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Integument
- epidermis: thick and keratinized surface cells (filled with keratin and lipids forming a protective layer)
- Basal Epidermal Layer: produces new epithelial cells
- Dermis: much thicker than the epidermis. has blood vessels (temp regulation)
- sebacious glands: secrete sebum to lubricate and water proof skin and hair
- Eccrine/Sweat glands: temp regulation
- mammal skin also includes: fat, hair and arrector pilli muscles (raise hair for temp and behaviour)
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Types of hair (2)
- Guard hairs: long and course (with oil are weather proof)
- Under Coat: short fine hairs for insulation (arctic mamals - carabou- have air filled hairs for extra insulation)
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Generalizations on support and locomotion
- 7 neck vertebrae (cervical): except for sloths and manatees that can be elongated (giraffe) or compressed (wales)
- trunk is divided into thoracic and lumbar regions: thoracic contain ribs for anterior organ protection and are articulated for flexibility. lumbar have interlocking processes for support at the expense of flexability.
- sacral vertebrae are fused: advantageouse for locomotion (weight bearing) but bad for birth
- last set of vertebrae contain caudal vertebrae: tails usefull for locomotion, thermoregulation , and balance. (apes instead have a coccyx)
- Appendicular skeleton is rotated under the body: therefore the appendicular skelly bears the weight of the body. (muscle mass is proximal to move the legs which fight gravity?)
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Food aquizition
- 2 sets of teeth in our lifetime: (milk teeth and adult teeth
- heterodont dentition: teeth different shapes and sizes
- homodont dentition: teeth all the same shape
- secondary palate: seperates digestive and respiratory paths (allow baby to suck and breath)
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Digestion
- ailamentary canal length based off of diet and phylogenetic history: (herbivores have longest as plants are poor in nutrition and are not easily digested)
- Liver and Pancreas: allow for high metabolic rate and endothermic balance
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Respiration
- bronchi branch into alveoli to increase surface area for oxygen exchange
- unlike book gills lungs only have 1 opening to the outside so some air remains (35%) in what is called the ded space
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Circulation
- 4 chambered heart
- 2 circuits (systemic and pulmonary)
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Excrition
- mammals have a metanephric kidney: modified for endothermy
- glomerular capillary tuft: (bowmans capsule) modified to enhance increased blood flow and higher blood pressure.
- parts: bowmans capsule, glomerulus, collecting tubule, loop of henle
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Sensory abilities
- complex brain best at: vision , hearing, smell, and touch
- ultrasound: used for echolocation, communication, and prey location (catacaens/dolphins, rodents, and insectavorous bats)
- high sound frequencies give a better description than lower frequencies
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Reproduction
- mammals are amniotes: 2 subclasses
- Prototheria: contains extinct species and monotremes and theria (marsupials and placentals)
- Monotremes: egglaying species (platypus)
- marsupials are viviparous and have a simple placenta (placentals have a complex placenta/ rat is placental)
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