Anatomy & Physiology Introduction Anatomy: The study of the structure of an organism and the relationship to its parts Anatomy is derived from the Greek word meaning “cutting up” which is still how we learn today through dissections. Physiology: The study of the functions of living organisms and their parts Structural Levels of 1. Atoms/Molecules 2. Cells Differing levels of organization progress from the least complex (chemical level) to the most complex (organism). 3. Tissues 4. Organs Organization is one of the most important characteristics of body structure. 5. Systems 6. Body Organization Cell are considered to be the smallest “living” units of structure and function. C O M P L E X I T Y Anatomical Position The body is in a erect or standing posture with the arms at the sides and palms turned forward. The anatomical position is a reference position that gives meaning to the directional terms used to describe the body parts and regions. “NOT” Anatomical Position SUPINE Laying face upward http://www.yogastudy.org/images/Supine-yoga-Postures.gif PRONE Laying face downward ANATOMICAL DIRECTIONS Anatomical Directions Superior Inferior “toward the head” “toward the feet” Upper or above Lower or below Anatomical Directions Anterior Posterior “front” or “in front of ” “back” or “in back of ” Ventral (toward the belly) can also be used instead of anterior Dorsal (toward the back) can also be used instead of poster Anatomical Directions Medial towards the midline of the body Lateral Toward the side of the body or away from midline Anatomical Directions Proximal Toward or nearest the trunk of the body or nearest the point of origin of one of it’s parts Distal Away from or farthest from the trunk or the point of origin of a body part Anatomical Directions Superficial Nearer the surface Deep Farther away from the body surface Planes or Body Sections 1. 2. 3. Sagittal • Length-wise plane running from front to back. • Divides into left and right halves Frontal (Coronal) • Length-wise plane running from side to side • Divides into anterior and posterior Transverse • Horizontal or crosswise plane • Divides into upper and lower portions Body Cavities Body Cavities Ventral Body Cavity Organ-containing space in the anterior trunk of the body that includes the thoracic and abdominopelvic cavities Dorsal Body Cavity Includes the cranial and spinal cavities Ventral Body Cavity Thoracic cavity Abdominopelvic cavity Everything above the diaphragm Mediastinum – Trachea, heart, blood vessels Pleural cavities – Lungs Everything below the diaphragm Abdominal cavity Liver, gallbladder, stomach, spleen, pancreas, small intestine, parts of the large intestine Pelvic cavity – Lower sigmoid colon, rectum, urinary bladder, reproductive organs. Ventral Body Cavity Ventral Body Cavity The Abdomen can be divided into 9 for abdominal regions. This makes it easier to locate organs. RH- right hypochondriac region RL- right lumbar region RI- right iliac (inguinal) region ER- epigastric region UR- umbilical region HR- hypogastric region LH- left hypochondriac region LL- left lumbar region LI- left iliac (inguinal) region Ventral Body Cavity An easier way to divide of the abdomen is to use the division of the abdomen into 4 quadrants. Dorsal Body Cavity Cranial cavity – Brain Spinal cavity - Spinal cord http://www.free-ed.net/sweethaven/Science/Biology/AnatomyPhysiol/Human01_LessonMain.asp?iNum=0106 Body Regions Subdivisions Body Regions Axial Head Neck Torso or trunk Appendicular – Upper and lower extremities The Balance of Body Functions Homeostasis Balance of Body Functions Homeostasis – The body maintaining relatively constant conditions within the body or a relative constancy of the internal environment. The body must constantly work to maintain or restore homeostasis. Balance of Body Functions Negative Feedback Loop – Oppose or negate a change in a controlled condition. They change back toward a normal value – stabilize conditions. Ex: Breathing heavier when exercising or producing more urine when there is more fluid in the body than usual. Balance of Body Functions Positive Feedback Loop – Instead of opposing a change in the internal environment and causing a return to normal, these PFL’s temporarily amplify the change that is occurring. Ex: Rapid increases in uterine contractions before the birth of a baby or rapid sticking together of platelets to form a blood clot. Maintaining Homeostatis Our physiological feedback systems have three key features: 1. A receptor that can evaluate the stimulus (change in environment) and sends a message to… 2. An integrating center (Brain) that processes the information and sends a message to… 3. An effector that acts on the stimulus and causes a response (reaction) in the organism.