Welcome to Anatomy & Physiology Chapter 1 -Human Organization What do you need to do to pass this class? MEMORIZE! The Scope of Human Anatomy • Human anatomy is the study of the structure of the human body. • Provides an essential foundation for the understanding of physiology, the study of function. • It is not just the structure of organs, but also the functional reasons behind that structure. Levels of Structural Organization • Chemical Level • Cellular Level • At least two tissue types that perform a specific function Organ System • Groups of similar cells that have common function Organ Level • Various cell types Tissue Level • Atoms Molecules At least two organs that work together to accomplish a common purpose Organism The sum total of all structural levels working together to promote life Homeostatic Control Mechanisms 1. 2. 3. Homeostasis is the relative constancy of the body’s internal environment. A homeostatic mechanism as 3 components: sensor- detects change- nerves regulatory center-activates the effectorshypothalmus effector-reverses the change and brings conditions back to normal.-muscle contraction Negative Feedback is the primary mechanism that keeps a variable close to a particular value or set point. It prevents change in the same direction. Example-furnace, body temp. Positive Feedback is a mechanism that brings about an ever greater change in the in the same direction. Can be harmful, examplefever. Childbirth (oxytocin) sensor Regulatory center effector Anatomical position – a common visual reference point Person stands erect with feet together and eyes forward Palms face interiorly with the thumbs pointed away from the body Regional terms – names of specific body areas Axial region – the main axis of the body Appendicular region – the limbs Directional terminology Refers to the body in anatomical position Standardized terms of directions are paired terms Orientation and Directional Terms Orientation and Directional Terms Orientation and Directional Terms Regional Terms Regional Terms Body Planes and Sections Frontal plane - Lies vertically and divides body into anterior (front) and posterior (back) parts Sagittal plane – lies vertically and divides the body into left and right sides. Median (midsagittal) plane - Specific sagittal plane that lies vertically in the midline Transverse plane - runs horizontally and divides body into superior (up) and inferior (down) parts Body Planes and Sections Body Planes and Sections Oblique section through the trunk Figure 1.6 Body Cavities and Membranes Dorsal body cavity Cavity subdivided into the cranial cavity and the vertebral cavity. Cranial cavity houses the brain. Vertebral cavity runs through the vertebral column and encloses the spinal cord Body Cavities and Membranes Ventral body cavity – subdivided into: cavity – divided into three parts Thoracic Two lateral parts each containing a lung surrounded by a pleural cavity Mediastinum – contains the heart surrounded by the pericardial sac Body Cavities and Membranes Ventral body cavity Abdominopelvic cavity – divided into two parts Abdominal cavity – contains the liver, stomach, kidneys, and other organs Pelvic cavity – contains the bladder, some reproductive organs, and rectum Body Cavities and Membranes Serous cavities – A thin membrane lining a closed body cavity and moistened with a serous fluid. Pleura(thoracic), pericardium (heart), and peritoneum (abdomen) Parietal serosa – forms outer wall of the cavity Visceral serosa covers the visceral organs (large inner organs) Body Cavities and Membranes Other Body Cavities Oral cavity Nasal cavity Orbital cavities Middle ear cavities Synovial cavities Abdominal Regions and Quadrants Abdominal regions divide the abdomen into nine regions Abdominal Quadrants Abdominal quadrants divide the abdomen into four quadrants Right upper and left upper quadrants Right lower and left lower quadrants