NTA Level 4 Semester One

DIAGNOSTIC RADIOGRAPHY · NTA LEVEL 4 · SEMESTER ONE Tissues CRT04101 · Anatomy, Physiology and Pathology START READING NOTES Study Tissues using the sections below. Use the topic navigation to continue through Anatomy, Physiology and Pathology. Contents of This Topic Four primary tissue types interweave to form the fabric of the body. Describe its general role, the terms would most likely be: Tissues are organized into organs such as the kidneys and the heart. EPITHILIAL TISSUE Epithelia form boundaries between different environments. In its role as an interface tissue, epithelium accomplishes many functions, including CLASSIFICATION OF EPITHELIA They are typically found where absorption and filtration occur and a thin epithelial barrier is desirable. Tissues 1.Squamous cells are flattened and scalelike SIMPLE EPITHELIA The cells of a simple squamous epithelium are flattened laterally, and their cytoplasm is sparse. Simple cuboidal epithelium consists of a single layer of cells as tall as they are wide . Simple columnar epithelium is seen as a single layer of tall, closely packed cells, aligned like soldiers in a row. 1) Dense microvilli on the apical surface of absorptive cells The cells of pseudostratified columnar epithelium vary in height. The short cells are relatively unspecialized and give rise to the taller cells. STRATIFIED EPITHELIA Stratified squamous epithelium is the most widespread of the stratified epithelia. Transitional epithelium forms the lining of hollow urinary organs, which stretch as they fill with urine. CONNECTIVE TISSUE There are four main classes of connective tissue and several subclasses. Its major functions include COMMON CHARACTERISTICS OF CONNECTIVE TISSUE STRUCTURAL ELEMENTS OF CONNECTIVE TISSUE GROUND SUBSTANCE FIBERS Collagen fibers are constructed primarily of the fibrous protein collagen. Elastic fibers are long, thin fibers that form branching networks in the extracellular matrix. Reticular fibers are short, fine, collagenous fibers and are continuous with collagen fibers. CELLS The primary blast cell types by connective tissue class are TYPES OF CONNECTIVE TISSUE CONNECTIVE TISSUE PROPER AREOLAR CONNECTIVE TISSUE ADIPOSE (FAT) TISSUE Adipose tissue is richly vascularized, indicating its high metabolic activity. RETICULAR CONNECTIVE TISSUE DENSE REGULAR CONNECTIVE TISSUE DENSE IRREGULAR CONNECTIVE TISSUE This type of tissue forms sheets in body areas where tension is exerted from many different directions. CARTILAGE It receives its nutrients by diffusion from blood vessels located in the connective tissue membrane surrounding it. Cartilage matrix also contains an exceptional amount of tissue fluid; in fact, cartilage is up to 80% water! There are three varieties of cartilage: HYALINE CARTILAGE Hyaline cartilage provides firm support with some pliability. Most of the embryonic skeleton is formed of hyaline cartilage before bone is formed. ELASTIC CARTILAGE FIBROCARTILAGE BONE (OSSEOUS TISSUE) Osteoblasts produce the organic portion of the matrix; then bone salts are deposited on and between the fibers. BLOOD TISSUES Groups of cells that are similar in structure and perform a common or related function are called tissues. Four primary tissue types interweave to form the fabric of the body. These basic tissues are: 1.Epithelial Tissue 2.Connective Tissue Muscle Tissue 4.Nervous tissue Each has numerous subclasses or varieties. Describe its general role, the terms would most likely be: Covering (epithelial) Support (connective) Movement (muscle) Control (nervous). However, these terms reveal only a fraction of the functions that each tissue performs. Tissues are organized into organs such as the kidneys and the heart. Most organs contain all four tissue types, and their arrangement determines the organ’s structure and capabilities. The study of tissues is called Histology EPITHILIAL TISSUE Epithelial tissue, or an epithelium, is a sheet of cells that covers a body surface or lines a body cavity. Covering and lining epithelium forms the outer layer of the skin, dips into and lines the open cavities of the cardiovascular, digestive, and respiratory systems, and covers the walls and organs of the closed ventral body cavity. Epithelia form boundaries between different environments. For example, the epidermis of the skin lies between the inside and the outside of the body, and epithelium lining the urinary bladder separates underlying cells of the bladder wall from urine. Nearly all substances received or given off by the body must pass through an epithelium In its role as an interface tissue, epithelium accomplishes many functions, including 1.Protection 2.Absorption Filtration Excretion 5.Secretion Sensory reception CLASSIFICATION OF EPITHELIA Each epithelium is given two names. The first name indicates the number of cell layers present; the second describes the shape of its cells. Based on the number of cell layers, there are simple and stratified epithelia. Simple epithelia are composed of a single cell layer. They are typically found where absorption and filtration occur and a thin epithelial barrier is desirable. Stratified epithelia, consisting of two or more cell layers stacked one on top of the other, are common in high-abrasion areas where protection is important, such as the skin surface and the lining of the mouth. Tissues In cross section, all epithelial cells have six sides, and an apical surface view of an epithelial sheet looks like a honeycomb. This polyhedral shape allows the cells to be closely packed. However, epithelial cells vary in height, and on that basis, there are three common shapes of epithelial cells. 1.Squamous cells are flattened and scalelike 2.Cuboidal cells are boxlike, approximately astall as they are wide. Columnar cells are tall and column shaped. In each case, the shape of the nucleus conforms to that of the cell. Tissues The nucleus of a squamous cell is a flattened disc; that of a cuboidal cell is spherical; and a columnar cell nucleus is elongated from top to bottom and usually located close to the cell base. SIMPLE EPITHELIA The simple epithelia are most concerned with absorption, secretion, and filtration. Because they consist of a single cell layer and are usually very thin, protection is not one of their specialties The cells of a simple squamous epithelium are flattened laterally, and their cytoplasm is sparse. In a surface view, the close-fitting cells resemble a tiled floor. Tissues Thin and often permeable, this epithelium is found where filtration or

DIAGNOSTIC RADIOGRAPHY · NTA LEVEL 4 · SEMESTER ONE Vertebral Column-Structure & Functions CRT04101 · Anatomy, Physiology and Pathology START READING NOTES Study Vertebral Column-Structure & Functions using the sections below. Use the topic navigation to continue through Anatomy, Physiology and Pathology. Contents of This Topic Vertebral Column Curvatures CT Vertebral Column-Structure & Functions Curvatures of Vertebral Column Structure and Function of Vertebrae The vertebral arch and the posterior surface of the vertebral body form the walls of the vertebral foramen. Seven Processes Arise From the Vertebral Arch of a Typical Vertebra Functions of the Vertebral Column Sacrum and Cocygeal Vertebrae STRUCTURE AND FUNCTIONS OF VERTEBRAL COLUMN Vertebral Column Curvatures The Vertebral Column The adult vertebral column typically consists of 33 vertebrae arranged in five regions: 7cervical, 12 thoracic, 5 lumbar, 5 sacral, and 4 coccygeal. CT The typical vertebrae consists of Body, transverse process, the foramen transversarium, the vertebral foramen and spinous process The vertebral column (spine), extending from the cranium (skull) to the apex of the coccyx. Vertebral Column-Structure & Functions The vertebral column protects the spinal cord and spinal nerves, supports the weight of the body superior to the level of the pelvis, provides a partly rigid and flexible axis for the body and a pivot for the head, and plays an important role in posture and locomotion. CT CT Significant motion occurs between only the superior 25 vertebrae. The 5 sacral vertebrae are fused in adults to form the sacrum, and the 4 coccygeal vertebrae are fused to form the coccyx. Vertebral Column-Structure & Functions The vertebrae gradually become larger as the vertebral column descends to the sacrum and then become progressively smaller toward the apex of the coccyx. These structural differences are related to the fact that the successive vertebrae bear increasing amounts of the body's weight CT Curvatures of Vertebral Column The vertebral column in adults has four curvatures: cervical, thoracic, lumbar, and sacral The curvatures provide a flexible support (shock-absorbing resilience) for the body. CT The thoracic and sacral curvatures are concave anteriorly, whereas the cervical and lumbar curvatures are concave posteriorly. The thoracic and sacral curvatures are primary curvatures, developing during the fetal period. VERTEBRAL COLUMN C1 & C2 …. Vertebral Column-Structure & Functions Primary curvatures are retained throughout life as a consequence of differences in height between the anterior and the posterior parts of the vertebrae. The cervical and lumbar curvatures are secondary curvatures, which begin to appear in the cervical region during the fetal period but do not become obvious until infancy. CT CT Secondary curvatures are maintained primarily by differences in thickness between the anterior and the posterior parts of the IV discs. The cervical curvature becomes prominent when an infant begins to hold his or her head erect. Vertebral Column-Structure & Functions The lumbar curvature becomes obvious when an infant begins to walk and assumes the upright posture. This curvature, generally more pronounced in females, ends at the lumbosacral angle, formed at the junction of the L5 vertebra with the sacrum. CT CT The sacral curvature of females is reduced so that the coccyx protrudes less into the pelvic outlet. The curvatures provide additional flexibility (shock-absorbing resilience) to the vertebral column, augmenting that provided by the IV discs Structure and Function of Vertebrae Vertebrae vary in size and other characteristics from one region of the vertebral column to another and to a lesser degree within each region. A typical vertebra consists of a vertebral body, vertebral arch, and seven processes. CT The vertebral body gives strength to the vertebral column and supports body weight. The size of vertebral bodies, especially from T4 inferiorly, increases to bear the progressively greater body weight. Vertebral Column-Structure & Functions In life, most of the superior and inferior surfaces of vertebral bodies are covered with hyaline cartilage, which are remnants of the cartilaginous model from which the bone develops, except at the periphery where there is a ring of smooth bone, the epiphysial rim. The cartilaginous remnants permit some diffusion of fluid between the IV disc and capillaries in the vertebral body. CT CT The vertebral arch lies posterior to the vertebral body and is formed by right and left pedicles and laminae. The pedicles are short, stout processes that join the vertebral arch to the vertebral body. The pedicles project posteriorly to meet two broad, flat plates of bone, called laminae, which unite in the midline. The vertebral arch and the posterior surface of the vertebral body form the walls of the vertebral foramen. The succession of vertebral foramina in the articulated column forms the vertebral canal, which contains the spinal cord, meninges (protective membranes), fat, spinal nerve roots, and vessels. CT The indentations formed by the projection of the body and articular processes superior and inferior of the pedicles are vertebral notches The superior and inferior vertebral notches of adjacent vertebrae contribute to the formation of the IV foramina, which give passage to spinal nerve roots and accompanying vessels and contain the spinal ganglia Seven Processes Arise From the Vertebral Arch of a Typical Vertebra One median spinous process projects posteriorly from the vertebral arch Two transverse processes project posterolaterally Four articular processes two superior and two inferior Functions of the Vertebral Column Strong bone protection for the delicate spinal cord The intervertebral foramina one on each side providing access to the spinal cord for spinal nerves, blood vessels and lymph vessels It enables certain amount of movements It support the skull Intervertebral disc acts as shock absorber It forms the axis of the trunk giving attachment to the ribs, shoulder, girdle and upper limbs and pelvic girdle and the lower limb Sacrum and Cocygeal Vertebrae The large, wedge-shaped sacrum in adults is composed of five fused sacral vertebrae. The sacrum provides strength and stability to the pelvis and transmits body weight to the pelvic girdle through the sacroiliac joints. The base of the sacrum is formed by the superior surface of the S1 vertebra. Its superior articular processes articulate

DIAGNOSTIC RADIOGRAPHY · NTA LEVEL 4 · SEMESTER ONE Anatomy and Physiology – Introduction CRT04101 · Anatomy, Physiology and Pathology START READING NOTES Study Anatomy and Physiology – Introduction using the sections below. Use the topic navigation to continue through Anatomy, Physiology and Pathology. Anatomy and Physiology – Introduction ANATOMY AND PHYSIOLOGY By ANATOMY AND PHYSIOLOGY The Anatomy and Physiology module introduces the structure and function of the human body. You will read about the cells, tissues and membranes that make up our bodies and how our major systems function to help us develop and stay healthy. In this module you will learn to: Describe basic human body functions and life process. Name the major human body systems and relate their functions. Describe the anatomical locations, structures and physiological functions of the main components of each major system of the human body. INTRODUCTION TO THE HUMAN BODY Human beings are arguably the most complex organisms on this planet. Imagine billions of microscopic parts, each with its own identity, working together in an organized manner for the benefit of the total being. The human body is a single structure but it is made up of billions of smaller structures of four major kinds: Cells Cells have long been recognized as the simplest units of living matter that can maintain life and reproduce themselves. The human body, which is made up of numerous cells, begins as a single, newly fertilized cell. Tissues Tissues are somewhat more complex units than cells. By definition, a tissue is an organization of a great many similar cells with varying amounts and kinds of nonliving, intercellular substance between them. Organs Organs are more complex units than tissues. An organ is an organization of several different kinds of tissues so arranged that together they can perform a special function. For example, the stomach is an organization of muscle, connective, epithelial, and nervous tissues. Muscle and connective tissues form its wall, epithelial and connective tissues form its lining, and nervous tissue extends throughout both its wall and its lining. Systems Systems are the most complex of the component units of the human body. A system is an organization of varying numbers and kinds of organs so arranged that together they can perform complex functions for the body. Ten major systems compose the human body: Skeletal Muscular Nervous Endocrine Cardiovascular Lymphatic Respiratory Digestive Urinary Reproductive Anatomy is the study of the structure and relationship between body parts. Physiology is the study of the function of body parts and the body as a whole. The structure of an organism or any of its parts. The scientific study of the shape and structure of organisms and their parts. Anatomy Definition. The structure of an animal or plant; also, the study of this structure through techniques such as microscopic observation and dissection. Anatomy is the branch of biology concerned with the study of the structure of organisms and their parts. In some of its facets, anatomy is related to embryology and comparative anatomy, which itself is closely related to evolutionary biology and phylogeny. Human anatomy is one of the basic essential sciences of medicine. The history of anatomy is characterized by a progressive understanding of the functions of the organs and structures of the human body. Methods have also improved dramatically, advancing from the examination of animals by dissection of carcasses and cadavers (corpses) to 20th century medical imaging techniques including X-ray, ultrasound, and magnetic resonance imaging. Anatomy and physiology, which study (respectively) the structure and function of organisms and their parts, make a natural pair of related disciplines, and they are often studied together. Anatomy is the scientific study of the structure of organisms including their systems, organs and tissues. It includes the appearance and position of the various parts, the materials from which they are composed, their locations and their relationships with other parts. Anatomy is quite distinct from physiology and biochemistry, which deal respectively with the functions of those parts and the chemical processes involved. For example, an anatomist is concerned with the shape, size, position, structure, blood supply and innervation of an organ such as the liver; while a physiologist is interested in the production of bile, the role of the liver in nutrition and the regulation of bodily functions Anatomical Structure of human body ← PREVIOUS TOPICNEXT TOPIC →VIEW ALL MODULE NOTESVIEW SEMESTER NOTESVIEW ALL LEVEL NOTESALL DIAGNOSTIC RADIOLOGY NOTES Need These Notes as PDF? Need a clean, well-formatted PDF copy for offline study, revision or printing? Request the complete notes directly through WhatsApp. GET WELL-FORMATTED PDF NOTES

DIAGNOSTIC RADIOGRAPHY · NTA LEVEL 4 · SEMESTER ONE Anatomy and Physiology – Body Functions and Life Processes CRT04101 · Anatomy, Physiology and Pathology START READING NOTES Study Anatomy and Physiology – Body Functions and Life Processes using the sections below. Use the topic navigation to continue through Anatomy, Physiology and Pathology. Anatomy and Physiology – Body Functions and Life Processes BODY FUNCTIONS & LIFE PROCESS Body Functions Body functions are the physiological or psychological functions of body systems. The body's functions are ultimately its cells' functions. Survival is the body's most important business. Survival depends on the body's maintaining or restoring homeostasis, a state of relative constancy, of its internal environment. More than a century ago, French physiologist, Claude Bernard (1813-1878), made a remarkable observation. He noted that body cells survived in a healthy condition only when the temperature, pressure, and chemical composition of their environment remained relatively constant. Later, an American physiologist, Walter B. Cannon (1871-1945), suggested the name homeostasis for the relatively constant states maintained by the body. Homeostasis is a key word in modern physiology. It comes from two Greek words – "homeo," meaning the same, and "stasis," meaning standing. "Standing or staying the same" then is the literal meaning of homeostasis. However, as Cannon emphasized, homeostasis does not mean something set and immobile that stays exactly the same all the time. In his words, homeostasis "means a condition that may vary, but which is relatively constant." Homeostasis depends on the body's ceaselessly carrying on many activities. Its major activities or functions are responding to changes in the body's environment, exchanging materials between the environment and cells, metabolizing foods, and integrating all of the body's diverse activities. The body's ability to perform many of its functions changes gradually over the years. In general, the body performs its functions least well at both ends of life – in infancy and in old age. During childhood, body functions gradually become more and more efficient and effective. During late maturity and old age the opposite is true. They gradually become less and less efficient and effective. During young adulthood, they normally operate with maximum efficiency and effectiveness. Life Process All living organisms have certain characteristics that distinguish them from non-living forms. The basic processes of life include organization, metabolism, responsiveness, movements, and reproduction. In humans, who represent the most complex form of life, there are additional requirements such as growth, differentiation, respiration, digestion, and excretion. All of these processes are interrelated. No part of the body, from the smallest cell to a complete body system, works in isolation. All function together, in finetuned balance, for the well being of the individual and to maintain life. Disease such as cancer and death represent a disruption of the balance in these processes. The following are a brief description of the life process: Organization At all levels of the organizational scheme, there is a division of labor. Each component has its own job to perform in cooperation with others. Even a single cell, if it loses its integrity or organization, will die. Metabolism Metabolism is a broad term that includes all the chemical reactions that occur in the body. One phase of metabolism is catabolism in which complex substances are broken down into simpler building blocks and energy is released. Responsiveness Responsiveness or irritability is concerned with detecting changes in the internal or external environments and reacting to that change. It is the act of sensing a stimulus and responding to it. Movement There are many types of movement within the body. On the cellular level, molecules move from one place to another. Blood moves from one part of the body to another. The diaphragm moves with every breath. The ability of muscle fibers to shorten and thus to produce movement is called contractility. Reproduction For most people, reproduction refers to the formation of a new person, the birth of a baby. In this way, life is transmitted from one generation to the next through reproduction of the organism. In a broader sense, reproduction also refers to the formation of new cells for the replacement and repair of old cells as well as for growth. This is cellular reproduction. Both are essential to the survival of the human race. Growth Growth refers to an increase in size either through an increase in the number of cells or through an increase in the size of each individual cell. In order for growth to occur, anabolic processes must occur at a faster rate than catabolic processes. Differentiation Differentiation is a developmental process by which unspecialized cells change into specialized cells with distinctive structural and functional characteristics. Through differentiation, cells develop into tissues and organs. Respiration Respiration refers to all the processes involved in the exchange of oxygen and carbon dioxide between the cells and the external environment. It includes ventilation, the diffusion of oxygen and carbon dioxide, and the transport of the gases in the blood. Cellular respiration deals with the cell's utilization of oxygen and release of carbon dioxide in its metabolism. Digestion Digestion is the process of breaking down complex ingested foods into simple molecules that can be absorbed into the blood and utilized by the body. Excretion Excretion is the process that removes the waste products of digestion and metabolism from the body. It gets rid of by-products that the body is unable to use, many of which are toxic and incompatible with life. The ten life processes described above are not enough to ensure the survival of the individual. In addition to these processes, life depends on certain physical factors from the environment. These include water, oxygen, nutrients, heat, and pressure. ANATOMICAL TERMINOLOGY Before we get into the following learning units, which will provide more detailed discussion of topics on different human body systems, it is necessary to learn some useful terms for describing body structure. Knowing these terms will make it much easier for us to understand the content of the following learning units. Three groups of terms

DIAGNOSTIC RADIOGRAPHY · NTA LEVEL 4 · SEMESTER ONE Anatomy and Physiology – Cell Structure and Functions CRT04101 · Anatomy, Physiology and Pathology START READING NOTES Study Anatomy and Physiology – Cell Structure and Functions using the sections below. Use the topic navigation to continue through Anatomy, Physiology and Pathology. Anatomy and Physiology – Cell Structure and Functions CELL FUNCTION The structural and functional characteristics of different types of cells are determined by the nature of the proteins present. Cells of various types have different functions because cell structure and function are closely related. It is apparent that a cell that is very thin is not well suited for a protective function. Bone cells do not have an appropriate structure for nerve impulse conduction. Just as there are many cell types, there are varied cell functions. The generalized cell functions include movement of substances across the cell membrane, cell division to make new cells, and protein synthesis. Movement of substances across the cell membrane The survival of the cell depends on maintaining the difference between extracellular and intracellular material. Mechanisms of movement across the cell membrane include simple diffusion, osmosis, filtration, active transport, endocytosis, andexocytosis. Simple diffusion is the movement of particles (solutes) from a region of higher solute concentration to a region of lower solute concentration. Osmosis is the diffusion of solvent or water molecules through a selectively permeable membrane. Filtration utilizes pressure to push substances through a membrane. Active transport moves substances against a concentration gradient from a region of lower concentration to a region of higher concentration. It requires a carrier molecule and uses energy. Endocytosis refers to the formation of vesicles to transfer particles and droplets from outside to inside the cell. Secretory vesicles are moved from the inside to the outside of the cell by exocytosis. Cell division Cell division is the process by which new cells are formed for growth, repair, and replacement in the body. This process includes division of the nuclear material and division of the cytoplasm. All cells in the body (somatic cells), except those that give rise to the eggs and sperm (gametes), reproduce by mitosis. Egg and sperm cells are produced by a special type of nuclear division called meiosis in which the number of chromosomes is halved. Division of the cytoplasm is called cytokinesis. Somatic cells reproduce by mitosis, which results in two cells identical to the one parent cell. Interphase is the period between successive cell divisions. It is the longest part of the cell cycle. The successive stages of mitosis are prophase, metaphase, anaphase, and telophase. Cytokinesis, division of the cytoplasm, occurs during telophase. Meiosis is a special type of cell division that occurs in the production of the gametes, or eggs and sperm. These cells have only 23 chromosomes, onehalf the number found in somatic cells, so that when fertilization takes place the resulting cell will again have 46 chromosomes, 23 from the egg and 23 from the sperm. DNA replication and protein synthesis Proteins that are synthesized in the cytoplasm function as structural materials, enzymes that regulate chemical reactions, hormones, and other vital substances. DNA in the nucleus directs protein synthesis in the cytoplasm. A gene is the portion of a DNA molecule that controls the synthesis of one specific protein molecule. Messenger RNA carries the genetic information from the DNA in the nucleus to the sites of protein synthesis in the cytoplasm. There are many different types, sizes, and shapes of cells in the body. For descriptive purposes, the concept of a "generalized cell" is introduced. It includes features from all cell types. A cell consists of three parts: the cell membrane, the nucleus, and, between the two, the cytoplasm. Within the cytoplasm lie intricate arrangements of fine fibers and hundreds or even thousands of miniscule but distinct structures called organelles. Cell membrane Every cell in the body is enclosed by a cell (Plasma) membrane. The cell membrane separates the material outside the cell, extracellular, from the material inside the cell, intracellular. It maintains the integrity of a cell and controls passage of materials into and out of the cell. All materials within a cell must have access to the cell membrane (the cell's boundary) for the needed exchange. The cell membrane is a double layer of phospholipid molecules. Proteins in the cell membrane provide structural support, form channels for passage of materials, act as receptor sites, function as carrier molecules, and provide identification markers. Nucleus and Nucleolus The nucleus, formed by a nuclear membrane around a fluid nucleoplasm, is the control center of the cell. Threads of chromatin in the nucleus contain deoxyribonucleic acid (DNA), the genetic material of the cell. The nucleolus is a dense region of ribonucleic acid (RNA) in the nucleus and is the site of ribosome formation. The nucleus determines how the cell will function, as well as the basic structure of that cell. Cytoplasm The cytoplasm is the gel-like fluid inside the cell. It is the medium for chemical reaction. It provides a platform upon which other organelles can operate within the cell. All of the functions for cell expansion, growth and replication are carried out in the cytoplasm of a cell. Within the cytoplasm, materials move by diffusion, a physical process that can work only for short distances. Cytoplasmic organelles Cytoplasmic organelles are "little organs" that are suspended in the cytoplasm of the cell. Each type of organelle has a definite structure and a specific role in the function of the cell. Examples of cytoplasmic organelles are mitochondrion, ribosomes,endoplasmic reticulum, golgi apparatus, and lysosomes. Organelles Organelles are parts of the cell which are adapted and/or specialized for carrying out one or more vital functions, analogous to the organs of the human body (such as the heart, lung, and kidney, with each organ performing a different function). Both eukaryotic and prokaryotic cells have organelles, but prokaryotic organelles are generally simpler and are not membrane-bound. There are several types of organelles in a cell. Some (such as

DIAGNOSTIC RADIOGRAPHY · NTA LEVEL 4 · SEMESTER ONE Anatomy and Physiology – Body Tissues CRT04101 · Anatomy, Physiology and Pathology START READING NOTES Study Anatomy and Physiology – Body Tissues using the sections below. Use the topic navigation to continue through Anatomy, Physiology and Pathology. Contents of This Topic Anatomy and Physiology – Body Tissues EPITHELIAL TISSUE CONNECTIVE TISSUE MUSCLE TISSUE NERVOUS TISSUE MEMBRANES Mucous Membranes Serous Membranes Connective Tissue Membranes Anatomy and Physiology – Body Tissues BODY TISSUES Tissue is a group of cells that have similar structure and that function together as a unit. A nonliving material, called the intercellular matrix, fills the spaces between the cells. This may be abundant in some tissues and minimal in others. The intercellular matrix may contain special substances such as salts and fibers that are unique to a specific tissue and gives that tissue distinctive characteristics. There are four main tissue types in the body: epithelial, connective, muscle, and nervous. Each is designed for specific functions. EPITHELIAL TISSUE Epithelial tissues are widespread throughout the body. They form the covering of all body surfaces, line body cavities and hollow organs, and are the major tissue in glands. They perform a variety of functions that include protection, secretion, absorption, excretion, filtration, diffusion, and sensory reception. The cells in epithelial tissue are tightly packed together with very little intercellular matrix. Because the tissues form coverings and linings, the cells have one free surface that is not in contact with other cells. Opposite the free surface, the cells are attached to underlying connective tissue by a noncellular basement membrane. This membrane is a mixture of carbohydrates and proteins secreted by the epithelial and connective tissue cells. Epithelial cells may be squamous, cuboidal, or columnar in shape and may be arranged in single or multiple layers. Simple cuboidal epithelium is found in glandular tissue and in the kidney tubules. Simple columnar epithelium lines the stomach and intestines. Pseudostratified columnar epithelium lines portions of the respiratory tract and some of the tubes of the male reproductive tract. Transitional epithelium can be distended or stretched. Glandular epithelium is specialized to produce and secrete substances. CONNECTIVE TISSUE Connective tissues bind structures together, form a framework and support for organs and the body as a whole, store fat, transport substances, protect against disease, and help repair tissue damage. They occur throughout the body. Connective tissues are characterized by an abundance of intercellular matrix with relatively few cells. Connective tissue cells are able to reproduce but not as rapidly as epithelial cells. Most connective tissues have a good blood supply but some do not. Numerous cell types are found in connective tissue. Three of the most common are the fibroblast, macrophage, and mast cell. The types of connective tissue include loose connective tissue, adipose tissue, dense fibrous connective tissue, elastic connective tissue, cartilage, osseous tissue (bone), and blood. MUSCLE TISSUE Muscle tissue is composed of cells that have the special ability to shorten or contract in order to produce movement of the body parts. The tissue is highly cellular and is well supplied with blood vessels. The cells are long and slender so they are sometimes called muscle fibers, and these are usually arranged in bundles or layers that are surrounded by connective tissue. Actin and myosin are contractile proteins in muscle tissue. Muscle tissue can be categorized into skeletal muscle tissue, smooth muscle tissue, and cardiac muscle tissue. Skeletal muscle fibers are cylindrical, multinucleated, striated, and under voluntary control. Smooth muscle cells are spindle shaped, have a single, centrally located nucleus, and lack striations. They are called involuntary muscles. Cardiac muscle has branching fibers, one nucleus per cell, striations, and intercalated disks. Its contraction is not under voluntary control. NERVOUS TISSUE Nervous tissue is found in the brain, spinal cord, and nerves. It is responsible for coordinating and controlling many body activities. It stimulates muscle contraction, creates an awareness of the environment, and plays a major role in emotions, memory, and reasoning. To do all these things, cells in nervous tissue need to be able to communicate with each other by way of electrical nerve impulses. The cells in nervous tissue that generate and conduct impulses are called neurons or nerve cells. These cells have three principal parts: the dendrites, the cell body, and one axon. The main part of the cell, the part that carries on the general functions, is the cell body. Dendrites are extensions, or processes, of the cytoplasm that carry impulses to the cell body. An extension or process called an axon carries impulses away from the cell body. Nervous tissue also includes cells that do not transmit impulses, but instead support the activities of the neurons. These are the glial cells (neuroglial cells), together termed the neuroglia. Supporting, or glia, cells bind neurons together and insulate the neurons. Some are phagocytic and protect against bacterial invasion, while others provide nutrients by binding blood vessels to the neurons. MEMBRANES Body membranes are thin sheets of tissue that cover the body, line body cavities, and cover organs within the cavities in hollow organs. They can be categorized into epithelial and connective tissue membrane. Epithelial Membranes Epithelial membranes consist of epithelial tissue and the connective tissue to which it is attached. The two main types of epithelial membranes are the mucous membranes and serous membranes. Mucous Membranes Mucous membranes are epithelial membranes that consist of epithelial tissue that is attached to an underlying loose connective tissue. These membranes, sometimes called mucosae, line the body cavities that open to the outside. The entire digestive tract is lined with mucous membranes. Other examples include the respiratory, excretory, and reproductive tracts. Serous Membranes Serous membranes line body cavities that do not open directly to the outside, and they cover the organs located in those cavities. Serous membranes are 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 abdomen

DIAGNOSTIC RADIOGRAPHY · NTA LEVEL 4 · SEMESTER ONE Anatomy and Physiology – Skeletal Anatomy CRT04101 · Anatomy, Physiology and Pathology START READING NOTES Study Anatomy and Physiology – Skeletal Anatomy using the sections below. Use the topic navigation to continue through Anatomy, Physiology and Pathology. Anatomy and Physiology – Skeletal Anatomy Skeletal System Anatomy The skeletal system includes all of the bones and joints in the body. Each bone is a complex living organ that is made up of many cells, protein fibers, and minerals. The skeleton acts as a scaffold by providing support and protection for the soft tissues that make up the rest of the body. The skeletal system also provides attachment points for muscles to allow movements at the joints. New blood cells are produced by the red bone marrow inside of our bones. New blood cells are produced by the red bone marrow inside of our bones. Bones act as the body‘s warehouse for calcium, iron, and energy in the form of fat. Finally, the skeleton grows throughout childhood and provides a framework for the rest of the body to grow along with it. The skeletal system in an adult body is made up of 206 individual bones. These bones are arranged into two major divisions: the axial skeleton and the appendicular skeleton. The axial skeleton runs along the body‘s midline axis and is made up of 80 bones in the following regions: Skull Hyoid Auditory ossicles Ribs Sternum Vertebral column The appendicle skeleton is made up of 126 bones in the following regions: Upper limbs Lower limbs Pelvic girdle Pectoral (shoulder) girdle Skull The skull is composed of 22 bones that are fused together except for the mandible. These 21 fused bones are separate in children to allow the skull and brain to grow, but fuse to give added strength and protection as an adult. The mandible remains as a movable jaw bone and forms the only movable joint in the skull with the temporal bone. The bones of the superior portion of the skull are known as the cranium and protect the brain from damage. The bones of the inferior and anterior portion of the skull are known as facial bones and support the eyes, nose, and mouth. Hyoid and Auditory Ossicles The hyoid is a small, U-shaped bone found just inferior to the mandible. The hyoid is the only bone in the body that does not form a joint with any other bone—it is a floating bone. The hyoid‘s function is to help hold the trachea open and to form a bony connection for the tongue muscles. The malleus, incus, and stapes—known collectively as the auditory ossicles—are the smallest bones in the body. Found in a small cavity inside of the temporal bone, they serve to transmit and amplify sound from the eardrum to the inner ear. Vertebrae Twenty-six vertebrae form the vertebral column of the human body. They are named by region: Cervical (neck) – 7 vertebrae Thoracic (chest) – 12 vertebrae Lumbar (lower back) – 5 vertebrae Sacrum – 1 vertebra Coccyx (tailbone) – 1 vertebra With the exception of the singular sacrum and coccyx, each vertebra is named for the first letter of its region and its position along the superiorinferior axis. For example, the most superior thoracic vertebra is called T1 and the most inferior is called T12. Ribs and Sternum The sternum, or breastbone, is a thin, knife-shaped bone located along the midline of the anterior side of the thoracic region of the skeleton. The sternum connects to the ribs by thin bands of cartilage called the costal cartilage. There are 12 pairs of ribs that together with the sternum form the ribcage of the thoracic region. The first seven ribs are known as ―true ribs‖ because they connect the thoracic vertebrae directly to the sternum through their own band of costal cartilage. Ribs 8, 9, and 10 all connect to the sternum through cartilage that is connected to the cartilage of the seventh rib, so we consider these to be ―false ribs.‖ Ribs 11 and 12 are also false ribs, but are also considered to be ―floating ribs‖ because they do not have any cartilage attachment to the sternum at all. Pectoral Girdle and Upper Limb The pectoral girdle connects the upper limb (arm) bones to the axial skeleton and consists of the left and right clavicles and left and right scapulae. The humerus is the bone of the upper arm. It forms the ball and socket joint of the shoulder with the scapula and forms the elbow joint with the lower arm bones. The radius and ulna are the two bones of the forearm. The ulna is on the medial side of the forearm and forms a hinge joint with the humerus at the elbow. The radius allows the forearm and hand to turn over at the wrist joint. The lower arm bones form the wrist joint with the carpals, a group of eight small bones that give added flexibility to the wrist. The carpals are connected to the five metacarpals that form the bones of the hand and connect to each of the fingers. Each finger has three bones known as phalanges, except for the thumb, which only has two phalanges. Pelvic Girdle and Lower Limb Formed by the left and right hip bones, the pelvic girdle connects the lower limb (leg) bones to the axial skeleton. The femur is the largest bone in the body and the only bone of the thigh (femoral) region. The femur forms the ball and socket hip joint with the hip bone and forms theknee joint with the tibia and patella. Commonly called the kneecap, the patella is special because it is one of the few bones that are not present at birth. The patella forms in early childhood to support the knee for walking and crawling. The tibia and fibula are the bones of the lower leg. The tibia is much larger than the fibula and

DIAGNOSTIC RADIOGRAPHY · NTA LEVEL 4 · SEMESTER ONE Anatomy and Physiology – Bone Structure, Growth and Skeletal Organization CRT04101 · Anatomy, Physiology and Pathology START READING NOTES Study Anatomy and Physiology – Bone Structure, Growth and Skeletal Organization using the sections below. Use the topic navigation to continue through Anatomy, Physiology and Pathology. Contents of This Topic Anatomy and Physiology – Bone Structure, Growth and Skeletal Organization STRUCTURE OF BONE TISSUE Compact Bone Spongy (Cancellous) Bone BONE DEVELOPMENT & GROWTH Endochondral Ossification Bone Growth CLASSIFICATION OF BONES Short Bones Irregular Bones DIVISIONS OF THE SKELETON AXIAL SKELETON (80 BONES)  Occipital (1)  Mandible (1) Auditory Ossicles  Sacrum (1)  Clavicle (2)  Carpals (16)  Femur (2)  Phalanges (28) Anatomy and Physiology – Bone Structure, Growth and Skeletal Organization INTRODUCTION TO THE SKELETAL SYSTEM Humans are vertebrates, animals having a vertabral column or backbone. They rely on a sturdy internal frame that is centered on a prominent spine. The human skeletal system consists of bones, cartilage, ligaments and tendons and accounts for about 20 percent of the body weight. The living bones in our bodies use oxygen and give off waste products in metabolism. They contain active tissues that consume nutrients, require a blood supply and change shape or remodel in response to variations in mechanical stress. Bones provide a rigid framework, known as the skeleton, that support and protect the soft organs of the body. The skeleton supports the body against the pull of gravity. The large bones of the lower limbs support the trunk when standing. The skeleton also protects the soft body parts. The fused bones of the cranium surround the brain to make it less vulnerable to injury. Vertebrae surround and protect the spinal cord and bones of the rib cage help protect the heart and lungs of the thorax. Bones work together with muscles as simple mechanical lever systems to produce body movement. Bones contain more calcium than any other organ. The intercellular matrix of bone contains large amounts of calcium salts, the most important being calcium phosphate. When blood calcium levels decrease below normal, calcium is released from the bones so that there will be an adequate supply for metabolic needs. When blood calcium levels are increased, the excess calcium is stored in the bone matrix. The dynamic process of releasing and storing calcium goes on almost continuously. Hematopoiesis, the formation of blood cells, mostly takes place in the red marrow of the bones. In infants, red marrow is found in the bone cavities. With age, it is largely replaced by yellow marrow for fat storage. In adults, red marrow is limited to the spongy bone in the skull, ribs, sternum, clavicles, vertebrae and pelvis. Red marrow functions in the formation of red blood cells, white blood cells and blood platelets. STRUCTURE OF BONE TISSUE There are two types of bone tissue: compact and spongy. The names imply that the two types differ in density, or how tightly the tissue is packed together. There are three types of cells that contribute to bone homeostasis. Osteoblasts are bone-forming cell, osteoclasts resorb or break down bone, and osteocytes are mature bone cells. An equilibrium between osteoblasts and osteoclasts maintains bone tissue. Compact Bone Compact bone consists of closely packed osteons or haversian systems. The osteon consists of a central canal called the osteonic (haversian) canal, which is surrounded by concentric rings (lamellae) of matrix. Between the rings of matrix, the bone cells (osteocytes) are located in spaces called lacunae. Small channels (canaliculi) radiate from the lacunae to the osteonic (haversian) canal to provide passageways through the hard matrix. In compact bone, the haversian systems are packed tightly together to form what appears to be a solid mass. The osteonic canals contain blood vessels that are parallel to the long axis of the bone. These blood vessels interconnect, by way of perforating canals, with vessels on the surface of the bone. Spongy (Cancellous) Bone Spongy (cancellous) bone is lighter and less dense than compact bone. Spongy bone consists of plates (trabeculae) and bars of bone adjacent to small, irregular cavities that contain red bone marrow. The canaliculi connect to the adjacent cavities, instead of a central haversian canal, to receive their blood supply. It may appear that the trabeculae are arranged in a haphazard manner, but they are organized to provide maximum strength similar to braces that are used to support a building. The trabeculae of spongy bone follow the lines of stress and can realign if the direction of stress changes. Microscopic Structure of Bones The skeleton makes up about 30-40% of an adult‘s body mass. The skeleton‘s mass is made up of nonliving bone matrix and many tiny bone cells. Roughly half of the bone matrix‘s mass is water, while the other half is collagen protein and solid crystals of calcium carbonate and calcium phosphate. Living bone cells are found on the edges of bones and in small cavities inside of the bone matrix. Although these cells make up very little of the total bone mass, they have several very important roles in the functions of the skeletal system. The bone cells allow bones to: Grow and develop Be repaired following an injury or daily wear Be broken down to release their stored minerals BONE DEVELOPMENT & GROWTH The terms osteogenesis and ossification are often used synonymously to indicate the process of bone formation. Parts of the skeleton form during the first few weeks after conception. By the end of the eighth week after conception, the skeletal pattern is formed in cartilage and connective tissue membranes and ossification begins. Bone development continues throughout adulthood. Even after adult stature is attained, bone development continues for repair of fractures and for remodeling to meet changing lifestyles. Osteoblasts, osteocytes and osteoclasts are the three cell types involved in the development, growth and remodeling of bones. Osteoblasts are bone-forming cells, osteocytes are mature bone cells and osteoclasts break down and reabsorb bone. There are

DIAGNOSTIC RADIOGRAPHY · NTA LEVEL 4 · SEMESTER ONE Anatomy and Physiology – Muscular System CRT04101 · Anatomy, Physiology and Pathology START READING NOTES Study Anatomy and Physiology – Muscular System using the sections below. Use the topic navigation to continue through Anatomy, Physiology and Pathology. Contents of This Topic Anatomy and Physiology – Muscular System Muscular System Muscle Types Smooth Muscle Cardiac Muscle MUSCLE GROUPS MUSCLES OF THE HEAD AND NECK MUSCLES OF THE TRUNK MUSCLES OF THE UPPER EXTREMITY STRUCTURE OF SKELETAL MUSCLE Skeletal Muscle Histology Sarcomere Structure Motor Units Contraction Cycle Anatomy and Physiology – Muscular System INTRODUCTION TO THE MUSCULAR SYSTEM The muscular system is composed of specialized cells called muscle fibers. Their predominant function is contractibility. Muscles, attached to bones or internal organs and blood vessels, are responsible for movement. Nearly all movement in the body is the result of muscle contraction. Exceptions to this are the action of cilia, the flagellumon sperm cells, and amoeboid movement of some white blood cells. The integrated action of joints, bones, and skeletal muscles produces obvious movements such as walking and running. Skeletal muscles also produce more subtle movements that result in various facial expressions, eye movements, and respiration. In addition to movement, muscle contraction also fulfills some other important functions in the body, such as posture, joint stability, and heat production. Posture, such as sitting and standing, is maintained as a result of muscle contraction. The skeletal muscles are continually making fine adjustments that hold the body in stationary positions. The tendons of many muscles extend over joints and in this way contribute to joint stability. This is particularly evident in the knee and shoulder joints, where muscle tendons are a major factor in stabilizing the joint. Heat production, to maintain body temperature, is an important by-product of muscle metabolism. Nearly 85 percent of the heat produced in the body is the result of muscle contraction. Muscular System The muscular system is responsible for the movement of the human body. Attached to the bones of the skeletal system are about 700 named muscles that make up roughly half of a person‘s body weight. Each of these muscles is a discrete organ constructed of skeletal muscle tissue, blood vessels, tendons, and nerves. Muscle tissue is also found inside of the heart, digestive organs, and blood vessels. In these organs, muscles serve to move substances throughout the body. Muscle Types There are three types of muscle tissue: Visceral, cardiac, and skeletal. Visceral Muscle. Visceral muscle is found inside of organs like the stomach, intestines, and blood vessels. The weakest of all muscle tissues, visceral muscle makes organs contract to move substances through the organ. Because visceral muscle is controlled by the unconscious part of the brain, it is known as involuntary muscle—it cannot be directly controlled by the conscious mind. The term ―smooth muscle‖ is often used to describe visceral muscle because it has a very smooth, uniform appearance when viewed under a microscope. This smooth appearance starkly contrasts with the banded appearance of cardiac and skeletal muscles. Cardiac Muscle. Found only in the heart, cardiac muscle is responsible for pumping blood throughout the body. Cardiac muscle tissue cannot be controlled consciously, so it is an involuntary muscle. While hormones and signals from the brain adjust the rate of contraction, cardiac muscle stimulates itself to contract. The natural pacemaker of the heart is made of cardiac muscle tissue that stimulates other cardiac muscle cells to contract. Because of its self-stimulation, cardiac muscle is considered to be auto rhythmic or intrinsically controlled. The cells of cardiac muscle tissue are striated—that is, they appear to have light and dark stripes when viewed under a light microscope. The arrangement of protein fibers inside of the cells causes these light and dark bands. Striations indicate that a muscle cell is very strong, unlike visceral muscles. The cells of cardiac muscle are branched X or Y shaped cells tightly connected together by special junctions called intercalated disks. Intercalated disks are made up of fingerlike projections from two neighboring cells that interlock and provide a strong bond between the cells. The branched structure and intercalated disks allow the muscle cells to resist high blood pressures and the strain of pumping blood throughout a lifetime. These features also help to spread electrochemical signals quickly from cell to cell so that the heart can beat as a unit. Skeletal Muscle. Skeletal muscle is the only voluntary muscle tissue in the human body—it is controlled consciously. Every physical action that a person consciously performs (e.g. speaking, walking, or writing) requires skeletal muscle. The function of skeletal muscle is to contract to move parts of the body closer to the bone that the muscle is attached to. Most skeletal muscles are attached to two bones across a joint, so the muscle serves to move parts of those bones closer to each other. Skeletal muscle cells form when many smaller progenitor cells lump themselves together to form long, straight, multinucleated fibers. Striated just like cardiac muscle, these skeletal muscle fibers are very strong. Skeletal muscle derives its name from the fact that these muscles always connect to the skeleton in at least one place. MUSCLE TYPES In the body, there are three types of muscle: skeletal (striated), smooth, and cardiac. Skeletal Muscle Skeletal muscle, attached to bones, is responsible for skeletal movements. The peripheral portion of the central nervous system (CNS) controls the skeletal muscles. Thus, these muscles are under conscious, or voluntary, control. The basic unit is the muscle fiber with many nuclei. These muscle fibers are striated (having transverse streaks) and each acts independently of neighboring muscle fibers. Smooth Muscle Smooth muscle, found in the walls of the hollow internal organs such as blood vessels, the gastrointestinal tract, bladder, and uterus, is under control of the autonomic nervous system. Smooth muscle cannot be controlled consciously and thus acts involuntarily. The non-striated (smooth) muscle cell is spindle-shaped and has one central nucleus. Smooth muscle contracts slowly and rhythmically.

DIAGNOSTIC RADIOGRAPHY · NTA LEVEL 4 · SEMESTER ONE Anatomy and Physiology – Cardiovascular System and Blood CRT04101 · Anatomy, Physiology and Pathology START READING NOTES Study Anatomy and Physiology – Cardiovascular System and Blood using the sections below. Use the topic navigation to continue through Anatomy, Physiology and Pathology. Contents of This Topic Anatomy and Physiology – Cardiovascular System and Blood The Heart Circulatory Loops Blood Vessels Coronary Circulation Hepatic Portal Circulation  ERYTHROCYTES  LEUKOCYTES THROMBOCYTES Fighting Disease Transporting Hormones Regulating Body Temperature The Circulatory Pump Cardiac Cycle Cardiovascular System THE LYMPHATIC THE TRANSFORMATION WHAT IS LYMPH? LYMPHATIC CIRCULATION THE ORIGIN OF LYMPH LYMPHATIC CAPILLARIES LYMPHATIC VESSELS LYMPH NODES DRAINAGE AREAS SPLEEN MUCOSA-ASSOCIATED TISSUES Anatomy and Physiology – Cardiovascular System and Blood Cardiovascular System The cardiovascular system consists of the heart, blood vessels, and the approximately 5 liters of blood that the blood vessels transport. Responsible for transporting oxygen, nutrients, hormones, and cellular waste products throughout the body, the cardiovascular system is powered by the body‘s hardest-working organ — the heart, which is only about the size of a closed fist. Even at rest, the average heart easily pumps over 5 liters of blood throughout the body every minute. The Heart The heart is a muscular pumping organ located medial to the lungs along the body‘s midline in the thoracic region. The bottom tip of the heart, known as its apex, is turned to the left, so that about 2/3 of the heart is located on the body‘s left side with the other 1/3 on right. The top of the heart, known as the heart‘s base, connects to the great blood vessels of the body: the aorta, vena cava, pulmonary trunk, and pulmonary veins. The Heart The heart is a hollow muscular organ which beats over 100,000 times a day to pump blood around the body's 60,000 miles of blood vessels. The right side of the heart receives blood and sends it to the lungs to be oxygenated, while the left side receives oxygenated blood from the lungs and sends it out to the tissues of the body. The Heart has three layers; the ENDOCARDIUM (inner layer), the EPICARDIUM (middle layer), and MYOCARDIUM (outer layer). The heart is protected by the PERICARDIUM which the protective membrane is surrounding it. The heart has FOUR CHAMBERS, in the lower heart the right and left Ventricles, and in the upper heart the right and left Atria. In a normal heart beat the atria contract while the ventricles relax, then the ventricles contract while the atria relax. There are VALVES through which blood passes between ventricle and atrium, these close in such a way that blood does not backwash during the pauses between ventricular contractions. The right and left ventricles are divided by a thick wall (the VENTRICULAR SEPTUM), babies born with "hole in the heart" have a small gap here, which is a problem since oxygenated and deoxygenated can blood mix. The walls of the left ventricle are thicker as it has to pump blood to all the tissues, compared to the right ventricle which only pumps blood as far as the lungs. The spleen This is a large flat oval organ located below the diaphragm, it's main function is to STORE BLOOD. The size of the spleen can vary, for example it may enlarge when the body is fighting infection also it's size tends to decrease with age. It is a non-vital organ and it is possible to survive after removal of the spleen. Perinicious anaemia is a Vitamin B12 deficiency resulting in a reduction in number of erythrocytes. Aplastic anemia is a failure of the bone marrow to produce the enough red blood cells. Septicaemia – bacterial toxins in blood. Circulatory Loops There are 2 primary circulatory loops in the human body: the pulmonary circulation loop and the systemic circulation loop. Pulmonary circulation transports deoxygenated blood from the right side of the heart to the lungs, where the blood picks up oxygen and returns to the left side of the heart. The pumping chambers of the heart that support the pulmonary circulation loop are the right atrium and right ventricle. Systemic circulation carries highly oxygenated blood from the left side of the heart to all of the tissues of the body (with the exception of the heart and lungs). Systemic circulation removes wastes from body tissues and returns deoxygenated blood to the right side of the heart. The left atrium and left ventricle of the heart are the pumping chambers for the systemic circulation loop. Blood Vessels Blood vessels are the body‘s highways that allow blood to flow quickly and efficiently from the heart to every region of the body and back again. The size of blood vessels corresponds with the amount of blood that passes through the vessel. All blood vessels contain a hollow area called the lumen through which blood is able to flow. Around the lumen is the wall of the vessel, which may be thin in the case of capillaries or very thick in the case of arteries. ARTERIES carry oxygenated blood away from the heart. They are thick hollow tubes which are highly ELASTIC which allows them to DILATE (widen) and constrict (narrow) as blood is forced down them by the heart. Arteries branch and re-branch, becoming smaller until they become small ARTERIOLES which are even more elastic. Arterioles feed oxygenated blood to the capillaries. The AORTA is the largest artery in the body, taking blood from the heart, branching into other arteries that send oxygenated blood to the rest of the body. CAPILLARIES distribute the nutrients and oxygen to the body's tissues and remove deoxygenated blood and waste. They are extremely thin, the walls are only one cell thick and connect the arterioles with the venules (very small veins). VENULES (very small veins) merge into VEINS which carry blood back to the heart. The vein walls are similar to arteries but thinner and less elastic. Veins carry deoxygenated blood towards the lungs