bio5endocrine.ppt
TRANSCRIPT
![Page 1: bio5endocrine.ppt](https://reader033.vdocuments.site/reader033/viewer/2022060109/55578cc5d8b42ad4278b4f54/html5/thumbnails/1.jpg)
The endocrine system
Its control over body functions
![Page 2: bio5endocrine.ppt](https://reader033.vdocuments.site/reader033/viewer/2022060109/55578cc5d8b42ad4278b4f54/html5/thumbnails/2.jpg)
What is an endocrine gland?
• Secretory structure
• Secretes into interstitial fluid, then blood
• Secretion rates are extremely low
• All are highly vascularized
• What ARE the endocrine glands?– Pituitary, thyroid, parathyroid, adrenal pineal– Many other organs and tissues have
endocrine function
![Page 3: bio5endocrine.ppt](https://reader033.vdocuments.site/reader033/viewer/2022060109/55578cc5d8b42ad4278b4f54/html5/thumbnails/3.jpg)
What is a hormone?
• Small molecule, protein, glycoprotein or lipid
• Released into blood
• Binds to specific receptors– Receptors can be blocked– Hormones can be synthesized– Cells may vary the number of receptors
![Page 4: bio5endocrine.ppt](https://reader033.vdocuments.site/reader033/viewer/2022060109/55578cc5d8b42ad4278b4f54/html5/thumbnails/4.jpg)
Overview of the endocrine system
![Page 5: bio5endocrine.ppt](https://reader033.vdocuments.site/reader033/viewer/2022060109/55578cc5d8b42ad4278b4f54/html5/thumbnails/5.jpg)
Important endocrine glands
• Structure and location
• Hormones produced
• Target cells
• Function
• Effects of insufficiency or overproduction
![Page 6: bio5endocrine.ppt](https://reader033.vdocuments.site/reader033/viewer/2022060109/55578cc5d8b42ad4278b4f54/html5/thumbnails/6.jpg)
Hypothalamus/pituitary gland
![Page 7: bio5endocrine.ppt](https://reader033.vdocuments.site/reader033/viewer/2022060109/55578cc5d8b42ad4278b4f54/html5/thumbnails/7.jpg)
Two lobes to (adult) pituitary
• Anterior (adenohyphosis)– Pars distalis, pars tuberallis– Secretes hormones that regulate many body
functions– Is itself regulated by releasing and inhibiting
hormones– Portal system delivers the hromones
![Page 8: bio5endocrine.ppt](https://reader033.vdocuments.site/reader033/viewer/2022060109/55578cc5d8b42ad4278b4f54/html5/thumbnails/8.jpg)
Hormones secreted by anterior pituitary cells
• Human growth hormone (somatotrophs)
• Thyroid-stimulating hormone (thyrotrophs)
• Follicle-stimulating hormone; luteinizing hormone (gondaotrophs)
• Prolactin (lactotrophs)
• ACTH (adrenocorticotropic hormone) and MSH (melanocyte-stimulating hormone)
![Page 9: bio5endocrine.ppt](https://reader033.vdocuments.site/reader033/viewer/2022060109/55578cc5d8b42ad4278b4f54/html5/thumbnails/9.jpg)
Posterior pituitary
• Neurosecretory cells– Oxytocin– Antidiuretic hormone
(ADH)– Transported out of
axons, into posterior hypophyseal veins
![Page 10: bio5endocrine.ppt](https://reader033.vdocuments.site/reader033/viewer/2022060109/55578cc5d8b42ad4278b4f54/html5/thumbnails/10.jpg)
The thyroid gland
![Page 11: bio5endocrine.ppt](https://reader033.vdocuments.site/reader033/viewer/2022060109/55578cc5d8b42ad4278b4f54/html5/thumbnails/11.jpg)
Thyroid hormone affects metabolic rate
Disorders are common
![Page 12: bio5endocrine.ppt](https://reader033.vdocuments.site/reader033/viewer/2022060109/55578cc5d8b42ad4278b4f54/html5/thumbnails/12.jpg)
Location and histology of the parathyroid gland
![Page 13: bio5endocrine.ppt](https://reader033.vdocuments.site/reader033/viewer/2022060109/55578cc5d8b42ad4278b4f54/html5/thumbnails/13.jpg)
What does parathyroid hormone (PTH) do?
• Increases number and activity of osteoclasts→more calcium in blood
• In kidneys, promotes reabsorption of calcium and excretion of phosphate
• Increases absorption of calcium from intestine through formation of calcitrol
![Page 14: bio5endocrine.ppt](https://reader033.vdocuments.site/reader033/viewer/2022060109/55578cc5d8b42ad4278b4f54/html5/thumbnails/14.jpg)
Adrenal glands
• Paired glands lie superior to kidneys• Cortex (outer part) and medulla (inner part)
derive from different tissues• Cortex produces “stress hormones”; can’t live
without them!– Zona glomerulosa (mineralocorticoids)– Zona fasciculata (glucocorticoids)– Zona reticularis (androgens)
• Medulla produces epinephrine and norepinephrine
![Page 15: bio5endocrine.ppt](https://reader033.vdocuments.site/reader033/viewer/2022060109/55578cc5d8b42ad4278b4f54/html5/thumbnails/15.jpg)
Location, blood supply, histology of adrenal glands
![Page 16: bio5endocrine.ppt](https://reader033.vdocuments.site/reader033/viewer/2022060109/55578cc5d8b42ad4278b4f54/html5/thumbnails/16.jpg)
Pancreas is an endocrine and exocrine gland
99% of tissue
A cells- glucagonB cells- insulinD cells- somatostatinF cells- pancreatic
polypeptide
Responds to eating or fasting
![Page 17: bio5endocrine.ppt](https://reader033.vdocuments.site/reader033/viewer/2022060109/55578cc5d8b42ad4278b4f54/html5/thumbnails/17.jpg)
Pineal gland
• Part of epithalamus
• Melatonin helps regulate biorhythms
• May regulate reproductive function
• Other tissues have endocrine function but primary role may be different (digestive system, heart, kidneys, etc.)
![Page 18: bio5endocrine.ppt](https://reader033.vdocuments.site/reader033/viewer/2022060109/55578cc5d8b42ad4278b4f54/html5/thumbnails/18.jpg)
Summary
• Endocrine organs are distributed over the body
• Some are regulated by hypohtalamus and pituitary, some by negative feedback
• Exert effects by releasing hormones that activate specific cells
• Abnormal levels of hormone secretion or activity can cause complex disorders