Gero 310 F'09 endocrine 1

Gero 310 F'09 endocrine 1 - Endocrine system functions: Chp...

Info iconThis preview shows pages 1–9. Sign up to view the full content.

View Full Document Right Arrow Icon
Endocrine system functions : general = to maintain homeostasis across multiple systems Chp 14 * specifically, to maintain constant internal environment in the presence of a constantly changing external and internal environments • works in concert with the nervous system * nervous system produces rapid, short-acting effects, endocrine system elicits slow but long-lasting responses • nervous system operates by direct synaptic connections * endocrine system communicates by release of factors * nerv. sys. direct contact; endocrine can be spatially distant
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
• types of communication/signaling : 1) autocrine = cell secret factors into extracellular space which then stimulate its own receptors 2) paracrine = cells secrete factors into extracellular space which then stimulate receptors on nearby cells (local effects ) 3) endocrine = cells secrete factors into bloodstream which can affect cells all over body 4) exocrine = cells secrete factor into lumen which has direct connection to external environment (e.g., digestive enzymes) 5) synaptic connection = cell secretes factor which affects cells directly associated via a synapse
Background image of page 2
Normal physiology of endocrine system • in general, endocrine system works by: 1) detector to measure current state, any changes from normal 2) effector to return altered system to normal range 3) mechanism to shut down effector when homeostasis is restored
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
• more specifically, endocrine system function involves: * detection by nervous system or endocrine gland * the effector is a hormone (chemical messenger secreted into bloodstream ) ** hormones cause response by binding to receptors and inducing signal transduction pathways on target organs - the organ response to the hormone will correct the imbalance in homeostasis
Background image of page 4
* effector is shut down by negative feedback : 1) detector is sensitive to parameter being regulated - can be hormone or substrate (e.g., Ca ++ ) 2) increase in hormone levels stops hormone release from Col. State Univ.
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Types of endocrine glands 1) pineal gland = in brain; regulates circadian rhythms 2) pituitary "master" gland that controls many other glands 3) thyroid = involved in growth and metabolic activity 4) parathyroid = calcium homeostasis 5) thymus = immune function 6) adrenal 7) pancreas = blood sugar levels 8) ovaries/testes = reproductive functions
Background image of page 6
1) pineal gland - located in brain - functions in the regulation of circadian rhythms - receives input and responds to info on light levels - detects total levels of light/dark each day to help regulate seasonal behaviors (e.g., reproduction)
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
- secreted hormone = melatonin - low levels of melatonin produced in other tissues, e.g., retina - melatonin secretion is highest at night when light is low - melatonin secretion also varies seasonally by length of day - shorter days/longer nights = higher melatonin levels - melatonin is derived from the neurotransmitter serotonin - serotonin is derived from tryptophan
Background image of page 8
Image of page 9
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 30

Gero 310 F'09 endocrine 1 - Endocrine system functions: Chp...

This preview shows document pages 1 - 9. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online