BIOL 260 - Chapter 1: Introduction to the Human Body PDF

An Introduction to the Human Body Unless otherwise indicated, An Introduction to the Human Body Lecture Slides by Yancy Aquino for Skyline College are derivative of OpenStax A&P Instructor Resources and are licensed CC BY....

An Introduction to the Human Body Unless otherwise indicated, An Introduction to the Human Body Lecture Slides by Yancy Aquino for Skyline College are derivative of OpenStax A&P Instructor Resources and are licensed CC BY. 1 } Physiology: The study of function at many levels ◦ Subdivisions are based on organ systems (e.g., renal or cardiovascular physiology) } Essential tools for the study of physiology: ◦ Ability to focus at many levels (from systemic to cellular and molecular) ◦ Basic physical principles (e.g., electrical currents, pressure, and movement) ◦ Basic chemical principles 2 } Chemical: atoms and molecules } Cellular: cells and their organelles } Tissue: groups of similar cells } Organ: contains two or more types of tissues } Organ system: organs that work closely together } Organismal: all organ systems 3 Figure 1.3 Levels of Structural Organization of the Human Body Atoms Molecule Organelle Smooth muscle cell 2 Cellular level 1 Chemical level Cells are made up of Atoms combine to form molecules. molecules. Smooth muscle tissue Cardiovascular system 3 Tissue level Tissues consist of similar Heart types of cells. Blood vessels Blood vessel (organ) Smooth muscle tissue Connective tissue Epithelial tissue 4 Organ level Organs are made up of different types of tissues. 6 Organismal level 5 Organ system level The human organism is made up Organ systems consist of different of many organ systems. organs that work together closely. 5 6 7 8 9 10  Mammary glands (in breasts) Prostate gland Ovary Penis Testis Ductus Scrotum deferens Uterus Uterine tube Vagina 11 } Anabolism is the process whereby smaller, simpler molecules are combined into larger, more complex substances. } Catabolism is the process by which larger more complex substances are broken down into smaller simpler molecules. Catabolism releases energy. 12 } Responsiveness is the ability of an organism to adjust to changes in its internal and external environments. } Human movement includes not only actions at the joints of the body, but also the motion of individual organs and even individual cells. Figure 1.7 Marathon Runners Runners demonstrate two characteristics of living humans— responsiveness and movement. 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) 13 1. Nutrients ◦ Chemicals for energy and cell building ◦ Carbohydrates, fats, proteins, minerals, vitamins 2. Oxygen o Essential for energy release (ATP production) 3. Water ◦ Most abundant chemical in the body ◦ Site of chemical reactions 4. Normal body temperature o Affects rate of chemical reactions 5. Appropriate atmospheric pressure ◦ For adequate breathing and gas exchange in the lungs 14 } Homeostasis ◦ Maintenance of a relatively stable internal environment despite continuous outside changes ◦ A dynamic state of equilibrium } Homeostatic Control Mechanisms ◦ Involve continuous monitoring and regulation of many factors (variables) ◦ Nervous and endocrine systems accomplish the communication via nerve impulses and hormones } Disturbance of homeostasis ◦ Increases risk of disease ◦ Contributes to changes associated with aging ◦ May allow destructive positive feedback mechanisms to take over (e.g., heart failure) 15 } A negative feedback system has three basic components (Figure 1.10). ◦ A sensor, also referred to a receptor, is a component of a feedback system that monitors a physiological value. ◦ The control center is the component in a feedback system that compares the value to the normal range. ◦ An effector is the component in a feedback system that causes a change to reverse the situation and return the value to the normal range. 16 Figure 1.10 Negative Feedback Loop In a negative feedback loop, a stimulus—a deviation from a set point—is resisted through a physiological process that returns the body to homeostasis. (a) A negative feedback loop has four basic parts. (b) Body temperature is regulated by negative feedback } Positive feedback ◦ intensifies a change in the body’s physiological ◦ A deviation from the normal range results in more change, and the system moves farther away from the normal range. ◦ Normal only when there is a definite end point. ◦ Childbirth and the body’s response to blood loss are two examples of positive feedback loops that are normal but are activated only when needed. Figure 1.11 Positive Feedback Loop 18 } X-ray is a form of high energy electromagnetic radiation with a short wavelength capable of penetrating solids and ionizing gases. Figure 1.18 X-Ray of a Hand 19 } Computed tomography (CT) is a noninvasive imaging technique that uses computers to analyze several cross- sectional X-rays in order to reveal minute details about structures in the body Figure 1.19 Medical Imaging Techniques (a) Results of a CT scan of head are shown as successive transverse sections. (b) MRI machine generates a magnetic field around a patient. (c) PET scans use radiopharmaceuticals to create images of active blood flow and physiologic activity of the organ or organs being targeted. (d) Ultrasound technology is used to monitor pregnancies because it is the least invasive of imaging techniques and uses no electromagnetic radiation. 20