Seeley's Anatomy & Physiology Textbook PDF

THE HUMAN ORGANISM Module #1 Anatomy- is the scientific discipline that investigates the body’s structures—for example, the shape and size of bones. The word anatomy means to dissect or cut apart and separate the parts of the body for study anatomy examines the relationship betw...

THE HUMAN ORGANISM Module #1 Anatomy- is the scientific discipline that investigates the body’s structures—for example, the shape and size of bones. The word anatomy means to dissect or cut apart and separate the parts of the body for study anatomy examines the relationship between the structure of a body part and its function. Anatomy at different levels: 1. Developmental anatomy- studies the structural changes that occur between conception and adulthood. a. Embryology (em-bree-OL-oh-jee), a subspecialty of developmental anatomy, considers changes from conception to the end of the eighth week of development. 2. Microscopic anatomy- some structures, such as cells, are so small that they must be studied using a microscope. a. Cytology (sigh-TOL-oh-jee; cyto, cell) examines the structural features of cells b. Histology (his-TOL- oh-jee; hist, tissue) examines tissues, which are composed of cells and the materials surrounding them. 3. Gross anatomy -is the study of structures that can be examined without the aid of a microscope, can be approached either systemically or regionally. 4. Surface anatomy involves looking at the exterior of the body to visualize structures deeper inside the body. 5. Anatomical imaging uses radiographs (x-rays), ultrasound, magnetic resonance imaging (MRI), and other technologies to create pictures of internal structures 6. Anatomical anomalies are physical characteristics that differ from the normal pattern. Physiology- is the scientific investigation of the processes or functions of living things. There are two major goals when studying human physiology: examining the body’s responses to stimuli and examining the body’s maintenance of stable internal conditions within a narrow range of values in a constantly changing environment. Physiology at different levels: 1. Cell physiology examines the processes occurring in cells such as energy production from food 2. Systemic physiology considers the functions of organ systems. Pathology (pa-THOL-oh-jee) is the medical science dealing with all aspects of disease, with an emphasis on the cause and development of abnormal conditions, as well as the structural and functional changes resulting from disease. Physiology at different levels: 1. Cell physiology examines the processes occurring in cells such as energy production from food 2. Systemic physiology considers the functions of organ systems. Pathology (pa-THOL-oh-jee) is the medical science dealing with all aspects of disease, with an emphasis on the cause and development of abnormal conditions, as well as the structural and functional changes resulting from disease. ASSESS YOUR PROGRESS Answers to these questions are found in the section you have just completed. Re-read the section if you need help in answering these questions. 1. How does the study of anatomy differ from the study of physiology? 2. What is studied in gross anatomy? In surface anatomy? 3. What type of physiology is employed when studying the endocrine system? 4. Why are anatomy and physiology normally studied together?  Structural and Functional Organization of the Human Body 1. Chemical level. The structural and functional characteristics of all organisms are determined by their chemical makeup. The chemical level of organization involves how atoms, such as hydrogen and carbon, interact and combine to form molecules. This is important because a molecule’s structure determines its function. For example, collagen molecules are strong ropelike protein fibers that give skin structural strength and flexibility. With aging, the structure of collagen changes, and the skin becomes fragile and more easily torn during everyday activities. 2. Cell level. Cells are the basic structural and functional units of all living organisms. Combinations of molecules form cells. Structures inside cells called organelles (OR-gah-nellz; little organs) carry out particular functions, such as digestion and movement, for the cell. For example, the nucleus is an organelle that contains the cell’s hereditary information, and mitochondria are organelles that manufacture adenosine triphosphate (ATP), a molecule cells use for energy. 3. Tissue level. Groups of cells combine to forms tissues. A tissue is composed of a group of similar cells and the materials surrounding them. The characteristics of the cells and surrounding materials determine the functions of the tissue. The body is made up of four basic tissue types: (1) epithelial, (2) connective, (3) muscle, and (4) nervous. 4. Organ level. Different tissues combine to form organs. An organ is composed of two or more tissue types that perform one or more common functions. 5. Organ system level. Multiple organs combine to form an organ system. An organ system is a group of organs that together perform a common function or set of functions and are therefore viewed as a unit. For example, the urinary system consists of the kidneys, ureters, urinary bladder, and urethra. The kidneys produce urine, which the ureters transport to the urinary bladder, where it is stored until being eliminated from the body through the urethra. 6. Organism level. An organism is any living thing considered as a whole—whether composed of one cell, such as a bacterium, or of trillions of cells, such as a human. The human organism is the combination of all the organ systems. These form a network of systems that are all mutually dependent on one another. Six Characteristics of Life______________ 1. Organization refers to the specific interrelationships among the parts of an organism and how those parts interact to perform specific functions. Six Characteristics of Life______________ 2. Metabolism (meh-TAB-oh-lizm) is the ability to use energy and to perform other vital functions. Metabolism refers to all of the chemical reactions taking place in the cells and internal environment of an organism. Six Characteristics of Life______________ 3. Responsiveness is an organism’s ability to sense changes in its external or internal environment and adjust to those changes. The third key concept of anatomy and physiology is very important for responsiveness: cell-to-cell communication. The nervous and endocrine systems regulate responses to changes in the environment through cell-to-cell communication. Six Characteristics of Life______________ 4. Growth refers to an increase in the size or number of cells, which produces an overall enlargement of all or part of an organism. Six Characteristics of Life______________ 5. Development includes the changes an organism undergoes through time, beginning with fertilization and ending at death. The greatest developmental changes occur before birth, but many changes continue after birth, and some go on throughout life. Development usually involves growth, but it also involves differentiation and morphogenesis. Six Characteristics of Life______________ 5. Development Differentiation - involves changes in a cell’s structure and function from an immature, generalized state to a mature, specialized state. Six Characteristics of Life______________ 5. Development Morphogenesis (mohr-foh-JEN-eh-sis) is the change in shape of tissues, organs, and the entire organism. Six Characteristics of Life______________ 6. Reproduction is the formation of new cells or new organisms. Reproduction of cells allows for growth and development. Reproduction allows all living organisms to pass on their genes to their offspring. HOMEOSTASIS______________ Homeostasis – the condition in which body functions, body fluids, and other factors of the internal environment are maintained within a range of values suitable to support life. To achieve and maintain homeostasis, the body must actively regulate responses to changes in variables. Variables include such conditions as body temperature, volume, chemical content and pH of body fluids, as well as many other variables. For our cells to function normally, all variables must be maintained within a narrow range. HOMEOSTASIS______________ Narrow range is referred to as a normal range. Homeostatic mechanisms normally maintain body conditions near an ideal normal value or set point. HOMEOSTASIS______________ Thermoregulation Blood Glucose Regulation Calcium Homeostasis Sweating: When the body's Insulin: After eating, blood Parathyroid Hormone (PTH): temperature rises, sweat glands glucose levels rise. The When blood calcium levels are produce sweat, which pancreas secretes insulin, which low, the parathyroid glands evaporates from the skin helps cells absorb glucose from secrete PTH, which increases surface and cools the body. the blood, reducing blood calcium levels by stimulating Shivering: When the body is glucose levels. bone resorption, increasing too cold, muscles contract Glucagon: Between meals, intestinal absorption, and involuntarily, generating heat when blood glucose levels drop, reducing calcium excretion by through increased metabolic the pancreas releases the kidneys. activity. glucagon, which signals the liver Calcitonin: When blood calcium to release stored glucose into levels are high, the thyroid gland the bloodstream. releases calcitonin, which helps lower calcium levels by inhibiting bone resorption and increasing calcium excretion by the kidneys. HOMEOSTASIS______________ Feedback Loops- A feedback loop is a biological occurrence where the output of a system amplifies the system (positive feedback) or inhibits the system (negative feedback). Feedback loops are important because they allow living organisms to maintain homeostasis. (1) negative feedback and (2) positive feedback. HOMEOSTASIS______________ Feedback Loops- A feedback loop is a biological occurrence where the output of a system amplifies the system (positive feedback) or inhibits the system (negative feedback). Feedback loops are important because they allow living organisms to maintain homeostasis. (1) negative feedback and (2) positive feedback. HOMEOSTASIS______________ Feedback loops have three components: (1) a receptor, which monitors the value of a variable by detecting stimuli; (2) a control center, such as a part of the brain, which determines the set point for the variable and receives input from the receptor about the variable; and (3) an effector, which generates the response that adjusts the value of a changed variable. A changed variable is a stimulus because it initiates a homeostatic mechanism. HOMEOSTASIS______________ Feedback loops have three components: (1) a receptor, which monitors the value of a variable by detecting stimuli; (2) a control center, such as a part of the brain, which determines the set point for the variable and receives input from the receptor about the variable; and (3) an effector, which generates the response that adjusts the value of a changed variable. A changed variable is a stimulus because it initiates a homeostatic mechanism. HOMEOSTASIS______________ Types of Feedback Loops / Feedback Mechanisms: (1) Negative Feedback- In the context of homeostasis mechanisms, negative means “to decrease.” Negative feedback is when any deviation from the set point is made smaller or is resisted. In other words, the response by the effector is stopped once the variable returns to its set point (2) Positive Feedback- occur when a response to the original stimulus results in the deviation from the set point becoming even greater. In other words, positive means “to increase.” HOMEOSTASIS______________ Negative Feedback HOMEOSTASIS______________ Negative Feedback HOMEOSTASIS______________ Negative Feedback HOMEOSTASIS______________ Positive Feedback LEARNING TERMINOLOGIES___________ Etymology (ET-ee-MOL-oh-jee)- the study of the origin of words and the way in which their meanings have changed throughout history. For example, foramen is a Latin word for “hole,” and magnum means “large.” The foramen magnum is therefore a large hole in the skull through which the spinal cord attaches to the brain. LEARNING TERMINOLOGIES___________ MORE: https://pressbooks.uwf.edu/medicalterminology/c hapter/prefixes-and-suffixes/ MORE: Seeley's Anatomy and Physiology 13th Edition BODY POSITION______________________ Anatomical position refers to a person standing erect with the face directed forward, the upper limbs hanging to the sides, and the palms of the hands facing forward (figure 1.9). A person is supine when lying face upward and prone when lying face downward. DIRECTIONAL TERMS_________________ DIRECTIONAL TERMS_________________ DIRECTIONAL TERMS_________________ BODY PARTS & REGIONS___________ SUBDIVISIONS OF ABDOMEN_______________ BODY PLANE_________ BODY PLANE_________ BODY CAVITIES_________ ▪ Thoracic Cavity – surrounded by rib cage & is separated from the abdominal cavity by the muscular diaphragm ▪ Abdominal Cavity – bounded primarily by abdominal muscles; contains stomach, intestines, liver, spleen, pancreas & kidneys ▪ Pelvic Cavity – a small space enclosed by the bones of the pelvis; contains the urinary bladder, part of the large intestine, and the internal reproductive organs. BODY CAVITIES_________ The walls of the body cavities and the surface of internal organs are in contact with membranes called serous (SEER-us) membranes. These membranes are double layered. The layer that lines the walls of the cavities is called the parietal (pa-RYE-ee-tal; wall) serous membrane. The layer covering the internal organs (the viscera) is the visceral serous membrane. BODY CAVITIES_________ Pericardial Cavity The pericardial cavity (peri = around; cardi = heart), containing the heart, is housed in the mediastinum. The parietal serous membrane is called the parietal pericardium and the visceral serous membrane is called the visceral pericardium. The space between the two pericardial membranes is called the pericardial cavity and is filled with pericardia fluid. BODY CAVITIES_________ Pleural Cavities Each of the two pleural cavities (pleuron = side of body, rib) houses a lung. The parietal serous membrane lining the pleural cavities is called the parietal pleura, while the visceral serous membrane covering the lungs is called the visceral pleura. The space between the two pleural membranes is called the pleural cavity and is filled with pleural fluid. BODY CAVITIES_________ Peritoneal Cavity The peritoneal cavity (peri = around; -tonos = stretched; stretched around) houses many internal organs, such as the liver, the digestive organs, and the reproductive organs. The parietal serous membrane in the peritoneal cavity is called the parietal peritoneum. The visceral serous membrane is called the visceral peritoneum. The space between the two serous membranes is the specific location of the peritoneal cavity and is filled with peritoneal fluid BODY CAVITIES_________ Peritoneal Cavity The peritoneal cavity (peri = around; -tonos = stretched; stretched around) houses many internal organs, such as the liver, the digestive organs, and the reproductive organs. The parietal serous membrane in the peritoneal cavity is called the parietal peritoneum. The visceral serous membrane is called the visceral peritoneum. The space between the two serous membranes is the specific location of the peritoneal cavity and is filled with peritoneal fluid