6. Detecting and regulating change Flashcards
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What is a receptor?
A structure that is able to detect change in the body’s internal and external environment
What is a sense organ?
Receptor cells of a particular type that are grouped together
What are thermoreceptors and what do they do?
Respond to hot and cold
In the skin, inform brain to changes outside the body received by the hypothalamus and cerebrum
What are skin thermoreceptors?
Are nerve endings and either are sensitive to either hot or cold, not both
How is temperature inside the body monitored?
Monitored by thermoreceptors in the hypothalamus, detecting the temperature of blood flowing through the brain
How is osmotic pressure determined?
By the concentration of substances dissolved in the water of the blood plasma
Where are osmoreceptors found?
In the hypothalamus and are sensitive to osmotic pressure
What do osmoreceptors do?
They respond to very small changes, stimulate the hypothalamus so the body’s water content is manipulated within narrow limits
Where are chemoreceptors found?
Chemoreceptors are present in the nose (odour sensitivity) and in the mouth (sensitivity to taste)
What are chemoreceptors sensitive to?
Internal chemoreceptors are sensitive to the composition of bodily fluids, especially those in certain blood vessels that are sensitive to the pH of the blood and to concentrations of O2 and CO2
Where are touch receptors found?
Mainly in the skin
There are different types
What are the types of touch receptors?
Close to the surface: sensitive to light touches, occurring in greater concentrations in sensitive areas (lips, fingertips, eyelids etc.)
Nerve endings: At the base of each hair follicle, respond to any light touch that bends a hair
Some are deeper in the skin and are sensitive to pressure and vibrations
Do touch receptors adapt quickly or slowly?
Both adapt rapidly and after a short amount of time, you are no longer aware of the touch
How are pain receptors stimulated?
Pain receptors are stimulated by damage to the tissues (cut, heavy bump, poor blood flow, excessive heat or chemical stimulation)
Where are pain receptors found?
Concentrated mostly in the skin and mucous membranes
Occur in most organs, but not the brain
Why are pain receptors essential?
Because it tells us when damage to the tissues are occurring to warn us to take evasive action or seek medical helps
Why does pain become worse over prolonged stimulation?
Because they adapt a very little amount so the pain continues when the stimulus is present
What is a reflex?
A rapid, automatic response to changes in internal and external environments