Textbook of Anatomy and Physiology Unit 1 PDF

UNIT 1 INTRODUCTION TO ANATOMY AND PHYSIOLOGY  CHAPTER 1 INTRODUCTION TO ANATOMICAL TERMS AND ORGANIZATION OF THE HUMAN BODY  INTRODUCTION ANATOMY Anatomy is the science which deals with the structure of human body. The...

UNIT 1 INTRODUCTION TO ANATOMY AND PHYSIOLOGY  CHAPTER 1 INTRODUCTION TO ANATOMICAL TERMS AND ORGANIZATION OF THE HUMAN BODY  INTRODUCTION ANATOMY Anatomy is the science which deals with the structure of human body. The term anatomy is derived from a Greek word “anatome” meaning cutting up. DIVISION OF ANATOMY Gross/Cadaveric/Macroscopic Anatomy The study of the structure of the human body by cadaveric dissection (dead bodies) with the naked eye. It can be studied by region (regional) such as the upper and lower limbs, the thorax, abdomen, head and neck, and the brain, or by system (systemic) such as the skeletal system, muscular system, nervous, respiratory, digestive, reproductive, and endocrine systems.  HISTOLOGY/MICROSCOPIC ANATOMY The study of human bodily structures by using a microscope. EMBRYOLOGY/DEVELOPMENTAL ANATOMY The study of growth and development of human body from fertilization through birth. ❑Surface anatomy ❑Radiologic anatomy ❑Living anatomy ❑Genetic anatomy ❑Applied anatomy INTRODUCTION TO ANATOMICAL TERMS ANATOMICAL POSITION The position in which a person is standing straight with eyes looking forwards, upper limbs by the sides, face and palms of the hands directed forwards, both feet together. PALMER AND DORSAL SURFACE PROXIMAL AND DISTAL  SUPINE POSITION PALMER AND DORSAL SURFACE PRONE POSITION LITHOTOMY ANATOMICAL PLANES POSITION  TERMS RELATED TO ANATOMICAL PLANES ❑Median/Midsagittal Plane ❑Vertical plane passing through the center of the body, splitting it into equal right and left halves. ❑Sagittal/Paramedian Plane ❑Plane parallel to median or mid sagittal plane situated to one or other side of the median plane. ❑Coronal Plane ❑A vertical plane that divides the body into anterior (front) and posterior (back) halves at a right angle to the median or mid sagittal plane. ❑Horizontal/Transverse plane Planes are at right angle to sagittal or median plane which divides the body into upper and lower parts. ❑Oblique Plane Planes other than coronal, transverse, and midsagittal are referred to as oblique planes. TERMS RELATED TO BODY MOVEMENT JOINT A joint is a point or junction of the body where two or more than two bones meet and are able to bend. Some joints have no movement (sutures of the skull), some have only slight movement (superior tibiofibular joint), and some are freely movable (shoulder joint). FLEXION It is the movement that reduces the angle between two bones or body parts so that their ventral surface comes close to each other. For example, flexion at the elbow decreases the angle between the ulna and humerus. EXTENSION Straightening, It is the movement that increases the angle between two bones or body parts usually take place in posterior direction. For example, extension at the elbow increases the angle between the ulna and humerus. FLEXION AND EXTENSION ABDUCTION It is movement of a limb away from the midline of the body, for example spreading of fingers and toes is abduction. ADDUCTION It is the movement of the limb toward the midline of the body, for example drawing together of fingers and toes is adduction. ROTATION Any movement of a part of the body around its long axis. Medial rotation is the movement of the body part towards the midline where as lateral rotation is the movement of the body part away from the midline. CIRCUMDUCTION Combination in sequence of the movements of flexion, extension, abduction and adduction PRONATION Medial rotation of the forearm so that the palm of the hand faces posteriorly (Opposite to anatomical position). SUPINATION Lateral rotation of the forearm so that palm of hand faces anteriorly (Anatomical position). PROTRACTION It is the movement of the jaw in forward direction to stick out the chin. RETRACTION It is the movement of the jaw in the backward direction to pull the jaw. INVERSION It is the movement of the foot towards the median plane so that sole faces towards medial direction. EVERSION It is the movement of the foot away from the median plane so that sole faces towards lateral direction. DORSAL FLEXION The flexion of the ankle joint in which the dorsum of foot bent towards anterior surface of the leg. PLANTER FLEXION The extension of the ankle joint in which the planter aspect of the foot faces backwards.  CELL STRUCTURE AND CELL DIVISION A microscopic anatomy is a visual, colorful science. The light source for the early microscopes was sunlight. In modern microscopes, electric illumination is used as the main light source. During embryonic development, the cells divide and multiply to form new cells, tissues, and organs. In an adult organism, however, not all cells retain the ability to further divide and reproduce. As a result, different populations of cells are recognized based on their ability or inability to divide and reproduce. Nerve cells in the nervous system and muscle cells (skeletal and cardiac) continue to divide during embryonic development. Once these cells establish the organs in postnatal life, however, their ability to further divide ceases and they cannot be replaced if they are damaged or destroyed. INTRODUCTION Cell is the fundamental structural and functional unit of the living matter and is capable of carrying on the processes of the life independently. The main function of these cells is to maintain a proper homeostasis in the organism. Cell can be divided as prokaryotic and eukaryotic kingdom.  CELL PROKARYOTIC EUKARYOTIC PLANTS ANIMALS STRUCTURE OF CELL ❑Cell membrane ❑Nucleus ❑Cytoplasm CELL MEMBRANE Cell membrane is also known as plasma membrane is the outer covering of the cell. The membrane isolates the individual cell and takes part in the maintenance of the internal environment by active transport of ions and nutrients.  CELL, ITS CYTOPLASM AND ORGANELLES  NUCLEUS Nucleus is the most easily spotted, membrane bound organelle and a characteristic feature of a eukaryotic cell. It houses the cell’s genetic material – DNA condensed in the form of chromosomes SCHEMATIC REPRESENTATIONS OF VARIOUS TYPES OF MEMBRANE TRANSPORT CYTOPLASM It is the gel like, clear colored solution made up of proteins, ions, enzymes and organelles all surrounded by plasma membrane. Each cell cytoplasm contains numerous organelles, each of which performs a specialized metabolic function that is essential for maintaining cellular homeostasis and cell life such as mitochondria, endoplasmic reticulum, Golgi apparatus or Golgi complex, lysosomes, ribosomes, centrioles, centrosomes and peroxisomes. Centrosome Centrosome is an area in the cytoplasm which is near the nucleus. It houses a pair of centrioles which are important for cell division. The centrioles are barrel-shaped organelles made up of microtubules. During the mitosis, centrioles form the region from where the mitotic spindle arises. Golgi complex Golgi complex or golgi apparatus is a membranous cytoplasmic organelle constituting of flattened stacks of various types of membranes. Some are called cisternae and others are in the form of tubules and vesicles. Perinuclear in location, these are located right next to endoplasmic reticulum. The vesicles leaving ER enter the golgi complex as cis-cisternae (cisternae nearest to ER) and leave at the trans-cisternae (cisternae farthest of ER) Membrane bound vesicles Lipid bilayer bound small sacs involved in various functions of storage and transportation within the cell is termed as membrane bound vesicle. These originate either from the plasma membrane or the ER/golgi complex. Mostly these contain enzymes, proteins, toxins, or other molecules. MITOCHONDRIA (LEFT) AND CELLULAR LOCATION (RIGHT)  TISSUES EPITHELIAL MINIMAL INTERCELLULAR MATERIAL TISSUE CONNECTIVE ABUNDANT EXTRACELLULAR MATRIX TISSUE MUSCLE TISSUE CONTRACTILE PROPERTIES NERVOUS TISSUE CONDUCT ELECTRICAL IMPULSE  EPITHELIAL TISSUE The epithelial tissue, also known as epithelium, is made up of sheets of cells that cover the external surfaces of the body and line the interior cavities of organs, glands, and ducts. The epithelium is made up of densely packed cells with little intercellular material. They are found on the thin basement membrane that divides the epithelium from the connective tissue beneath it. FUNCTION OF EPITHELIUM SHAPES OF EPITHELIAL CELLS  CLASSIFICATION OF EPITHELIUM Simple epithelium Stratified epithelium ❑ Simple squamous ❑ Stratified squamous epithelium. epithelium ❑ Simple cuboidal ❖ Keratinized epithelium ❖ Non-keratinized ❑ Simple columnar ❑ Stratified cuboidal ❑ Epithelium epithelium ❑ Pseudostratified ❑ Stratified columnar columnar Epithelium ❑ Epithelium ❑ Transitional epithelium SIMPLE SQUAMOUS EPITHELIUM SIMPLE CUBOIDAL EPITHELIUM PSEUDOSTRATIFIED EPITHELIUM  STRATIFIED EPITHELIUM Stratified Squamous Epithelium Multiple cell layers are present. Basal cells range in shape from cuboidal to columnar, and they produce cells that migrate to the surface and become (flat) squamous. Squamous epithelium is divided into two types: nonkeratinized and keratinized Epithelium. STRATIFIED SQUAMOUS KERATINIZED EPITHELIUM STRATIFIED SQUAMOUS NON KERATINIZED EPITHELIUM SURFACE PROJECTION OF THE EPITHELIAL CELLS Epithelial cells show some specialized structure on their apical surfaces for specific functions. These structures are cilia, microvilli, stereocilia, villi and flagellae.  CONNECTIVE TISSUE Among the four basic tissues (epithelium, connective tissue proper, muscle and nervous tissues (Fig. 41)) connective tissue is the most abundant tissue in the human body. Connective tissue consists of: Cells Extracellular matrix Ground substance Fibres VARIOUS TYPES OF CELLS AND FIBERS IN THE CONNECTIVE TISSUE  CARTILAGE Cartilage is a form of connective tissue in which the cells and fibres are embedded in a gel like matrix. It is a specialized connective tissue characterized by elasticity and flexibility. FEATURES OF CARTILAGE ❑Lacks blood supply (avascular), lymphatic and nerves. ❑The chondrocyte cells occur singly or in groups within spaces called lacunae. ❑ Cartilage consists of ground substance, fibers and cells ❑(chondrocytes).  TYPE OF CARTILAGE It is the most abundant type of cartilage in human body. All long bones are performed this cartilage.  ELASTIN CARTILAGE Chondrocytes single not in groups, large, numerous and closely packed in lacunae covered by perichondrium. The matrix consists of elastic fibers and ground substance. Elastic cartilage found in Auricle, pinna of ear, external auditory meatus, auditory tube, epiglottis, corniculate, cuneiform and apices of arytenoid cartilage.  FIBROCARTILAGE Chondrocytes are fewer and in row between the layers of collagen with in lacunae. Fibro cartilage has many collagen fibers embedded in a small amount of matrix. Fibrocartilage found in Articular discs pubic symphysis, inter vertebral discs (annulus fibrosus), temporomandibular joint and knee. Collagen fibers oriented in the direction of stress. DISTRIBUTION OF DIFFERENT TYPE OF CARTILAGE IN BODY  MUSCULAR TISSUE The muscle can be identified by their structure and function. Each muscle type shows the morphological and functional similarities as well as difference. There are three types of muscle tissue in the body:  GLANDS Body contains variety of glands. These glands develop from epithelial cells that extend from the surface into underlying connective tissue. The material secreted by the gland is usually a liquid (enzyme, hormone, mucus or fat). They are classified as 1. Exocrine glands 2. Endocrine glands EXOCRINE GLANDS: Exocrine glands are connected to the surface epithelium by excretory ducts, into which their secretory products pass to the external surface. Exocrine glands are either unicellular or multicellular. 1. CLASSIFICATION OF EXOCRINE GLANDS According to the Branching of the Duct ❖Simple glands ❖Compound glands 2. ACCORDING TO NATURE OF THEIR SECRETIONS ❖Merocine ❖Apocrine ❖Holocrine COILED TUBULAR EXOCRINE COMPOUND ACINAR AND GLAND TUBULOACINAR EXOCRINE GLAND ENDOCRINE GLANDS Endocrine glands do not have excretory ducts. The endocrine glands have lost their connection to the surface epithelium and their secretory products are delivered directly in to the blood.  MAJOR SURFACE AND BONY LANDMARKS IN EACH BODY REGION, ORGANIZATION OF HUMAN BODY The study of the external characteristics of the body is known as surface anatomy (also known as superficial anatomy or visible anatomy). It is concerned with anatomical aspects that can be observed without dissection. Along with endoscopic and radiological anatomy, it is a branch of gross anatomy. The science of surface anatomy is a descriptive one. TECHNIQUES TO EXAMINE SURFACE ANATOMY  SURFACE LANDMARKS ❑Anterior Axillary Fold ❑Posterior Axillary Fold ❑Coracoid Process ❑Deltoid ❑Sternal Angle (Angle of Louis) ❑Breast ❑Nipple ❑Apex Beat of Heart ❑Axillary Artery ❑Brachial Artery ❑Brachial Vein ❑Cephalic Vein SURFACE MARKING OF MALE PECTORAL REGION SURFACE MARKING OF FEMALE PECTORAL REGION SURFACE LAND MARK THORAX HEART STERNOCOSTAL SURFACE AXILLARY ARTERY BRACHIAL ARTERY BASILIC VEIN AND CEPHALIC VEIN  INJECTION SITES Deltoid (commonly used for adult vaccinations) Vastus Dorsogluteal lateralis Rectus femoris Ventrogluteal INTRAMUSCULAR INJECTION IN DELTOID REGION INTRAMUSCULAR INJECTIONS IN GLUTEAL REGION Intramuscular Injections in Gluteus Medius and Gluteus Maximus INJECTION SITES OF IM INJECTION  COMMON BONE MARKINGS ANGLES Sharp bony angulations that may serve as bony or soft tissue attachments but often are used for precise anatomical description. Examples include the superior, inferior, and acromial angles of the scapula and the superior, inferior, lateral angles of the occiput. BODY This usually refers to the largest, most prominent segment of bone. Examples include the diaphysis or shaft of long bones like the femur and humerus. CONDYLE Refers to a large prominence, which often provides structural support to the overlying hyaline cartilage. Examples include the knee joint (hinge joint), formed by the femoral lateral and medial condyles, and the tibial lateral and medial condyles. CREST A raised or prominent part of the edge of a bone. Crests are often the sites where connective tissue attaches muscle to bone. The iliac crest is found on the ilium. DIAPHYSIS Refers to the main part of the shaft of a long bone. Long bones, including the femur, humerus, and tibia, all have a shaft. FACET A smooth, flat surface that forms a joint with another flat bone or another facet, together creating a gliding joint. Examples can be seen in the facet joints of the vertebrae, which allow for flexion and extension of the spine. TROCHANTER A large prominence on the side of the bone. Some of the largest muscle groups and most dense connective tissues attach to the trochanter. The most notable examples are the greater and lesser trochanters of the femur. TUBEROSITY A moderate prominence where muscles and connective tissues attach. Its function is similar to that of a trochanter. Examples include the tibial tuberosity, deltoid tuberosity, and ischial tuberosity. TUBERCLE A small, rounded prominence where connective tissues attach. Examples include the greater and lesser tubercle of the humerus.  APPLICATION AND IMPLICATION IN NURSING ❑Wounds of the skin heel quickly ❑Cartilages do not break whereas bones do ❑Deltoid is a preferred site for intramuscular injection in the upper limb ❑Mark of pregnancy ❑Healthy females feel less cold compared to healthy males ❑Mark of pregnancy  CHAPTER 1 General Physiology- Basic Concepts INTRODUCTION TO PHYSIOLOGY Physiology is the study of normal body function. It explains how different systems of the body are organized and how they interact with each other to perform different functions. It also explains how these functions are maintained by different controlling mechanisms in normal conditions and how they are adjusted when body tries to adapt to a changing environment. The knowledge of physiology extends from molecules to cell and organs and finally to bodily systems. MAJOR ORGAN SYSTEMS OF THE BODY  BODY FLUIDS Water is the most abundant compound of the human body, comprising about 60–70% of adult body weight. Due to the specific arrangement pattern of oxygen and hydrogen atoms, the water is a polar molecule and can combine with a variety of negatively and positively charged ions. Due to this property the water is considered as a universal solvent. Various electrolytes of the body remain dissolved in the body water and form the body fluid.  BODY FLUID COMPARTMENTS INTRACELLULAR COMPARTMENT This is conceptualized as the total space present within all the cells. The fluid presents in this compartment is termed as the intracellular fluid (ICF). EXTRACELLULAR COMPARTMENT This is conceptualized as the total space available outside the cells. The fluid present in this compartment is termed as the Extracellular Fluid (ECF). The extracellular space and the extracellular fluid within it are further classified into three main divisions: INTERSTITIAL SPACE This represents the total space present in between the cells. Accordingly, the fluid present in this space is called interstitial fluid (ISF). INTRAVASCULAR SPACE This is the space present within the blood vessels. The fluid present in this space represents the plasma portion of the blood. TRANSCELLULAR FLUID This represents the fluid present in different body spaces. About 5% is the transcellular fluid. Usually, any increase in transcellular fluid indicates a pathological condition.  DISTRIBUTION OF BODY FLUID IN RELATION TO FAT AND MUSCLE TISSUE Muscle cells hold more water; and fat cells have less water content. So, when muscularity is increased, the body water content increases and when body fat increases, the body water content is decreased. About 50% of body water remains in muscle tissue. Females have less amount of total body water due to higher content of body fat. TBW bears a constant relationship with the fat-free body mass also called lean body mass (LBM) and it has been estimated that the total body water is 70% of LBM, irrespective of age and gender.  ELECTROLYTES Chemically, electrolytes are substances present in body fluids, that become ions; either positively or negatively charged in solution and acquire the capacity to conduct electricity. Electrolytes in body fluids include potassium (K), sodium (Na), chloride (Cl), magnesium (Mg) and phosphate (HPO4). Plasma concentrations of K+, Ca2+, Mg2+, and phosphate are very low compared with their concentrations in cells and bone. MAJOR INTRACELLULAR ELECTROLYTES Potassium Calcium Magnesium Phosphate  CONCEPT OF HOMEOSTASIS There is every possibility that the properties of ECF can change. This is because the ECF represents an open system. It is exposed to the external environment through the skin, lungs, and GI tract. So, external changes will influence ECF. When there is increased sweating due to increased environmental temperature, it can deplete ECF volume and loss of sodium ions. Again, decreased oxygen in atmosphere can reduce the normal oxygen level of the blood leading to hypoxic (less oxygen supply to the cells) condition. Furthermore, internal pathological conditions can also alter ECF conditions. A close interrelation exists between ECF and ICF, cell function and organ function.  CONCEPT OF FEEDBACK CONTROL According to model of homeostatic control, the output from effectors affects the initial change of the variable. This is called feedback mechanism. It is of two types: ❖Negative feedback mechanism ❖Positive feedback mechanism In the negative feedback mechanisms, the parameter if increased initially is reduce back to normal, or if decreased initially is increased to its original state by the effects produced by the effectors. Therefore, the negative feedback mechanisms dampen the initial effects of the stimulus or the stimulus itself. In positive feedback, if initially, the parameter was increased it is increased further or if initially it was decreased, it is decreased further. Therefore, the positive feedback the effect produced by the effectors intensifies the initial effects of the stimulus or the stimulus itself.  MEMBRANE AND GLANDS MEMBRANES Membranes are boundaries, Cell membrane acts as cell boundaries. Similarly, membranes are present outside and inside of different organs, and body cavities and tubes. Two basic membrane types are mucous membrane and serous membrane. BASIC MEMBRANE TYPES ▪ Mucous Membranes ▪ Serous Membranes  GLANDS A gland consists of one or more epithelial cells that produce and secrete a product. Goblet cell, which is a mucus-secreting cells within the columnar epithelium lining of the digestive tracts an example of a single cell gland. Most of the other glands of the body, like sebaceous gland, salivary glands, endocrine glands, glands of stomach etc. are made of multiple cells.  CELL MEMBRANE STRUCTURE AND FUNCTION Membrane Structure This membrane serves to separate and protect a cell from its surrounding environment. Composition of Cell Membrane Membrane is composed of proteins, lipids, and carbohydrates. Proteins are most abundant followed by lipids and carbohydrates. Membrane lipids are composed of phospholipids (major amount) and cholesterol (fewer amount). STRUCTURE OF CELL MEMBRANE  FUNCTION OF CELL MEMBRANE ❑Barrier ❑Transport ❑Cell to cell interaction ❑Signaling ❑Metabolic function ❑Support ❑Cell recognition and antigenic property  MEMBRANE TRANSPORT MECHANISMS Membrane transport is a collective term for various mechanisms by which substances move in and out of the cell across the cell membrane. Transport processes maintain intracellular (ICF) fluid volume and composition that are vital for maintaining cellular function and hence life.  DIFFERENT TRANSPORT MECHANISMS Osmosis Osmosis is the movement of solution from an area of high concentration to an area of low concentration through a selective permeable membrane which allows the solvent but not the solutes. Diffusion Diffusion is a passive transport mechanism and does not require any carrier molecule. It is a process of spontaneous passive movement (without requiring any energy) of molecules from an area of high concentration to an area of low concentration. MECHANISM OF OSMOSIS Active Transport Active transport, as the name implies, requires energy for transport. Energy is required because movement occurs against the concentration gradient. This process also requires a carrier protein molecule. Active transport can be of two different types: Primary Active transport and Secondary Active transport. PRIMARY AND SECONDARY ACTIVE TRANSPORT MECHANISM  ENDOCYTOSIS Endocytosis is an energy-using process by which cells engulf molecules in vesicles formed by the in folding of the cell membrane. Endocytosis occurs in three different ways: 1. Phagocytosis This is called cell eating. First the molecule to be internalized is attached with the cell membrane, next, the in folding of the membrane surrounds the particle and forms a food vacuole, which is then engulfed. 2. Pinocytosis This is called cell drinking. The cell membrane pinches in to engulf a portion of ECF containing solutes required by the cell. This process is non-specific; any solutes in the solution will be engulfed. 3. Receptor-mediated Endocytosis It involves some membrane receptor proteins for transportation. The receptors have specific receptor sites that bind to specific molecules. The receptor-molecule then cluster on the cytoplasm side and remain covered with another class of proteins called coat proteins in form of pits. The coated pits then pinches off as a vesicle, taking with it high concentrations of the specified molecule but also some other molecules from the ECF. After the molecules are delivered to their destination, the receptor proteins are recycled to the plasma membrane.  EXOCYTOSIS Exocytosis is the process in which the cell releases materials to the outside by discharging them in membrane-bounded vesicles. Therefore, it is the reverse of endocytosis. Exocytosis can be constitutive (occurring all the time) or regulated.  CELL CYCLE Cell division is an ongoing process that contributes to growth and repair. Most body cells have limited lifespan, and by cell division, these worn-out cells are replaced by new cells. In eukaryotic cells, cell cycle can be defined as the ordered sequence of events taking place between two successive cell divisions. It can be broadly divided into two events: Growth phase Mitotic phase Summary of cell cycle of an animal cell Growth Phase The growth phase is further of G1, S and G2 phases. G1: It begins with the ‘birth’ of the cell right after previous mitosis and before the start of DNA replication. S phase: It is the one in which centrioles and DNA replicate. By now the DNA is visible as sister chromatids. G2: Next follows the G2 phase marked by the appearance of mitotic spindle. This entire sequence of G1, S and G2 phases is known as interphase. Mitosis Mitosis is essentially the process of replicating the cellular chromosomes and then segregating these into two identical daughter cells (Fig. 13). It is thus a means of reproduction (for organisms with asexual means of reproduction), growth and replacement of the old worn-out cells with new ones. Mitosis is divided into five phases – interphase, prophase, metaphase, anaphase and telophase. The telophase is followed by cytokinesis. STAGES OF CELL CYCLE  DISEASE AND ILLNESS Disease is a state of the body characterized by altered normal structure and function of the bodily systems with deleterious consequences. The homeostatic imbalances are the root cause of diseases. In disease, the feedback regulations become nonfunctional or they fail to normalize the altered condition. A disease may be described in relation to the following terms: ❑Etiology: Cause of the disease ❑ Pathogenesis: The nature of the disease process and its effect on normal body functioning ❑Complications: The consequences which might arise if the disease progresses ❑Prognosis: The likely outcome of a disease Etiology ❑Genetic Abnormalities, Either Inherited or Acquired ❑Infection by Micro-organisms ❑Physical and Chemical Agents ❑Malnutrition  APPLIED ASPECTS (DISORDERS RELATED TO MEMBRANES) Peritonitis This is the inflammation of the peritoneum, the serous membrane that lines the digestive organs and the wall of the abdominopelvic cavity. Pneumothorax A pneumothorax or collapsed lung occurs when air accumulates in the pleural cavity surrounding the lings. This can cause due to trauma and chronic lung disease.  APPLICATIONS IN NURSING ❑Intravenous (IV) therapy or IV infusion is the infusion of fluid directly into the venous circulation of a patient, usually via a cannula. This therapy is indicated when a patient suffers from dehydration, electrolyte imbalance or blood loss due to haemorrhage. ❑Safe administration of intravenous fluid requires the knowledge of the role of electrolytes and water in the body, the mechanism for movements between different body compartments and how fluid balance is maintained. ❑Calculating the drip rate is an important step before IV administration. The drip rate determines the speed at which the fluid is infused into the patient’s venous circulation and it refers to the number of drops that enters into the filling chamber per minute. ❑Intravenous fluids are based on their tonicity. They can be isotonic, hypotonic and hypertonic. They can also classified as colloid or crystalloid. THANK YOU