HUMAN-ORGANISM-1.pdf

ANATOMY AND PHYSIOLOGY ANATOMY AND PHYSIOLOGY ANATOMY PHYSIOLOGY The scientific discipline that The scientific investigation of investigates the body’s the processes or functions of structures—for example, the living...

ANATOMY AND PHYSIOLOGY ANATOMY AND PHYSIOLOGY ANATOMY PHYSIOLOGY The scientific discipline that The scientific investigation of investigates the body’s the processes or functions of structures—for example, the living things. shape and size of bones. The word anatomy means to dissect or cut apart and separate the parts of the body for study.  ANATOMY 01 Developmental 02 03 Gross Anatomy Gross Anatomy Anatomy Studies the The study of structures that Involves looking at the structural changes can be examined without exterior of the body to that occur between the aid of a microscope, visualize structures conception and can be approached either deeper inside the adulthood. systemically or regionally. body. Physiology Cell Physiology examines the processes occurring in cells such as energy production from food Systemic Physiology Considers the functions of organ systems. Ex. Cardiovascular physiology; neurophysiology  Structural and Functional Organization of the Human Body Structural and Functional Organization of the Human Body Chemical Level Cell Level Tissue Level The chemical level of Cells are the basic A tissue is a group of organization involves structural and similar cells and the materials surrounding how atoms, such as functional units of them. The characteristics hydrogen and carbon, organisms, such as of the cells and interact and combine plants and animals. surrounding materials into molecules. Most cells contain determine the functions of smaller structures the tissue inside them, called organelles. Structural and Functional Organization of the Human Body Organ System Organ Level Organism Level Level An organ is composed An organ system is a An organism is any of two or more tissue group of organs that living thing considered types that together together perform a as a whole, whether perform one or more common function or set composed of one cell, common functions. of functions. such as a bacterium, or of trillions of cells, such as a human. MAJOR ORGANS OF THE BODY Levels of Organizati on for the Human Body Organ System of the Body Organ System of the Body Organ System of the Body  Organ System of the Body Characteristics of Life  Characteristics of Life ORGANIZATION A refers to the specific interrelationships among the individual parts of an organism, and how those parts interact to perform specific functions METABOLISM B The ability to use energy to perform other vital functions, such as growth, movement, and reproduction. RESPONSIVENESS C An organism’s ability to sense changes in the external or internal environment and adjust to those changes. Characteristics of Life GROWTH D refers to an increase in the size or number of cells, which produces an overall enlargement in all or part of an organism, cell size, or the amount of substance surrounding cells. DEVELOPMENT E Includes the changes an organism undergoes through time, beginning with fertilization and ending at death. Development usually involves growth, but it also involves differentiation. REPRODUCTION F the formation of new cells or new organisms. Reproduction of cells allows for growth and development. Formation of new organisms prevents extinction of species. HOMEOSTASIS Homeostasis → The maintenance of a relatively constant environment within the body. → One of the most well-known examples of homeostasis is body temperature. → Body temperature is a variable that increases when you are too hot and decreases when you are too cold.  Homeostasis 01 Negative Feedback Negative- feedback mechanisms have three components: (1) a receptor, which monitors the value of a variable such Negative means “to as body temperature by detecting stimuli decrease.” Negative (2) a control center, determines the set point for the feedback is when any deviation from the set point is variable and receives input from the receptor about the made smaller or is resisted. variable Negative feedback does not (3) an effector, such as sweat glands, which can adjust the prevent variation but maintains variation within a value of the variable when directed by the control normal range. center, usually back toward the set point. Negative-Feedback Mechanism: Body Temperature  Homeostasis 02 Positive Feedback → For example, during blood loss, a chemical responsible for blood clot formation, called thrombin, stimulates production of even more Occur when a response to thrombin. the original stimulus results in the deviation from the → Birth is another example of a normally occurring set point becoming even positive- feedback mechanism. greater. In other words, positive means “increase.” Homeostasis : Positive Feedback  Homeostasis Two basic principles about homeostatic mechanisms to remember are that: (1) Many disease states result from the failure of negative-feedback mechanisms to maintain homeostasis (2) Some positive-feedback mechanisms can be detrimental instead of helpful. → One example of a detrimental positive-feedback mechanism is inadequate delivery of blood to cardiac (heart) muscle. Terminology and the Body Plan  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. A person is supine when lying face upward and prone when lying face downward. DIRECTIONAL TERMS ✓ Directional terms describe parts of the body relative to each other. ✓ For human anatomy, the term superior is used interchangeably with the term cephalic, and the term inferior is used interchangeably with caudal ✓ Anterior is synonymous with ventral (belly) and posterior is synonymous with dorsal (back).  Body Parts and Region BODY PARTS AND REGION ✓ The central region of the body consists of the head, neck, and trunk. PLANES  PLANES ✓ PLANES - imaginary flat surfaces that pass through the body ✓ A plane divides, or sections, the body, making it possible to “look inside” and observe the body’s structures. PLANES 01 SAGITTAL PLANE Separates the body or a structure into right and left halves. 02 MEDIAL PLANE A sagittal plane that passes through the midline of the body, dividing it into equal right and left halves.  PLANES 03 Transverse Plane Runs parallel to the ground, dividing the body into superior and inferior portions. 04 Frontal Plane Divides the body into front (anterior) and back (posterior) halves. PLANES PLANES THROUGH AN ORGAN 01 Longitudinal section cut through the length of the organ 02 Transverse section a cut at a right angle to the length of an organ 03 Oblique section cut is made across the the length of an organ at other than a right angle BODY CAVITIES  BODY CAVITIES ✓ The body contains two types of internal cavities: 01 Dorsal Body Cavity The dorsal body encloses the organs of the nervous system, the brain and spinal cord. The two subdivisions of the dorsal body cavity are (1) the cranial cavity, which houses the brain (2) the vertebral canal, which houses the spinal cord. → Both the brain and spinal cord are covered by membranes called meninges BODY CAVITIES 02 Ventral Body Cavity The ventral body cavity houses the vast majority of our internal organs, collectively referred to as the viscera The ventral body cavity also has two major subdivisions, which are: (1) the thoracic cavity (2) the abdominopelvic cavity BODY CAVITIES Thoracic Cavity Superior to the abdominopelvic cavity and houses primarily the heart and lungs, among other organs. This cavity is further subdivided into sections: (1) two lateral pleural cavities – which encloses a lung, and are surrounded by the ribs (2) a medial mediastinum – which houses the heart and its major blood vessels, in addition to the thymus, the trachea, and the esophagus BODY CAVITIES Abdominal Cavity The abdominopelvic cavity is enclosed by abdominal muscles and consists of: (1) the more superior abdominal cavity (2) the more inferior pelvic cavity. → The organs of the abdominopelvic cavity are housed within the peritoneal (stretch over) cavity. → The abdominal cavity contains most of the digestive organs → The pelvic cavity continues below the pelvis and contains the urinary bladder, urethra, rectum of the large intestine, and reproductive organs. BODY CAVITIES Abdominal Cavity Serous Membranes of the Ventral Body Cavity The walls of the body cavities and the surface of internal organs are in contact with membranes called serous membranes. The layer that lines the walls of the cavities is called the parietal serous membrane. The layer covering the internal organs (the viscera) is the visceral serous membrane. The two membranes are separated by a thin film of serous fluid produced by the membranes.  Thoracic Cavity Membranes 01 Pericardial Cavity Containing the heart, is housed in the mediastinum. The parietal serous membrane is called the parietal pericardium 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 pericardial fluid. Thoracic Cavity Membranes 02 Pleural Cavity Each of the two pleural cavities houses a lung. The parietal serous membrane lining the pleural cavities is called the parietal pleura 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.  Thoracic Cavity Membranes 03 Peritoneal Cavity The peritoneal cavity 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. Mesenteries – a double-folded sheet of visceral peritoneum attaches the digestive organs at certain points to the posterior abdominopelvic cavity wall. These organs have a retroperitoneal (behind the peritoneum)