Endocrine System Flashcards
What kinds of glands synthesize substances that are released into ducts connecting to another structure?
exocrine
What kinds of glands synthesize substances that are released into the bloodstream to affect target tissue?
endocrine
Endocrine cells can comprise a single gland or…
be scattered throughout the tissue of an organ with other functions
The endocrine system and nervous system work together to keep the body in…
homeostasis
Endocrine cells produce substances that are released into the bloodstream to have an effect on target structures - these substances are called…
hormones
What are hormones?
substances released into the bloodstream that are chemical messengers that will have an effect on tissues/structures that have receptors for the specific hormone
Hormone levels in the blood are regulated by self-adjusting mechanisms, or…
feedback loops
- can be either positive or negative
What is the master controller of the endocrine system?
hypothalamus
How does the hypothalamus control the endocrine functions of the body?
- Produces regulatory hormones which have an effect on the anterior pituitary gland (which produces its own hormones). Regulating hormones can either stimulate the release of hormones or inhibit them.
- Produces hormones that are transported and stored in the posterior pituitary gland until they are needed.
Stimulates sympathetics to the adrenal medulla during “fight or flight” which causes the adrenal medulla to release adrenaline.
Pituitary Gland (AKA Hypohphysis)
- sits in the hypohyseal fossa of the sphenoid bone
- suspended from hypothalamus by a stalk or infundibulum
- divided into anterior and posterior parts
What part of the pituitary gland synthesizes and releases hormones into the bloodstream under the control of the hypothalamus?
the anterior pituitary
What hormones do the anterior pituitary glands make?
- thyroid-stimulating hormone
- growth hormone
- follicle stimulating hormone & lutenizing hormone
- prolactin
- adrenococorticotropic hormones
- melanocyte-stimulating hormones
Thyroid-Stimulating Hormone
acts on the thyroid gland to release thyroid hormone, especially when cold or stressed
Growth Hormone
acts on all body tissues (especially bones and muscles to stimulate growth and size of the body
Follicle-Stimulating Hormone and Lutenizing Hormone
acts on the gonads (testes and ovaries) to stimulate the development of gametes (sperm cells and oocytes)
Prolactin
acts on the mammary glands of the breast to stimulate growth and milk production (not ejection)
Adrenocorticotropic Hormone
acts on the adrenal cortex to cause the release of corticosteroids
Melanocyte-Stimulating Hormone
acts on the melanocytes in the skin to produce melanin
The hypothalamus controls the anterior pituitary glandby releasing its regulating hormones in to the…
hypothalamic-hypophyseal portal system
Venous blood carrying regulating hormones from the hypothalamus to the capillary plexus surrounding the anterior pituitary gland are called the…
hypophyseal portal veins
The regulating hormones leave the capillary plexus to have an effect on the…
anterior pituitary
The anterior pituitary releases its hormones into the capillary plexus and are carried away by the __________ ______, back to the heart to be distributed throughout the body.
hypophyseal vein
The stalk of the pituitary gland is made up of _______ _______ running from the hypothalamus into the posterior.
nerve axons
There are ___ nuclei in the hypothalamus whose axons make up the stalk and carry hormones to the posterior pituitary gland for storage.
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