Unit 7 Notes 10/8/13

• Animals have exoskeletons that can be made of chitin. Animals with ingrowths of the exoskeleton are apodemes, which is shown in shedding.
• Diffusion is the downward slope of the amount of a substance
• Circulatory systems help remove waste, which is dissipation
• Energy requirements vary for body size
• Epithelial tissues cover the outsides of organs and structures in the body. Different subsections of the tissue are different shapes to serve the different functions of the body
• Connective tissues?
• Muscle tissues are made up of smooth, skeletal, and cardiac muscles
• Smooth muscle happens involuntarily, like the tubes of the digestive system
• Skeletal muscles are under voluntary control
• Cardiac muscle is only in the heart, and is involuntary 
• Nervous tissues transmit electrical impulses to specific parts of the body
• Homeostasis is the maintenance of the equilibrium. A change of the environment is a stimulus.
• Negative feedback is what the body does to move towards homeostasis
• Positive feedback moves the body away from homeostasis
• Blood glucose levels are an example of Feedback Mechanisms
• An example of positive feedback is contractions during childbirth
• A set point is the standard of the body for homeostasis
• A maintained body temperature belongs to ectotherms
• A varying body temperature is with endotherms
• Animals conserve heat with fur or feathers or shivering
• They dissipate heat with radiation and heat transfer to the outside of the body