Adaptations and Regulation Flashcards
Stimulus
change
Receptor
receives change
detects change
Control Centre
interprets the change and triggers a response
Effector
produces body’s response to the stimulus
- always a muscle or gland
Feedback: Negative
returns the body to normal
Evaporation
heat loss through water (sweat)
Convention
heat loss through air (vasodilation)
Homeostasis
the ability of organisms to the constant internal environment despite variations in external conditions
- stays the same
Thermoregulation
control of internal temperature
Hypothalamus
control centre for homeostasis
linked to the endocrine system via pituitary gland
Two pathways for homeostatic responses
nervous and hormonal
External receptors of the human body
- skin (mechano, thermo)
- eyes (photo)
- ears (mechano)
- tongue (chemo)
- nose
What do enzymes do for chemical reactions within the body?
speed up reactions
What can changes in internal conditions do to enzymes?
slow them down
What is the collective name for the parts of an organism that detect external and internal stimuli?
receptors
What is the collective name for the parts of an organism that carry out homeostatic responses?
effectors
What is the constant level of an organism’s internal environment known as?
set point
What are some of the body systems maintained by homeostasis?
- pH
- temperature
- blood pressure
- concentration of waste products
- water/salt balance
Vasoconstriction
narrowing of blood vessels so heat does not get released through the skin
Vasodilation
releases heat through blood vessels dilating
Piloerection
hair standing on end
Adaptation
enhances survival and reproductive potential of an organism in a particular environment conditions
Structural adaptations
physical features
- shape, size, body parts, colour
Behavioural adaptations
the way the organism acts
- nocturnal, migration, hibernation
