Mammals have hair and the ability to nourish their young with milk thanks to the mammary glands present in female mammals. All mammals breathe air, have four chambered hearts and are endotherms, which means they can generate heat internally and is an example of homeostasis.
Other Characteristics:
- Much higher metabolic rate than most other chordates
- External hair and subcutaneous fat
- Sweat glands that help cool the body
Mammals Body Plan and rat Dissection
Reproduction in mammals:
When mammals mate, the male deposits sperm inside the reproductive tract of the female and fertilization occurs. Mammals can be classified according to their modes of development and birth, however all new born mammals feed on their mother´s milk.
Oviparous: egg-laying
Viviparous: live-bearing which means the embryos develop within the mother for a while and then are born alive.
Respiration in mammals:
All mammals use lungs to breathe, these are controlled by two sets of muscles.
Mammals inhale when muscles in the chest lift the rib cage up and outward, at the same time the diaphragm pulls the bottom of the chest cavity downward,increasing the volume of the chest cavity and pulling air to the lungs. When the chest muscles lower the rib cage, the diaphragm relaxes and the volume of the chest cavity decreases; pushing the air out of the lungs.
