NH-+8-27

p. 17 #2 what is homeostasis, and how is it maintained? Give some examples that show how systems work together to maintain homeostasis. p. 83 #7 Explain why skin is sometimes referred to as the integumentary system. p. 245 #9 How does the muscular system help maintain homeostasis? p. 271 #1 What are the three functions of the nervous system? p. 293 #1 Contrast exteroceptors and interoceptors
 * homeostasis is an internal environment for cells that usually varies only with certain limits
 * in order to maintain homeostasis the digestive system absorbs nutrients and the respiratory system exchanges gases with the environment. then, the cardiovascular system distributes the nutrients and oxygen to cells and picks up their waste. the urinary system excretes the metabolic waste products. the nervous and endocrine systems coordinate the functions of the other systems.
 * it is called the integumentary system because it has many accessory organs.
 * 1) 11 Why is homeostasis defined as the "//relative// constancy of the internal environment?" Does negative feedback or positive feedback tend to promote homeostasis?
 * it is the relative constancy because it isn't always the same but always close to the same value
 * negative promotes homeostasis because it helps regulate rather than help when the body is in extreme conditions
 * movement helps in maintaining homeostasis. contraction of skeletal muscles allow for movement. movement can be getting out of the sun, chewing, heartbeat, ect. all of these movement aid in blood being pumped through the body which generates heat.
 * receiving sensory input
 * performing intgration
 * generating motor output
 * 1) 2 What are the functions performed by the three types of neurons? Describe the structure and function of the three parts of a neuron.
 * a sensory neuron takes nerve impulses from a sensory receptor to the CNS
 * an interneuron is in the CNS. it receives input from sensory neurons and other interneurons and then sums up all of the information before communicating with the motor neurons.
 * a motor neuron takes nerve impulses away from the CNS to an effector.
 * 3 parts
 * the cell body contains the nucleus and other organelles
 * the dendrites receive signals from sensory receptors
 * the axon conducts nerve impulses
 * Both are dendrites. Exteroceptors detect stimuli from outside the body (i.e. taste, smell ect) while interoceptors detect stimuli from inside the body (i.e. blood pressure)
 * 4