ADDIS ABABA UNIVERSITY COLLEGE OF HEALTH SCIENCE SCHOOL OF MEDICEN DEPARTMENT of ANATOMY INTRODUCTION TO HUMAN ANATOMY FOR Pharmacy Objectives • • • • • Define what is anatomy Describe the divisions and approaches of anatomy Recognize Body planes, terms of movement and relative positions Describe the anatomy of cells and tissues General embryology Introduction • Anatomy( Greek; anatome, ana=up and tome=cutting) • deals with the structural organization of living things • arrangement of structures and/or relationship to each other • History????? • Anatomy is an old science and its knowledge began in prehistoric times, when people cut up carcasses of animals they hunted, fished or herded before cooking them • The ancient Egyptians probably had some knowledge of the internal anatomies of humans, cats and other species because they mummified these animals Cont… •In the practice of mummifying these animals the Egyptians removed the internal organs from the dead body and filled the internal cavities of the body with materials that retard decay •The proper understanding of structure, however, implies knowledge of function in the living organisms ;physiology •Anatomy is therefore almost inseparable from physiology which is sometimes called functional anatomy Cont… • Modern anatomy began with the publication work of the Belgian anatomist Andreas Vesalius in 1543 ;the first anatomy textbook • He described anatomy on his own observations of human corpses • The scope of human anatomy covers a wide range of aspects and it is convenient to subdivide the study of anatomy in several different ways Approaches of studying anatomy • There are three main approaches to study anatomy: - Regional - Systemic - and clinical (applied) Regional anatomy • Is the method of studying the body's structure by focusing attention on a specific part • Considers the organization of the human body as major parts • consisting of: - Head and neck, thorax, abdomen, back - pelvis/perineum, paired upper limbs and lower limbs • also recognizes the body’s organization by layers. • All the major parts may be further subdivided into regions and zones Systemic Anatomy • is the study of the body’s organ systems that work together to carry out complex functions • each system of the body is studied and followed throughout the entire body • The basic systems of the body are: - integumentary system - skeletal system - muscular system - nervous system - circulatory system Cot… - cardiovascular system - lymphatic system - digestive system - respiratory system - urinary system - Reproductive system - endocrine system • None of the systems functions in isolation Applied anatomy • Is Clinical anatomy • stresses on clinical application - E.g., instead of thinking, “The action of this muscle is to . . . ,” clinical anatomy asks, “How would the absence of this muscle’s activity be manifest?” • Incorporates the regional and systemic approaches to studying anatomy Anatomical Terminology • Applies logical reasons for the names of parts of the body • Enables precise communication worldwide Anatomical Position: • body position when the person: - standing upright - head, eyes, and toes directed anteriorly - arms adjacent to the sides with the palms facing anteriorly - lower limbs close together with the feet parallel Cont… Lithotomy position • A person is lying back with legs up and feet supported in straps • This position is assumed during child delivery Anatomical Planes •Intersect the body in the anatomical position •Four imaginary planes: 1. Median (median sagittal) plane -vertical plane passing longitudinally through the body -divides the body into right and left equal halves -defines the midline of the head, neck, and trunk where it intersects the surface of the body 2. Sagittal planes - Vertical planes passing through the body parallel to the median plane 3. Frontal (coronal) planes -Vertical planes -passing through the body at right angles to the median plane -Divide the body into anterior and posterior parts 4. Transverse planes - Horizontal planes - passing through the body at right angles to the median and frontal planes - Divide the body into superior and inferior parts Terms of Relationship and Comparison • Describe the relationship of parts of the body • Compare the position of two structures relative to each other - Superior refers to a structure that is nearer the vertex ;head - Inferior refers to a structure that is nearer the sole of the foot Posterior (dorsal) denotes the back surface of the body or nearer to the back Anterior (ventral) denotes the front surface of the body Cont… Medial indicates that a structure is nearer to the median plane of the body Lateral stipulates that a structure is farther away from the median plane ▪External means outside of or farther from the center of an organ or cavity ▪Internal means inside or closer to the center, independent of direction •Combined terms describe intermediate positional arrangements: -Inferomedial means nearer to the feet and median plane -Superolateral means nearer to the head and farther from the median plane proximal closer to origin of a structure distal further away from origin of a structure Cephalic toward the head back Caudal toward the tail (feet) • Dorsum usually refers to the superior or posterior (back) surface of any part that protrudes anteriorly from the body • It is also used to describe the back of the hand • The palm refers to the flat of the hand, exclusive of the thumb and other fingers, and is the opposite of the dorsum of the hand Cont… • Superficial, intermediate, and deep describe the position of structures relative to: - the surface of the body - The relationship of one structure to another underlying or overlying structure Terms of Laterality: ✓ Bilateral means paired structures having right and left members ✓ Unilateral means occurring on one side only ➢ Ipsilateral something occurring on the same side of the body relative to another structure ➢ Contralateral means occurring on the opposite side of the body relative to another structure Terms of Movement • Flexion indicates bending or decreasing the angle between the bones or parts of the body • Extension indicates straightening or increasing the angle between the bones or parts of the body • Elevation raises or moves a part superiorly • Depression lowers or moves a part inferiorly • Rotation involves turning or revolving part of the body around its longitudinal axis . • Abduction means moving away from the median plane except for the digits • Adduction means moving toward it toward the median plane •abduction of the digits (fingers or toes) means spreading them apart - moving the other fingers away from the neutrally positioned 3rd (middle) finger - or moving the other toes away from the neutrally positioned 2nd toe - Adduction of the digits is the opposite . • Eversion refers to movement of the sole of the foot away from the median plane - turning the sole laterally • Inversion describes movement of the sole of the foot toward the median plane • Pronation is rotation of the radius medially - the palm of the hand faces posteriorly - Its dorsum faces anteriorly • Supination is the opposite rotational movement C o n t … . ▪ Opposition is the movement by which the pad of the 1st digit (thumb) is brought to another digit pad ▪ Reposition describes the opposite movement • Circumduction combined movements of flexion, extension, abduction, adduction medial and lateral rotation circumscribe a cone • Protrusion describes a movement forwards - protruding the mandible , lips, or tongue • Retrusion describes a movement backward - retruding the mandible, lips, or tongue • Dorsiflexion describes flexion at the ankle joint, as occurs when walking uphill or lifting the toes off the ground • Plantarflexion turns the foot or toes toward the plantar surface (e.g., when standing on your toes) Body Cavities • Spaces within the body which contain vital organs • Help protect, separate, and support internal organs • Permit changes in size and shape of internal organs • Two sets of internal body cavities - Dorsal cavity - Ventral cavity • Closed to environment Cont… • Ventral cavity • Houses the internal organs (viscera) • divided into two subdivisions: - Thoracic - Abdominopelvic cavities . Thoracic cavity (chest cavity) •The upper ventral cavity •contains the heart, lungs, trachea, esophagus, large blood vessels, and nerves •bound laterally by the ribs (covered by costal pleura) and the diaphragm caudally (covered by diaphragmatic pleura) •Divided into 2 pleural and 1 pericardial cavities by mediastinum 3 7 Abdominopelvic cavity • separated from the thoracic cavity by the dome-shaped diaphragm • It is composed of two subdivisions: I. Abdominal cavity • Contains most of the GIT as well as the kidneys and adrenal glands • Bound cranially by the diaphragm, laterally by the body wall, and caudally by the pelvic cavity II. Pelvic cavity • lies within the pelvis • contains the bladder, reproductive organs, and rectum Dorsal cavity • protects the nervous system • smaller of the two main cavities • divided into two subdivisions: • Cranial cavity - within the skull - encases the brain • Vertebral cavity - runs within the vertebral column - encases the spinal cord Body membranes • are thin sheets of tissue that cover or line the body cavities, and cover organs within the cavities in hollow organs • categorized into epithelial and connective tissue membranes 1. Epithelial Membranes • consist of epithelial tissue and the connective tissue to which it is attached • The two main types of epithelial membranes are: - mucous membranes - and serous membranes . I Mucous Membranes •line the body cavities that open to the outside •Line the entire digestive tract ,respiratory, and reproductive tracts and much of the urinary system • The epithelial layer of a mucous membrane secretes mucus •mucus prevents the cavities from drying out - It also traps particles in the respiratory passageways, lubricates and absorbs food as it moves through the GIT, and secretes digestive enzymes • The connective tissue layer helps bind the epithelium to the underlying structures - It also provides the epithelium with oxygen and nutrients and removes wastes via its blood vessels II. Serous Membranes . •line body cavities that do not open directly to the outside, • and the organs located in those cavities covered by a thin layer of serous fluid that is secreted by the epithelium •Serous fluid lubricates the membrane and reduces friction and abrasion when organs in the thoracic or abdominopelvic cavity move against each other or the cavity wall •Serous membranes have special names given according to their location; ✓ For example, the serous membrane that lines the thoracic cavity and covers the lungs is called pleura ;pericardium for heart . 2. Connective Tissue Membranes • Contain only connective tissue • Synovial membranes and meninges belong to this category Meninges: • the connective tissue covering on the brain and spinal cord • They provide protection for these vital structures . Synovial Membranes •line the cavities of freely movable joints such as the shoulder, elbow, and knee •Like serous membranes, they line cavities that do not open to the outside •Unlike serous membranes, they do not have a layer of epithelium •Synovial membranes secrete synovial fluid into the joint cavity, and this lubricates the cartilage on the ends of the bones so that they can move freely without friction 5 0 Cellular Organization of the Body Microscopic anatomy • Cytology – study of the cell • Histology – study of tissues The cell • The smallest unit of life • capable of carrying out all the functions of living things • self-contained and fully operational living entity Cont… • The cell contains various structural components to allow it to maintain life which are known as organelles • All the organelles are suspended within a gelatinous matrix, the cytoplasm, ✓ which is contained within the cell membrane • One of the few cells in the human body that lacks almost all organelles are the red blood cells Cont… • • • • Animal cells are eukaryotic cells. Each cell carries out basic life processes that allow the body to survive. All human cell are microscopic in size, shape and function. The diameter range from 7.5 micrometer to 150 mm. Cont… • all cells have typical structures such as: - cytoplasm - cell membrane - nucleus -cytoplasmic organelles • In general cells can be divided into two major compartments: - the cytoplasm - and the nucleus. The cell membrane: • is thin, dynamic membrane that encloses the cell • actively participates in many physiologic and biochemical activities essential to cell function and survival • Visible with transmission electron microscopy • composed of phospholipids, cholesterol, proteins, and chains of oligosaccharides • The lipid molecules form a lipid bilayer with an amphipathic character • range from 7.5 to 10 nm in thickness Cont… • The orientation of the phospholipids form the bilayer of biological membranes • hydrophilic polar heads, toward each surface of the membrane • hydrophobic heads, away from water Cont… • Membrane proteins are Integral proteins and peripheral proteins • integrins are linked to both cytoplasmic cytoskeletal filaments and extracellular matrix component • integral membrane proteins are embedded within the lipid bilayer or pass through the lipid bilayer completely • peripheral membrane proteins are not embedded within the lipid bilayer Cont… • Functions: - as a selective barrier that regulates the passage of certain materials into and out of the cell - the transport of specific molecules - keep constant the ion content of the cytoplasm - carry out a number of specific recognition and regulatory functions - Play an important role in the interactions of the cell with its environment The Cytoplasm • Is a gel-like matrix of water, enzymes, nutrients, wastes, and gases. • contains cell structures (organelles). • Also contains inclusions which are generally deposits of carbohydrates, lipids, or pigments. • The shape and motility of eukaryotic cells are determined by components of the cytoskeleton • Fluid around the organelles called cytosol • Most of the cells metabolic reactions occur in the cytoplasm Cytoplasmic organelles • Can be membranous or non-membranous protein complexes. Mitochondria • are membrane-enclosed organelles • have two membranes • The inner membrane is folded to form cristae • Enzymes specialized for aerobic respiration and production ATP • cells with a high-energy metabolism have abundant mitochondria Ribosomes • about 20 x 30 nm in size • often associated with the rER • composed of four segments of rRNA and approximately 80 different proteins • Composed of two different-sized subunits Endoplasmic Reticulum • Network of interconnected parallel membranes, that is continuous with the nuclear membrane. • continuous membrane encloses a space called cisterna. • Two types: - continuous with one another. - Rough Endoplasmic Reticulum - and Smooth Endoplasmic Reticulum ER I. Rough Endoplasmic Reticulum • Its name indicates the presence of polyribosomes on the cytosolic surface of its membrane. • prominent in cells specialized for protein secretion such us: - Pancreatic acinar cells - Fibroblasts RER Smooth Endoplasmic Reticulum (SER) • Regions of ER that lack bound polyribosomes. • In cells that synthesize steroid hormones it occupies a large portion of the cytoplasm. • abundant in liver cells ;detoxification • major role is synthesis of various phospholipid molecules. SER Cont… • Functions: - lipid biosynthesis - Detoxification RER Golgi Apparatus • system of membrane vesicles and cisternae. Functions: 1. Modification: modifies new proteins destined for lysosomes, secretion, and plasma membrane 2. Packaging: packages enzymes for lysosomes and proteins for secretion 3. Sorting: sorts all materials for lysosomes, secretion, and incorporation in to the plasma M. Lysosomes are sites of intracellular digestion and turnover of cellular components. abundant in cells with great phagocytic activity. contain about 40 different hydrolytic enzymes. During lysosomal digestion of macromolecules, released nutrients diffuse into the cytosol through the lysosomal membrane. - Indigestible materials are retained within the vacuoles and called residual bodies. • In some long-lived cells residual bodies can accumulate and are referred to as lipofuscin granules. • • • • Microbodies peroxisome • • • • • • membrane-limited organelles approximately 0.5 micro m in diameter contain enzymes that use O2 to remove hydrogen atoms from substrates Oxidize specific organic substrates produces hydrogen peroxide (H2O2) H2O2 immediately broken down by catalase to water and O2. also contain enzymes involved in lipid metabolism The Cytoskeleton • The cytoplasmic cytoskeleton is a complex network of: - microtubules - microfilaments (actin filaments) - intermediate filaments • These protein structures determine the shape of cells, - play an important role in the movements of organelles and cytoplasmic vesicles, - allow the movement of entire cells. Nucleus • large rounded or oval structure, often near the center of the cell - Houses genetic material - Produces ribosomal subunits in nucleolus and exports them into the cytoplasm • Consisting of - nuclear envelope - Chromatin - nucleolus Cell division • Cell division, or mitosis can be observed with the light microscope. • The parent cell is divided. • each of the daughter cells receives a chromosomal set identical to that of the parent cell. • The phase b/n two mitoses is called interphase. • subdivided into four phases - Prophase - Metaphase - Anaphase - telophase Cont… ✓ Prophase: • characterized by the gradual coiling of nuclear chromatin , giving rise to several individual rod-shaped bodies. • The centrosomes with their centrioles separate, and a centrosome migrates to each pole of the cell. ✓ Metaphase • chromosomes, due to the activity of microtubules, migrate to the equatorial plane of the cell. • where each divides longitudinally to form two chromosomes called sister chromatids. Cont… ✓ Anaphase • the sister chromatids separate from each other and migrate toward the opposite poles of the cell, pulled by microtubules. • Throughout this process, the centromeres move away from the center, pulling the remainder of the chromosome along. ✓ Telophase • characterized by the reappearance of nuclei in the daughter cells. • The chromosomes revert to their semidispersed state, and the nucleoli, chromatin, and nuclear envelope reappear. Introduction to Histology Tissues • • 1. 2. 3. 4. • Tissues are groups of cells that perform the same function the human body is composed of four basic types of tissue Nervous tissue Epithelial tissue Connective tissue Muscle tissue These tissues vary in their composition and their function Epithelial Tissue • • • • • • Epithelial tissue lines every body surface and all body cavities Organs are lined on the outside and inside by epithelial tissue The majority of glands are derived from epithelial tissue Epithelial tissue possesses little to no extracellular matrix Found above a connective tissue layer (epi = above) Lines the cavities, tubes, ducts, and blood vessels inside the body Characteristics of Epithelial Tissue • Innervation - richly innervated • Regeneration -replaced as quickly as they are lost • Avascular- Epithelium typically lacks its own blood supply Functions of Epithelial Tissue - Physical protection - Selective permeability - Secretions - Sensations ❖The basement Membrane • A specialized structure of epithelium • Found b/n the epithelium and underlying connective tissue • Provides physical support and anchoring of epithelial tissue Cont… • Acts as a barrier to regulate passage of large molecules b/n epithelium and underlying connective tissue Classifying Epithelia • • Many different types of epithelial tissue Classified according to two criteria: – number of layers of cells – shape of the cells ✓ Typically, the arrangement of the cells is stated first, then the shape, and is followed by “epithelium” to complete the naming Cont… ➢ Epithelial Cell Layers I. Simple epithelium • Cells are found in a single layer attached to the basement membrane Cont… II. Stratified epithelium • Cells are found in 2 or more layers stacked atop each other III. Pseudostratified epithelium • a single layer of cells that appears to be multiple layers due to variance in height and location of the nuclei in the cells IV. Transitional epithelium • cells are rounded and can slide across one another to allow stretching Epithelial Cell Shapes 1. Squamou -Flattened, like fish scales II. Cuboidal - Cube-shaped, like dice - Typically the cell's height and width are about equal III. Columnar - Column-like - tall, rectangular or column-shaped cells. Typically taller than they are wide. Types of Epithelium • To decide the type of epithelium, determine how many layers there are and what is the shape of surface cells – start with a single layer simple epithelium – then consider multiple layered stratified epithelium ✓ Simple Squamous Epithelium ✓ Simple Cuboidal Epithelium ✓ Simple Columnar Epithelium ✓ Simple Columnar Ciliated Epithelium ✓ Stratified Squamous Epithelium ✓ Stratified Cuboidal Epithelium Cont… • Stratified Columnar Epithelium • Pseudostratified Columnar Epithelium • Transitional Epithelium ❖Glandular Epithelium • Two major gland types ➢ Endocrine gland • Ductless; secretions diffuse into blood vessels • All secretions are hormones • Examples include thyroid, adrenals, and pituitary Cont… ➢ Exocrine gland • Secretions empty through ducts to the epithelial surface • Include sweat and oil glands, liver, and pancreas Connective Tissue (CT) • Arises from mesoderm • Most diverse, abundant and widely distributed. • Function is to “connect” one structure to another structure • CT is the “glue” and “filler” of the body ✓ Functions: • Physical protection • Support and structural framework • Binding of structures • Storage • Transport • Immune protection Cont… • CT can be classified into three broad categories: ✓ CT proper - Loose CT - Dense CT ✓ Supporting CT - Cartilage - Bone ✓ Fluid CT • Comprised of plasma, Erythrocytes, Leukocytes and Platelets Muscle Tissue • Comprised of cells called fibers. • When stimulated by the nervous system, fibers shorten or contract. • The result of contraction is movement (i.e., movement of bones, blood, food, sperm) ➢ Three types: - Skeletal - Cardiac - Smooth Cont… ❖Skeletal muscle • Attached to bones of skeleton and some skin • Cells (muscle fibers) are: - cylindrical and long (some as long as whole muscle) • multinucleated • striated (striped internal appearance) and voluntary • Contraction causes movement of skeleton or skin. Cardiac Muscle • • • • • Involuntarily controlled Found only in the heart Pumps blood through blood vessels Characteristics of cardiac muscle cells Striations Uninucleate, short, branching cells Intercalated discs contain gap junctions to connect cells together Smooth Muscle • Found in walls of most internal organs • stomach, intestines, urinary bladder ✓ Cells are: • relatively short, wide in the middle, and tapered at the ends (fusiform) • involuntary and non-striated • Contraction causes movement of food, blood, sperm Nervous Tissue • Contains two types of cells: ✓ Neurons: nerve cells that are capable of initiating and conducting electrical activity throughout the body ✓ Neuroglia: cells that support the neurons • Function is communication and control of body functions
