Intro to Anatomy

Planes, Body Cavities, Membranes, and Directional Terms

**Anatomy**

The study of **structure**

**Physiology**

The study of **function**

**Medial/mid-sagittal** plane

Divides **left and right** into **equal** sections

**Sagittal** plane

Divides **left and right** into **unequal** sections

**Transverse** plane

Divides **upper and lower** (superior and inferior) into **equal or unequal** sections

**Frontal** plane

Divides **front and back** (anterior and posterior) into **equal or unequal** sections

**Cranial** cavity

The **head**

**Optic/orbital** cavity

The **eyes**

**Nasal** cavity

The **nose**

**Oral** cavity

The **mouth**

**Pleural** cavity

The **lungs**

**Pericardial** cavity

The heart

**Thorasic** cavity

The **chest** (thorax)

**Diaphragm**

Between the **chest** (thorax) and the **abdomen**, separating the two regions

**Abdominopelvic** cavity

The **abdomen**

**Abdominal** cavity

The upper **abdomen**; within the abdominopelvic cavity

**Pelvic** cavity

The lower abdomen (**pelvis**); within the abdominopelvic cavity

**Anterior/ventral** cavity

The **front** of the body

**Posterior/dorsal** cavity

The **back** of the body

**Axial** region

The **core** and the **head**; vital organs

**Appendicular** regions

The **arms** and the **legs**; appendages

Purpose of **membranes**

To **line** and help **protect** organs in the body

Contents of **serous membranes**

The **visceral** (inner) and **parietal** (outer) membranes

Types of **serous membranes**

**Pleural** (surrounds the lungs), **pericardium** (surrounds the heart), and **peritoneum** (surrounds all other organs)

Purpose of **serous fluid**

To **reduce friction** between the organ and other membranes/organs

**Proximal**

**Closer** to the point of attachment; only used for describing locations on the appendages

**Distal**

**Farther** from the point of attachment; only used for describing locations on the appendages

**Medial**

Closer to the **midline**

**Lateral**

Closer to the **side**

**Bilateral**

Two organs closer to the **side**; only used for paired organs

**Superficial**

Closer to the **surface** (skin); shallow

**Deep**

Closer to the **internal organs**; farther in

**Superior**

**Above**

**Inferior**

**Below**

**Cephalic**

**Closer** to the **head**

**Caudal**

**Farther** from the **head**