Chapter 9: Homeostasis Flashcards
What is homoeostasis?
The maintenance of relatively constant internal environment within small tolerance limits, despite changes in the external environment
What are tolerance limits?
The highest and lowest values of a particular factor (for example temperature, blood glucose levels) that an organism can tolerate
What are the five main categories of receptors?
Chemoreceptors, mechanoreceptors, photoreceptors, thermoreceptors and nociceptors
What are chemoreceptors?
A receptor that detects a chemical stimulus such as oxygen concentration and pH
What are mechanoreceptors?
A detector that detects a physical stimulus such as touch and sound
What are photoreceptors?
A detector that detects light
What are thermoreceptors?
A detector that detects changes in temperature
What are nociceptors?
A detector that detects only intense (painful) chemical, mechnical or thermal stimulation
What are exteroceptors?
A receptor that specifically receives signlas from outside the body, such as air tmeperature, painful pressure or smells
What are interoceptors?
A receptor that recieves signals from inside the body, such as body temperature, oxygen concentration or pH
What is interstitial fluid?
Extracellular tissue fluid; fluid in spaces surrounding cells
What are the two categories of effectors?
Muscles and glands
What is a motor neuron?
A cell that transmits nerve impulses from the central nervous system to an effector
What are the two types of glands?
Endocrine and exocrine glands
What are endocrine glands?
A gland that secretes substances directly into the bloodstream
