Anatomy Basics
Subdisciplines of Anatomy
Gross anatomy- a.k.a. macroscopic anatomy, study of anatomical structures that can be viewed with the naked eye (e.g., muscles, bones, blood vessels, nerves, etc.)
Image shows the macroscopic structures within the axillary region (arm pit).
Histology- a.k.a. microscopic anatomy, study of anatomical structures that are so small they can only be seen with a microscope (cells & tissues)
Image shows a type of tissue called a pseudostratified columnar epithelium.
Embryology- study of how body structures develop before birth
Image shows the development of the face in an embryo from week 4 through week 8
Pathology- study of structural changes in cells, tissues, and organs caused by disease or trauma
Image shows a non-pathological radius on the left and a radius with a healed midshaft fracture on the right
Anatomical Position
Anatomical position is a common reference position used to describe the location and relationships of anatomical parts and directions. The position is described as:
standing upright
toes point forward
palms face forward
face forward
arms by the sides
When describing anatomy, this position is always assumed. The image below demonstrates anatomical position.
Directional Terms and Planes
Body planes
Median (midsagittal) plane- divides body into right and left portions
Frontal (coronal) plane- divides body into anterior and posterior portions
Transverse (axial) plane- divides body into superior and inferior portions
Directional terms
Anterior- towards the front. Ventral is another commonly used term that means “towards the belly”. These can be used interchangeably in humans since the belly is in the front. However, they may not correspond in other animals. Think of the ventral fin of a fish is on the belly-side of the body but anterior may be towards the head instead.
Posterior- towards the back. Dorsal is another commonly used term that means “towards the back or spine”. Think of a dorsal fin of a shark or dolphin is on the back. Posterior and dorsal can also be used interchangeably in humans.
Superior- towards the head. Cranial is another term that means “towards the head”.
Inferior- towards the feet. Caudal means “towards the tail”. It is commonly used in embryology or comparative anatomy but less common in gross anatomy since it does not directly correspond with the term “inferior”.
Anterior/Ventral Posterior/Dorsal Superior/Cranial Inferior/Caudal
Medial- towards midline
Lateral- away from the midline
Proximal- towards the body or beginning of the limb, generally used in reference to limb parts. A helpful way to remember this is it refers to a structure in closer proximity to the body
Distal- towards the end of the limb, generally used in reference to limb parts. A helpful way to remember this is it refers to a structure a farther distance away from the body
Medial Lateral Proximal Distal
Superficial- closer towards the surface
Deep- further inside from the surface
Regions of the Body
Throughout this course we will refer to various regions of the body. Familiarize yourself with location of the following regions of the body:
cephalic (or head)
cervical (or neck)
thoracic
abdominal
pelvic
pubic (or genital)
arm (or brachial)
forearm (or antebrachial)
thigh (or femoral)
leg (or crural)
Keep in mind that terms such as “arm” and “leg” are used colloquially to refer to the upper and lower limbs, respectively. However, these terms have a specific meaning in anatomy: “arm” refers only to the part of the upper limb between the shoulder and elbow joints; “leg” refers only to the part of the lower limb between the knee and ankle joints.