the thermoregulatory system Flashcards
what is homeostasis?
the process by which the internal environment of an organism is controlled
what can responses to change be made through?
nerves and hormones
what does homeostasis allow the control of?
-blood glucose levels
-internal body temperature
what happens when the body detects changes in temperature?
they respond and corrects them to a ‘set point’ by a mechanism known as negative feedback
what is the body temperature of… human?
36.1-37.2 degrees C
what is the body temperature of… dog?
37.9- 39.9 degrees C
what is the body temperature of… pig?
38.7- 39.8 degrees C
what is the body temperature of… chicken?
40.6- 43.0 degrees C
where is the thermoregulatory system located?
the hypothalamus
what is the change in temperature detected by?
thermoreceptors in brain and skin
what are the 3 stages when change in temperature is detected?
- stimulates thermoreceptors- this relays info via sensory neurons to the hypothalamus
2.the hypothalamus sends information via motor neurons to effectors- e.g., skin
3.response occurs- e.g., sweating or shivering
response to high temperature:
what is vasodilation?
arterioles dilate -allows more blood to enterthe capilliaries
response to high temperature:
what is Pilorelaxation?
Pilli erector muscles relax- lowers hairs feathers on skin- so air can circulate
response to high temperature:
what is sweating?
glands secrete sweat onto the skin - when it evaporates it takes heat away
response to high temperature:
what is gular fluttering?
increases heat loss through mouth -occurs in birds
response to high temperature:
what is panting?
panting is the process of evaporation of water within nasal passages, mouth, lungs and air sacs (in birds)
response to high temperature:
what are behavioral changes?
changing out body gives a larger surface area for heat loss
response to low temperature:
what is vasoconstriction?
arterioles constrict- so less blood flows
response to low temperature:
what is piloerection?
Pilli erector muscles contract causing hair and feathers on skin to be raised- traps a layer of insulating air
response to low temperature:
what is shivering?
muscles contract and relax rapidly and cause heat to be produced by friction and respiration
response to low temperature:
what is brown adipose tissue (BAT)?
cells take lipids and run them through the mitochondria to generate heat
response to low temperature:
what are behavioral changes?
curling up causes a smaller surface area for heat to escape
what is metabolic rate?
it gives of heat so that animals can alter their internal body temperature
what is hypothermia?
when body temperature drops below normal temperature
what are the symptoms of hypothermia?
mild symptoms- weakness, shivering, lack of alertness
moderate symptoms- muscle stiffness, low blood pressure
severe symptoms- fixed or dilate pupils, in audible heartbeat, difficulty breathing, coma
can result in death
what is hyperthermia?
the elevation of body temperature from normal body temperature
what are the symptoms of hyperthermia?
panting, dehydration, reddening of gums, decease of urination, uncoordinated movement, unconsciousness
can lead to organ dysfunction and death
what are three types of adaptations?
-physiological
-anatomical
-behavioral
what are physiological adaptations?
adaptations in animals body processes
what are anatomical adaptations?
adaptations in animals shape and structures
what are behavioral adaptations?
adaptations in the animal’s language, tool, survival strategies
what are the three-selection pressure on variation?
-stabilizing
-directional
-diversifying/ disruptive
what is stabilizing selection pressure?
reducing the variation between DNA
what is directional selection pressure?
encourages a particular new phenotype -due to changes in the environment
what is diversifying/disruptive selection pressure?
increases the variation between animals’ DNA
