What is homeostasis?
Homeostasis is the body’s internal system adjusting to changing conditions in the internal/external environment
All homeostatic systems have three components. What are they?
What kind of receptors in the skin detect a decrease in temperature?
Thermoreceptors
Breakdown of thermoreceptors:
Breakdown of thermoreceptors:
Thyroxine tells all body cells to increase _______ metabolism, increasing ________ in the body.
glucose metabolism, heat production (temperature)
What is a dynamic equilibrium?
A condition that remains stable with fluctuating limits
In regards to TRH and TSH, which part of the pituitary are they involved in?
(anterior or posterior)
Anteriori pituitary
When the body becomes too _____, ________ feedback tells the hypothalamus to slow the production of _____.
hot (too much thyroxine), hypo slows production of TRH
There are two types of thyroxine, T3 and T4. What is the diff between the two?
T4: four iodine atoms and T3: three iodine atoms
What is the main characteristic of hyperthyroidism?
Too much thyroxine in the blood.
In hyperthyroidism, ________ is too high. This may cause which 3 symptoms?
Metabolism is too high.
Symptoms:
1. loss of weight
2. excessive sweating
3. bulging eyes (Grave’s disease)
4. goiter (swelling of the thyroid)
What is an autoimmune disease? What are autoimmune diseases related to hypo/hyper?
Condition in which the body’s immune system mistakes its own healthy tissues as foreign and attacks them
Hyper: Graves
Hypo: Hashimotos
What are three causes of Hyperthyroidism ?
Why is radioactive iodine used to treat hyperthyroidism?
Radioactive iodine kills thyroid cells such that less thyroxine is produced
What Hypothyroidism? What are 3 symptoms?
A condition in which the thyroid does not produce enough thyroxine (levels in blood are too low)
What are 3 causes of hypothyroidism and a treatment option?
Causes:
1. Treatment of hyper can cause hypo
2. Hashimoto’s
3. Pituitary disorder (not enough TSH)
Treatment: thyroxine supplements
In both hypo and hyper thyroidism, a goiter forms. Why?
Hyper: thyroid produces excess ______
Hypo: ______ levels are too high due to low levels of thyroxine. No _______ feedback to ________.
Hyper: thyroid produces excess thyroxine
Hypo: TSH levels are too high due to low levels of thyroxine. No negative feedback to hypothalamus.
Thermoregulation is how the body controls _______.
Temperature
What is the difference between how endotherms and ectotherms regulate temperature?
Endotherms: maintain body temp w internal mechanisms (ex. shivering, dilation of vessels in humans)
Ectotherms: absorb therm energy from environment (fish, reptiles)
Which region of the brain controls temp?
Hypothalamus
What is the difference between peripheral and central nerve receptors?
Central receptors: arteries/organs monitor core temp (slightly higher)
Peripheral receptors: in skin monitor skin temp
What is the difference between skeletal and smooth muscle?
Skeletal: can contract
Smooth: non-contractable (rib/diaphragm)
What is the difference between positive and negative feedback loops?
Negative loop: wants to offset the stimulus
Positive loop: wants to increase the effect of the stimulus
How do negative feedback loops control temp? (3 steps)