Chapter 2

Anatomy Overview

  • Anatomy: The study of the structure of the human body.

  • Physiology: The study of body function.

Subdisciplines of Anatomy

  • Gross Anatomy:

    • Regional Anatomy: Focuses on specific regions of the body.

    • Systemic Anatomy: Studies systems, such as the muscular or skeletal system.

  • Surface Anatomy: Examines the study of internal structures as they relate to the overlying skin.

  • Microscopic Anatomy (Histology): Involves the study of tissues and cells on a microscopic level.

Other Branches of Anatomy

  • Developmental Anatomy: Focuses on the development of the human body from conception through adulthood.

  • Embryology: Specifically studies the developmental stages of embryos.

  • Pathological Anatomy (Pathology): Studies structural changes in cells, tissues, and organs caused by disease.

  • Radiographic Anatomy: Examines the structures of the body using imaging techniques.

  • Functional Morphology: Studies the relationship between structure and function in biological systems.

Hierarchy of Structural Organization

  • Chemical Level:

    • Atoms bond to form molecules.

  • Cellular Level:

    • Cells and their functional subunits constitute this level.

  • Tissue Level:

    • A group of cells performing a common function forms a tissue.

  • Organ Level:

    • An organ is a discrete structure made up of more than one tissue type.

  • Organ System Level:

    • Organ systems consist of organs that work together for a common purpose.

  • Organismal Level:

    • The entire living individual made up of all simpler levels working together.

Integumentary System

  • Functions:

    • Forms external body covering.

    • Protects deeper tissues from injury.

    • Synthesizes vitamin D.

    • Site of cutaneous receptors (pain, pressure, etc.) and sweat and oil glands.

Skeletal System

  • Functions:

    • Protects and supports body organs.

    • Provides a framework for muscles.

    • Blood cells are formed within bones.

    • Stores minerals.

Muscular System

  • Functions:

    • Allows manipulation of the environment.

    • Facilitates locomotion.

    • Enables facial expressions.

    • Maintains posture.

    • Produces heat.

Nervous System

  • Functions:

    • Fast-acting control system.

    • Responds to internal and external changes.

    • Activates muscles and glands.

Endocrine System

  • Functions:

    • Glands secrete hormones that regulate:

    • Growth.

    • Reproduction.

    • Nutrient usage.

Cardiovascular System

  • Functions:

    • Blood vessels transport blood, carrying oxygen and carbon dioxide, nutrients, and wastes.

    • The heart pumps blood through blood vessels.

Lymphatic System/Immunity

  • Functions:

    • Picks up fluid leaked from blood vessels.

    • Returns fluid to blood.

    • Disposes of debris in the lymphatic system.

    • Houses white blood cells (lymphocytes).

    • Mounts attacks against foreign substances in the body.

Respiratory System

  • Functions:

    • Keeps blood supplied with oxygen and removes carbon dioxide.

    • Gas exchange occurs through the walls of air sacs in the lungs.

Digestive System

  • Functions:

    • Breaks down food into absorbable units.

    • Indigestible foodstuffs are eliminated as feces.

Urinary System

  • Functions:

    • Eliminates nitrogenous wastes.

    • Regulates water, electrolyte, and acid-base balance of the blood.

Male and Female Reproductive Systems

  • Overall Function: To produce offspring.

    • Male:

    • Testes produce sperm and male sex hormones.

    • Male ducts and glands aid in the delivery of sperm to the female reproductive tract.

    • Female:

    • Ovaries produce eggs and female sex hormones.

    • Female structures serve as sites for fertilization and development of the fetus.

    • Mammary glands produce milk.

Units of Measurement in Anatomy

  • Metric System:

    • Meter, centimeter, micrometer, liter, milliliter, kilogram, gram.

Anatomical Terminology

  • Based on ancient Greek or Latin terminology which provides a standard nomenclature worldwide.

Gross Anatomy—An Introduction

  • Regional and Directional Terms:

    • Anatomical Position: Common visual reference point.

    • Person stands erect with feet together and eyes forward.

    • Palms face anteriorly, thumbs pointed away from the body.

Anatomical Position and Regional Terms

  • Cephalic (Head):

    • Includes the regions:

    • Frontal, cervical (neck), thoracic, abdominal, pelvic, pubic (genital), etc.

  • Appendicular Region:

    • Comprises upper and lower limbs.

Standard Directional Terms

  • Terms are used to describe the location of one body part in relation to another; they include:

    • Superior/Inferior: Toward the head/toward the lower part of the body.

    • Anterior (Ventral)/Posterior (Dorsal): Toward the front of the body/toward the back.

    • Medial/Lateral: Toward the midline/away from the midline.

    • Superficial/Deep: Toward the body surface/away from the body surface.

Orientation and Directional Terms

  • These terms help orient the structure in relations to the body:

    • Ipsilateral: On the same side.

    • Example: The right hand and right foot.

    • Contralateral: On opposite sides.

    • Example: The right hand and left foot.

Body Planes and Sections

  • Sagittal Planes: Extend vertically, dividing the body into right and left parts.

  • Frontal (Coronal) Plane: Lies vertically, dividing the body into anterior and posterior parts.

  • Transverse Plane: Runs horizontally, dividing the body into superior and inferior parts.

Body Cavities and Membranes

  • Dorsal Body Cavity:

    • Includes cranial cavity (contains the brain) and vertebral cavity (contains spinal cord).

  • Ventral Body Cavity:

    • Thoracic Cavity:

    • Has two lateral parts and a mediastinum (contains the heart).

    • Abdominopelvic Cavity:

    • Divided into abdominal cavity (contains organs like the liver and stomach) and pelvic cavity (contains bladder and some reproductive organs).

Serous Cavities

  • A slitlike space lined by a serous membrane:

    • Parietal Serosa: Outer wall of a cavity.

    • Visceral Serosa: Covers the visceral organs.

  • Serous Fluid: Produced by both layers of the serous membranes.

Abdominal Quadrants

  • Abdominal quadrants divide the abdomen into four sections:

    • Right Upper Quadrant (RUQ): Contains organs such as the liver and gallbladder.

    • Left Upper Quadrant (LUQ): Contains organs such as the stomach and spleen.

    • Right Lower Quadrant (RLQ): Contains the appendix.

    • Left Lower Quadrant (LLQ): Contains parts of the large intestine.

Visual Aids

  • References include figures illustrating anatomical positions and various body systems, aiding in understanding structural organization and relations.