Lecture # 1: Fundamentals 1 (Chapter 1, Atlas A) Objectives: 1- Define Anatomy and Physiology and state the relationship between structure and function. 2- Explain the levels of structural organization of the human body. 3- Define cell, tissue, organ, organ system, and organism. 4- List the systems of the human body, describe their functions, and itemize their component organs. A new life begins – a human embryo on the point of a pin

The Scope of Anatomy and Physiology (page 2) The study of internal and external structures of the body and the physical relationships among body parts Anatomy: Physiology: The study of how living organisms perform their vital functions Anatomy and Physiology are complementary branches of science, which help us to understand the human body. Anatomy and Physiology are closely integrated both theoretically and practically Anatomical information provides clues about functions, and physiological mechanisms can be explained only in terms of the underlying anatomy The Unity of Form and Function or The Principle of Complementarity of Structure and Function: What structure can do (its function), depends on its specific form (all specific functions are performed by specific structures)

Anatomy - The Study of Form 1- Examining structure of the living human body Inspection, Palpation, Auscultation, Percussion Medical Imaging (Radiology) Exploratory Surgery 2- Cadaver dissection 3- Comparative anatomy It is the careful cutting and separation of tissues to reveal their relationships It is the study of several species in order to examine structural similarities and differences

Anatomy - The Study of Form 1- Gross or Macroscopic Anatomy It is the study of structures that can be seen with the naked eye 2- Microscopic Anatomy It is the study of structures that are not visible without magnification

2- Microscopic Anatomy Cytology: It is the study of structure and function of individual cells Ultrastructure: Histology: Histopathology: It is the study of the cell structures seen in the electron microscope It is the microscopic examination of normal tissues It is the microscopic examination of tissues for signs of disease Cartilage Bone Blood Muscle Cancer cells Fungi infection Bacterial infection

Physiology - The Study of Function Physiology has many subdisciplines: - Endocrinology (physiology of hormones) - Neurophysiology (physiology of nervous system) - Pathophysiology (mechanisms of disease) Because of limitations on experimentation with humans, much of what we know about human physiology has been obtained through the Comparative Physiology Comparative Physiology: It is the study of the physiology of different species in order to examine the differences and similarities with humans Comparative Physiology is the basis for the development of new drugs and medical procedures

Human Structure (page 12) The human body is extremely complex It consists of about 100 trillion cells (100 000 000 000 000 cells) Each of these 100 000 000 000 000 cells has in it a genome that occupies a total of 3,100 000 000 DNA base pairs. That is why the organization of living matter is extremely important

The human body is organized in a “Hierarchical Manner” Hierarchical Manner: Levels of organization are progressively integrated to make up higher levels. Atoms Molecules Cells Tissues Organs Systems CHEMICAL LEVEL CELLULAR LEVEL TISSUE LEVEL ORGAN LEVEL ORGAN SYSTEM LEVEL Organisms Humans have a hierarchy of complexity ORGANISM LEVEL

Complex protein molecule Atoms Molecules The smallest particle with unique chemical identity A particle composed of at least two atoms MACROMOLECULES Complex protein molecule SMALL MOLECULE H O 2 Chemical or Molecular Level

Atoms Molecules Organelles Cells The smallest particle with unique chemical identity A particle composed of at least two atoms Microscopic structures that carry out specific cell functions (“little organs”) Cells They are the smallest units that carry out all the basic functions of life Nothing simpler than a cell is considered alive There are about 200 two hundred types of cells in the human body, and they vary greatly in appearance

Atoms Molecules Organelles Cells Tissues The smallest particle with unique chemical identity A particle composed of at least two atoms Microscopic structures that carry out specific cell functions (“little organs”) Cells Tissues They are the smallest units that carry out all the basic functions of life A tissue is a mass of similar cells and cell products that perform a specific function Nothing simpler than a cell is considered alive The human body is composed of only four primary classes of tissue Epithelial tissue Connective tissue Muscular tissue Nervous tissue

Cardiac muscle tissue Tissues Organs Organ is a structure composed of two or more tissue types that work together to carry out a particular function Connective tissue Epithelial tissue

Connective tissue Epithelial tissue Smooth muscle tissue Tissues Organs Organ is a structure composed of two or more tissue types that work together to carry out a particular function

Tissues Organs Smooth muscle tissue Connective tissue Organ is a structure composed of two or more tissue types that work together to carry out a particular function Smooth muscle tissue Connective tissue Epithelial tissue

Organs Organ Systems An organ system is a group of organs with a unique collective function, such as circulation, respiration, or digestion Cardiovascular System: The heart pumps blood, and blood vessels transport the blood to different tissues

These systems may be classified according to their principal functions The human body has 11 organ systems and an immune system, which is better described as a population of cells than as organ system These systems may be classified according to their principal functions Protection, Support, and Movement Defense 8- Immune System 1- Integumentary System 2- Skeletal System 3- Muscular System Input and Output 9- Respiratory System 10- Urinary System 11- Digestive System Internal Communications and Integration 4- Nervous System 5- Endocrine System Reproduction 12- Reproductive System Fluid Transport 6- Circulatory System 7- Lymphatic System

All the organ systems work together to detect changes, to activate mechanism that oppose it, and thereby to maintain relatively stable internal conditions in the organism The ability of the organism to maintain internal stability is called “homeostasis” Homeostasis is so important that most disease can be regarded as a result of its disturbance, a condition called homeostatic imbalance

Interrelationships Among Body Organ Systems Food CO 2 2 O Interrelationships Among Body Organ Systems Blood Respiratory System Heart Digestive System Circulatory System Cells Nutrients Interstitial Fluid External Environment Integumentary System Excretory System Unabsorbed matter (feces) Nitrogen-containing waste products (urine)