Anatomy Study Approaches and Terminology

Approaches to Studying Anatomy

• Anatomy is the study of structure, which relates to the functions of life
• Three main approaches: regional, systemic, and clinical (applied)
• Regional Anatomy studies the body's organization into parts and segments (e.g., head, neck, trunk); it considers structures within a specific region in detail and relating adjacent areas
• Systemic Anatomy is the study of the body's organ systems—the individual systems studied separately, highlighting interactions
• Clinical Anatomy focuses on aspects of bodily structure and function essential for medical practice, emphasizes clinical relevance and application
• Surface anatomy involves the study of external form and surface of the body, helping to visualize deep structures. It can be used for physical examinations and diagnosis

Anatomical Terminology

• Anatomical terminology is a large part of medical terminology
• Terms are derived from Latin and Greek
• Terminology conforms to the International Anatomical Nomenclature and the International Embryological Terminology (i.e., Latin) and English translations

Anatomical Position

• Descriptions of the body are standardized using the anatomical position
• Body is upright; facing forward; arms at the sides; palms forward; feet are parallel
• Physical examination is used for application of surface anatomy, which uses observation and palpation for examining body features.

Anatomical Planes

• Imaginary planes used to describe locations on the body.
• Median, sagittal, frontal (coronal), and transverse
• Longitudinal planes are parallel with the long axis; sagittal, frontal planes are considered longitudinal
• Horizontal planes are transverse planes that are perpendicular to longitudinal planes
• Oblique sections are slices that are made along planes that aren't in line—sagittal, transverse, or coronal

Terms of Relationship and Comparison

• Terms like superior, cranial, inferior, caudal define spatial relationships relative to the head or feet.
• Medial (closer to midline) and lateral (further from midline) define positioning relative to the midline
• Proximal and distal are used relative to a point of origin or the center of a structure
• Superficial/intermediate/deep define relationships relative to the surface of the body
• Internal and external describe locations inside or outside a body cavity, in relation to a structure

Terms of Movement

• Terms like flexion/extension, abduction/adduction, rotation and circumduction are defined by how movements interact with anatomical planes (sagittal, frontal, etc.)
• These terms are used to explain movements of the body or parts of the body, around axes or planes.
• Examples of movements are flexion, extension, abduction, adduction, rotation, circumduction, dorsiflexion, inversion, eversion, etc.

Integumentary System

• The skin, an organ, is essential for health because it is accessible and an excellent indicator of general health.
• Skin has functions such as protection, containment, heat regulation, sensation, and synthesis of vitamin D
• Skin is composed of the epidermis (a superficial cellular layer and the dermis (a deep connective tissue layer)
• Subcutaneous tissue (superficial fascia) is located between the dermis and deep fascia

Fascias, Fascial Compartments, Bursae, and Potential Spaces

• Fasciae are deep connective tissue sheets important for body structures and their positions
• Fasciae have layers and compartments that are present to provide support, packing, and insulation for organs and structures within the body
• Bursae (sacs filled with fluid) and synovial tendon sheaths (elongated bursae) reduce friction and ease movement of tissues and organs in relation to one another.

Skeletal System

• The skeletal system is divided into an axial portion (e.g. skull, neck, back, ribcage) and appendicular portion (e.g., limbs, girdles)
• Cartilage and bones form part of the skeletal tissue—the skeleton.
• Bone is a living tissue, forms the basic support, protection, and lever for movement, and is crucial for storing minerals (e.g., calcium) and producing blood cells.
• Cartilage is a semi-rigid connective tissue, it fills parts needing flexibility
• Bones and cartilage are covered in perichondrium and periosteum

Bone Development

• Bone is formed by intramembranous ossification (directly from mesenchyme) and endochondral ossification (from cartilage forming a model)
• Bone growth occurs through several centers: primary and secondary ossification centers.
• This growth results in the formation of the diaphysis, metaphysis, and epiphysis, including the epiphyseal plate, which closes as the bone develops fully.

Bone Markings and Formations

• Bone markings are locations where tendons, ligaments, and fascia attach, and where blood vessels enter the bone
• Markings include tubercles, spines, condyles, fossae, etc.
• They are important for locating anatomical structures and functions on the surface or inside of the bone.

Joints

• Joints are connections between bones; they are classified according to the types of tissue that unite the bones (fibrous, cartilaginous, and synovial)
• There's a variety types of synovial joints with varied shapes and degrees of movement: plane, hinge, pivot, condyloid, saddle, and ball-and-socket
• Examples of joints include the shoulder, elbow, hip, knee, and the joints in the spine

Muscle Tissue and Muscular System

• Muscles are organs made up of muscle tissue, providing movement and support, and for body form
• Three types of muscle tissue: skeletal (striated), cardiac (striated), and smooth (unstriated)
• Skeletal muscle is responsible for voluntary movement of body parts
• Cardiac muscle forms most of the heart and other organs
• Smooth muscle is responsible for involuntary movement within the body's organs

Cardiovascular System

• The cardiovascular system is responsible for transporting oxygen and nutrients through the body and removing waste
• The system comprises the heart, blood vessels—arteries, viens, and capillaries
• The heart acts as a pump propelling blood through a network of arteries, arterioles, capillaries, venules, and veins.
• Blood travels in circuits—pulmonary (lungs) and systemic (body)
• Arteries have thick muscular walls to propel blood and adjust blood flow within the body
• Veins have thin walls with valves to prevent back flow
• Capillaries are thin-walled tubes where exchange occurs between the blood and surrounding tissue

Lymphoid System

• The lymphoid system removes excess fluid, wastes, and pathogens from body tissues
• The system is part of the immune system.
• Lymph nodes filter lymph, a fluid that circulates through the lymphatic vessels
• Lymph nodes, lymphatic vessels, lymph, and lymphatic tissues are components of the lymphoid system

Nervous System

• The nervous system is responsible for communication between the body's parts, sensory information, integration, and actions within the body
• It's divided into the central nervous system (CNS—brain and spinal cord) and the peripheral nervous system (PNS—nerves)
• Neurons are the fundamental structural and functional components, composed of cell bodies, dendrites, and axons to transmit signals
• Different types of neurons—multipolar and pseudounipolar—are based on the structure of their axons or dendrites
• Neuroglia (supporting cells) are the other significant cell type in nervous tissue
• The nervous system is divided into divisions or axes—the SNS (somatic nervous system) (voluntary) and the ANS (autonomic nervous system) (involuntary)