Chapter 1: Terminology, Positioning, and aimaging Principles

Atoms: Basic unit of matter.
Molecules: Combinations of atoms.
Cells: Basic units of life.
Tissue: Groups of similar cells performing specific functions.
Organs: Structures composed of multiple tissue types (e.g., heart, liver).
Systems: Groups of organs that work together (10 systems total in the body).
Organism: Entire living entity.

Circulatory System:
- Distributes oxygen to cells and transports waste products away.
- Includes cardiovascular and lymphatic organs.
Digestive System:
- Responsible for absorption (taking nutrients in) and elimination of waste.
Respiratory System:
- Supplies oxygen and eliminates carbon dioxide.
Urinary System:
- Regulates blood and eliminates waste products.
Reproductive System:
- Functions to reproduce the organism (male and female components).
Nervous System:
- Regulates body activities through nerve signals.
Muscular System:
- Enables movement; composed of skeletal, visceral, and cardiac muscles.
Endocrine System:
- Comprised of ductless glands that regulate body functions through hormones.
Integumentary System:
- Protects body, eliminates waste through perspiration.

Axial Skeleton:
- Comprises 80 bones including skull, vertebral column, ribs, and sternum.
Appendicular Skeleton:
- Comprises 126 bones including limbs and girdles (shoulder and pelvic).

Long Bones:
- e.g., Limbs, featuring compact and spongy bone and periosteum.
Short & Flat Bones:
- e.g., Carpal and tarsal bones, calvarium, sternum, ribs, scapulae.
Irregular Bones:
- Characterized by peculiar shapes, e.g., vertebrae, facial bones, pelvic bones.

Arthrology: The study of joints.
Structural Classification:
- Fibrous: Joints held together by fibrous tissue.
- Cartilaginous: Joints held together by cartilage.
- Synovial: Joints have a synovial fluid-filled capsule.
Functional Classification:
- Synarthrodial: Immovable joints.
- Amphiarthrodial: Slightly movable joints.
- Diarthrodial: Freely movable joints.

Types of Synovial Joints:
- Plane (gliding): Motion occurs in a plane (e.g., intercarpal).
- Ginglymus (hinge): Allows movement like a hinge (e.g., elbow).
- Trochoid (pivot): One bone rotates around another (e.g., C1-2 joint).
- Ellipsoid (condyloid): Similar to a ball-andsocket but with less range of motion (e.g., wrist).
- Sellar (saddle): Complex movement (e.g., thumb joint).
- Spheroidal (ball and socket): Allows for a wide range of motion (e.g., hip joint).
- Bicondylar: Limited movement along two axes (e.g., knee).

Anatomic Position: Standard position for reference, standing upright, facing forward, arms at the sides.
Body Planes:
- Sagittal: Divides body into right and left.
- Coronal (frontal): Divides body into front (anterior) and back (posterior).
- Transverse (horizontal): Cuts body into superior and inferior parts.
- Oblique: Any plane that is not a coronal, sagittal, or transverse.

Projections depend on how the X-ray beam is directed relative to the body part being imaged and may include:
- AP (Anteroposterior): X-ray enters front and exits back.
- PA (Posteroanterior): X-ray enters back and exits front.
- Oblique Projections: Patient rotated to 45° angle.
- Lateral Projections: Side view of the body part depicted.

Radiographs should be placed for viewing with the patient's right side to the viewer's left.
General Body Positions: Include various standard positions such as supine (lying down), standing, and sitting for imaging.

Flexion: Decreasing the angle between two body parts.
Extension: Increasing the angle between two body parts.
Supination: Rotating the hand or forearm so the palm faces up.
Pronation: Rotating the hand or forearm so the palm faces down.
Abduction: Movement away from the midline.
Adduction: Movement towards the midline.
Medial vs Lateral Rotation: Refers to rotation towards or away from the midline.

Minimum of two projections for all anatomical structures to ensure clarity on superimposed structures or foreign bodies.
Exception: For certain procedures like pelvis studies where specific guidelines can exempt from standard rules.
Evaluation criteria should be followed to ensure accurate representations in imaging, including aspects of no rotation in limbs or joints being imaged.