Chapter 2 - General Anatomy and Radiographic Positioning Terminology

*** : Important for Test

Need to know

Anatomy

The term applied to the science of the structure of the body.

Physiology

The study of the function of the body organs.

Osteology

The detailed study of the body of knowledge relating to the bones of the body.

Body Planes

Imaginary planes that subdivide the body in reference to anatomic position.

Fundamental Planes (4)

Sagittal, Coronal, Horizontal, and Oblique.

Sagittal planes :

Divide the body into right and left segments, passing vertically from front to back.

*** MSP (midsagittal plane) : (also known as "median plane")

A specific sagittal plane that passes through midline and divides the body into equal right and left halves

***

The MSP is perpendicular to the image receptor when the patient is in anatomical position.

Coronal planes :

Pass through the body vertically from side to side, dividing the body into anterior and posterior parts.

*** MCP (midcoronal plane) : (also known as "midaxillary plane")

The specific plane that passes through the midline and divides the body into equal anterior and posterior halves.

Horizontal planes : (also called "transverse, axial, or cross-sectional planes ***)

Pass crosswise through the body or body part at right angles to the longitudinal axis. (Superior and Inferior portions.)

Oblique planes :

pass through a body part at any angle between the previous three planes. (between sagittal and coronal plane.)

Planes are used in radiographic positioning to center a body part to the IR or CR.

CR: Central Ray - Centermost ray that hits the subject. (Path of the X-Ray beam.) Usually at 45 degrees oblique.

Body Planes

1. Interiliac Plane : Transects the body at the pelvis at the top of the iliac crests (level of L4) (Top of pelvis.)2. Occlusal Plane : Formed by the biting of surfaces of the upper and lower teeth with jaws closed. (When clenching teeth, it is the line when the top and bottom teeth meet.)3. *** Intermalleolar Plane : (ankle) - The line from one malleolus to the other (look up images.)

Body Cavities :

Two great cavities : - Thoracic Cavity- Diaphragm - In - Between- Abdominal Cavity

Abdominal Cavity :

Has no lower partition, but the lower portion is called the pelvic cavity. Often referred to as the abdominopelvic cavity.

*** Thoracic Cavity contains :

- Pleural membranes - Visceral and Parietal- Lungs- Trachea- Esophagus- Pericardium- Heart and great vessels - Aorta, SVC, etc.

*** Abdominal Cavity contains :

- Peritoneum- Liver- Gallbladder - Pancreas- Spleen vessels- Stomach- Intestines- Kidneys- Ureters- Major blood

*** Pelvic portion contains :

- Rectum- Urinary bladder- Part of the reproductive system - Uterus, Ovaries, etc.

Divisions of the Abdomen (4) :

- Right upper quadrant (RUQ)- Right lower quadrant (RLQ)- Left upper quadrant (LUQ)- Left lower quadrant (LLQ)

Diaphragm

Muscle of respiration

***

The diaphragm separates the thoracic cavity from the abdominal cavity

C1

Mastoid tip

C2, C3

Gonion (angle of mandible)

C3, C4

Hyoid bone

C4, C5

Thyroid cartilage

C7, T1

Vertebra prominens

T1

approximately 2 inches above level of jugular notch

T2, T3

Level of jugular notch

T4, T5

Level of sternal angle

T7

Level of inferior angles of scapulae

T9, T10

Level of xiphoid process

L2, L3

Inferior costal margin

L4, L5

Level of superior most aspect of iliac crests

S1, S2

Level of anterior superior iliac spine (ASIS)

Coccyx

Level of pubic synthesis and greater trochanters