Summary
Highlights
This section introduces anatomy as the science of body structures and physiology as the science of body functions, emphasizing their interrelated nature. It also briefly explains science as a method of investigating the world through observation, critical questioning, the scientific method, hypothesis testing, data collection, and conclusion reporting.
The human body is organized from the simplest to the most complex levels: chemical (atoms and molecules), cellular (organelles and cells), tissue (e.g., muscle, bone), organ (e.g., brain, heart), organ system, and finally, the entire human organism. There are 11 main organ systems that work together to maintain life.
This part details the components and functions of the 11 main organ systems: Integumentary (skin, hair, nails, sweat glands), Skeletal (bone, cartilage, ligaments, joints), Muscular (skeletal, cardiac, smooth muscle), Nervous (brain, spinal cord, sense organs, nerves), Endocrine (glands producing hormones), Cardiovascular (heart, blood vessels, blood), Lymphatic/Immune (lymph, lymph vessels, lymph nodes, spleen), Respiratory (lungs, trachea, air passageways), Digestive (mouth, pharynx, esophagus, stomach, intestines, liver, pancreas, salivary glands), Urinary (kidneys, bladder, ureters), and Reproductive (gonads and associated structures).
The body is composed of ions, inorganic compounds (water, salts, acids, bases), and organic compounds (carbohydrates, lipids, proteins, nucleic acids). Organic compounds are large, complex, carbon-containing molecules vital for fuel, energy storage, cell membranes, hormones, enzymes, and genetic information. The concept of pH, cations, anions, acids, bases, and salts is also introduced.
Metabolism refers to all chemical activities in the body. It consists of catabolism (breaking down processes that release energy, e.g., cellular respiration converting nutrients to ATP) and anabolism (building processes that use energy to create chemical compounds, cells, and tissues).
Homeostasis is the body's ability to maintain a stable internal environment through self-regulating control systems. Stressors activate homeostatic mechanisms. Negative feedback systems (e.g., body temperature regulation) counteract changes, while positive feedback systems (e.g., childbirth) intensify changes, moving the system away from its starting state.
This section defines the anatomical position and introduces directional terms like superior/inferior, anterior/posterior, medial/lateral, proximal/distal, superficial/deep, cranial/caudal/rostral, and ipsilateral/contralateral. It also describes the three main anatomical planes: sagittal (left/right divisions), coronal/frontal (anterior/posterior divisions), and axial/transverse (superior/inferior divisions).
The body is divided into axial (head, neck, trunk) and appendicular (limbs) regions. The torso includes the thorax, abdomen, and pelvis. The human body has two main cavities: the dorsal cavity (cranial and spinal) and the ventral cavity (thoracic and abdominopelvic). The abdominopelvic cavity is further divided into four quadrants and nine regions for easier description.
A comprehensive list of regional terms is provided to reference specific anatomical structures or areas of the body, such as abdominal, antebrachial, axillary, brachial, carpal, cephalic, cervical, costal, cubital, femoral, flank, gluteal, inguinal, lumbar, mammary, occipital, ophthalmic, pectoral, pelvic, perineal, plantar, popliteal, sacral, sternal, thoracic, umbilical, and vertebral.
This final part presents various internal views of the human body, including anterior and posterior dissections, and different levels of computed tomography (CT) scans, to familiarize viewers with the location and appearance of organs and skeletal structures.