Chapter 1 Introduction Fall 2024 PDF

8/28/24 1 Anatomy & Physiology Chapter 1 2 Anatomy vs physiology Anatomy A study of the internal and external structures of body and the physical relationships to each other shape,...

8/28/24 1 Anatomy & Physiology Chapter 1 2 Anatomy vs physiology Anatomy A study of the internal and external structures of body and the physical relationships to each other shape, size, position Physiology Function Form and function are interrelated 3 Form and Function are interrelated 4 Basic Functions of Life 5 Characteristics That Describe Living Things 1. Organization All organisms exhibit a complex structure and order 2. Metabolism the sum of all chemical reactions that occur within the body 3. Movement Not just locomotion but movement within the organism 4. Responsiveness ability to sense and react to stimuli 5. Growth, development, Reproduction Produce new cells for growth, maintenance, and repair With sex cells, can develop into new organisms 6 Functions of Human Life: 1. Organization The organization of the body often is discussed in terms of six distinct levels of increasing complexity, from the smallest chemical building blocks to a unique human organism. 7 1 6 7 The View from Simplest to Most Complex Levels of organization from simplest to most complex: Chemical level – atoms, molecules, macromolecules Cellular level – cells, basic units of life Tissue level – tissues, similar cells performing common functions Organ level – organs, multiple tissues working together Organ system level – related organs work together Organismal level – organ systems function together 8 Figure 1.4 Organ Systems of the Human Body Organs that work together are grouped into organ systems. 11 organ systems of the human body: 1.Nervous system 2.Respiratory system 3.Circulatory system 4.Digestive system 5.Excretory system 6.Muscular system 9 Figure 1.5 Organ Systems of the Human Body (continued) Organs that work together are grouped into organ systems. 7.Skeletal system 8.Integumentary system 9.Immune system 10.Endocrine system 11.Male and female reproductive systems 10 Functions of Human Life: 2. Metabolism Sum of all chemical reactions in the body 10 Sum of all chemical reactions in the body Basic function of all organisms: Consume energy in food and convert it into fuel to sustain activity Two types of reactions: Catabolic and Anabolic reactions 11 Figure 1.6 Metabolism Anabolic reactions are building reactions, and they consume energy. Catabolic reactions break materials down and release energy. Metabolism includes both anabolic and catabolic reactions. 12 Functions of Human Life: 3. Movement Human movement includes not only actions at the joints of the body, but also the motion of individual organs and even individual cells. 13 Figure 1.7 Runners demonstrate two characteristics of living humans— responsiveness and regulation. Anatomic structures and physiological processes allow runners to coordinate the action of muscle groups and sweat in response to rising internal body temperature. (credit: Phil Roeder/flickr) 14 Functions of Human Life: 5. Development, Growth, and Reproduction Development is all of the changes the body goes through in life. includes the process of differentiation unspecialized cells become specialized to perform certain tasks in the body. Growth is the increase in body size. Reproduction is the formation of a new organism from parent organisms. 15  Reproduction is the formation of a new organism from parent organisms. 15 Requirements for Human Life: Oxygen Needed to access energy from nutrients Nutrients 3 basic: water, the macronutrients, and the micronutrients Narrow Range of Temperature Narrow Range of Atmospheric Pressure Atmospheric pressure is pressure exerted by the mixture of gases (primarily nitrogen and oxygen) in the Earth’s atmosphere. 16 Homeostasis Regulation is the ability to adjust internal bodily function to accommodate environment changes Homeostasis the ability of an organism to maintain consistent internal environment in response to changing internal or external conditions 17 Components of a Homeostatic Control Mechanism 18 Homeostatic Mechanisms Negative Feedback Loops Controls most processes in the body Variable fluctuates within a normal range around a set point Resulting action is in the opposite direction of the stimulus Positive Feedback Loops Occurs much less frequently than negative feedback Stimulus reinforced to continue moving variable in same 19 20  Occurs much less frequently than negative feedback Stimulus reinforced to continue moving variable in same direction until a climactic event occurs, then body returns to homeostasis 19 Thermoregulation: Negative Feedback Loop 20 Figure 1.11 Normal childbirth is driven by a positive feedback loop. A positive feedback loop results in a change in the body’s status, rather than a return to homeostasis.