Biology 322 Human Anatomy I Orientation to the Human Body

This is a course in Human Anatomy – that is, the structure of the human body. However, we will often relate the structure of the body to its function, that is its physiology, since the two are intimately interdependent upon each other. That is: changes in anatomy produce changes in physiology, and changes in physiology produce changes in anatomy

The structures and functions of all complex animals are based on a “structural heirarchy” These are interdependent. Abnormalilties at one level will affect all higher levels

Example #1: Your body consists of trillions of cells of at least 400 different types About a dozen types are Lymphocytes One type of lymphocyte is the CD4 cell Suppose a virus attacks and destroys your CD4 cells, while all other cells (including all other lymphocytes) remain healthy.

Example #2: Your body consists of trillions of cells of at least 400 different types Four types are found in pancreatic islets One type of islet cell is the beta cell, which produces insulin Suppose your body attacks and destroys the beta cells, while all other cells (including other islet cells) remain healthy.

Example #3: Your body consists of trillions of cells of at least 400 different types One type of cell in nervous system is the oligodendrocyte Oligodendrocytes: dozens of organelles One organelle: plasma membrane Plasma membrane: hundreds of types of molecules One type of molecule: myelin Suppose your body attacks and destroys the myelin in the plasma membranes of oligodendrocytes, while all molecules and all other cells remain healthy.

Two Terms You Need to Know: Gross Anatomy: The study of structures you can see with the unassisted eye Microscopic Anatomy: The study of structures which are too small to see without a microscope Histology = study of tissues Cytology = study of cells

A few basic concepts of anatomy which we will use throughout this course 1) Planes or sections 2) Terms indicating relative positions 3) Regions of the body 4) Three-dimensional relationships

1) In discussing the organization of the human body and its parts, we establish our "point of view" according to three three planes or sections relative to the “anatomical position: Coronal or Frontal Plane Horizontal or Transverse Plane Sagittal Plane

How a structure appears depends on the plane in which you view it:

2) In discussing parts of the human body, we also use a number of terms of relative position: Superior (cranial): Toward head or upper part of structure Inferior (caudal): Toward sacrum or lower part of structure Anterior (ventral): Toward the front Posterior (dorsal): Toward the back Medial: Toward the midline of the body or of a structure Lateral: To side of midline of the body or of a structure Proximal: Closer to center or origin Distal: Away from center or origin Superficial: Toward the surface of the body or of a structure Deep: Toward the center of the body or of a structure

3) Various regions of body have specific names: Anterior Posterior

You should know the following regions of the human body: Abdominal Crural Pedal Acromial Cubital Perineal Antebracheal Facial Plantar Axillary Femoral Popliteal Brachial Gluteal Pubic Calcaneal Inguinal Sacral Carpal Lumbar Scapular Cephalic Nuchal Sternal Cervical Palmar Tarsal Coxal Patellar Thoracic Cranial Pectoral Umbilical

For example: The region of the upper limb between the shoulder and elbow is the_________ region brachial carpal For example: The _________ region is immediately distal to the antebracheal region For example: The region of the body commonly known as the “lower leg” is the _______region crural

4) Finally: As we discuss the human body, get your brain to think three-dimensionally and focus on relationships . . .