Unit 3: Pharm: Chapter 34

Question 1

Hormones

Answer 1

Hormones are chemicals that are transported in bodily fluids and act on specific target cells. Most hormones
•Are produced in small amounts
•Are secreted directly into the bloodstream
•Travel through the blood to specific receptor sites throughout the body
•Act to increase or decrease the normal metabolic cellular processes when they react with their specific receptor sites
•Are present in the body at all times, but their amount may fluctuate

Question 2

Hypothalamus

Answer 2

Coordinating center for the nervous and endocrine responses to internal and external stimuli.
functions: body temperature, thirst, hunger, water retention, blood pressure, respiration, reproduction, and emotional reactions.
Situated at the base of the forebrain, the hypothalamus receives input from virtually all other areas of the brain, including the limbic system, cerebral cortex, and the special senses that are controlled by the cranial nerves—smell, sight, touch, taste, and hearing.

Question 3

Hypothalamic Pituitary Axis

Answer 3

the hypothalamus and the pituitary function closely using a series of negative feedback systems to maintain endocrine activity and regulate levels of certain endocrine hormones.

Question 4

Negative Feedback System

Answer 4

Hypothalamus senses a need for a particular hormone, it secretes the releasing hormone or factor TRH directly into the anterior pituitary.
In response TRH, the anterior pituitary secretes TSH, which in turn stimulates the thyroid gland to produce thyroid hormone.
Hypothalamus senses the rising levels of thyroid hormone, it stops secreting TRH, resulting in decreased TSH production and subsequently reduced thyroid hormone levels. The hypothalamus, sensing the falling thyroid hormone levels, secretes TRH again.

Question 5

Pancreas

Answer 5

Hormones produced: insulin, glucagon, somatostatin
Effects: of glucose, fat metabolism (islets of Hnagerhans)

Question 6

Pituitary Gland

Answer 6

located in the skull in the bony sella turcica under a layer of dura mater. It is divided into three lobes: an anterior lobe, a posterior lobe, and an intermediate lobe.
Produces hormones, endorphins, and enkephalins and stores two hypothalamic hormones.

Question 7

Intermediate Lobe Of Pituitary

Answer 7

produces endorphins and enkephalins, which are released in response to severe pain or stress and occupy specific endorphin receptor sites in the brainstem to block the perception of pain.
They are released in response to overactivity of pain nerves, sympathetic stimulation, transcutaneous stimulation, guided imagery, and vigorous exercise.

Question 8

Melanocyte Stimulating Hormone (MSH)

Answer 8

Produced by anterior pituitary
plays an important role in animals that use skin color changes as an adaptive mechanism.
It might also be important for nerve growth and development in humans.
Lipotropins stimulate fat mobilization but have not been clearly isolated in humans.

Question 9

ADH

Answer 9

Or vasopressin
Stored by the posterior pituitary
Produced by the hypothalamus

ADH is directly released in response to increased plasma osmolarity or decreased blood volume (which often results in increased osmolarity).
The osmoreceptors in the hypothalamus stimulate the release of ADH. ADH acts in the kidneys to increase retention of water in order to decrease the osmolarity of the blood volume.

Question 10

Parathyroid Gland

Answer 10

release parathyroid hormone, or parathormone, in response to local calcium levels.

Question 11

Releasing Hormones or Factors

Answer 11

Produced and secreted by the Hypothalamus
cChemicals that stimulate the anterior pituitary, which in turn stimulates or inhibits various endocrine glands throughout the body
These releasing hormones include growth hormone (GH)-releasing hormone, thyrotropin-releasing hormone (TRH), gonadotropin-releasing hormone (GnRH), corticotropin-releasing hormone (CRH), and prolactin (PRL)-releasing hormone.