2_Hypothalamic-Pituitary Axis Flashcards
Campbell Biology (11th ed): CH 45, pg 1005-1007, Figures 45.14, 45.15, 45.16 AND Figure 44.18 (Regulation of fluid retention in the kidney...) in section 44.5
Define a true endocrine gland and a tropic hormone/factor.
Where are the hypothalamus and pituitary gland located?
What processes and organs are regulated by the hypothalamic-pituitary axis? (Hint: Look carefully at the slide illustrating this concept, and pay attention to the functions listed in the reading). All of the functions might not be mentioned verbally in the video.
Mentioned in video:
body temperatue
threatening scenarios
ion and water balance in circulatory fluids and tissues
emotional stress
nurturing of offspring
circulating nutrients
Is the anterior pituitary gland a true endocrine gland? How about the posterior pituitary gland?
The anterior pituitary gland is a true gland because it both produces and secretes hormones from the same location.
What is the role of the hypothalamus in the hypothalamic-pituitary axis?
The hypothalamus (a collection of brain cells) continuously monitors the internal environment and receives information from higher brain centers to coordinate functions throughout the entire organism. e.g.
body temperatue
threatening scenarios
ion and water balance in circulatory fluids and tissues
emotional stress
nurturing of offspring
circulating nutrients
tissue growth
The hypothalamus and pituitary glands (fused into one organ) work together.
What feature of the hypothalamus enables it to regulate so many organ systems?
According to Figure 44.18 in section 44.5 of the textbook, is the hypothalamus capable of monitoring the composition of blood?
Describe the sequence of events resulting in hormone release from the anterior pituitary gland, beginning with a physiological stimulus and ending with hormones entering the systemic blood supply.
How do portal vessels and tropic hormones contribute to this process of hormone release from the anterior pituitary gland?
Describe the mechanism by which hormones are secreted via the posterior pituitary gland, beginning with a physiological stimulus and ending with hormones entering the systemic blood supply.
Only 3 organs are affected by the Posterior Pituitary Gland- mamary gland, kidney, and uterus.
It secretes 2 hormones:
oxytocin
vasopresin
It is NOT a true gland. It is an extension of the nervous system. It is an extention of the hypothalamus. The hormones are synthesized in the hypothalamus, and then transported and stored in the posterior pituitary gland.
In what way is this process of hormone release different in the posterior pituitary gland than that occurring in the anterior lobe
No portal vessels
No trophic factors
But you DO still have neurohormones secreted by the hypothalamus, onto some capillaries withint the pituitary gland and directly into the bloodstream.
Which lobe of the pituitary gland affects more organs?
The Anterior Pituitary gland impacts more organs.
What organs are coordinated by the Anterior Pituitary Gland?
What organs are coordinated by the Anterior Pituitary Gland?
mamary glands
gonads (ovaries and testes)
musculoskeletal
thyroid
adrenal glands
What hormones are secreted by the Anterior Pituatary Gland?
- TSH (Thyroid Stimulating Hormone) eventually causes thyroid gland to impact growth and metabolism
- ACTH (Adrenal Cortex Hormone) goes to adrenal cortex and causes gluco-corticoids to be released into bloodstream (e.g. cortisol, corticosteroids) which mediate stress responses and metabolism.
- Growth Hormone
- gonadotropins
- hormones that cause mammary glands to secrete milk
How does the hypothalamus coordinate hormone release by the Anterior Pituitary Gland?
