03 Anatomical Principles

Introduction to Gross Anatomy Objectives: • Define what is meant by gross anatomy • Describe what material will be covered • Define the anatomical position • How to use anatomical terminology to describe body planes, regions, directions and movement

MEDICAL GROSS ANATOMY • Dfn.: The word anatomy has its origins in Greece, “temnein”. • A literal translation would be to cut open. • Anatomy is the study of internal and external structures and the physical relationships between parts. • Anatomical information provides clues about probable functions, and physiological mechanisms can be explained only in terms of the underlying anatomy. All specific functions are performed by specific structures.

How to know anatomy? • It is not just memorizing facts • An understanding of anatomy requires an understanding of the context in which the terminology can be remembered • e.g., Three main branches of Aorta

The Aorta Three main branches Right brachiocephalic trunk Left common carotid Left subclavian artery

ivided into right and left sides by l plane s function to carry blood away from art ocephalic artery: carries blood to um and head mmon carotid: eventually divides into ajor arteries – superficial and deep s. Gr. Karos – deep sleep bclavian artery: carries blood to under clavicle, then to upper limb

R. brachiocephalic artery L. common carotid artery L. subclavian artery

Define what is meant by gross anatomy: Anatomy at different scales

Describe what material will be covered in class PROVIDE STUDENTS WITH AN INTRODUCTION TO: 1. MEDICAL TERMINOLOGY 2. ANATOMICAL STRUCTURES AT THE GROSS LEVEL IN A CLINICAL CONTEXT 3. DISSECTION OF HUMAN CADAVERIC MATERIAL http://dml.georgetown.edu/students/5586.html 4. CONVENTIONAL & MODERN IMAGING TECHNIQUES X-RAYS http://dml.georgetown.edu/resources/32790.html CT MRI

ANATOMICAL VERNACULAR The language of anatomical vernacular is an internationally agreed upon nomenclature with Latin and Greek roots forming its basis.

Physiological Systems

REGIONAL ANATOMY

De humani corporis fabrica (On the Structure of the Human Body• ) Vesalius is the only person touching cadaver

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Menials (barber-surgeons) are placed below table

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Demonstration is outside students, physicians, and leaders of city and church in attendance

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Monkey and dog away from center of picture

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Articulated skeleton in center – importance of knowing the bones

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Nude figure indicates importance of knowing surface anatomy

ANATOMY POSITION •

Standard reference position

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Standing upright

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Feet together, hands face outwards

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Fingers together

FUNDAMENTAL PLANES IN THE BODY Superior

HORIZONTAL, (TRANSVERSE, Axial)

Posterior

Anterior

CORONAL •

Oriented vertically

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Divides body into anterior/posterior

Divides body into Superior/inferior

Inferior

MEDIAN SAGITTAL • Oriented vertically •

At right angles to coronal plane

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Divides body into R/L

ESSENTIAL TERMS FOR ORIENTATION (Location) Superior (Cranial)

P O DS OT RE SR A I LO R

A N T E R I O R

V E N T R A L

R

L Transverse

Sagittal

Inferior (Caudal) Coronal

Anterior/Posterior Trachea

Imp. relationship to keep in mind when an anesthesiologist intubates a patient.

Esophagus

Right vs. Left Left recurrent laryngeal n.

Anatomical knowledge will allow you to make diagnosis

Superior vs. Inferior

Liver Stomach Abnormal relationship, e.g., hiatal hernia, likely to indicate pathological condition

ORIENTATION (Medial and Lateral, Everything is Relative) Clavicle

Sternum

Shoulder

Sagittal

ESSENTIAL TERMS FOR ORIENTATION (Superficial and Deep) Coronal

Superficial to Deep

Deep to Superficial

Medial to Lateral

Superficial to Deep

Deep to Superficial

Sagittal

Superficial vs. Deep Location of phrenic n.

Location of vagus n.

Functions of Skin • Protection • Containment • Heat Regulation • Sensation • Synthesis and storage of

Superficial Structures Skin Epidermis

Dermis Collagen Elastic tissue

Superficial fascia

Deep fascia Muscle

Superficial Structures

Skin

Superficial fascia

Skin: Langer Lines Skin Incisions •

Surgical incisions are made parallel with tension lines

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Allow for distention of skin

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Heal better, little scarring

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Incisions perpendicular to these lines more likely to produce keloids

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Ice picks produce slit like wounds rather than rounded cuts

Stretch Marks

Stretch Marks • Striae gravidarum (pregnant women) • Appear on abdomen, buttocks, thighs, breast • Striae distensae (obese people) • Caused by the rapid increase in size – damaging collagen fibers of dermis

ESSENTIAL TERMS FOR ORIENTATION (Proximal and Distal: Near and Far) Shoulder

Elbow

Wrist

Sagittal

ACTION TERMS

ABDUCT-ADDUCT FLEX-EXTEND MEDIAL ROTATION-LATERAL ROTATION Pronation -Supination CIRCUMDUCTION

Terms of Movement

Terms of Movement