Chapter 1 Organization of The Human Body

Overview of Anatomy and Physiology Anatomy: Scientific discipline that investigates the body’s structure Physiology: Scientific investigation of the processes or functions of living things

Topics of Anatomy Gross or macroscopic: Structures examined without a microscope Regional: Studied area by area Systemic: Studied system by system Surface: External form and relation to deeper structures as x-ray in anatomic imaging Microscopic: Structures seen with the microscope Cytology: Cellular anatomy Histology: Study of tissues

Topics of Physiology Reveals dynamic nature of living things Consider operations of specific organ systems Cell physiology: Examines processes in cells Neurophysiology: Focuses on the nervous system Pathology Exercise Physiology

Structural & Functional Organizations Chemical level Atoms Molecules Cellular Level Tissue Level Organ Level Organ System Level

Structural & Functional Organizations

Organ Systems of the Body

Organ Systems of the Body

Organ Systems of the Body

Organ Systems of the Body

Characteristics of Living Human Organism Organization: Condition in which there are specific relationships and functions Metabolism: All chemical reactions of the body Responsiveness: Ability to sense changes and adjust Growth Development: Changes over time Differentiation: Change from general to specific Morphogenesis: Change in shape of tissues, organs Reproduction: New cells versus organisms

Homeostasis Values of variables fluctuate around the set point to establish a normal range of values Set Point: The ideal normal value of a variable What is the set point for body temperature?

Negative Feedback

Changes in Blood Pressure During Exercise Deviation from the usual range of values helps meet changing demands

Positive Feedback Positive Feedback: When a deviation occurs, response is to make deviation greater Leads away from homeostasis Can result in death

Positive Feedback during Childbirth Stretch receptors in walls of the uterus send signals to the brain Brain releases a hormone (oxytocin) into bloodstream Uterine smooth muscle contracts more forcefully More stretch  more hormone  more contraction  etc. The cycle ends with birth of the baby & decrease in stretch The positive feedback system reinforces a change in a controlled condition

Terminology and Body Plan Anatomical Position Body erect, face forward, feet together, palms face forward Other Body Positions Supine: lying face upward Prone: lying face downward Directional Terms Superior versus Inferior Anterior versus Posterior Medial versus Lateral Proximal versus Distal Superficial versus Deep

Directional Terms

Body Parts and Regions

Body Parts and Regions

Body Planes Sagittal / Midsagittal / Median Frontal or Coronal Transverse / Cross Oblique: Other than at a right angle

Body Cavities

Abdominal Subdivisions

Serous Membranes Cover the organs of trunk cavities & line them Parietal lines cavity walls Visceral covers organs Serous fluid secreted for lubrication by membranes Named for their specific cavity & organs Pericardium refers to heart Pleura refers to lungs and thoracic cavity Peritoneum refers to abdominopelvic cavity Inflammation of the serous membranes

Serous Membranes

Serous Membranes

Medical Imaging - Clinical Focus X-Ray or radiograph is shadowy negative of internal body structures CT or computed tomography is refined version of an x-ray and slices body DSR or dynamic spatial reconstruction is three dimensional imaging and allows movement DSA or Digital Subtraction Angiography is comparison of radiographs with and without dye. Used often in blood vessel studies.

Sonography or ultrasound is inexpensive and safer than ionizing radiation MRI or magnetic resonance imaging produces high-contrast imaging of soft tissues PET or Positron emission tomographic scan is used to study active cells