Lesson 1 Flashcards
(12 cards)
What is homeostasis?
Maintenance of a constant internal environment and within a living organism irrespective of the external conditions
Name some examples of homeostatic control
• Regulation of blood glucose levels
• Regulation of solute potential
• Regulation of core body temperature and pH
How does negative feedback work in homeostasis?
• Detector/receptor monitors condition and provides input to control centre/coordinator
• That evaluates information snd provides output to effector
• That makes response designed to return the change to normal
Describe difference between negative and positive feedback
Negative feedback decreases a change whereas positive feedback increases it
Name some examples of positive feedback
• Oxytocin stimulates contraction of uterus at the end of pregnancy and this contraction stimulates production of oxytocin
• Platelets adhere to a cut and secrete signalling molecules which attract more platelets
What is thermoregulation?
Restoration of core body temperature back to norm
Where is control centre of thermoregulation?
Hypothalamus in the brain
What is nitrogenous extraction?
Surplus amino acids not used for synthesis of proteins and other nitrogenous compounds are deaminated in liver because they can’t be stored
How is nitrogenous extraction carried out?
• Amine group removed
• Removed amine group converted to ammonia
• CO2 added so less toxic urea formed which is transported in blood plasma to kidney
• Urea is removed by the kidneys and excreted in urine
What is osmoregulation?
Control of water content by balancing water gain and loss and solute composition of body fluids such as blood and tissue fluid
Name methods of water gain
• Food
• Metabolic water from respiration
Name methods of water loss
• Urination and egestion of faeces
• Sweating
• Moist exchange surfaces during ventilation
