Anterior Pituitary Flashcards
What are the major releasing hormones produced by the hypothalamus?
- Antidiuretic Hormone (ADH or VP)
- Oxytocin
- Corticotropin Releasing Hormone (CRH)
- Growth Hormone Releasing Hormone (GHRH)
- Gonadotropin Releasing Hormone (GnRH)
- Thyrotropin Releasing Hormone (TRH)
- PRL-inhibitory hormone (Dopamine)
- GH-inhibitory hormone (Somatostatin)
These hormones play crucial roles in regulating various physiological processes.
What is the function of the hypophyseal portal system?
It connects the hypothalamus with the anterior pituitary and quickly transports hormones between these two areas
This system enables efficient communication between the hypothalamus and the anterior pituitary gland.
What are the characteristics of releasing hormones?
- Secretion in pulses
- Act on specific membrane receptors (G-protein coupled receptors)
- Transduce signals via second messengers
- Stimulate synthesis of pituitary hormones
- Stimulate release of stored pituitary hormones
- Stimulate hyperplasia & hypertrophy of target cells in the pituitary gland
These characteristics are essential for the proper functioning of the endocrine system.
What are the main targets and effects of anterior pituitary hormones?
- Growth Hormone (GH): Promotes muscle and skeletal growth
- Prolactin (PRL): Stimulates breast development and milk production
- Adrenocorticotropic Hormone (ACTH): Stimulates adrenal cortex for corticosteroid production
- Thyroid Stimulating Hormone (TSH): Stimulates thyroid hormone synthesis
- Luteinizing Hormone (LH): Stimulates sex steroid hormone synthesis
- Follicle Stimulating Hormone (FSH): Induces spermatogenesis and proliferation of granulosa cells
Each hormone has specific target organs and effects that contribute to overall body regulation.
Fill in the blank: The most abundant pituitary hormone is _______.
Growth Hormone (GH)
GH accounts for approximately 40-50% of pituitary cells.
What are the direct effects of Growth Hormone (GH)?
The direct effects are the result of GH binding its receptor on target cells, such as fat cells, leading to triglyceride breakdown and suppression of lipid accumulation
GH also has indirect effects mediated by IGF-1, which is secreted in response to GH.
True or False: Dopamine inhibits the secretion of Prolactin.
True
This inhibition is crucial for regulating milk production and reproductive functions.
What role does ACTH play in the body?
It stimulates the adrenal cortex to produce corticosteroids and is involved in stress response, nutrient mobilization, and osmoregulation
In nonmammalian vertebrates, ACTH stimulates interrenal glands.
What does Thyroid Stimulating Hormone (TSH) do?
It stimulates thyroid cells to trap iodide and synthesize and secrete thyroid hormones
TSH is critical for regulating metabolism and energy levels.
What is the main function of Follicle Stimulating Hormone (FSH)?
It stimulates the proliferation of granulosa cells in the ovary and binds to Sertoli cells to induce spermatogenesis
FSH plays a vital role in reproductive health.
What is the significance of the anterior pituitary hormones in the endocrine system?
They regulate various physiological processes by acting on target organs and tissues, influencing growth, metabolism, and reproductive functions
Understanding these hormones is essential for comprehending endocrine disorders.
