5. Homeostasis Flashcards
What are the components of homeostasis?
- receptor or sensor
- control centre
- effector or response
How does the function of homeostasis create a physiological and behavioural response?
the physiological response will be something to support their body - internally
the behavioural response will be an external voluntry decision to change the situation, eg seeking sheleter in the cold
Define what an ectotherm is and what kind of environment they can live in
gain heat from the external enviornment
Define what an endotherm is and how tolerable they are to envionrment change
warmed by heat generated by metabolism
Name two positives and two negatives of being an endotherm
positives: animals can maintain a high level of aerobic metabolism (can move faster) can maintain more stable body temperatures
negatives: more energetically expensive, require more food for energy
What are the four modes of heat exchange that can cause a loss or gain of heat?
- Radiation: emmision of electromagnetic waves eg lizard absorbs heat from sun
- evaporation: removal of heat from the surface of a liquid that is losing some of its molecules as gas
- convection: transfer of heat by movement of air or liquid passing
- conduction: direct transfer of heat such as sitting on a hot rock
How does insulation physiologically work in animals? name this process of adjustment
acclimisation -
changes in the level of metabolic heat
amount of isulation - thickness of coat
What is the integumentary system? (Its a fancy word for someting not so hard)
The organ system in mammals that protects the inside of the body from the outside. Eg skin, hair and nails
How does the structure of the integumentary system relate to its function for thermoregulation?
- the capillaries can regualte how much blood goes through which can regulate temperature
- muscle contraction of hair follicles which stops the free movement of air on the skin surface
- sweat gland externally release fluid to cool down skin
What is vasconstriction and how does it help thermoregulation?
its a circulatory adaption to regulate the blood flow near surfaces to control body temperature. The contraction of blood vessels. Reduces heat
what can ectortherms adjust to acclimitise?
have celluar adjustment - enymes, lipids in cell membranes
How does decreased osmotic pressure in the blood occur and what are three things that occur
its when an animal is overhydrtaed -
reduced water absorbtion in the digestive tract occurs
reduced thrist
greater water loss via urine
How does an increased osmotic pressure of the blood occur and what are three things that happen
happens from being dehydrated. causes ADH (atidiuretic hormone) to promote reabsorbition of water from the kidney
reduces the urine excreted.
stimulates water thrirst
What does low blood glucose stimulate (1 point) and what does it release from the liver?
- stimulates hunger
- releases the hormone glucgon
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What does high blood glucose stimulate (2 points) and what regulates it?
- inhibits desire to eat
- stimulates storage of energy
- regulated by insulin
What does regulation of blood pH acidosis stimulate? Two points
- its a low ph
- A high heart rate
- decrease loss of bicarbonate (HCO3) - the kidney and digestive tract retains it
What are two physiological homeorhetic mechanisms during early pregnancy
- nutrients are directed to the uterus
- stores excess energy as triglyceride in adipose and glycogen in liver and muscle
