Regulation Of Systems Flashcards
(26 cards)
What facilitates material through plants
vascular tissue xylem and phloem
What is stomata?
A pore or hole regulated by two guard cells turgid cell (open stomata) and flaccid guard cell (closed stomata)
How do plants maximise water uptake?
Plsnts called water tappers have roots that grow long snd penetrate the moist soil until it finds moisture and absorbs the water.
How does surface srea contribute to heat dispersion
The greater the surface area to volume ratio the higher its ability to disperse heat.
How do plants prevent from freezing
Plant cells make antifreeze proteins and secrete into intercellular spaces (cell wall region)the proteins prevent ice from forming in extracellular spaces.
What is homeostasis?
Homeostasis is the maintenance of a relatively stable internal environment
Which srea in the brain control physiological processes?
Hypothalamus
What are most homeostatic mechanisms regulated by?
Endocrine system and nervous system
What is the stimulus response model?
- Stimulus
- Receptor
- Control centre
- Effector
- Response
Negative feedback loop?
The negative feedback loop is when the response counteracts the stimuli
What is the positive feedback loop?
A positive feedback
Loop is a cycle of continuing change where the stimulus is amplified
What is regulation of body temperature called?
Thermoregulation
Whats tje body temperatures?
Core body temperature is 36.5°-37° and peripheral surface temperature (close to skin) is 25°-30°
What is ectothermic?
Ectothermic heat sources depend on external sources of energy. For this less food is needed and periods of activity is restricted due to conditions.
What is endothermic?
Endothermic hest sources are built inside and rely on body heat. Due to this lots of food is needed and 80% goes to maintaining body temp.
Strategies to control hear gain/loss
- shivering
- Metabolic rate
- piloerection
- sweating
- behavioural activities
- vasoconstriction/vasodilation
What is shivering?
Shivering is the involuntary action of small muscle contractions and relaxation.
What is metabolic rate?
Metabolic processes in the body produce heat due to more energy burning quickly.
What is vasoconstriction?
Vasoconstriction is when the arterioles narrow and all the blood flows through the shunt vessels. Keeping heat to the core of the body
What is vasodilation
Vasodilation is the process of the blood vessels widening allowing for blood to flow freely and closer to the skin. This lowers heat temp since the heat can be released.
What is piloerection
Piloerection is the process of air getting trapped in the erect hair above the skin and insulating the skin.
What is sweating
Sweating is the process of the body heat evaporating off the skin via the sweat glands that r triggered by the hypothalamus
Stimulus response model for temp too low?
- Decrease in body temp
- Detected by thermoreceptors in skin, organs and hypothalamus.
- Hypothalamus sends signal to effector via hormonal system and nerve
- Effector (skeletal muscle, blood vessel, cerebral cortex and body cell)
- Shivering, vasoconstriction, behavioural changes and increased metabolic rate.
Stimulus response model too high
- Increase im body temp
- Detected by thermoreceptor in skin, organ and hypothalamus.
- Hypothalamus sends signals to effector via hormonal system and nerve
- Sweat gland, blood vessel, cerebral cortex, body cells
- Sweating, vasodilation, behavioural changes and decrease metabolic rate.
