St. Alexius College Anatomy and Physiology Lesson 1 PDF

LESSON 1: The Human Organism OBJECTIVES 1. Discuss the importance of physiology in studying anatomy. 2. Define and know the directional terms sed to locate body structures as well as describe the three major planes of the body and the body organs. 3. Identify the different structural and func...

LESSON 1: The Human Organism OBJECTIVES 1. Discuss the importance of physiology in studying anatomy. 2. Define and know the directional terms sed to locate body structures as well as describe the three major planes of the body and the body organs. 3. Identify the different structural and functional organization of the body. “Human anatomy and physiology is the study of the structure and function of the human body.” Anatomy is the scientific discipline that investigates the structure of the body. means to dissect, or cut apart and separate, the parts of the body for study. Examines the relationship between the structure of a body part and its function. Two basic approaches to the study of anatomy. 1. Regional Anatomy 2. Systemic Anatomy  APPROACHES IN STUDYING ANATOMY Systemic Anatomy Is the study of the body by systems.  APPROACHES IN STUDYING ANATOMY Regional Anatomy Is the study of the organization of the body by areas. Physiology is the scientific discipline that deals with the process or functions of living things. MAJOR GOALS OF PHYSIOLOGY 1. To understand and predict the body’s responses to stimuli 2. To understand how the body maintains conditions within a narrow range of values in the presence of continually changing internal and external environments. STRUCTURAL AND FUNCTIONAL ORGANIZATION OF THE HUMAN BODY  CHARACTRISTICS OF LIFE 1. ORGANIZATION –refers to the specific interrelationships among the parts of an organism and how those parts interact to perform specific functions. 2. METABOLISM – the ability to use energy to perform vital functions, such as growth, movement, and reproduction. 3. RESPONSIVENESS – the ability of an organism to sense changes in the environment and make the adjustments that help maintain its life. 4. GROWTH – refers to an increase in size of all part of the organism. 5. DEVELOPMENT – includes the changes an organism undergoes through time. 6. REPRODUCTION – is the formation of new cells or new organism.  HOMEOSTASIS Homeostasis – is the existence and maintenance of a relatively constant environment within the body despite fluctuations in either the external environment or the internal environment.  TERMS TO UNDERSTAND FOR HOMEOSTASIS: VARIABLES – conditions that might affect homeostasis. Its values are subjected to constant changes. HOMEOSTATIC MECHANISMS – these are mechanisms that help regulate the body. SET POINT – an ideal normal value NORMAL RANGE – a set of value that decreases or increases slightly around the set point.  NEGATIVE FEEDBACK This process maintains homeostasis It does not prevent variation, but it maintains variations in a normal range Most systems in the body is regulated by negative feedback mechanism NEGATIVE – deviation from the set point is made smaller or resisted.  POSITIVE FEEDBACK Positive feedback mechanism – occurs when an initial stimulus further stimulates the response. The deviation from the set point becomes even greater.  TERMINOLOGY AND BODY PLAN Body Positions Anatomical positions – 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. Supine– when a person is lysing with the face upward Prone – when lying face downward  TERMINOLOGY AND BODY PLAN Body Parts and Regions Central region of the body – head, neck and trunk Trunk: Thorax – (chest) Abdomen – (region between the thorax and pelvis) Pelvis (inferior end of the trunk) Upper limb Arm – extends from shoulder to elbow Forearm – extends from elbow to wrist Wrist Hand Lower Limb Thigh – extends from the knee to the ankle Leg– extends from the knee to ankle Ankle Foot  ABDOMEN It is often subdivided superficially into 4 sections of quadrant by 2 imaginary lines (1 horizontal and 1 vertical) which intersects at the navel.  The abdomen may also be subdivided into 9 regions namely: Epigastric Right and left hypochondriac Umbilical Right and left lumbar Hypogastric Right and left iliac  PLANES Body planes are imaginary planes or flat surfaces that cut through and section of the body in its anatomical position. Sagittal plane is also a vertical plane that splits the body into left and right parts. Median plane is a sagittal plane that passes through the midline of the body, dividing it into right and left halves. Transverse plane/Horizontal plane runs parallel to the surface of the ground, dividing the body into superior and inferior parts. Frontal plane/Coronal plane runs vertically from the right to left and divides the body into anterior and posterior parts. Organs may also be sectioned in order to see its internal structures. Longitudinal section – cut through the long axis of the organ. Transverse section/ cross section – cut at the right angle to length of the organ. Oblique section – cut made across the longs axis at other than the right angle. Body cavity is a space created in an organism which house organs. It is lined with a layer of cells and is filled with fluid, to protect the organs from damage as the organism moves around. Trunk Cavity 1. Thoracic cavity 2. Abdominal cavity 3. Pelvic cavity  Thoracic cavity – the space occupied by the ventral internal organs superior to the diaphragm. Abdominopelvic cavity – the abdominal cavity and pelvic cavity in combination. Abdominal cavity – the space occupied by the ventral internal organs inferior to the diaphragm and superior to the pelvic cavity. Pelvic cavity – the space occupied by the ventral internal organs that are bordered by the bones of the pelvic girdle.  Dorsal body cavity – the cranial cavity and the spina cavity in combination. Cranial cavity – the space occupied by the brain, enclosed by the skull bones. Spinal cavity – the space occupied by the spinal cord enclosed by the vertebrae column making up the backbone. The spinal cavity is continuous with the cranial cavity. Ventral body cavity – the thoracic cavity, the abdominal cavity, and the pelvic cavity in combination.  SEROUS MEMBRANE Serous membranes line the trunk cavities and cover the organs of these cavities. Visceral serous membrane Parietal serous membrane Cavity/space between the visceral or parietal serous membrane. Thoracic cavity Pericardial cavity – surrounds the heart.  Pleural cavities Abdominopelvic cavity – contains a serous membrane lined called peritoneal cavity The peritoneal cavity is located between the visceral peritoneum and the parietal peritoneum. It contains peritoneal fluid. Pericarditis – inflammation of the pericardium Pleurisy – inflammation the pleura Peritonitis – inflammation of the peritoneum Mesenteries – connect the visceral peritoneum of some abdominopelvic organs to the parietal peritoneum on the body wall or to the visceral peritoneum of the other abdominopelvic organs. Anchor organs to the body wall and provide a pathway for nerves and blood vessels to reach the organs. Some organs in the abdominopelvic cavity are closely attached to the body wall and they do not have mesenteries. Instead, these organs are covered by parietal peritoneum. These are called, retroperitoneal organs. Kidneys Adrenal glands Pancreas Parts of intestines Urinary bladder OBJECTIVES 1. Discuss the importance of physiology in studying anatomy. 2. Define and know the directional terms sed to locate body structures as well as describe the three major planes of the body and the body organs. 3. Identify the different structural and functional organization of the body. LESSON 1: The Human Organism