CHAPTER 1 Introduction to the Human body Objective E To explain what is meant by homeostasis ly stable ey body so that cellular metabolic functions can proceed at maximum efficiency. Homeostasis is maintained by effectors(generally muscles or glands), which are regulated by sensory informa- on from the internal environment 1. 13 What is negative feedback, and how is it used to help maintain homeostasis? Negative feedback is an important mechanism of homeostasis and is essential for virtually all body sys- tems. If a factor within the internal environment deviates too far from a normal set point, the system responsible for monitoring that factor initiates a counter change that returns the factor to its normal state (see fig. 1. 12). 1. 14 What is the relationship between homeostasis and pathophysiology? They are opposed in meaning in the sense that health reflects homeostasis, whereas abnormal function (i.e pathophysiology)marks a deviation from homeostasis. Pathophysiology is the basis for diagnosing dis- ease and instituting treatment intended to restore normal function Fight or flight ress=increased blood pressure Controlled condition Baroreceptors ↑ Blood pressure Nerves sensitive to pressure in blood vessels Return to homeostasis. blood pressure drops to Control center Vasmotor area erve Heart rate ↓ Blood pressure Figure 1.12 Homeostasis of blood pressure Feedback mechanisms in the form of input (stimulus),a monitoring center, and output(response)maintain dynamic constancy ctive F To describe the anatomical position sfvey all terms of direction that describe the relationship of one body part to another are made in ret the feet are parallel and flat on the floor, the eyes are directed forward, and the at the sides of the body with the palms of the hands turned forward and the fingers pointing downward.Objective E To explain what is meant by homeostasis. Homeostasis is the process by which a nearly stable internal environment is maintained in the body so that cellular metabolic functions can proceed at maximum efficiency. Homeostasis is maintained by effectors (generally muscles or glands), which are regulated by sensory informa￾tion from the internal environment. 1.13 What is negative feedback, and how is it used to help maintain homeostasis? Negative feedback is an important mechanism of homeostasis and is essential for virtually all body sys￾tems. If a factor within the internal environment deviates too far from a normal set point, the system responsible for monitoring that factor initiates a counter change that returns the factor to its normal state (see fig. 1.12). 1.14 What is the relationship between homeostasis and pathophysiology? They are opposed in meaning in the sense that health reflects homeostasis, whereas abnormal function (i.e., pathophysiology) marks a deviation from homeostasis. Pathophysiology is the basis for diagnosing dis￾ease and instituting treatment intended to restore normal function. CHAPTER 1 Introduction to the Human Body 7 Fight or flight response-due to stress=increased blood pressure Blood pressure Return to homeostasis; blood pressure drops to normal Blood pressure Nerve output Nerve input Control center Vasmotor area Baroreceptors Nerves sensitive to pressure in blood vessels Heart rate Cardiac output Response Controlled condition Figure 1.12 Homeostasis of blood pressure. Feedback mechanisms in the form of input (stimulus), a monitoring center, and output (response) maintain dynamic constancy. Survey Objective F To describe the anatomical position. All terms of direction that describe the relationship of one body part to another are made in ref￾erence to a standard anatomical position (fig. 1.13). In the anatomical position, the body is erect, the feet are parallel and flat on the floor, the eyes are directed forward, and the arms are at the sides of the body with the palms of the hands turned forward and the fingers pointing downward. Survey