Introduction to the Human Body
Topics Covered
Organization of the body
Anatomical position
Sectional planes of the body
Directional terms
Organ systems
Body cavities
Regions of the body
Regions of the abdomen
Introduction
Physiology is the study of organ function and interaction. Physiology may be studied from the molecular level to the organism level. The hierarchical levels of organization of the human body from the smallest structure to the largest structure are molecular, cellular, tissue, organ system, and organism. Section 1.3.1- Organization
Anatomical Position
Aantomical position is used as a standard frame of reference for describing the relationship of anatomical structures, anomalies, injuries and pathologies during dissection or treatment of a patient. When a person or cadaver is in anatomical position, he or she is standing erect, with feet flat on the floor, arms at the sides, palms and eyes facing forward, eyes open. Descriptions of left and right always refer to the left and right of the subject or patient, not the observer.
Anatomical Planes
Anatomical planes are imaginary flat surfaces passing through the body. Anatomical sections are anatomical views in which the body is cut on a plane. There are 4 planes: coronal or frontal, sagittal, transverse or horizontal, and oblique. The frontal, or coronal plane divides the body into front and back portions (or anterior and posterior). The Sagittal plane divides the body into left and right halves. A midsagittal plane divides the body equally into left and right halves, while a parasagittal plane falls off center of the mid-line of the body. A transerves or horizontal plane divides the body into upper and lower portions (superior and inferior). And oblique plane passes through the body at an oblique angle. Section 1.6.4- Body Planes
Directional Terms
Directional terms are terms used to describe the location of
one body part relative to another.
They include:
Superior and inferior
Anterior and posterior
Superficial and deep
Proximal and distal
Medial and lateral
Figure 1.13- Directional Terms Applied to the Human Body
Organ Systems
There are 12 organ systems: the integumentary, skeletal, muscular, nervous, lymphatic, reproductive, endocrine, cardiovascular, respiratory, digestive, renal and sensory systems.
Review the location and function of the organ systems in your openstax text book.
Figure 1.4- Organ Systems of the Human Body
Figure 1.5- Organ Systems of the Human Body (continued)
Body Cavities
There are two major body cavities: the dorsal body cavity, which is made up of the cranial cavity and the ventral body cavity (also called the coelom), which is made up of the thoracic cavity and the abdominopelvic cavity. The thoracic cavity contains the pericardial cavity and two pleural cavities. The mediastinum is the region of the thoracic cavity that contains the heart, the large vessels, the thymus gland, and the esophagus. The adominopelvic cavity contains the abdominal and pelvic cavities. (Figure 1.15- Dorsal and ventral Body Cavities; section 1.6.5.1- Subdivisons of the Posterior (Dorsal) and Anterior (Ventral) Cavitites)
Regions of the Body
Figure 1.12 Regions of the Human Body