of hormones?
(1) amines and amino acids; (2) peptides and proteins; and (3) steroids, which are made
from cholesterol
What is the function of the hypothalamus?
The hypothalamus serves to link the nervous system to the endocrine system. It
regulates homeostasis, body temperature, hunger, behavior, emotion, and pain. The
hypothalamus produces releasing hormones, which stimulate the pituitary to release
stimulating hormones.
What is the role of the pituitary gland?
The pituitary gland is known as the "master gland," since it stimulates target organs to
secrete their hormones.
Explain the concept of negative feedback and give an example:
Negative feedback is how the body maintains homeostasis, or equilibrium. The brain is
constantly monitoring hormone levels to keep levels within its certain range or set-
point. Negative feedback prevents over-secretion of any hormone. The action of ADH,
which dilutes the blood, is one example. Once the blood is dilute, the hypothalamus
detects the dilute levels and stops releasing ADH.
Explain the concept of positive feedback and give an example:
Positive feedback enhances or increases the amount of the hormone that is released.
One example is oxytocin, a hormone that causes the uterus to contract. The action of the
uterus contracting causes more oxytocin to be released.
Explain the ways in which hormones can be over-secreted:
Increased hormone secretion can occur from any of the following reasons: (1) the target
gland over-secretes due to pathology; (2) the pituitary or hypothalamus over-stimulates
the target gland; (3) hormones are being produced from a different site (i.e. hormone
producing tumor); (4) hyperactive genetic mutation of the target hormone receptors.
, How does decreased hormone secretion occur?
Decreased hormone secretion can occur from any of the following reasons: (1) a
congenital or acquired disorder of the target gland; (2) the pituitary does not secrete
enough stimulating hormone; (3) the hypothalamus does not secrete enough releasing
hormone; (4) the hormone is defective; (5) the receptors of the target organ do not
respond.
Adrenal insufficiency can be caused by what ways?
(1) Primary adrenal insufficiency, or Addison's disease, due to dysfunction in the
adrenal glands. (2) Decreased ACTH stimulation from the pituitary, or secondary
adrenal insufficiency. (3) Decreased CRH from the hypothalamus, or tertiary adrenal
insufficiency.
With Addison's disease, what hormones and lab values will be altered?
With Addison's disease, both cortisol and aldosterone secretion are decreased and
ACTH levels are elevated. With low aldosterone, there will be low sodium, and increased
potassium. Low sodium will also cause hypotension.
What can cause Cushing syndrome?
(1) Iatrogenic, from long-term treatment with steroids (2) Over-secretion by one or both
adrenal glands (due to adrenal adenoma or carcinoma) (3) Over-stimulation of the
adrenal glands by an ACTH-secreting tumor in the pituitary (this is know as Cushing's
disease.) (4) Over-stimulation of the adrenal glands by an ectopic ACTH producing
tumor (most common being small cell lung cancer)
What are the signs and symptoms of Cushing syndrome?
Cushing syndrome can present with a buffalo hump (fat pads) in the back, abdominal
obesity, moon (round) face, muscle weakness, easy bruising, thin skin, edema, purple
striae, osteoporosis and/or osteonecrosis, acne, hirsutism, virilization,
immunosuppression, diabetes, and cognitive changes, including mood changes to
psychosis.
What lab values will be altered in primary and secondary hyperthyroidism?
With primary hyperthyroidism, TSH will be low, since the thyroid is secreting a lot of
the hormone without being told by the pituitary. With secondary hyperthyroidism, the
TSH will be high, since the pituitary is over-secreting it. In both cases, T4 and T3 will be
elevated, since this is what differentiates hyper- from hypo- thyroidism.
What are signs and symptoms of hypothyroidism?
Signs and symptoms of hypothyroidism include weight gain, fatigue, weakness,
bradycardia, hypoventilation, cold intolerance, constipation, arthralgias, myalgias,
and/or anemia. Goiter may be present.
What are the roles of insulin and glucagon?
Insulin moves glucose into cells to reduce blood sugar levels. Glucagon causes a release
of glucose into the blood when levels are low. These hormones work together to
