Anatomy and Physiology Chapter 1

Anatomical Approaches

• Anatomists study the body's structures using two primary approaches: regional and systemic.
• Regional anatomy focuses on the interrelationships of all structures within a specific body region, such as the abdomen.
• Systemic anatomy focuses on structures that make up a specific body system, such as the skeletal muscles.

Physiology & Homeostasis

• Physiology is the study of how the body's structures function.
• Homeostasis is the state of steady internal conditions maintained by living organisms.
• Many physiological studies center on the body's tendency toward homeostasis.

Negative Feedback

• The body uses negative feedback mechanisms to control physiological values and maintain homeostasis.
• Negative feedback systems consist of three components: a sensor, a control center, and an effector.
• Sensors detect changes in a physiological value, which is then relayed to the control center.
• The control center compares the value to the normal range and activates an effector if necessary.
• Effectors cause changes to reverse the deviation and return the value to the normal range.

Anatomical Terminology

• Anatomists use specific terminology for precision and to avoid medical errors.
• Anatomical terms are derived from ancient Greek and Latin.
• Terms consist of roots, prefixes, and suffixes.
• The root often refers to an organ, tissue, or condition.
• The prefix or suffix describes the root, for example, "hyper-" means "high" or "over" in hypertension.

Anatomical Position

• Anatomists use a standardized position to view the body, called the anatomical position.
• The body is visualized as standing upright, feet shoulder-width apart and parallel, toes forward.
• Upper limbs are held out to each side, palms facing forward.

Body Regions & Planes

• Anatomical regions are described using precise terms instead of common phrases for clarity.
• Directional terms such as anterior and posterior are used to describe relative locations.
• The body is commonly viewed along three planes: sagittal, frontal, and transverse.

Body Cavities

• Major body cavities are divided into dorsal (posterior) and ventral (anterior) cavities.
• The dorsal cavity contains the cranial cavity (brain) and vertebral cavity (spinal cord).
• The ventral cavity contains the thoracic cavity (heart and lungs) and abdominopelvic cavity (digestive organs, urinary organs, reproductive organs).

Serous Membranes

• Serous membranes are double-layered membranes that line body cavities and cover organs.
• The two layers are a parietal layer (lining the cavity wall) and a visceral layer (covering the organ).
• The space between the layers is filled with fluid that lubricates and reduces friction between the layers.
• Examples include the pleural serosa (lungs), pericardial serosa (heart), and peritoneal serosa (abdominopelvic organs).

Medical Imaging

• Medical imaging techniques, such as X-rays, allow for non-surgical visualization of the body's interior.
• Detailed anatomical drawings were first available in the 15th and 16th centuries.
• X-rays revolutionized anatomical and medical practice in the late 19th century.