: hormonal signaling pathways between endocrine glands and tissues Ex. Hypothalamic-pituitary axis Hypothalamus releases trace amounts of peptide hormones called releasing factors, which bind to receptors on cells in the anterior pituitary gland, causing it to release a much larger amount of associated hormones (ex. Adrenocorticotropic hormone (ACTH)) Evolution of hormones o The structures of many hormones are evolutionarily conserved o Many animals use the same hormones, sometimes for different purposes o Recent genomic analysis has shown that the receptors for many hormones evolved well before the hormones with which they now interact
Endocrine System Notes Chapter 38 o Many peptides originally identified as hormones in various tissues have also been found to function as neurotransmitters in the nervous system The Vertebrate Endocrine System Hypothalamic-pituitary axis Hypothalamus relays signals to pituitary gland, which releases several hormones that coordinate the action of many other endocrine glands and tissues The vertebrate endocrine system is not localized in one part of the body, but is present throughout Anterior pituitary gland : region of the pituitary gland that forms from epithelial cells that develop and push up from the roof of the mouth Receives hormones from the hypothalamus that stimulate it to release hormones in turn Releases tropic hormones Tropic hormones : hormones released by the anterior pituitary gland that stimulate the release of other hormones o Thyroid-stimulating hormone (TSH): causes thyroid to release hormones that regulate the metabolic state of the body Gonadotropic hormone
Endocrine System Notes Chapter 38 o Follicle-stimulating hormone (FSH) and luteinizing hormone (LH): cause ovaries to release estrogen and progesterone and the testes to release testosterone Gonadotropic hormones o Adrenocorticotropic hormone (ACTH): causes adrenal glands to release cortisol Posterior pituitary gland : region of the pituitary gland that develops from neural tissue at the base of the brain and into which neurosecretory cells of the hypothalamus extend that secrete releasing factors o Oxytocin
You've reached the end of your free preview.
Want to read all 5 pages?
- Fall '19
- Endocrine System