Mammals
Mammals are characterized by being warm-blooded, also endothermic in having the capability to regulate their own body temperature; either have hair or fur, use lungs to breathe, have mammary glands providing milk to their young for growth at early development stages and the majority of mammals give birth to live young.
Mammals are estimated to have derived about 320 million years ago in the late Carboniferous period from early synapsids. However, it was not until the late Triassic period, 250 to 200 million years ago, that adaptive radiation occurred in significant quantites to assist in the change after the Cretaceous period.
Hominoids, our ancient cousins, developed from the old world monkeys in Africa or Asia about 25 million years ago. Our most recent ancestors hominids developed around 6-7 million years ago. Homo sapiens, (that's us) have only been around for 160,000 years. We are still babies in the evolution time frame.
Mammals digestive systems starts with consumption of food into the mouth which travels down the esophagus tube, into the stomach for enzyme breakdown and onto the small intestine for absorption. The large intestine will then house all the waste the body does not require to function and this waste will be passed out the rectum.
Mammals use many ways to aid in their survival by maintaining a balance in their homeostasis. In homo sapiens the kidneys are an important role in maintaining this regulation by removing excess water and salt from the body.
Homo sapiens also sweat, secrete water from the skin, to aid in cooling off when the body becomes overheated. Other mammals may open their mouth to inhale extra oxygen to cool down, we have all seen dogs panting trying catch their breathe to calm and cool their body temperature back to a homeostatic balance.
Positive or negative feedback is performed when trying to obtain homeostasis. Mammals use thermo-receptors in the skin to ascertain the level of heat or cold they are in. The nerve signals are sent to the brain where they are registered either too hot or cold and the mammal will adjust its behaviour to either warm or cool itself.
Mammals have a four chambered heart and double circulation. This means that the blood will be circulated twice before it is pumped once from the heart and then throughout the body.
In our dissection lab we performed a dissection on a rat.
Mammals are estimated to have derived about 320 million years ago in the late Carboniferous period from early synapsids. However, it was not until the late Triassic period, 250 to 200 million years ago, that adaptive radiation occurred in significant quantites to assist in the change after the Cretaceous period.
Hominoids, our ancient cousins, developed from the old world monkeys in Africa or Asia about 25 million years ago. Our most recent ancestors hominids developed around 6-7 million years ago. Homo sapiens, (that's us) have only been around for 160,000 years. We are still babies in the evolution time frame.
Mammals digestive systems starts with consumption of food into the mouth which travels down the esophagus tube, into the stomach for enzyme breakdown and onto the small intestine for absorption. The large intestine will then house all the waste the body does not require to function and this waste will be passed out the rectum.
Mammals use many ways to aid in their survival by maintaining a balance in their homeostasis. In homo sapiens the kidneys are an important role in maintaining this regulation by removing excess water and salt from the body.
Homo sapiens also sweat, secrete water from the skin, to aid in cooling off when the body becomes overheated. Other mammals may open their mouth to inhale extra oxygen to cool down, we have all seen dogs panting trying catch their breathe to calm and cool their body temperature back to a homeostatic balance.
Positive or negative feedback is performed when trying to obtain homeostasis. Mammals use thermo-receptors in the skin to ascertain the level of heat or cold they are in. The nerve signals are sent to the brain where they are registered either too hot or cold and the mammal will adjust its behaviour to either warm or cool itself.
Mammals have a four chambered heart and double circulation. This means that the blood will be circulated twice before it is pumped once from the heart and then throughout the body.
In our dissection lab we performed a dissection on a rat.
Reference
National Geography, 2013, "Mammals", retrieved from website April 13, 2013, http://animals.nationalgeographic.com/animals/mammals/
Victoria College, "Science Learning Hub", retrieved from website April 13, 2013, http://www2.victoriacollege.edu/dept/bio/sciencehub/Science%20Hub/Web%20Page%20Resources%20for%20Educators.html
Vertebrate Zoology, "Snake Dissection", retrieved from website April 13, 2013, http://www.savalli.us/BIO370/Anatomy/8.RatDissectionLabel.html
Victoria College, "Science Learning Hub", retrieved from website April 13, 2013, http://www2.victoriacollege.edu/dept/bio/sciencehub/Science%20Hub/Web%20Page%20Resources%20for%20Educators.html
Vertebrate Zoology, "Snake Dissection", retrieved from website April 13, 2013, http://www.savalli.us/BIO370/Anatomy/8.RatDissectionLabel.html