Mammals and environment: Haemoglobin, Hibernation and Circadian Rhythms Flashcards
What common features do all mammals share?
- four chambered heart atria and ventricles
- hair at some point during development
- high constant body temperature (endothermic)
- muscular diaphragm
- a lower jaw consisting of a single bone
- three bones in middle ear (malleus, incus and stapes or hammer, anvil, stirrup)
- females have milk producing glands
What are monotremata
egg-laying mammal subclass
What are marsupialia
pouched mammal subclass
What are placentalia
plaental mammal subclass
How many a days does it take for an embryo to become a developed baby at birth?
266 days
What is Estivation
Summer dormancy of an animal
What is the cranial radiator?
The blood cooled by evaporation of sweat on the face and head penetrate the skull through small emissary veins, thus delivering cooled blood to the brain.
What are the bends and what causes it?
Decompression sickness
caused when nitrogen dissolves in blood is released. The bubbles of gas become lodged in the joints or blood vessels preventing the circulation of blood.
How have marine mammals adapted to overcome decompression sickness?
Mammals have evolved so that their lungs collapse as they dive.
They have a flexible rib cage that gets pushed in by the pressure of the water.
The air in the lungs is pushed into a central location where nitrogen is not readily absorbed.
What is the function of myoglobin?
Store oxygen and to facilitate oxygen diffusion in contracting muscle tissue.
The primary oxygen carrying pigment of muscle cells
During what periods is myoglobin released?
During hypoxia and anoxia
Is myoglobin found in smooth muscle cells?
Not thought to be
Define circadian rhythm
• Physiological and behavioural characteristics that follow a daily, or circadian, pattern
E.g. sleep wake cycle, body temperature, hormone secretion
