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DIAGNOSTIC RADIOGRAPHY · NTA LEVEL 4 · SEMESTER ONE Cell Structure And Its Functions CRT04101 · Anatomy, Physiology and Pathology START READING NOTES Study Cell Structure And Its Functions using the sections below. Use the topic navigation to continue through Anatomy, Physiology and Pathology. Contents of This Topic CELLS AND IT’S STRUCTURES CELL STRUCTURE Cell membrane molecules and their functions C. Proteins Composed of double layer of phospholipids and proteins NUCLEUS Each cell has fixed number of Functions of the nucleus and chromosomes. Diagram of nucleus and chromosomes. CYTOPLASM CELL ORGANELLES Ribosomes Endoplasmic Reticulum (Smooth and Rough) Cilia and Lysosomes Centrioles FUNCTIONS OF THE CELL Cell Structure And Its Functions CELLULAR TRANSPORT MECHANISMS. 1. DIFFUSION 3. FACILITATED DIFFUSION 5. FILTRATION CELLS AND IT’S STRUCTURES What is cell? Cell is the smallest basic unit of life. These are building blocks of human body. Microorganisms such as amoebas and bacteria are single-celled that function independently. Human cells work together and each of them function independently. These cells vary in size, shape and functions. All cells are made of water, carbon, oxygen, hydrogen and nitrogen. CELL STRUCTURE Despite their differences in size, shape and functions, cells have several similar structures; a cell membrane, a nucleus, cytoplasm, and cell organelles ( Ribosomes, mitochondria, centrioles, lysosomes, vacuole, endoplasmic reticulum, golgi body, cilia and microvilli). CELL MEMBRANE Are also called plasma membrane, Is the thin semi-permeable membrane of the cells that controls movement of substances in and out of the cell. It also maintain the shape of the cell and keep it intact. It is made up of a double layer of lipids (fats) and proteins. Cell membrane molecules and their functions Cell membrane is made up of three organic molecules ie, Phospholipids Cholesterol and Proteins. A. Phospholipids Organic molecule made of diglycerides that forms a bilayer or double layer and makes up most of the membrane. Permit lipid-soluble materials to easily enter orleave the cell by diffusion through the cell membrane. B. Cholesterol Play role by decreasing the fluidity of the membrane, thus making it more stable. C. Proteins Functions of proteins…. Proteins form channels or pores to permit passage of materials such as water or ions. Proteins are carrier enzymes or transporters that also help substances enter the cell. Acts as antigenic markers that identify the cells of an individual as “self.” Some proteins serves as hormone receptors Composed of double layer of phospholipids and proteins Surrounds outside of ALL cells Controls what enters or leaves the cell Living layer Outside of cell Inside of cell (cytoplasm) Cell membrane Proteins Protein channel Lipid bilayer Carbohydrate chains NUCLEUS Is the control center of the cell Nucleus is also called the brain of the cell without it cell would die. The nucleus contains genetic information called DNA (deoxyribonucleic acid). These genetic information (DNA) is arranged in threads called chromosomes. Every normal cell contains 23 pairs of chromosomes (total 46). Surrounded by a double membrane called the nuclear membrane. NUCLEOLUS This is a small spherical body made of DNA, RNA and protein The nucleoli form a type of RNA called ribosomal RNA which becomes part of ribosomes (a cell organelle) involved in protein synthesis. Each cell has fixed number of chromosomes that carry genes Genes control cell characteristics Functions of the nucleus and chromosomes. Controls the cells functions Store for DNA and / RNA Site for transcription- DNA is transcribed into mRNA Nucleolus makes ribosomes for protein synthesis Centre for cellular growth For cell division Control enzyme synthesis Play role in reproduction and Controls hereditary traits Diagram of nucleus and chromosomes. Inside nucleus Disappears when cell divides Makes ribosomes that make proteins CYTOPLASM Is the gel like fluid found within the cell that suspend cell organelles Made up of water and dissolved substances like gases, glucose, waste, salts and hormones. Cytosol Is the water portion of cytoplasm, and many chemical reactions take place within it. Nucleoplasm Is a gel like fluid founs within the nucleus of the cell. CELL ORGANELLES Cell organelles are intracellular structures bounded by their own membrane with specific functions in metabolism. Mitochondria Are oval or spherical organelles bounded by double membrane where energy (ATP) production takes place. Its also called power house of the cell. This energy is provided through a process called respiration. Site of aerobic cell respiration ( ATP production) Ribosomes Are very small structures made of protein and ribosomal RNA. Some are found on the surface of rough Endoplasmic reticulum, while others float freely within the cytoplasm. Ribosomes are the site of protein synthesis. Endoplasmic Reticulum (Smooth and Rough) This consists of a network of tiny tubes, or channels running throughout the cytoplasm. These act as a passageways for transport of materials within the cell ER associate with ribosomes in protein production and transport. Site for most enzyme activities. Golgi Body This is a large organelle responsible for processing proteins and lipids. These may include hormones, or other proteins required elsewhere in the body. The Golgi body packages and stores these in smaller organelles called the Golgi apparatus until they are required in the cell or other part of the body. Main packaging centre of the cell Cilia and Are hair-like projections on their surface of the cell lining the nose and respiratory tract that sweep the materials across the cell surface. These cilia beat to trap dust, bacteria and viruses and push them out of the body. Flagella Hair like projections on the cell surface that provides motility, or movement. Forexample, flagellum in the sperm cell Microvilli Are finger like projections over the cell surface that increase the available surface area for absorption. Cells in the intestinal surface layers typically have lots of microvilli. Lysosomes These single membrane organelles act as the ‘stomach’ or ‘waste disposal unit’ of the cell. Contain the digestive enzymes which can digest ingested material or damaged tissue ( break down, foreign bodies and worn out cell parts) Liver cells contain the greatest concentration of lysosomes for removing waste products from the body. Centrioles

DIAGNOSTIC RADIOGRAPHY · NTA LEVEL 4 · SEMESTER ONE Cell Injury Adaptation And Cell Death CRT04101 · Anatomy, Physiology and Pathology START READING NOTES Study Cell Injury Adaptation And Cell Death using the sections below. Use the topic navigation to continue through Anatomy, Physiology and Pathology. Contents of This Topic LEARNING OBJECTIVES ….. CELLULAR ADAPTATIONs TO STIMULI Pathologic adaptations: are responses to stress that allow cells to modulate their structure and function and thus escape injury. Five (5) types of cellular adaptations 1.Atrophy Cell Injury Adaptation And Cell Death Causes of atrophy 2.HYPERTROPHY 3.HYPERPLASIA Examples: (physiological hyperplasia) Pathological hyperplasia is caused by excessive hormonal stimulation or growth factors on target cells. 4.METAPLASIA 5.DYSPLASIA Examples of dysplasia CELL INJURY Types of cell death Examples of physiological apoptosis Adaptation mechanisms and Cell injury LEARNING OBJECTIVES Understand the concept of cell and tissue adaptation: 1.Hypertrophy (increase in size of cell) 2.Hyperplasia (increase in number of cells) 3.Atrophy (shrinkage in size of cell) 4.Metaplasia (change of shape of cell) 5.Dysplasia (disorderly growth) ….. Describe the causes of cell injury Know types of cell death & their clinical examples: 1.Apoptosis= programmed death (physiologic & pathologic) 2.Necrosis= group cell death (pathologic) Differentiate between apoptosis & necrosis CELLULAR ADAPTATIONs TO STIMULI Adaptations are reversible changes in the number, size, phenotype, metabolic activity, or functions of cells in response to changes in their environment. Physiologic adaptations: Usually represent responses of cells to normal stimulation by hormones or endogenous chemical mediators (e.g. the hormone-induced enlargement of the breast and uterus during pregnancy). Pathologic adaptations: are responses to stress that allow cells to modulate their structure and function and thus escape injury. Such adaptations can take several distinct forms. Five (5) types of cellular adaptations 1.Atrophy Hypertrophy Hyperplasia Metaplasia Dysplasia Types of cellular adaptations…. 1.Atrophy It is a decrease in the size (shrinkage) of the cell, tissue or organ which is brought by decrease in substances within cells. Atrophic cells may have diminished function but are not dead. Atrophy as other cell adaptations can be classified as either physiological or pathological. Physiologic atrophy occurs with aging and involved essentially all organs in the body Examples: 1.Decrease in breast glandular tissues after menopause 2.Decrease in size of uterus after child birth (parturition) 3.Decrease in size of brain tissue of advanced aged man 4.The decrease of thymus tissue after puberty which remains essentially as fibrous tissue. Cell Injury Adaptation And Cell Death Pathological atrophy occur as a result of lack of inadequate nutrients (ischaemia), innervations of an organ, disuse of an organ (lack of exercise after long term of inability) and loss of endocrine stimulation. Example: Hypogonadism Causes of atrophy A decreased workload (e.g. immobilization of a limb to permit healing of a fracture) Loss of innervations Diminished blood supply Inadequate nutrition Loss of endocrine stimulation Aging ( leads to senile atrophy) 2.HYPERTROPHY Hypertrophy and hyperplasia can also occur together, and obviously both result in an enlarged (hypertrophic) organ. Examples: 1.The massive physiologic enlargement of the uterus during pregnancy occurs as a consequence of estrogen-stimulated smooth muscle hypertrophy and smooth muscle hyperplasia. Increase in muscle mass in weightlifter 3.Pathological hypertrophy can also be demostrated in the heart. Myocardium subjected to persistent increased load, as in hypertension or with a stenosis valve, adapts by undergoing hypertrophy-an increase in the size of the individual cells and ultimately the entire heart-to generate the required higher contractile force. Hypertrophic cardiomyopathy 3.HYPERPLASIA It is an increase in the number of cells in an organ or tissue usually results in increased size of the organ or tissue. ! Although hypertrophy and hyperplasia are two distinct processes, both frequently occur together and they may be triggered by the same external stimulus. ! Physiologic hyperplasia can be divided into :- -Hormonal hyperplasia which increases the functional capacity of a tissue when needed. -Compensatory hyperplasia which increases tissue mass after damage or partial resection. Examples: (physiological hyperplasia) 1.Increase in breast glandular tissue during pregnant 2.When a liver is partially resected, mitotic activity in the remaining cells begins as early as 12 hours later, eventually restoring the liver to its normal weight. After restoration of the liver mass, cell proliferation is turned off by various growth inhibitors. Pathological hyperplasia is caused by excessive hormonal stimulation or growth factors on target cells. Examples 3.Benign prostate hyperplasia (BPH) 4.Endometrial hyperplasia Hyperplasia is an adaptive response in cells capable of replication. Hyperplasia is also an important response of connective tissue cells in wound healing, in which proliferating fibroblasts and blood vessels aid in repair. 4.METAPLASIA Is a reversible change in which one mature differentiated cell type (epithelial or mesenchymal) is replaced by another mature differentiated cell type. In this type of cellular adaptation, cells sensitive to a particular stress are replaced by other cell types better able to withstand the stressful environment. Examples: 1.Epithelial metaplasia is exemplified by the squamous change that occurs in the respiratory epithelium in habitual cigarette smokers. The normal ciliated columnar epithelial cells of the trachea and bronchi are focally or widely replaced by stratified squamous epithelial cells. 2.Vitamin A deficiency may also induce squamous metaplasia in the respiratory epithelium. Squamous metaplasia in respiratory epithelia of a cigarette smoker Cell Injury Adaptation And Cell Death However, the influences that induce metaplastic transformation, if persistent, may predispose to malignant transformation of the epithelium. o In a common form of lung cancer, squamous metaplasia of the respiratory epithelium often coexists with cancers composed of malignant squamous cells. 5.DYSPLASIA Means disordered growth. Dysplasia is encountered principally in epithelia and is characterized by loss in the uniformity of individual cells as well as a loss in their architectural orientation. Examples of dysplasia Achondroplasia Fibrous dysplasia Cervical dysplasia (can become cervical cancer) Fibrous dysplasia Achondroplasia CELL INJURY Cell injury or cell demage refers to a variety of changes of stress that a cell suffers due to external or internal environmental changes. When cells are injured, one of two patterns must dominate: reversible cell injury leading to adaptation of the cell and tissue, or irreversible cell

DIAGNOSTIC RADIOGRAPHY · NTA LEVEL 4 · SEMESTER ONE Cardiovascular System CRT04101 · Anatomy, Physiology and Pathology START READING NOTES Study Cardiovascular System using the sections below. Use the topic navigation to continue through Anatomy, Physiology and Pathology. Contents of This Topic The Cardiovascular System: The Heart Chapter 18, Cardiovascular System STRUCTURE OF BLOOD VESSELS BLOOD VESSELS ARTERIES VEIN CAPILLARIES The Cardiovascular System: The Heart Harrison, MD Chapter 18, Cardiovascular System Heart Anatomy Approximately the size of your fist Location Superior surface of diaphragm Left of the midline Anterior to the vertebral column, posterior to the sternum Chapter 18, Cardiovascular System Heart Anatomy Figure 18.1 Chapter 18, Cardiovascular System Coverings of the Heart: Anatomy Pericardium – a double-walled sac around the heart composed of: A superficial fibrous pericardium A deep two-layer serous pericardium The parietal layer lines the internal surface of the fibrous pericardium The visceral layer or epicardium lines the surface of the heart They are separated by the fluid-filled pericardial cavity Chapter 18, Cardiovascular System Coverings of the Heart: Physiology The Function of the Pericardium: Protects and anchors the heart Prevents overfilling of the heart with blood Allows for the heart to work in a relatively friction-free environment Chapter 18, Cardiovascular System Heart Wall Epicardium – visceral layer of the serous pericardium Myocardium – cardiac muscle layer forming the bulk of the heart Fibrous skeleton of the heart – crisscrossing, interlacing layer of connective tissue Endocardium – endothelial layer of the inner myocardial surface Chapter 18, Cardiovascular System Vessels returning blood to the heart include: Superior and inferior venae cavae Right and left pulmonary veins Vessels conveying blood away from the heart include: Pulmonary trunk, which splits into right and left pulmonary arteries Ascending aorta (three branches) – Brachiocephalic Left common carotid Subclavian arteries External Heart: Major Vessels of the Heart (Anterior View) Chapter 18, Cardiovascular System Arteries – right and left coronary (in atrioventricular groove), marginal, circumflex, and anterior interventricular arteries Veins – small cardiac, anterior cardiac, and great cardiac veins External Heart: Vessels that Supply/Drain the Heart (Anterior View) Chapter 18, Cardiovascular System External Heart: Anterior View Figure 18.4b Chapter 18, Cardiovascular System Vessels returning blood to the heart include: Right and left pulmonary veins Superior and inferior venae cavae Vessels conveying blood away from the heart include: Aorta Right and left pulmonary arteries External Heart: Major Vessels of the Heart (Posterior View) Chapter 18, Cardiovascular System Arteries – right coronary artery (in atrioventricular groove) and the posterior interventricular artery (in interventricular groove) Veins – great cardiac vein, posterior vein to left ventricle, coronary sinus, and middle cardiac vein External Heart: Vessels that Supply/Drain the Heart (Posterior View) Chapter 18, Cardiovascular System External Heart: Posterior View Figure 18.4d Chapter 18, Cardiovascular System Gross Anatomy of Heart: Frontal Section Figure 18.4e Chapter 18, Cardiovascular System Atria of the Heart Atria are the receiving chambers of the heart Each atrium has a protruding auricle Pectinate muscles mark atrial walls Blood enters right atria from superior and inferior venae cavae and coronary sinus Blood enters left atria from pulmonary veins Chapter 18, Cardiovascular System Ventricles of the Heart Ventricles are the discharging chambers of the heart Papillary muscles and trabeculae carneae muscles mark ventricular walls Right ventricle pumps blood into the pulmonary trunk Left ventricle pumps blood into the aorta Chapter 18, Cardiovascular System Myocardial Thickness and Function Thickness of myocardium varies according to the function of the chamber Atria are thin walled, deliver blood to adjacent ventricles Ventricle walls are much thicker and stronger right ventricle supplies blood to the lungs (little flow resistance) left ventricle wall is the thickest to supply systemic circulation Chapter 18, Cardiovascular System Thickness of Cardiac Walls Myocardium of left ventricle is much thicker than the right. Chapter 18, Cardiovascular System Pathway of Blood Through the Heart and Lungs Right atrium  tricuspid valve  right ventricle Right ventricle  pulmonary semilunar valve  pulmonary arteries  lungs Lungs  pulmonary veins  left atrium Left atrium  bicuspid valve  left ventricle Left ventricle  aortic semilunar valve  aorta Aorta  systemic circulation Chapter 18, Cardiovascular System Pathway of Blood Through the Heart and Lungs Figure 18.5 Chapter 18, Cardiovascular System Coronary Circulation Coronary circulation is the functional blood supply to the heart muscle itself Collateral routes ensure blood delivery to heart even if major vessels are occluded Chapter 18, Cardiovascular System Coronary Circulation: Arterial Supply Figure 18.7a Chapter 18, Cardiovascular System Coronary Circulation: Venous Supply Figure 18.7b Chapter 18, Cardiovascular System Heart Valves Heart valves ensure unidirectional blood flow through the heart Atrioventricular (AV) valves lie between the atria and the ventricles AV valves prevent backflow into the atria when ventricles contract Chordae tendineae anchor AV valves to papillary muscles Chapter 18, Cardiovascular System Heart Valves Semilunar valves prevent backflow of blood into the ventricles Aortic semilunar valve lies between the left ventricle and the aorta Pulmonary semilunar valve lies between the right ventricle and pulmonary trunk Chapter 18, Cardiovascular System Heart Valves Figure 18.8a, b Chapter 18, Cardiovascular System Microscopic Anatomy of Heart Muscle Cardiac muscle is striated, short, fat, branched, and interconnected The connective tissue endomysium acts as both tendon and insertion Intercalated discs anchor cardiac cells together and allow free passage of ions Heart muscle behaves as a functional syncytium InterActive Physiology®: Cardiovascular System: Anatomy Review: The Heart PLAY STRUCTURE OF BLOOD VESSELS Chapter 18, Cardiovascular System BLOOD VESSELS Made up of three layer -tunica externa-compose of loose fibrous connective tissue -tunica media-smooth muscles -tunica intima-endothelial cells DIFFERENCES BTN VEIN AND ARTERY. Chapter 18, Cardiovascular System ARTERIES CARRIES BLOOD AWAY OF THE HEART Large Thick-walled, Muscular Elastic Oxygenated blood Exception Pulmonary Artery Carried under great pressure Steady pulsating Arterioles: smaller vessels, enter tissue Chapter 18, Cardiovascular System VEIN Chapter 18, Cardiovascular System Carries blood that contains waste and CO2 Exception pulmonary vein Blood not under much pressure Valves to prevent much gravity pull Venules: larger than capillaries CAPILLARIES Smallest vessel Microscopic Walls one cell thick Nutrients

DIAGNOSTIC RADIOGRAPHY · NTA LEVEL 4 · SEMESTER ONE Brain Anatomy and Functions CRT04101 · Anatomy, Physiology and Pathology START READING NOTES Study Brain Anatomy and Functions using the sections below. Use the topic navigation to continue through Anatomy, Physiology and Pathology. Brain Anatomy and Functions > 1 Overview The human brain is an amazing three-pound organ that controls all functions of the body, interprets information from the outside world, and embodies the essence of the mind and soul. Intelligence, creativity, emotion, and memory are a few of the many things governed by the brain. Protected within the skull, the brain is composed of the cerebrum, cerebellum, and brainstem. The brain receives information through our five senses: sight, smell, touch, taste, and hearing – often many at one time. It assembles the messages in a way that has meaning for us, and can store that information in our memory. The brain controls our thoughts, memory and speech, movement of the arms and legs, and the function of many organs within our body. The central nervous system (CNS) is composed of the brain and spinal cord. The peripheral nervous system (PNS) is composed of spinal nerves that branch from the spinal cord and cranial nerves that branch from the brain. Brain The brain is composed of the cerebrum, cerebellum, and brainstem (Fig. 1). Cerebrum: is the largest part of the brain and is composed of right and left hemispheres. It performs higher functions like interpreting touch, vision and hearing, as well as speech, reasoning, emotions, learning, and fine control of movement. Cerebellum: is located under the cerebrum. Its function is to coordinate muscle movements, maintain posture, and balance. Brainstem: acts as a relay center connecting the cerebrum and cerebellum to the spinal cord. It performs many automatic functions such as breathing, heart rate, body temperature, wake and sleep cycles, digestion, sneezing, coughing, vomiting, and swallowing. Right brain – left brain The cerebrum is divided into two halves: the right and left hemispheres (Fig. 2). They are joined by a bundle of fibers called the corpus callosum that transmits messages from one side to the other. Anatomy of the Brain Figure 1. The brain has three main parts: the cerebrum cerebellum, and brainstem. Figure 2. The cerebrum is divided into left and right hemispheres. The two sides are connected fibers corpus callosum.> 2 Each hemisphere controls the opposite side of the body. If a stroke occurs on the right side of the brain, your left arm or leg may be weak or paralyzed. Not all functions of the hemispheres are shared. In general, the left hemisphere controls speech, comprehension, arithmetic, and writing. The right hemisphere controls creativity, spatial ability, artistic, and musical skills. The left hemisphere is dominant in hand use and language in about 92% of people. Lobes of the brain The cerebral hemispheres have distinct fissures, which divide the brain into lobes. Each hemisphere has 4 lobes: frontal, temporal, parietal, and occipital (Fig 3). Each lobe may be divided, once again, into areas that serve very specific functions. It’s important to understand that each lobe of the brain does not function alone. There are very complex relationships between the lobes of the brain and between the right and left hemispheres. Language In general, the left hemisphere of the brain is responsible for language and speech and is called the "dominant" hemisphere. The right hemisphere plays a large part in interpreting visual information and spatial processing. In about one third of people who are left-handed, speech function may be located on the right side of the brain. Left-handed people may need special testing to determine if their speech center is on the left or right side prior to any surgery in that area. Aphasia is a disturbance of language affecting speech production, comprehension, reading or writing, due to brain injury. The type of aphasia depends on the brain area damaged. Broca’s area: lies in the left frontal lobe (Fig 3). If this area is damaged, one may have difficulty moving the tongue or facial muscles to produce the sounds of speech. A person can still read and understand spoken language but has difficulty in speaking and writing (i.e. forming letters and words, doesn't write within lines) – called Broca's aphasia. Wernicke's area: lies in the left temporal lobe (Fig 3). Damage to this area causes Wernicke's aphasia. The person may speak in long sentences that have no meaning, add unnecessary words, and even create new words. They can make speech sounds, however they have difficulty understanding speech and are therefore unaware of their mistakes. Figure 3. The cerebrum is divided into four lobes: frontal, parietal, temporal, and occipital. Frontal lobe (blue) Personality, behavior, emotions Judgment, planning, problem solving Speech: speaking and writing (Broca’s area) Body movement (motor strip) Intelligence, concentration, self awareness Parietal lobe (orange) Interprets language, words Sense of touch, pain, temperature (sensory strip) Interprets vision, hearing, sensory and memory Spatial and visual perception Occipital lobe (purple) Interprets vision (color, light, movement) Temporal lobe (green) Understanding language (Wernicke’s area) Memory Hearing Sequencing and organization> 3 Cortex The surface of the cerebrum is called the cortex. It has a folded appearance with hills and valleys. The cortex contains 16 billion neurons (the cerebellum has 70 billion = 86 billion total) that are arranged in specific layers. The nerve cell bodies color the cortex grey-brown giving it its name – gray matter (Fig. 4). Beneath the cortex are long nerve fibers (axons) that connect brain areas to each other — called white matter. The folding of the cortex increases the brain’s surface area allowing more neurons to fit inside the skull and enabling higher functions. Each fold is called a gyrus, and each groove between folds is called a sulcus (Fig. 4). There are names for the folds and grooves that help define specific brain regions. Deep structures Pathways called white matter tracts connect areas of the cortex to each other. Messages can travel from one gyrus to another, from one

DIAGNOSTIC RADIOGRAPHY · NTA LEVEL 4 · SEMESTER ONE Bone Tissue CRT04101 · Anatomy, Physiology and Pathology START READING NOTES Study Bone Tissue using the sections below. Use the topic navigation to continue through Anatomy, Physiology and Pathology. Contents of This Topic Bone is a hard and rigid tissue that forms the bony skeleton of the body. The bone is highly vascularized, and in living conditions the bone appears pinkish in colour Types of Bones Parts of the long bone Bone formation Functions of bones 3.Movement; when muscles contract, they pull on bones to produce movement. BONE TISSUE Bone is a hard and rigid tissue that forms the bony skeleton of the body. Bone supports the body weight and provides attachment to muscles whereas act as lever for movements and provides protection to organs. Inside the bone there are spaces, which are filled with the bone marrow that produce red blood cells, platelets and cells of the immune system. Cells of the immune system produced in bone marrow include monocytes, lymphocytes, mast cells, neutrophils, eosinophils and basophils. The only difference with other connective tissues is that its ground substance is made up of inorganic salts, mostly calcium ions. The bone is highly vascularized, and in living conditions the bone appears pinkish in colour Bone consists of: Cells Fibers Ground substances Bone Cells; The bone contains four types of cells namely the osteoprogenator cells, osteoblasts, osteocytes, and the osteoclasts. Bone Matrix (Intercellular substance);It is made up of the collagen fibers (osteocollagenous fibers), amorphous ground substance and inorganic salts which constitute about 74% of bone mass. Types of Bones 1.Long bones e.g. femur, tibia and fibula 2.Short bones e.g. carpals (wrist bones) 3.Flat bones e.g. sternum, ribs and most skull bones (skull) 4.Irregular bones e.g. vertebrae and some skull bones 5.Sesamoid bones e.g. patella (kneecap) Parts of the long bone A long bone is one that has greater length than width. A typical long bone consists of the following parts: The diaphysis is the bone’s shaft or body—the long, cylindrical, main portion of the bone. The epiphyses (singular is epiphysis) are the proximal and distal ends of the bone. The metaphyses (singular is metaphysis) are the regions between the diaphysis and the epiphyses. Bone formation Bones formation occurs in four main stages which are; 1.Development of the ossification canters (special membrane) 2.Formation of bone matrix 3.Deposition of minerals or calcification 4.Formation of trabeculae and appearance of periosteum Functions of bones 1.Support,the skeleton serves as the structural framework for the body by supporting soft tissues providing attachment points for the tendons of most skeletal muscles. 2.Protection; The skeleton protects the most important internal organs from injury for example, cranial bones protect the brain, vertebrae (backbones) protect the spinal cord, and the ribcage protects the heart and lungs. 3.Movement; when muscles contract, they pull on bones to produce movement. 4.Mineral homeostasis (storage and release);Bone tissue stores several minerals, especially calcium and phosphorus, which contribute to the strength of bone. 5.Blood cell production; bone marrow produces red blood cells, white blood cells, and platelets, a process called hemopoiesis. ← 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 Body Cavities And Membranes CRT04101 · Anatomy, Physiology and Pathology START READING NOTES Study Body Cavities And Membranes using the sections below. Use the topic navigation to continue through Anatomy, Physiology and Pathology. Contents of This Topic Cavity is an empty space in the body of multicellular organism,containing the viscera or fluid. DORSAL BODY CAVITY VENTRAL BODY CAVITY The superior subdivision, is surrounded by the ribs and muscles of the chest. The abdominopelvic cavity, has two parts. When the body is subjected to physical trauma e.g MTA/RTA, the abdominopelvic organs are most vulnerable. MEMBRANES IN THE VENTRAL BODY CAVITY Body Cavities And Membranes When serous membranes are inflamed, their normally smooth surfaces become roughened. ABDOMINOPELVIC REGIONS AND QUADRANTS The umbilical region is the centermost region deep to and surrounding the umbilicus (navel). Medical personnel usually use a simpler scheme to localize the abdominopelvic cavity organs . OTHER BODY CAVITIES 4. Middle ear cavities. The middle ear cavities carved into the skull lie just medial to the eardrums. BODY CAVITIES AND MEMBRANES Cavity is an empty space in the body of multicellular organism,containing the viscera or fluid. Membrane is a thin sheet of tissue or layers of cells acting as a boundary,lining,or partition in an organism. DORSAL BODY CAVITY The dorsal body cavity, which protects the fragile nervous system organs, has two subdivisions. The cranial cavity, in the skull, encases the brain. The vertebral, or spinal, cavity, which runs within the bony vertebral column, encloses the delicate spinal cord. The spinal cord is essentially a continuation of the brain, and the cranial and spinal cavities are continuous with one another VENTRAL BODY CAVITY The more anterior and larger of the closed body cavities is the ventral body cavity . Like the dorsal cavity, it has two major subdivisions: The thoracic cavity. 2.The abdominopelvic cavity. The ventral body cavity houses internal organs collectively called the viscera, or visceral organs. The superior subdivision, is surrounded by the ribs and muscles of the chest. The thoracic cavity is further subdivided into lateral pleural cavities, each enveloping a lung, and the medial mediastinum. The mediastinum contains the pericardial cavity, which encloses the heart, and it also surrounds the remaining thoracic organs. The thoracic cavity is separated from the more inferior abdominopelvic cavity by the diaphragm, a dome-shaped muscle important in breathing The abdominopelvic cavity, has two parts. However, these regions are not physically separated by a muscular or membrane wall. Its superior portion, the abdominal cavity, contains the stomach, intestines, spleen, liver, and other organs. The inferior part, the pelvic cavity, lies in the bony pelvis and contains the bladder, some reproductive organs, and the rectum. The abdominal and pelvic cavities are not aligned with each other. Instead, the bowl-shaped pelvis tips away from the perpendicular. When the body is subjected to physical trauma e.g MTA/RTA, the abdominopelvic organs are most vulnerable. This is because the walls of the abdominal cavity are formed only by trunk muscles and are not reinforced by bone. The pelvic organs receive a somewhat greater degree of protection from the bony pelvis. MEMBRANES IN THE VENTRAL BODY CAVITY The walls of the ventral body cavity and the outer surfaces of the organs it contains are covered by a thin, double-layered membrane, the serosa, or serous membrane. The part of the membrane lining the cavity walls is called the parietal serosa. It folds in on itself to form the visceral serosa, covering the organs in the cavity. Body Cavities And Membranes In the body, the serous membranes are separated not by air but by a thin layer of lubricating fluid, called serous fluid, which is secreted by both membranes. Although there is a potential space between the two membranes, the barely present, slitlike cavity is filled with serous fluid. Body Cavities And Membranes The slippery serous fluid allows the organs to slide without friction across the cavity walls and one another as they carry out their routine functions. The serous membranes are named for the specific cavity and organs with which they are associated. The parietal pericardium lines the pericardial cavity and reflects back as the visceral pericardium, which covers the heart. Likewise, the parietal pleura lines the walls of the thoracic cavity, and the visceral pleura covers the lungs. The parietal peritoneum is associated with the walls of the abdominopelvic cavity, while the visceral peritoneum covers most of the organs within that cavity. When serous membranes are inflamed, their normally smooth surfaces become roughened. This leads to excruciating pain as the organs stick together and drag across one another, as anyone who has experienced pleurisy (inflammation of the pleurae) or peritonitis (inflammation of the peritonea) ABDOMINOPELVIC REGIONS AND QUADRANTS Because the abdominopelvic cavity is large and contains several organs, it helps to divide it into smaller areas for study. One division method, used primarily by anatomists, uses two transverse and two parasagittal planes. These planes, positioned like a tic-tac-toe grid on the abdomen, divide the cavity into nine regions The umbilical region is the centermost region deep to and surrounding the umbilicus (navel). The epigastric region is located superior to the umbilical region. The hypogastric (pubic) region is located inferior to the umbilical region. The right and left iliac, or inguinal, regions are located lateral to the hypogastric region. The right and left lumbar regions lie lateral to the umbilical region. The right and left hypochondriac regions flank the epigastric region laterally. Medical personnel usually use a simpler scheme to localize the abdominopelvic cavity organs . In this scheme, one transverse and one median sagittal plane pass through the umbilicus at right angles. The resulting quadrants are named according to their positions from the subject’s point of view: The right upper quadrant (RUQ), Left upper quadrant (LUQ), Right Lower quadrant (RLQ), and Left lower quadrant (LLQ). OTHER BODY CAVITIES In addition to the large closed body cavities, there are several smaller body cavities. Most of these are in the head

DIAGNOSTIC RADIOGRAPHY · NTA LEVEL 4 · SEMESTER ONE Blood groups CRT04101 · Anatomy, Physiology and Pathology START READING NOTES Study Blood groups using the sections below. Use the topic navigation to continue through Anatomy, Physiology and Pathology. Contents of This Topic BLOOD GROUPS IMPORTANCE OF BLOOD GROUPING: THE HISTORY OF BLOOD TRANSFUSION ABO BLOOD GROUPS OTHER BLOOD GROUPS LANDSTEINER’S LAW FORMATION OF ANTIBODIES INHERITANCE OF ABO BLOOD GROUP GENETIC INHERITANCE OF ABO BLOOD GROUP BLOOD GROUPING THE RHESUS (Rh) BLOOD SYSTEM RHESUS CONT. CLINICAL SIGNIFICANCE OF Rh FACTOR CLINICAL SIGNIFICANT OF Rh CONT. BLOOD GROUPS Department of Physiology IMPORTANCE OF BLOOD GROUPING: Practical importance of blood grouping includes: Blood transfusion Paternity disputes Medicolegal use eg blood stain on clothes Association with susceptibility to disease: Blood group O: more susceptible to peptic ulcers Blood group A : more susceptible to carcinoma of stomach THE HISTORY OF BLOOD TRANSFUSION In 1901 Karl Landsteiner published his work He discovered the ABO blood group system by mixing blood samples from his colleagues Later, it was also noted that: Some people were given blood with no reaction While others received blood there were some reactions even death Landsteiner and Weiner discovered Rh system (1940) The best known groups are the ABO & Rhesus systems are of great importance in blood transfusion today ABO BLOOD GROUPS Depending on the presence or absence of A & B antigens, humans can be divided into A, B, AB & O groups The antibodies reacting with the: Antigen A is called antibody A (alpha) Antigen B is called antibody B (beta) Antigen O is not antigenic and has no corresponding antibodies The prevalence of ABO blood groups among the Europeans: TYPE FREQUENCY (%) O 47 A 41 B 9 AB 3 OTHER BLOOD GROUPS In addition to the ABO & Rh blood groups are: M, N, P, Lutheran, Kell, Duffy, Kid, Diego etc etc These blood groups have demonstrable antigens but the corresponding antibodies in the plasma are generally not present. LANDSTEINER’S LAW The Law states that: “If an antigen (agglutinogen) is present on the Rbc of an individual, the corresponding antibody (agglutinin) must be absent and that IF an antigen is absent on the Rbc of an individual, corresponding antibody must be present in the plasma” LANDSTEINER’S LAW Blood groups, antigens & antibodies according to Landsteiner’s law: Blood group Antigens Antibodies O NO A & B A A B B B A AB A & B NO FORMATION OF ANTIBODIES The specific blood group antibodies (Antibodies A & B) are absent at birth, but they appear and reach a maximum concentration by the age of 10 years. INHERITANCE OF ABO BLOOD GROUP ABO blood groups are inherited in accordance with Mendelian principle: by a means of 3allelic genes A, B, and O. The A & B genes are co-dominant while O gene is functionless ie has no demonstrable product GENETIC INHERITANCE OF ABO BLOOD GROUP GENETIC OFFSPRING From Parent-1 Parent-2 Genotype Phenotype A B AB AB A A AA A A O AO A B B BB B B O BO B O O OO O BLOOD GROUPING Before blood transfusion, the patient’s (recipient) and donor’s blood group are determined. Anti A Anti B Blood Group Cells 1 – – O Cells 2 + – A Cells 3 – + B Cells 4 + + A & B NB: + Reaction & – No reaction THE RHESUS (Rh) BLOOD SYSTEM The Rh System derives its name from the findings that the antibody produced in the rabbit by injection of Rbc from the Rhesus monkey would: Agglutinate 85% of human cells (Rhesus Positive) The remaining 15% could not agglutinate (Rhesus Negative) This type of antibody was also found in: Some people who had transfusion before. Mothers who had given birth to a child with Haemolytic Disease of the Newborn (HDN) People who were originally labelled as Rhesus positive (Rh + ve) have actually the D antigen on their Rbc’s membrane RHESUS CONT. Similar to D antigens are C & D antigens, but are not clinically important D antigen is much more potent ie it stimulate antibody production with greater frequency than any other Rh antigen CLINICAL SIGNIFICANCE OF Rh FACTOR Although there are no natural antibody Rh(D) These antibodies can however develop in two ways: When an Rh Negative person is given Rh positive blood. First transfusion of Rh+ve into Rh-ve there will be no reaction However subsequent transfusion of Rh+ve of blood causes haemolysis of transfused blood due to Anti Rh (D) CLINICAL SIGNIFICANT OF Rh CONT. When an Rh –ve mother gets Rh +ve fetus from a Rh +ve father. Thefirst pregnancy will have no reaction However, subsequent pregnancies with Rh+ve fetus result into Haemolytic Disease of the Newborn (HDN) THANK YOU ← 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 Blood And Its Functions CRT04101 · Anatomy, Physiology and Pathology START READING NOTES Study Blood And Its Functions using the sections below. Use the topic navigation to continue through Anatomy, Physiology and Pathology. Contents of This Topic COMPONENTS OF THE BLOOD Blood And Its Functions The average adult has a blood volume of roughly 5 litres, composed of: Functions of Blood Function of blood Blood Plasma and Platelets Blood Platelets Production and Functions of Red Blood Cell Erythropoiesis is the process by which red blood cells (erythrocytes) are produced In the process of red blood cell maturation, a cell undergoes a series of differentiations. Regulation of Erythropoiesis Functions of Red Blood Cells As blood flows through the lungs, the carbon dioxide is released from haemoglobin and then exhaled. Production and Functions of White Blood Cells Types of White Blood Cells Agranulocytes (Mononuclear Leucocytes) Functions of White Blood Cells Eosinophil Monocyte Macrophage KEY POINTS EVALUATION Composition and Functions of Blood COMPONENTS OF THE BLOOD What are the components of blood? Blood And Its Functions Blood is the specialized( connective tissue) bodily fluid that delivers necessary substances to the body's cells such as nutrients, oxygen and transports waste products away from those same cells Blood accounts for 7% of the human body weight By volume the red blood cells constitute about 45% of whole blood, the plasma constitutes about 55% The average adult has a blood volume of roughly 5 litres, composed of: Plasma Formed elements These formed elements of the blood are Erythrocytes (red blood cells) Adult humans have roughly 2–3 × 10>13 red blood cells Leukocytes (white blood cells) and 4,000–11,000 white blood cells Thrombocytes (platelets). 150,000–400,000 platelets in each microliter Women have about 4 to 5 million erythrocytes per microliter (cubic millimeter) of blood and men about 5 to 6 million; people living at high altitudes with low oxygen tension will have more. Functions of Blood What are the functions of blood? Function of blood Supply of oxygen to tissues (bound to haemoglobin which is carried in red cells) bound to plasma proteins Removal of waste such as carbon dioxide, urea and lactic acid Immunological functions, including circulation of white cells, and detection of foreign material by antibodies Coagulation, which is one part of the body's self-repair mechanism Messenger functions, including the transport of hormones and the signalling of tissue damage Regulation of body pH (the normal pH of blood is in the range of 7.35 – 7.45) Regulation of core body temperature Blood Plasma and Platelets Blood Plasma Is the fluid portion of the blood, The plasma, is a remarkable solution containing an immense number of ions, inorganic molecules, and organic molecules that are in transit to various parts of the body or aid in the transport of other substances The normal plasma volume is about 5% of body weight, or roughly 3500 mL in a 70kg man Plasma clots on standing, remain fluid only if an anticoagulant is added If whole blood is allowed to clot and the clot is removed, the remaining fluid is called serum PLASMA Vs SERUM Blood And Its Functions Serum has essentially the same composition as plasma except that its fibrinogen an clotting factors II, V, and VIII have been removed and it has higher serotonin content because of the breakdown of platelets during clotting The plasma consist of protein; albumin, globulin, and fibrinogen fractions The capillary walls are relatively impermeable to the plasma proteins, and the proteins are therefore exerting an osmotic force of about 25 mm Hg across the capillary wall (oncotic pressure) that pulls water into the blood Blood Platelets Platelets or thrombocytes are minute fragment of cells consisting of a small amount of cytoplasm surrounded by a plasma membrane Platelets are roughly disk-shaped and an average about 3μm in diameter. They play an important role in controlling blood loss by forming platelets plugs which seal holes in small vessels The life expectancy of platelets is about 5 – 9 days Platelets arise in a unique manner by the shedding of thousands of cytoplasmic fragments from the tips of processes of megakaryocytes in the bone marrow The first detectable cell of this line is the highly basophilic megakaryoblast, followed by a promegakaryocyte stage, in which synthesis of granules begins Finally, the fully differentiated megakaryocyte, a giant cell with a large, dense, polyploid, multilobed nucleus, appears Production and Functions of Red Blood Cell Red Blood Cells Red blood cells (Erythrocytes) are the most common type of blood cell The cells are filled with haemoglobin, a biomolecule that can bind to oxygen They take up oxygen in the lungs and release it while squeezing through the body's capillaries. The blood's red colour is due to the colour of haemoglobin. In humans, red blood cells develop in the bone marrow, take the form of flexible biconcave disks, lack a cell nucleus, subcellular organelles and the ability to synthesize protein, It takes about 7 days for erythrocytes to mature and live a total of about 120 days Erythropoiesis is the process by which red blood cells (erythrocytes) are produced In human adults, this usually occurs within the bone marrow. In the early foetus, erythropoiesis takes place in the mesodermal cells of the yolk sac. By the third or fourth month, erythropoiesis moves to the spleen and liver. In humans with certain diseases, erythropoiesis also occurs outside the bone marrow, within the spleen or liver. This is termed extramedullary erythropoiesis The tibia and femur cease to be important sites of haematopoiesis by about age 25; the vertebrae, sternum, pelvis and ribs, and cranium bones continue to produce red blood cells throughout life. Erythrocytes and granulocytes belong to the myeloid lineage. The earliest identifiable erythroid stem cells are capable of rapid bursts of cell division to form numerous daughter cells. In the process of red blood cell maturation, a cell undergoes a series of differentiations. The following stages of development all occur within the bone

DIAGNOSTIC RADIOGRAPHY · NTA LEVEL 4 · SEMESTER ONE Anatomy of reproductive Organs CRT04101 · Anatomy, Physiology and Pathology START READING NOTES Study Anatomy of reproductive Organs using the sections below. Use the topic navigation to continue through Anatomy, Physiology and Pathology. Contents of This Topic Female Reproductive System …… Ovaries Anatomy of reproductive Organs Uterus Vagina External genitals (Vulva) Labia majora and minora Male reproductive organs Testes The testes are surrounded by three layers of tissues which are (outer-inner layer) Cells of testis Epididymis Ejaculatory ducts Seminal vesicles Their secretion contains fructose to provide an energy source for sperm and is alkaline to enhance sperm motility. Prostate gland Bulbourethral (Cowper‘s) glands Urethra Anatomy of reproductive Organs Female Reproductive System Is made up of the internal and external sex organs The female reproductive system consists of the: Internal genitalia which include: Paired ovaries Fallopian tubes Single uterus Vagina AND External genital structures (vulva) which include: Clitoris Labia majora and minora …… Bartholin‘s glands Ovaries The ovaries are a pair of oval structures on either side of the uterus in the pelvic cavity (with size approx. 3.5 cm in length, 2 cm wide, and 1 cm thick) Within an ovary are several hundred thousand primary follicles, which are present at birth and later matures to become ova Fallopian /uterine tubes or oviduct There are two fallopian tubes(oviducts) The lateral end of a fallopian tube encloses an ovary, and the medial end opens into the uterus. They are line by ciliated columnar Epithelium. Parts of Oviduct include isthmus,Ampulla and Infindubilum (contains fimbriae) !!Fertilization takes place in oviduct (ampulla) Anatomy of reproductive Organs Isthmus=narrowed part of a structure. There are two isthmuses. The one is between the body of uterus and cervix and the other is the first medial part of fallopian tube. Uterus The uterus is shaped like an upside-down pear, superior to the urinary bladder and between the two ovaries in the pelvic cavity …… Uterus…. It is divided in to fundus (upper part), body/corpus (central part),Isthmus and cervix (lower part) Layers of uterus (from innermost-outermost): Endometrium- inner lining and consists of glandular cells (simple columnar epithelium) that make secretions and undergoes cyclic shedding during menstruation It forms the maternal portion of the placenta during pregnancy Anatomy of reproductive Organs The myometrium is the smooth muscle layer during pregnancy these cells increase in size to accommodate the growing foetus and contract for labour and delivery at the end of pregnancy. Perimetrium: consists of Subserosa tissue Vagina The vagina is a muscular tube that extends from the cervix to the vaginal orifice The vaginal opening is usually partially covered by a thin membrane called the hymen which ruptures after sexual intercourse The functions of the vagina are to receive sperm from the penis during sexual intercourse, To provide the exit for menstrual blood flow, and To become the birth canal at the end of pregnancy. External genitals (Vulva) Clitoris Is a small mass of erectile tissue anterior to the urethral orifice. The only function of the clitoris is sensory. It responds to sexual stimulation. Labia majora and minora Are paired folds of skin which covers the urethra and vagina openings and prevent drying of their mucous membranes Bartholin‘s glands They secrete lubricant which keep the vagina moist during sexual intercourse. Male reproductive organs They include: Testes Epididymis Dactus deferens (vas deferens) Ejaculatory ducts ….. Seminal vesicles Prostate gland Bulbourethral (Cowper‘s) glands Urethra-penis Testes The testes are located in the scrotum, a sac of skin between the upper thighs. Internally is divided in to lobes Each lobe contains several seminiferous tubules where spermatogenesis takes place. The testes are surrounded by three layers of tissues which are (outer-inner layer) Tunica vaginalis Tunica albuginea Tunica vasculosa Cells of testis sertoli cells which produce inhibin hormone when stimulated by testosterone Leydig cells: produce Testosterone is responsible for maturation of sperm and secondary male characteristics Epididymis It is a tube about 6m long that is coiled in the posterior surface of each testis. Within it the sperm complete the maturation and their flagella become functional. … Smooth muscle of the wall of epididymis propels the sperm to dactus deferens Dactus deferens (vas deferens) Extends from the epididymis in the scrotum on its own side into the abdominal cavity through the inguinal canal … Spermatic cord is a connective tissue sheath that contains the ductus deferens, testicular blood vessels(Cremasteric artery,Testicular artery, artery to vas deferens & pampinifom venous plexus), and nerves, [well discussed in inguinal canal session] Ejaculatory ducts Each of the two ejaculatory ducts receives sperm from the ductus deferens and the secretion of the seminal vesicle on its own side. Both ejaculatory ducts empty into the single urethra Seminal vesicles The paired seminal vesicles are posterior to the urinary bladder Their secretion contains fructose to provide an energy source for sperm and is alkaline to enhance sperm motility. The duct of each seminal vesicle joins the ductus deferens on that side to form the ejaculation duct Prostate gland A muscular ,walnut-shaped gland just below the urinary bladder It surrounds the first inch of the urethra as it emerges from the bladder The glandular tissue of the prostate secretes an alkaline fluid that helps maintain sperm motility. The smooth muscle of the prostate gland contracts during ejaculation to contribute to the expulsion of semen from the urethra Bulbourethral (Cowper‘s) glands They are located below the prostate gland and empties to the urethra Their alkaline secretion coats the interior of the urethra just before ejaculation, which neutralizes any acidic urine that might be present. Urethra The urethra is the last of the ducts through which semen travels, and its longest portion is enclosed within the penis. Anatomy of reproductive Organs The penis is an external genital organ; its distal end is called the glans penis and is covered with a fold of skin called the prepuce or foreskin which is removed by surgical procedure of circumcision Within the penis are three masses of cavernous (erectile) tissue by

DIAGNOSTIC RADIOGRAPHY · NTA LEVEL 4 · SEMESTER ONE Accessory organs of digestive systems CRT04101 · Anatomy, Physiology and Pathology START READING NOTES Study Accessory organs of digestive systems using the sections below. Use the topic navigation to continue through Anatomy, Physiology and Pathology. Contents of This Topic By the end of this session, students are expected to be able to: Overview of Accessory Organs of Digestive System Accessory organs of digestive systems Structure and Functions of the Liver The Quadrate lobe Structures related to Liver The connective tissue septa divide the liver into hexagon-shaped lobules with a portal triad at each corner Functions of hepatocytes Hepatocytes have six major functions, which are: Main Functions of the Liver Breakdown of erythrocytes and defence against microbes Vascular Supply and Lymphatic Drainage Structure and functions of the Gallbladder Organisation of the Biliary System This completes the formation of the bile duct Bile Production, Circulation and Functions Bile circulation. Composition of Bile Structure and Functions of Pancreas In the lower part of the head of pancreas, the pancreatic duct joins the bile duct The main and accessory pancreatic ducts usually communicate with each other Key points evaluation Accessory Organs of Digestive System By the end of this session, students are expected to be able to: Describe the Accessory Organs of Digestive System Describe the Structure and Functions of the Liver Describe the Structure and Functions of Gallbladder Explain Organization of the Biliary System Explain Bile Production, Circulation and Functions Identify Structure of Pancreas Overview of Accessory Organs of Digestive System What are the accessory organs of the digestive system? Accessory organs of digestive systems Accessory organs of gastrointestinal tract: The organs which are not directly part of gastrointestinal tract but their products are essential for the digestive system to accomplish its primary function These organs include: The liver Gallbladder and bile duct Pancreas These are essential for the digestive system as they either produce or store secretions essential the digestion to take place Structure and Functions of the Liver Liver is the largest gland in the body, weighing between 1 and 2.3Kg In adults the liver weighs 2% of body mass Occupying the greater part the right hypochondriac, part of the epigastric and frequently extending into the left hypochondriac regions as far as the left lateral line The liver is divided into right and left lobes by fossae for the gallbladder and the inferior vena cava The right lobe of liver is the largest lobe, whereas the left lobe of liver is smaller wedge shaped The quadrate and caudate lobes are described as arising from the right lobe of liver, but functionally are distinct these are seen on the posterior side of the liver making it to have four lobes: The Quadrate lobe It is visible on the upper part of the visceral surface of the liver It is bounded on the left by the fissure for ligamentum teres and on the right by the fossa for the gallbladder Functionally it is related to the left lobe of the liver The caudate lobe It is visible on the lower part of the visceral surface of the liver It is bounded on the left by the fissure for the ligamentum venosum and on the right by the groove for the inferior vena cava Functionally, it is separate from the right and the left lobes of the liver Structures related to Liver The right anterior part of the stomach The superior part of the duodenum The lesser omentum The gallbladder The right colic flexure The right transverse colon The right kidney The right suprarenal gland Accessory organs of digestive systems The porta hepatis serves as the point of entry into the liver for the hepatic arteries and the portal vein, and the exit point for the hepatic ducts The liver is attached to the anterior abdominal wall by the falciform ligament and, except for a small area of the liver against the diaphragm (the bare area), the liver is almost completely surrounded by visceral peritoneum Additional folds of peritoneum connect the liver to the stomach (hepatogastric ligament), the duodenum (hepatoduodenal ligament), and the diaphragm (right and left triangular ligaments and anterior and posterior coronary ligaments) The connective tissue septa divide the liver into hexagon-shaped lobules with a portal triad at each corner *The triad are so named because three vessels – the hepatic portal vein, hepatic artery and hepatic duct are commonly located in them Hepatic nerves and lymphatic vessels often too small to be easily seen in light microscope are also located in these areas Liver lobules are hexagonal in outline and are formed by cubical-shaped cells; the hepatocytes arranged in pair, between them are columns of cells called sinusoids Hepatic macrophages (Kupffer cells) are also present which function in destroy and ingest worn out cells and foreign particles in the liver A central vein is in the centre of each lobule Accessory organs of digestive systems Central veins unite to form hepatic veins, which exit the liver on its posterior and superior surface and empty into the inferior vena cava Hepatic cord radiate out from the central vein of each lobule like the spokes of a wheel The hepatic cords are composed of hepatocytes, the functional cells of the liver The spaces between the hepatic cords are blood channels called hepatic sinusoids The sinusoids are lined with a very thin, irregular squamous epithelium consisting of two cell populations; endothelial cells and Hepatic phagocytic cells (kupffer cells) A cleft-like lumen, the bile canaliculus lie between the cells within each cord Functions of hepatocytes What are the function of hepatocyte Hepatocytes have six major functions, which are: o Bile production o Storage o Interconversion of nutrients o Detoxication o Phagocytosis (kuppfer cells) o Synthesis of blood components Main Functions of the Liver Nutrient and vitamin metabolism and storage o Glucose and other sugars o Amino acids (Deamination of amino acids),the end product is urea which is then excreted in the urine) o Lipids o