Topic 9 Endocrine System Flashcards
Def.
A system of glands and cells that secrete hormones to regulate and integrate body systems
A control system
Endocrine System
Organs that secrete substances into the blood response to stimuli
Endocrine glands
*glands work slower (seconds - hours - days)
Def.
Chemical messengers (aka mediator molecules)
Released into the interstitial fluid which then enters the bloodstream, and via the circulation, have access to body cells
They are released in one part of the body to regulate activity in another
Hormones
To function (able to deliver their message), hormones must bind to THESE on the cell membranes of target cells/ organs When hormones bind to THESE, it changes the shape of it Changing the \_\_\_\_\_\_ shape activates pathways that modify cellular functions (eg. the message delivered)
Hormone receptors
T/F
1) One hormone can regulate different body functions
2) One body function can be regulated by different hormones
True
The increase in target cell receptors due to a lack of circulating hormone
This increases sensitivity to hormones
Up regulation
- Need to increase doorway to increase sensitivity to hormones
The decrease in target cell receptors due to an excess of circulating hormone
This increases sensitivity to the hormone
Down regulation
- Remove doorways to decrease sensitivity to hormone
_____ will fluctuate depending on demand and normal body rhythms
Normal ______ can be altered by environment, stress, inflammation, and pathologies
Normal rhythms are often absent in disease states
Hormone levels
*24 hr cycle (circadian rhythm)
Most hormones are present in the body at all times
Secretion control is caused by ? (3)
Nervous system (endocrine syst) Chemical changes in the blood Other hormones
T/F
In most cases, hormones levels are managed through a negative feedback loop
True
Name the endocrine glands (5)
Pituitary Thyroid Parathyroid Adrenal Pineal
Other organs that secrete hormones (their PT job) (11)
Hypothalamus Thymus Ovaries/ testes Pancreas Kidneys Stomach/ small intestine Heart Adipose tissue Placenta Liver Skin
These 2 organs regulate all aspects of growth, development, metabolism and homeostasis
Hypothalamus & Pituitary
It is the major integrating centre b/w the nervous and endocrine systems
Received input/ information from many different structures
Controls the Autonomic Nervous system, regulates body temperature, thirst, hunger, some emotions
Hypothalamus
Hormonally - regulates the synthesis and release of anterior pituitary hormones
Neurologically - regulates the synthesis and release of posterior pituitary hormones
Hypothalamus
***** Hypothalamus controls the Pituitary
