Introduction to Anatomy and Physiology PDF

Introduction to Anatomy Dr. P. De Gabriele MD DipWH(ICGP) MMCFD  What is Anatomy? The study of structure and the relationships among structures Structure that can be seen with the naked eye – Gross Anatomy Surface anatomy that deals with the...

Introduction to Anatomy Dr. P. De Gabriele MD DipWH(ICGP) MMCFD  What is Anatomy? The study of structure and the relationships among structures Structure that can be seen with the naked eye – Gross Anatomy Surface anatomy that deals with the form and markings of the surface of the body Histology that is the microscopic study of the structure of the tissues THE ANATOMICAL POSITION Subject is standing erect facing the observer. The upper extremities are placed at the sides. The palms of the hands are turned forward. Regional Terms  Directional Terms Superior - Toward the head or the upper part of a structure Inferior - Away from the head or toward the lower part of a structure Anterior - Nearer to or at the front of the body Posterior - Nearer to or at the back of the body Medial - Nearer to the midline of the body or a structure Lateral - Farther from the midline of the body or a structure Intermediate - Between two structures  Directional Terms Ipsilateral - On the same side of the body Contralateral - On the opposite side of the body Proximal - Nearer to the attachment of an extremity to the trunk or a structure Distal - Farther from the attachment of an extremity to the trunk or a structure Superficial - Toward or on the surface of the body Deep - Away from the surface of the body Parietal - Pertaining to or forming the outer wall of a body cavity Visceral - Pertaining to the covering of an organ BODY PLANES AND SECTIONS When a section is made through the body wall or through an organ, it is made along an imaginary line called a plane. There are 3 types of planes or sections: Sagittal Section Frontal Section Transverse Section Sagittal Section The cut is made along the longitudinal plane of the body dividing the body into right and left halves. If these halves are equal in size, the cut is called a midsagittal or median section.  Frontal Section The cut is made along the longitudinal plane of the body dividing the body into anterior and posterior parts. This is also called a coronal section. Transverse Section The cut is made along a horizontal plane of the body dividing the body into superior and inferior parts. This is also called a cross section. Body Cavities  Body Cavities & Membranes The body is internally divided into 2 major body cavities: Dorsal Body Cavity Ventral Body Cavity The organs within the cavities are called viscera. Various membranes line the cavities and cover the viscera and hold them in place. Dorsal Body Cavity This made up of: The Cranial Cavity – enclosed by the cranium and contains the brain The Vertebral Canal – enclosed by the vertebral column and contains the spinal cord It is lined by 3 membranes called the meninges. Ventral Body Cavity This is made up of : The Thoracic Cavity The Abdominopelvic Cavity seperated by the diaphragm. The cavities are lined by serous membranes The pleura The peritoneum  What is Physiology? The science of functional mechanisms of living organisms Examples: The processes that maintain the identity of a living body during its exchange with its surroundings The manner in which information is received from the surroundings and how the organism reacts to influence its environment The Hierarchy of Complexity System Level Organ Level Tissue Level Cellular Level Chemical Level  Tissues & Organs A tissue is a mass of similar cells and cell products that forms a discrete region of an organ and performs a specific function. An organ is a structure composed of two or more tissue types that work together to carry out a particular function.  Organ Systems An organ system is a group of organs with unique collective function. The body has 11 organ systems: Integumentary System Circulatory System Skeletal System Lymphatic System Muscular System Respiratory System Nervous System Urinary System Endocrine System Digestive System Reproductive System Integumentary System Skin Hair Nails Cutaneous Glands Skeletal System Bones Cartilage Ligaments Muscular System Skeletal Muscles Nervous System Brain Spinal Cord Nerves Ganglia Endocrine System Reproductive System Circulatory System Heart Blood Vessels Lymphatic System Lymph Nodes Lymphatic Vessels Thymus Spleen Tonsils Respiratory System Nose Trachea Pharynx Bronchi Larynx Lungs Urinary System Digestive System Teeth Tongue Salivary Glands Oesophagus Stomach Small & Large Intestine Liver Gallbladder Pancreas  Life Processes (1) 1. METABOLISM - the sum of the chemical reactions which occur in the body Anabolism – the process of using energy to build up the body structures Catabolism – the process of breaking down substances to provide energy needed to sustain life 2. EXCITABILITY – the ability of living things to sense changes within and around them, and then respond in such a manner which is beneficial to them 3. CONDUCTIVITY – the ability to carry the effect of a stimulus from one part of a cell to another. It is highly developed in nerve cells and to a lesser extent in muscle cells.  Life Processes (2) 4. CONTRACTILITY – the capacity of cells to undergo shortening and change form. For example, muscle cells have a high degree of contractility. 5. GROWTH – an increase in cell size and numbers 6. DIFFERENTIATION – the mechanism by which unspecialized cells change to specialized cells with specific structure and function 7. REPRODUCTION – the formation of new cells or the reproduction of a new individual. Through this process, life is transmitted from one generation to another.  Homeostasis The maintenance of constant conditions in the body’s internal environment The internal environment contains oxygen, glucose, different ions, fatty substances and other constituents. The body cells can LIVE, GROW and FUNCTION only if the proper concentrations of these substances are maintained. All the organs play a part in homeostasis. The lungs provide oxygen. The kidneys maintain constant ion concentrations. The gastrointestinal tract provides nutrients.  CONTROL SYSTEMS The body has many regulating devices that oppose change and bring the internal environment back into balance. One such device is a feedback system in which information is continually reported (fed back) to a control centre that responds in a positive or negative way.  NEGATIVE FEEDBACK When the variable departs from its normal limits, the central control centre issues impulses to regulate it and bring it back to its usual level. This type of feedback reverses the direction of the initial condition. e.g. NERVOUS CONTROL OF BLOOD PRESSURE Pressure-sensitive cells situated in the walls of large arteries These can detect an increase in blood pressure. They send this information to the control centre in the brain. This, in turn, will send impulses to the heart to beat slower the arterioles to dilate. Blood pressure will decrease until it reaches its usual level.  POSITIVE FEEDBACK If, instead, the brain had signalled the heart to beat even faster, the blood pressure would have kept on rising the system would have been a positive feedback system. Such a system would lead to instability and death. Nearly all control systems of the body operate by negative rather than positive feedback.