Unit 2 - Hypothalamus and Pituitary Flashcards
What are the main anatomical parts of the hypothalamic-pituitary system?
hypothalamus, neurohypophysis, and adenohypophysis
How does the hypothalamus communicate with the posterior pituitary?
it sends neurons into the posterior pituitary to release neurotransmitters into the capillary system
What is the major difference between the posterior and anterior pituitary?
the posterior pituitary does not contain endocrine cells but the anterior pituitary does
Which hormones are released into the blood stream in the posterior pituitary?
oxytocin and antidiuretic hormone (ADH)
Where are the hormones that are released in the posterior pituitary synthesized and how they get to the posterior pituitary?
They are synthesized in the hypothalamus and released into the posterior pituitary via long neurons that project into the posterior pituitary
What hormones are secreted by the anterior pituitary?
follicle-stimulating hormone (FSH), Luteinizing hormone (LH), thyrotropin (TSH), adrenocorticotropin (ACTH), prolactin (PRL), Somatotropin (GH), and melanotropin (MSH)
How does the hypothalamus control secretion of hormones from the anterior pituitary?
neurohormones that are produced by various nuclei of they hypothalamus control the release or inhibition of these hormones
How do the neurohormones of the hypothalamus reach the anterior pituitary?
they are released into a capillary bed in the hypothalamus, then flow through portal venules that are connected to a capillary bed in the anterior pituitary
Once neurohormones reach the capillary bed in the anterior pituitary, what happens?
they diffuse into the extracellular fluid of the anterior pituitary where they either stimulate or inhibit the release of hormones of the anterior pituitary
Which pituitary hormones control the activity of other endocrine glands?
follicle-stimulating hormone (FSH), Luteinizing hormone (LH), thyrotropin (TSH), adrenocorticotropin (ACTH)
Which endocrine glands are controlled by the autonomic nervous system?
pancreas, adrenal medulla, and the kidney
Which part of the pituitary secretes MSH?
the anterior pituitary
What is main the function of MSH in mammals?
acquisition of brown summer hair and skin darkening in response to sunlight
What is the main function of MSH in lower vertebrates?
it disperses melanin contained in melanosomes
How does light effect cells with high concentration of melanin?
it reflects more making it appear lighter
