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OPTOMETRY · SEMESTER 1 Body Fluids Human Anatomy and Physiology START READING NOTES Contents of This Topic BODY FLUIDS COMPARTMENT INTRODUCTION INTRODUCTION CONT … Body Water Content BODY FLUIDS Total Body Water Fluid Compartments Intracellular Fluid Compartment (ICF) FLUID COMPARTMENTS Fluid Compartments in the Human Body Intracellular Fluid Intracellular Fluid CONT … Extracellular Fluid Extracellular Fluid CONT … Extra Cellular Fluid Compartment (ECF) Blood Volume Composition of Body Fluids Composition of Body Fluids CONT … The Concentrations of Different Elements in Key Bodily Fluids PART II Fluid Movement between Compartments Fluid Movement between Compartments CONT … Capillary Exchange Capillary Exchange CONT … Exchange Between Plasma and ISF Exchange Between ECF and ICF PART III Solute Movement between Compartments Solute Movement between Compartments CONT … Facilitated Diffusion OF GLUCOSE Water Balance Water Balance CONT … Regulation of Water Intake Regulation of Water Intake CONT … Regulation of Water Output Regulation of Water Output CONT … Role of ADH Role of ADH CONT … Aquaporins diuretic ANY QUESTIONS? BODY FLUIDS COMPARTMENT BODY FLUIDS 1 INTRODUCTION Homeostasis, or the maintenance of constant conditions in the body, is a fundamental property of all living things. In the human body, the substances that participate in chemical reactions must remain within narrows ranges of concentration. Too much or too little of a single substance can disrupt your bodily functions. BODY FLUIDS 2 INTRODUCTION CONT … Because metabolism relies on reactions that are all interconnected, any disruption might affect multiple organs or even organ systems. Water is the most ubiquitous substance in the chemical reactions of life. The interactions of various aqueous solutions—solutions in which water is the solvent—are continuously monitored and adjusted by a large suite of interconnected feedback systems in your body. Understanding the ways in which the body maintains these critical balances is key to understanding good health. BODY FLUIDS 3 INTRODUCTION CONT … The chemical reactions of life take place in aqueous solutions. The dissolved substances in a solution are called solutes. In the human body, solutes vary in different parts of the body, but may include proteins—including those that transport lipids, carbohydrates, and, very importantly, electrolytes. Often in medicine, a mineral dissociated from a salt that carries an electrical charge (an ion) is called an electrolyte. For instance, sodium ions (Na+) and chloride ions (Cl-) are often referred to as electrolytes. BODY FLUIDS 4 INTRODUCTION CONT … In the body, water moves through semi-permeable membranes of cells and from one compartment of the body to another by a process called osmosis. Osmosis is basically the diffusion of water from regions of higher concentration of water to regions of lower concentration of water, along an osmotic gradient across a semi-permeable membrane. As a result, water will move into and out of cells and tissues, depending on the relative concentrations of the water and solutes found there. An appropriate balance of solutes inside and outside of cells must be maintained to ensure normal function. BODY FLUIDS 5 Body Water Content Human beings are mostly water, ranging from about 75 percent of body mass in infants to about 60 percent in adults, to as low as 45 percent in old age. The percent of body water changes with development, because the proportions of the body given over to each organ and to muscles, fat, bone, and other tissues change from infancy to adulthood. Your brain and kidneys have the highest proportions of water, which composes 80–85 percent of their masses. In contrast, teeth have the lowest proportion of water, at 8–10 percent. BODY FLUIDS 6 BODY FLUIDS 7 Total Body Water In normal adult human 70 kg Total body water = 60% of body weight = 42 liters (70*0.6) However, % can change depending on Age, sex, degree of obesity An increase in age is accompanied by increase in fat Hence % of body wt that is water decreases By age of 60 TBW = 50% of body wt in men BODY FLUIDS 8 Total Body Water Women have more fat Contain less water than men Total body water is 45 – 50% of body wt Children Neonate contain more water than adults (75 – 80% TBWt) By about 1 yr body water = 60% of body wt BODY FLUIDS 9 Fluid Compartments Intracellular Fluid Volume = 28 L, 2/3 TBW Interstitial Fluid Volume = 10.5 L, 75% of ECF Plasma Vol = 3.5 L, 25% of ECF BODY FLUIDS ICF (2/3 TBW) ECF (1/3 TBW) Total Body Water (TBW) 42 L, 60% of Body Wt 10 Intracellular Fluid Compartment (ICF) About 28 liters of the 42 liters are inside body cells ICF constitutes 40% of total body weight (for 70kg), or 2/3 of total body water (60% of body water) BODY FLUIDS 11 FLUID COMPARTMENTS EXTRACELLUAR FLUID INTRACELLULAR FLUID INTERSTITIAL FLUID PLASMA TRANSCELLULAR FLUID CSF Intra ocular Pleural Peritoneal Synovial Digestive Secretions BODY FLUIDS 12 Fluid Compartments Body fluids can be discussed in terms of their specific fluid compartment, a location that is largely separate from another compartment by some form of a physical barrier. The intracellular fluid (ICF) compartment is the system that includes all fluid enclosed in cells by their plasma membranes. Extracellular fluid (ECF) surrounds all cells in the body. Extracellular fluid has two primary constituents: the fluid component of the blood (called plasma) and the interstitial fluid (IF) that surrounds all cells not in the blood. BODY FLUIDS 13 FLUID COMPARTMENTS BODY FLUIDS 14 Fluid Compartments in the Human Body The intracellular fluid (ICF) is the fluid within cells. The interstitial fluid (IF) is part of the extracellular fluid (ECF) between the cells. Blood plasma is the second part of the ECF. Materials travel between cells and the plasma in capillaries through the IF. BODY FLUIDS 15 Intracellular Fluid The ICF lies within cells and is the principal component of the cytosol/cytoplasm. The ICF makes up about 60 percent of the total water in the human body, and in an average-size adult male, the ICF accounts for about 25

OPTOMETRY · SEMESTER 1 Blood Human Anatomy and Physiology START READING NOTES Contents of This Topic Overview Blood Composition Cells of the body are serviced by 2 fluids Blood The haematocrit Components of Blood Blood Plasma Plasma Constituents Formed Elements of Blood Erythrocytes (RBC) Erythrocytes Concentration of RBC in Blood Erythropoeisis Substances Required for Synthesis of RBC Genesis of RBC Myeloid stem cells give rise to RBCs, platelets, and all WBCs except for lymphocytes. Regulation of RBC Production Hemopoietic Growth Factors Role of erythropoeitin Regulation of Erythropoiesis Feedback Control of RBC Production Medical Uses of Growth Factors Formation of Haemoglobin Formation of haemoglobin Haemoglobin Iron Metabolism Transport of Iron Absorption of Iron Daily Loss of Iron Destruction of RBC Anaemia Blood Loss Anaema Aplastic anaemia Megaloblastic anaemia Haemolytic anaemia THE BLOOD Overview Blood Composition and functions Red blood cells: -Characteristics & functions, formation and destruction White blood cells: -Characteristics, functions, formation Platelets : -Haemostasis, fibrinolysis Blood groups and transfusion problems Blood Composition Blood Is an opaque, red liquid Consisting of several types of cells suspended in a complex, amber fluid Plasma Composed of Cells Plasma, liquid in which the cells are suspended The cells (formed elements) include Erythrocytes (RBCs) Leukocytes (WBCs) Platelets (cell fragments) The branch of science concerned with the study of blood, blood-forming tissues, and the disorders associated with them is called Hematology. Cells of the body are serviced by 2 fluids blood composed of plasma and a variety of cells transports nutrients and wastes interstitial fluid bathes the cells of the body Nutrients and oxygen diffuse from the blood into the interstitial fluid and then into the cells Wastes move in the reverse direction. Blood Its pH is 7.4 (7.35-7.45) 99% of the cells are RBC which are the O2 carrying cells of blood Blood is thicker (more viscous) than water and flows more slowly than water Average blood volume = 8% of body weight = 5.6L (70*0.08) On the average 60% of blood vol = plasma ( 3 liters) 40% of blood vol = RBC (2 liters) Values vary considerably in different people depending on sex and other factors The haematocrit Defined as the % of total blood that is erythocytes It is determined by centrifuging a sample of blood in a haematocrit tube Erythrocytes are forced to the bottom Plasma remains at the top Leucocyte and platelets form a thin layer in between Blood Plasma = 55% Leukocytes and platelets (buffy coat) RBC = 45% (Hct = 45%) Components of Blood Hematocrit 55% plasma 45% cells 99% RBCs < 1% WBCs and platelets Blood Plasma Non-cellular part of blood 0ver 90% water 7% plasma proteins created in liver confined to bloodstream albumin maintain blood osmotic pressure globulins (immunoglobulins) antibodies bind to foreignsubstances called antigens form antigen-antibody complexes fibrinogen for clotting 2% other substances electrolytes, nutrients, hormones, gases, waste products Plasma Constituents Constituent Functions 1 Water =92% of plasma wt Medium for carrying all other constituents 2 Electrolytes (inorganic) Total < 1% plasma wt Keep water in ECF, act as buffers, for blood clotting, for excitability of cells 3 Proteins 7% of plasma wt.= 7.3 g/100 ml Albumin, globulin, fibrinogen Provide non penetrating solute of plasma, Act as buffers, transport protein,clotting factors, enzymes, antibodies Blood Plasma Constituents Constituent Functions 4 Gases CO2, O2 CO2 is waste product, O2, for oxidative metabolism, 5 Nutrients Glucose, amino acids, lipids and cholesterol, vitamins, trace elements Nutrition Blood Plasma Constituents Constituent Functions 6 Waste products: urea, creatinine, uric acid, bilirubin 7 Individual hormnes Metabolic, Control system Blood Formed Elements of Blood Red blood cells ( erythrocytes ) White blood cells ( leukocytes ) Granular leukocytes neutrophils, eosinophils, basophils Agranular leukocytes lymphocytes = T cells, B cells, and natural killer cells monocytes Platelets (special cell fragments) Erythrocytes (RBC) Blood Erythrocytes Functions of RBC To transport Haemoglobin Hb carries O2 Hb carries O2 form lungs to tissue In lower animals Hb circulates as free protein in plasma In human being when it is free 3% leaks from capillaries Into tissue spaces; glomerular filtrate Erythrocytes Blood Hence for Hb to remain in blood stream It must exist inside the RBC Other functions of RBC include; Buffer function Contain carbonic Anhydrase which catalyze H2o + Co2 H2co3 Hco3- + H+ -Thus transport CO2 from tissues to lungs in the form of HCO3- Hb is an excellent acid/base buffer -Thus RBC are responsible for most buffering capacity of the blood Erythrocytes Blood Shape and size of RBC Biconcave discs Diameter = 7.8 µm Thickness at the thickest point = 2.5 µm average volume = 90 – 95 µ3 The shape of the RBC can change remarkably It is a bag which can be deformed To any shape; This allows it to pass through capillaries without problem Normal RBC Has great excess cell membrane for quantity inside Hence deformation does not stretch the membrane to cause it to rapture Concentration of RBC in Blood Blood In normal men average number of RBC Is 5,200,000 (+/- 300,000) per cubic ml In women average number of RBC Is 4,700,000 (+/- 300,000) Quantity of Hb in RBC When Hb formation is deficient in bone marrow % Of Hb in RBC may fall and volume of RBC may decrease Concentration of RBC in Blood Blood When Haematocrit = 40 – 45% Quantity of Hb in each cell is normal Whole blood of men contain 16 gm Hb/dl Whole blood of women contain 14 gm Hb/dl Each gram of pure Hb Combine with 1.39 ml of O2 Hence in normal man total amount carried Is = 1.39 * 16 = 21 ml of O2 per dl of blood In normal woman Is = 1.39 * 14 = 19 ml of O2 per dl of blood RBC have the ability to conc HB up to 34 g/dl Erythropoeisis Blood Sites of RBC production include York sack During early weeks of embryonic life Liver, spleen, lymph nodes Middle trimester Bone marrow Last trimester, after birth Bone marrow of all bones Up to

OPTOMETRY · SEMESTER 1 Blood Physiology Human Anatomy and Physiology START READING NOTES Contents of This Topic INTROD CONT … INTRODUCTION INTRODUCTION cont … COMPONENTS OF BLOOD COMPONENTS OF BLOOD CONT … BLOOD PLASMA Plasma proteins Plasma proteins CONT … Albumins Globulins BLOOD CELLS FUNCTIONS OF BLOOD CLASSIFICATION OF BLOOD CELLS RED BLOOD CELLS RED BLOOD CELLS CONT.. erythroPOIESIS SITES FOR ERYTHROPOIESIS erythroPOIESIS CONT… MATURATION OF ERYTHROCYTE Differentiation of Formed Elements from Stem Cells HAEMATOPIOESIS Hemopoietic Growth Factors Haemoglobin Control of erythropoiesis Control of erythropoiesis CONT … function of erythrocytes function of erythrocytes CONT … Destruction of erythrocytes Destruction of erythrocytes CONT .. Blood groups Blood groups CONT … The ABO system Leukocytes (white blood cells) Granulocytes (polymorphonuclear leukocytes) Neutrophils Neutrophils CONT … Eosinophils Eosinophils CONT … Basophils Agranulocytes Monocytes The monocyte–macrophage system The monocyte–macrophage system CONT .. Lymphocytes Examples of antigens include: Platelets (thrombocytes) Platelets (thrombocytes) CONT … Haemostasis 1 Vasoconstriction 2 Platelet plug formation 3 Coagulation (blood clotting) CLOTTING FACTORS CLOTTING FACTORS CONT … CLOTTING PATHWAYS BLOOD PHYSIOLOGY PART I INTROD CONT … BLOOD: Is a liquid connective tissue or viscous fluid that: Circulates in a virtually “CLOSED” system of blood vessels Blood, a connective tissue, that is composed of plasma and formed elements. INTRODUCTION Blood is a specialized body fluid that circulates through the cardiovascular system of humans and other vertebrates. It serves multiple critical functions, including the delivery of necessary substances such as oxygen and nutrients to cells, as well as the removal of metabolic waste products. INTRODUCTION cont … It circulates continually around the body, allowing constant communication between tissues distant from each other. Blood makes up about 7% of body weight (about 5.6 litres in a 70 kg man). This proportion is less in women and considerably greater in children, gradually decreasing until the adult level is reached. Blood in the blood vessels is always in motion because of the pumping action of the heart. INTRODUCTION cont … The continual flow maintains a fairly constant environment for body cells. Blood volume and the concentration of its many constituents are kept within narrow limits by homeostatic mechanisms. COMPONENTS OF BLOOD Composition of blood is divided into two aspects, the formed elements part and fluid part, namely; Blood Plasma (Fluid part) – occupies 55% of blood Blood Cells (Formed Element part) – occupies 45% of blood COMPONENTS OF BLOOD CONT … Blood is composed of a clear, straw-coloured, watery fluid called plasma in which several different types of blood cell are suspended. Plasma normally constitutes 55% of the volume of blood. The remaining 45% is accounted for by the cellular fraction of blood. The two fractions of blood, blood cells and plasma, can be separated by centrifugation (spinning) or by gravity when blood is allowed to stand. Because the cells are heavier than plasma, they sink to the bottom of any sample. BLOOD PLASMA Blood plasma is the liquid component of blood that constitutes approximately 55% of its total volume. It is a light amber-colored fluid that serves several critical functions in the body. Plasma is primarily composed of water (about 92%), with the remaining content consisting of plasma proteins, electrolytes, hormones, nutrients, and waste products. Plasma proteins Plasma proteins, which make up about 7% of plasma, are normally retained within the blood, because they are too big to escape through the capillary pores into the tissues. They are largely responsible for creating the osmotic pressure of blood, which keeps plasma fluid within the circulation. If plasma protein levels fall, because of either reduced production or loss from the blood vessels, osmotic pressure is also reduced, and fluid moves into the tissues (oedema) and body cavities. Plasma proteins CONT … Plasma Proteins include albumin, immunoglobulins, fibrinogen Plasma viscosity (thickness) is due to plasma proteins, mainly albumin and fibrinogen. Plasma proteins, with the exception of immunoglobulins, are formed in the liver. Albumins These are the most abundant plasma proteins (about 60% of total) and their main function is to maintain normal plasma osmotic pressure. Albumins also act as carrier molecules for free fatty acids, some drugs and steroid hormones. Globulins Their main functions are: as antibodies (immunoglobulins), which are complex proteins produced by lymphocytes that play an important part in immunity. They bind to, and neutralise, foreign materials (antigens) such as microorganisms. Transportation of some hormones and mineral salts, e.g. thyroglobulin carries the hormone thyroxineand transferrin carries the mineral iron inhibition of some proteolytic enzymes, e.g. α2 macroglobulin inhibits trypsin activity. BLOOD CELLS Blood cells are specialized cells produced through a process known as hematopoiesis, primarily found in the blood. They play crucial roles in various physiological functions, including oxygen transport, immune defense, and blood clotting. There are three main types of blood cells: Red blood cells (erythrocytes) White blood cells (leukocytes) Platelets (thrombocytes). SUMMARY OF BLOOD CONSTITUENTS FUNCTIONS OF BLOOD The major functions of blod includes; Oxygen Transport Nutrient Distribution Waste Removal Hormone Transport Temperature Regulation pH Balance Fluid Balance Immune Response Clotting Mechanism CLASSIFICATION OF BLOOD CELLS Blood cells can be classified into three main types: red blood cells, white blood cells, and platelets. Each type has distinct functions and characteristics. RED BLOOD CELLS Red blood cells are the most abundant type of blood cell, accounting for approximately 40 to 45 percent of the blood’s volume. Their primary function is to transport oxygen from the lungs to the body’s tissues and return carbon dioxide from the tissues back to the lungs for exhalation. Red blood cells contain hemoglobin, a protein that binds oxygen and gives blood its red color. They are characterized by their biconcave disk shape, which allows for flexibility as they navigate through various sizes of blood vessels. RED BLOOD CELLS CONT.. Red blood cells are biconcave discs; they have no nucleus, and their diameter is about 7 micrometres. Their main function is in gas transport, mainly of oxygen, but they also carry some carbon dioxide. Their characteristic shape is suited to their purpose; the biconcavity increases their surface area for gas

OPTOMETRY · SEMESTER 1 Brain, Cranial Nerve And Supply Human Anatomy and Physiology START READING NOTES Contents of This Topic General structure of NS (1) General structure of NS Brain, Cranial Nerve And Supply General structure of NS (4) General structure of NS (5) Neuroglia in the CNS include astrocytes, microglial cells, ependymal cells and oligodendrocytes. Ependymal cells are another glial subtype that line the ventricles of the CNS to help circulate the CSF. The Brain: The largest part of the human brain is the cerebrum, which consists of two hemispheres separated by the longitudinal fissure. The cerebral cortex is divided into lobes that have the same names as the cranial bones external to them The Precentral (Motor) Area The Brain: Cerebrum (Specialized areas) cont.. The Parietal Area Auditory Area Visual Area The Brain: Thalamus Also called Basal ganglia The Brain: Hypothalamus The Brain: Cerebellum The Brain: Brainstem Pons Other special features in medulla oblongata Ventricular System of the Brain Communicate through holes or foramen as summarized below Fourth ventricle Cerebro-Spinal Fluid (1) Cerebrospinal fluid is formed by choroidal epithelial cells of the choroid plexuses in the lateral, 3rd, and 4th ventricles Flow of CSF (1) CSF also passes into the extensions of the subarachnoid space around the cranial nerves. Cranial nerves Olfactory nerve (I) Optic nerve (II) Optic nerve (II) cont.. Oculomotor nerve (III) Trochlear nerve (IV) Trigeminal nerve (V) Abducens nerve (VI) Facial nerve (VII) Vestibulocochlear nerve (VIII) Glossopharyngeal nerve (IX) Vagus nerve (X) Accessory nerve (XI) Hypoglossal nerve (XII) Blood supply of the head and neck Common Carotid Artery Carotid Sinus Relations External Carotid Artery Branches Superior Thyroid Artery Ascending Pharyngeal Artery Lingual Artery Facial Artery Occipital Artery Posterior Auricular Artery Superficial Temporal Artery Maxillary Artery Branches of Maxillary Artery Internal Carotid artery Arterial blood supply to the brain Anterior choroidal artery Vertebral arteries Meningeal branch –supplying falx cerebelli,a sheet of dura matter The two arteries converge to form the basilar artery Arterial circle of willis Circle of willis Three main branches of circle of Willis To complete the circle two connecting vessels are also present External Jugular Vein Anterior Jugular Vein Internal Jugular Vein Tributaries of Internal Jugular Vein Lymphatic drainage of the head and neck INTRODUCTION INTRODUCTION CONTD… SUPERFICIAL LYMPH NODES SUPERFICIAL CERVICAL NODES ANTERIOR CERVICAL NODES DEEP LYMPH NODES NODES OF MIDLINE DEEP CERVICAL LYMPH NODES DEEP CERVICAL LYMPH NODES CONTD… UPPER DEEP CERVICAL LYMPH NODES LOWER DEEP CERVICAL LYMPH NODES LOWER DEEP CERVICAL LYMPH NODES CONTD… LYMPH NODES OF HEAD &NECK LYMPH NODES OF HEAD &NECK CONTD… PRELARYNGEAL NODES SUBMENTAL NODES SUBMANDIBULAR NODES SUBMANDIBULAR NODES CONTD… SUBMANDIBULAR NODES CO NTD… BUCCAL NODES PAROTID (PREAURICULAR) NODES MASTOID (POSTAURICULAR) NODES MASTOID (POSTAURICULAR) NODES CONTD… OCCIPITAL NODES HEAD AND NECK General structure of NS (1) The nervous system has two divisions. The central nervous system (CNS) consists of the brain and spinal cord. The peripheral nervous system (PNS) consists of cranial nerves and spinal nerves. The PNS includes the autonomic nervous system (ANS). The brain is contained within the cranial cavity of the skull, and the spinal cord is contained within the vertebral cavity of the vertebral column. General structure of NS Nervous tissue, present in both the CNS and PNS, contains two basic types of cells: neurons and glial cells. Neurons are cells and therefore have a cell body, axon and the dendrite. Looking at nervous tissue, there are regions that predominantly contain cell bodies and regions that are largely composed of just axons. These two regions within nervous system structures are often referred to as gray matter (the regions with many cell bodies and dendrites) or white matter (the regions with many axons). Brain, Cranial Nerve And Supply A localized collection of neuron cell bodies in the CNS is referred to as a nucleus. In the PNS, a cluster of neuron cell bodies is referred to as a ganglion. A bundle of axons, or fibers, found in the CNS is called a tract whereas the same thing in the PNS would be called a nerve. In the peripheral nervous system, axons and dendrites are “wrapped” in specialized cells called Schwann cells General structure of NS (3) General structure of NS (4) Neurons may be classified into three groups: sensory neurons, motor neurons, and interneurons. Sensory neurons (or afferent neurons) carry impulses from receptors to the central nervous system. Interneurons are found entirely within the central nervous system. They are arranged so as to carry only sensory or motor impulses, or to integrate these functions. Motor neurons (or efferent neurons) carry impulses from the central nervous system to effectors General structure of NS (5) Glial cells oA supportive cell in the central nervous system. oUnlike neurons, glial cells do not conduct electrical impulses. oThe glial cells surround neurons and provide support for and insulation between them. oGlial cells are the most abundant cell types in the central nervous system. Types of glial cells include oligodendrocytes, astrocytes, ependymal cells, Schwann cells, microglia, and satellite cells. Neuroglia in the CNS include astrocytes, microglial cells, ependymal cells and oligodendrocytes. Neuroglia in the PNS include Schwann cells and satellite cells. Astrocytes support and brace the neurons and anchor them to their nutrient supply lines. They also play an important role in making exchanges between capillaries and neurons. Microglial cells can transform into a special type of macrophage that can clear up the neuronal debris, while monitoring the health of the neuron. General structure of NS (6) Ependymal cells are another glial subtype that line the ventricles of the CNS to help circulate the CSF. Oligodendrocytes are cells that wrap their process tightly around the fibers producing an insulating covering called myelin sheath. Schwann cells are similar in function to oligodendrocytes and microglial cells. Satellite cells perform a similar function to astrocytes General structure of NS (7) The Brain: The brain constitutes about 2% of the body weight and lies within the cranial cavity, the parts are: Cerebrum Cerebellum Brain stem Midbrain Pons Medulla oblongata The largest part of

OPTOMETRY · SEMESTER 1 Haemostasis Human Anatomy and Physiology START READING NOTES Contents of This Topic Response to Blood Vessel Injury Haemostasis: In general, blood clotting occurs in three stages: 1. FORMATION OF PROTHROMBIN ACTIVATOR Intrinsic pathway 2. CONVERSION OF PROTHROMBIN ANTICLOTTING MECHANISM IN THE BODY Chemical Factors – Natural Anticoagulants Response to Blood Vessel Injury Haemostasis: Haemostasis: The process of forming clots in the walls of damaged blood vessels and preventing blood loss while maintaining blood in a fluid state within the vascular system. or.defined as the process in which blood loses its fluidity and becomes a jelly-like mass. A collection of complex interrelated systemic mechanisms operates to maintain this balance between coagulation and anticoagulation. When a small blood vessel is damaged, the injury initiates a series of events that lead to the formation of a clot (haemostasis). This seals off the damaged region and prevents further blood loss In general, blood clotting occurs in three stages: 1. Formation of prothrombin activator 2. Conversion of prothrombin into thrombin 3. Conversion of fibrinogen into fibrin. 1. FORMATION OF PROTHROMBIN ACTIVATOR Blood clotting commences with the formation of a substance called prothrombin activator, which converts prothrombin into thrombin. Its formation is initiated by substances produced either within the blood or outside the blood. Thus, formation of prothrombin activator occurs through two pathways: i. Intrinsic pathway ii. Extrinsic pathway. Intrinsic pathway In this pathway, the formation of prothrombin activator is initiated by platelets, which are within the blood itself Extrinsic pathway. In this pathway, the formation of prothrombin activator is initiated by the tissue thromboplastin, which is formedfrom the injured tissues. 2. CONVERSION OF PROTHROMBIN INTO THROMBIN Prothrombin activator that is formed in intrinsic and extrinsic pathways converts prothrombin into thrombin 3. CONVERSION OF FIBRINOGEN INTO FIBRIN The final stage of blood clotting involves the conversion of fibrinogen into fibrin by thrombin. ANTICLOTTING MECHANISM IN THE BODY Under physiological conditions, intravascular clotting does not occur. It is because of the presence of some physicochemical factors in the body Physical Factors i. Continuous circulation of blood. ii. Smooth endothelial lining of the blood vessels Chemical Factors – Natural Anticoagulants i. Presence of natural anticoagulant called heparin that is produced by the liver iii. All the clotting factors are in inactive state. ← PREVIOUS TOPICNEXT TOPIC →VIEW MODULE NOTESVIEW SEMESTER NOTESALL OPTOMETRY NOTES Need These Notes as PDF? Request a formatted copy for offline study, printing or revision. GET PDF NOTES ON WHATSAPP

OPTOMETRY · SEMESTER 1 Muscles Of The Head And Neck Human Anatomy and Physiology START READING NOTES Contents of This Topic MUSCLES OF THE HEAD MUSCLE OF SCALP THE SCALP: OCCIPITOFRONTALIS MUSCLES OF FACIAL EXPRESSION ORBITAL GROUP ORBICULARIS OCULI CORRUGATOR SUPERCILII NASAL GROUP NASALIS ALAR PART OF THE NASALIS PROCERUS DEPRESSOR SEPTI NASI ORAL GROUP THE ORBICULARIS ORIS BUCCINATOR DEPRESSOR ANGULI ORIS DEPRESSOR LABII INFERIORIS MENTALIS RISORIUS ZYGOMATICUS MAJOR AND ZYGOMATICUS MINOR LEVATOR LABII SUPERIORIS LEVATOR LABII SUPERIORIS ALAEQUE NASI LEVATOR ANGULI ORIS MASSETER TEMPORALIS LATERAL PTERYGOID (TWO MEDIAL PTERYGOID (TWO INTRODUCTION ANTERIOR TRIANGLE. MUSCLES OF THE ANTERIOR TRIANGLE OF THE NECK SUPRAHYOID MUSCLES INFRAHYOID MUSCLES ANTEROLATERAL NECK MUSCLE MUSCLES OF THE HEAD AND NECK MUSCLES OF THE HEAD MUSCLES OF THE HEAD Grouped into: Muscle of Scalp Muscles of Facial Expression Muscles of Mastication MUSCLE OF SCALP THE SCALP: The scalp consists of five layers. the first three of which are intimately bound together and move as a unit. To assist one in memorizing the names of the five layers of the scalp, use each letter of the word SCALP to denote the layer of the scalp. Skin: which is thick and hair bearing and contains numerous sebaceous glands Connective tissue Beneath the skin. The fibrous septa uniting the skin to the underlying aponeurosis of the occipitofrontalis muscle. Numerous arteries and veins are found in this layer. Aponeurosis (epicranial), which is a thin, tendinous sheet that unites the occipital and frontal bellies of the occipitofrontalis muscle. THE SCALP: Loose areolar tissue: Occupies the subaponeurotic space. Loosely connects the epicranial aponeurosis to the periosteum of the skull (the pericranium). The areolar tissue contains a few small arteries, but it also contains some important emissary veins OCCIPITOFRONTALIS Consist of two bells: Occipital belly Frontal belly OCCIPITAL BELLY ORIGIN: Highest nuchal line of occipital bone INSERTION: Epicranial aponeurosis NERVE SUPPLY: Facial nerve FUNCTION: Moves scalp on skull and raises eyebrows FRONTAL BELLY ORIGIN: Skin and superficial fascia of eyebrows INSERTION: Epicranial aponeurosis NERVE SUPPLY: Facial nerve FUNCTION: Moves scalp on skull and raises eyebrows MUSCLES OF FACIAL EXPRESSION MUSCLES OF FACIAL EXPRESSION These are muscles of the face. Because these muscles control expressions of the face, they are sometimes referred to as muscles of "FACIAL EXPRESSION." They also act as sphincters and dilators of the orifices of the face (i.e., the orbits, nose, and mouth). ORBITAL GROUP orbicularis oculi and the corrugator supercilii. ORBICULARIS OCULI The orbicularis oculi is a muscle in the face that closes the eyelids. It consist of: Palpebral part. Orbital part. PALPEBRAL PART ORIGIN: Medial palpebral ligament INSERTION: Lateral palpebral raphe NERVE SUPPLY: Facial nerve FUNCTION: Closes eyelids and dilates lacrimal sac ORBICULARIS OCULI ORBITAL PART. thicker and of a reddish color ORIGIN: Medial palpebral ligament and adjoining bone INSERTION: Loops return to origin NERVE SUPPLY: Facial nerve FUNCTION: Throws skin around orbit into folds to protect eyeball CORRUGATOR SUPERCILII The second muscle in the orbital group. Much smaller. Found deep to the eyebrows and the orbicularis oculi muscle and is active when frowning. ORIGIN: Superciliary arch INSERTION: Skin of eyebrow NERVE SUPPLY: Facial nerve FUNCTION: It draws the eyebrows toward the midline, causing vertical wrinkles above the nose. NASAL GROUP NASALIS, THE PROCERUS, AND DEPRESSOR SEPTI NASI NASALIS The largest and best developed of the muscles of the nasal group Active when the nares are flared It consists of: transverse part (the compressor naris) alar part (the dilator naris) TRANSVERSE PART OF THE NASALIS: ORIGIN: Frontal process of maxilla INSERTION: Aponeurosis of bridge of nose NERVE SUPPLY: Facial nerve FUNCTION: Compresses mobile nasal cartilages ALAR PART OF THE NASALIS ORIGIN: Maxilla INSERTION: Ala of nose NERVE SUPPLY: Facial nerve FUNCTION: Widens nasal aperture PROCERUS Small muscle superficial to the nasal bone Active when an individual frowns ORIGIN: Nasal bone INSERTION: Skin between eyebrows NERVE SUPPLY: Facial nerve FUNCTION: Wrinkles skin of nose WRINKLE ON SKIN OF NOSE DEPRESSOR SEPTI NASI ORIGIN: Maxilla INSERTION: Lower part of the nasal septum NERVE SUPPLY: Facial nerve FUNCTION: Pulls the nose inferiorly. Assisting the alar part of the nasalis in opening the nares. ORAL GROUP Orbicularis oris. Buccinators. Lower group of muscles (depressor anguli oris, depressor labii inferioris and mentalis) Upper group of muscles (risorius, zygomaticus major, zygomaticus minor, levator labii superioris, levator labii superioris alaeque nasi, and levator anguli oris) THE ORBICULARIS ORIS Complex muscle consisting of fibers that completely encircle the mouth, Originate near the midline from the maxilla superiorly and the mandible inferiorly. It inserts into the skin and mucous membrane of the lips. Function is apparent when pursing the lips, as occurs during whistling. Contraction of the orbicularis oris narrows the mouth and closes the lips. BUCCINATOR The buccinator forms the muscular component of the cheek. It is in the space between the mandible and the maxilla. The buccinator arises from the posterior part of the maxilla and mandible opposite the molar teeth and the pterygomandibular raphe. Contraction of the buccinator presses the cheek against the teeth. This keeps the cheek taut and aids in mastication by preventing food from accumulating between the teeth and the cheek. Assists in the forceful expulsion of air from the cheeks. LOWER GROUP OF ORAL MUSCLES DEPRESSOR ANGULI ORIS Is active during frowning. It arises along the side of the mandible below the canine, premolar, and first molar teeth. Inserts into skin and the upper part of the orbicularis oris near the corner of the mouth. FUNCTION: It depresses the corner of the mouth. DEPRESSOR LABII INFERIORIS Depressor labii inferioris arises from the front of the mandible, deep to depressor anguli oris. Inserting into the lower lip. It depresses the lower lip and moves it laterally. MENTALIS It is the deepest muscle of the lower group, Arising from the mandible just inferior to the incisor teeth. Insert into the skin of the chin. FUNCTION It raises and protrudes the lower lip as it wrinkles the skin of the chin. Helps position the lip when drinking from a cup or when

OPTOMETRY · SEMESTER 1 Vertebral Column: Structure and Function Human Anatomy and Physiology START READING NOTES Contents of This Topic Structural organization and functions of vertebral column Objectives Vertebral column Figure1: Parts of A Typical Vertebra The Vertebral Column(1) The Vertebral Column(2) The Vertebral Column(3) Curvatures of Vertebral Column(1) Curvatures of Vertebral Column(2) Curvatures of Vertebral Column(3) Curvatures of Vertebral Column(4) Curvatures of Vertebral Column(5) Structure of intervertebral Disc(1) Structure of intervertebral Disc(2) Structure of intervertebral Disc(3) Function of the intervertebral Disc(1) Function of the intervertebral Disc(2) Structure of Vertebrae(1) Structure of Vertebrae(2) Structure of Vertebrae(3) Structure of Vertebrae(4) Structure of Vertebrae(5) Structure of Vertebrae(6) Seven Processes Arise From the Vertebral Arch of a Typical Vertebra(1) Seven Processes Arise From the Vertebral Arch of a Typical Vertebra(2) Functions of the Vertebral Column Characteristics of typical cervical vertebrae(1) Characteristics of typical cervical vertebrae(2) Characteristics of typical cervical vertebrae(3) Characteristics of the atypical cervical Vertebrae (1) Characteristics of the atypical cervical Vertebrae (2) Characteristics of the atypical cervical Vertebrae (3) Characteristics of Thoracic Vertebrae(1) Characteristics of Thoracic Vertebrae(2) Characteristics of lumbar Vertebrae Sacrum and Cocygeal Vertebrae Key Points Evaluation Structural organization and functions of vertebral column 1 Objectives Explain vertebral column curvatures Describe structure and function of vertebrae 2 Vertebral column 3 Vertebral column 4 Figure1: Parts of A Typical Vertebra 5 The Vertebral Column(1) The vertebral column is the central bony pillar of the body The adult vertebral column typically consists of 33 vertebrae arranged in five regions: 7 cervical, 12 thoracic, 5 lumbar, 5 sacral, and 4 coccygeal. The typical vertebrae consists of Body, transverse process, the foramen transversarium, the vertebral foramen and spinous process 6 The Vertebral Column(2) The vertebral column (spine), extending from the cranium (skull) to the apex of the coccyx. 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. Significant motion occurs between only the superior 25 vertebrae 7 The Vertebral Column(3) The 5 sacral vertebrae are fused in adults to form the sacrum, and the 4 coccygeal vertebrae are fused to form the coccyx 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 8 Curvatures of Vertebral Column(1) 9 10 Curvatures of Vertebral Column(2) 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. The thoracic and sacral (pelvic) curvatures (kyphoses) are concave anteriorly, whereas the cervical and lumbar curvatures (lordoses) are concave posteriorly. 11 Curvatures of Vertebral Column(3) The thoracic and sacral curvatures are primary curvatures, developing during the fetal period. 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. 12 Curvatures of Vertebral Column(4) 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 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. 13 Curvatures of Vertebral Column(5) 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 14 Structure of intervertebral Disc(1) The intervertebral discs are the main structures that bind together the vertebral bodies, and they extend from C2 to the sacrum (C1 has no vertebral body) The discs are responsible for one quarter of the length of the vertebral column below the level of C2 They are thickest in the cervical and lumbar regions, where the movements of the vertebral column are greatest They may be regarded as semielastic discs, which lie between the rigid bodies of adjacent vertebrae Their physical characteristics permit them to serve as shock absorbers when the load on the vertebral column is suddenly increased, as when one is jumping from a height. 15 Structure of intervertebral Disc(2) Their elasticity allows the rigid vertebrae to move one on the other Unfortunately, their resilience is gradually lost with advancing age Each disc consists of a peripheral part, the anulus fibrosus, and a central part, the nucleus pulposus The anulus fibrosus is composed of fibrocartilage, in which the collagen fibers are arranged in concentric layers or sheets The nucleus pulposus in children and adolescents is an ovoid mass of gelatinous material containing a large amount of water, a small number of collagen fibers, and a few cartilage cells. It is normally under pressure and situated slightly nearer to the posterior than to the anterior margin of the disc 16 Structure of intervertebral Disc(3) No discs are found between the first two cervical vertebrae or in the sacrum or coccyx 17 Function of the intervertebral Disc(1) The semifluid nature of the nucleus pulposus allows it to change shape and permits one vertebra to rock anteriorly or posteriorly on another, as in flexion and extension of the vertebral column A sudden increase in the compression load on the vertebral column causes the semifluid nucleus pulposus to become flattened. The outward thrust of the nucleus is accommodated by the resilience of the surrounding annulus fibrosus Sometimes, the outward thrust is too great for the anulus fibrosus and it ruptures, allowing the

OPTOMETRY · SEMESTER 1 Blood and Blood forming organs introduction Human Anatomy and Physiology START READING NOTES Contents of This Topic Mention constituent of blood Blood is the body’s only fluid tissue, It is composed of liquid plasma and formed elements The blood components. The liquid component of blood is called plasma, a mixture of water, sugar, fat, protein, and salts. Constituents of plasma: Clotting factors If whole blood is allowed to clot and the clot is removed, the remaining fluid is called serum Plasma Proteins – constitute 7-9% of the plasma Plasma Proteins Most of Gamma globulins are immunoglobulins; Functions of Plasma Clotting factor (fibrinogen) plays a key role in the clotting of blood Blood Cells. Blood cells.. Formed elements Production of Red Blood Cells Erythrocytes (RBCs) RBCs Is the process of red blood cell formation Red Blood Cells (3) FACTORS NECESSARY FORERYTHROPOIESIS GENERAL FACTORS MATURATION FACTORS FACTORS NECESSARY FOR HEMOGLOBIN FORMATION Haemoglobin (1) ANAEMIA They are also known as leukocytes or leucocytes White Blood Cells (1) White Blood Cells (2) Classification of Leucocytes Classification of Leucocytes (2) Neutrophils (2) Eosinophils Basophils Macrophages (1) Macrophages (2) Lymphocyte B-lymphocytes (B cells) Platelets (thrombocyte) Production of Platelets Platelets (Thrombocytes) (3) Functions of blood… Functions of blood. Functions of blood.. References. Mention constituent of blood Classify blood cells Outline sites for the synthesis of blood cells Describe requirements for production of blood cells Describe functions of blood cells Describe metabolism of haemoglobin Describe blood typing and transfusion Describe mechanism of blood coagulation(haemostasis) Blood and blood forming organs Blood is the body’s only fluid tissue, It is composed of liquid plasma and formed elements Formed elements include: Erythrocytes(RBCs), Leukocytes(WBCs), Platelets Blood and blood forming organs The blood components. Blood and blood forming organs The liquid component of blood is called plasma, a mixture of water, sugar, fat, protein, and salts. It makes up about 55% of total blood volume Blood and blood forming organs Constituents of plasma: It is mostly water – 92% by volume Dissolved proteins (plasma proteins) Albumin (60%) Globulin (36%) Fibrinogen (4%) Nutrients (glucose, amino acids, fats, salts, minerals, etc.) Blood and blood forming organs Clotting factors Electrolytes (Na+, Ca2+, Mg2+, HCO3-, Cl- etc.) Hormones Antibodies Waste products of metabolism (CO2, lactic acid, urea, uric acid, creatinine, etc.) If whole blood is allowed to clot and the clot is removed, the remaining fluid is called serum Blood and blood forming organs serum clot Plasma Proteins – constitute 7-9% of the plasma Albumins (60% – 80%) Produced by the liver, Provide the osmotic pressure which is necessary to maintain blood volume and pressure. Blood and blood forming organs Plasma Proteins Globulins, divided into three types: Alpha and beta globulin, produced by the liver and function to transport lipids and fat soluble vitamins in the blood. Gamma globulins are antibodies produced by lymphocytes and function in immunity. Blood and blood forming organs Most of Gamma globulins are immunoglobulins; IgA IgD IgE IgG- 3/4 of all immunoglobulins IgM Blood and blood forming organs Functions of Plasma Serves as the protein reserve of the human body Albumin maintains the colloid osmotic pressure, which regulates the movement of water between blood and tissue Albumin transports bilirubin, fatty acids and some drugs Protects the body from infection and other blood disorders Clotting factor (fibrinogen) plays a key role in the clotting of blood Transports nutrients and gases Transports metabolic waste products Blood and blood forming organs Blood Cells. Red blood cells (RBC) a.k.a erythrocytes) White blood cells (WBC), leucocytes Platelets (thrombocytes). Blood and blood forming organs Blood cells.. Formed elements Erythrocytes, leukocytes, and platelets make up the formed elements Only WBCs are complete cells, RBCs have no nuclei or organelles, and platelets are just cell fragments Most formed elements survive in the bloodstream for only a few days, Most blood cells do not divide but are renewed by cells in bone marrow Blood and blood forming organs Production of Red Blood Cells Areas of the Body That Produce Red Blood Cells. In the early weeks of embryonic life, primitive, nucleated RBC are produced in the yolk sac. During the middle trimester of gestation, the liver is the main organ for production of RBC but reasonable numbers are also produced in the spleen and lymph nodes. Blood and blood forming organs Production of Red Blood Cells Then, during the last month or so of gestation and after birth, red blood cells are produced exclusively in the bone marrow. Blood and blood forming organs Erythrocytes (RBCs) Biconcave discs, anucleate, essentially no organelles Filled with hemoglobin (Hb), a protein that functions in gas transport. Contain the plasma membrane protein spectrin and other proteins that: Give erythrocytes their flexibility Allow them to change shape as necessary Blood and blood forming organs RBCs Biconcave disk shape of the RBC Blood and blood forming organs Is the process of red blood cell formation Blood and blood forming organs Red Blood Cells (3) Synthesis of RBC needs iron, folic acid, vitamin B12, manganese, iodine, erythropoietin and protein Erythropoietin hormone (EPO) secreted by kidneys, is a glycoprotein that serves as the primary regulator of red blood cells Blood and blood forming organs FACTORS NECESSARY FORERYTHROPOIESIS Development and maturation of erythrocytes require variety of factors, which are classified into three categories: 1. General factors 2. Maturation factors 3. Factors necessary for hemoglobin formation. Blood and blood forming organs GENERAL FACTORS General factors necessary for erythropoiesis are: i. Erythropoietin hormone ii. Thyroxine iii. Hemopoietic growth factors iv. Vitamins. Blood and blood forming organs MATURATION FACTORS Vitamin B12, intrinsic factor and folic acid are necessary for the maturation of RBCs. Blood and blood forming organs FACTORS NECESSARY FOR HEMOGLOBIN FORMATION First class proteins and amino acids Iron Copper Cobalt and nickel Vitamins Blood and blood forming organs Haemoglobin (1) Haemoglobin (Hb or Hgb) is the iron-containing oxygen-transport substance in the red blood cells The adult haemoglobin (HbA) molecule is made up of four chains 2 alpha chains and 2 beta chains (α2 β2) The fetal haemoglobin

OPTOMETRY · SEMESTER 1 Skull: Structure and Function Human Anatomy and Physiology START READING NOTES Contents of This Topic bony function of the the of The Eight bones (i) FRONTAL : The (ii) OCCIPITAL : The (iii) SPHENOID : The (iv) ETMOID : The (v) PARIETAL : The (vi) TEMPORAL : There are 14 bones in the (i) ZYGOMATIC : The (ii) LACRIMAL : (iii) NASAL : The (iv) INFERIOR (v) PALATINE: The (vi) VOMER: The (vii) MAXILLA: The (viii) MANDIBLE: External Surface of Cranial Base The alveolar arch of the maxillae (supporting the maxillary teeth), Skull: Structure and Function CT Internal Surface of Cranial Base The Anterior Cranial Fossa The Middle Cranial Fossa The Posterior Cranial Fossa Boundaries Function of the Skull 5. Facilitate breathing by bone of nasal cavities SKULL-STRUCTURES AND FUNCTIONS bony that its hape.  Skull is the framework, gives the head, characteristic s function of the protect and the tissues of rly the The skull is to the soft vital the head, particula brain. the The Skull consists of Cranium bony box housing the brain) and face. of in cranium the The skull is composed 22 bones, the and 14 in face. 8 The Eight bones (1) Frontal (2) Occipital (3) Sphenoid (4) Ethmoid of the Cranium are :- (5) Two Parietal bones (6) Two Temporal bones (i) FRONTAL : The frontal bone forms the forehead , the anterior (front) part of the cranial vault and the roof of the orbits (eye sockets). Inside the bone, just behind the eyebrows are the frontal sinuses. two air spaces called (ii) OCCIPITAL : The occipital bone forms the posterior (back) part of the floor and vault of the cranium. It is the bone which supports the head upon the spinal column. The spinal cord leaves the cranium through an opening in the occipital bone called the foramen magnum (iii) SPHENOID : The sphenoid bone is the central part of the base of the cranium. It forms part of the orbits, transmits the optic nerve and supports the posterior part of the maxilla. The sphenoid air sinuses lie in this bone. The pituitary gland lies in a bony socket called the sella turcica, located on the superior aspect of the sphenoid bone. Dental Tip: When a patient is seated in the dental chair, the headrest should support the occipital bone and thereby support the entire head. (iv) ETMOID : The Ethmoid bone lies between the eyes and extends from the frontal bone to the sphenoid bone. It forms the anterior part of the skull, the medial wall of each orbit, part of the nasal septum and the roof of the nose. It transmits the olfactory smell) nerve (nerve of (v) PARIETAL : The Parietal bones forms large part of the a cranial extend frontal vault and from the bone to the occipital bone. The two bones join at the midline on the top of the cranium and form the saggital suture. From this suture, these bones extend down and out to about the level of the top of the external ear where they meet the temporal bones. (vi) TEMPORAL : Temporal bones complete the sides and part of the base of the cranium. These bones contain organs of hearing and equilibrium. The external acoustic meatus in the side of each bone forms a passage from the external ear to the middle ear which lies within each bone. There are 14 bones in the (i) Mandible (1) (ii) Maxillae (2) (iii) Zygomatic Bones (2) (iv) Lacrimal Bones (2) (v) Nasal Bones (2) (vi) Inferior conchae (2) (vii) Palatine Bones (2) (viii) Vomer (1) face. (i) ZYGOMATIC : The right and left zygomatic bones form the lower and outer edges of each orbit and that part of each zygomatic arch nearest the eye. The Zygomatic bone and Zygomatic process of the temporal bone form the Zygomatic arch. The anterior edge of the zygomatic bone joins the maxilla. That part of the maxilla which joins the zygomatic bone is called the zygomatic process. (ii) LACRIMAL : The paired (right and left) Lacrimal bones form small parts of the medial walls the orbits. of The lacrimal bones transmits the naso-lacrimal duct from the eye to the nose or nasal fossa. (iii) NASAL : The nasal bones (right and left) are long, thin pieces of bone that form the upper part of the bridge of the nose. The anterior lower part cartilage of the nasal septum is composed of (iv) INFERIOR CONCHAE: The inferior nasal conchae (right and left) are scroll like bones lying horizontally along the lateral walls of the nasal cavity. The bony elements of the middle and superior conchae are extensions of the lateral parts of the ethmoid bones. (v) PALATINE: The palatine bones (right and left) join in the midline to form the posterior part of the palate . hard Palatine bones also form part of the floor and lateral walls of the nasal cavity and part of the floor of the orbits. (vi) VOMER: The vomer forms the inferior part of the nasal septum, the vertical partition separating the right and left nasal cavities. (vii) MAXILLA: The right and left maxillary bones forms the upper jaw and palate of the mouth. The two halves are fused form the upper jaw. at the intermaxillary suture to (viii) MANDIBLE: The horse shoe- shaped bone forming the lower jaw, articulating with the skull at the temporomandi – -bular joint. Mandible is the largest, strongest face. and lowest bone in the External Surface of Cranial Base The external aspect of the cranial base or basicranium features……. The alveolar arch of the maxillae (supporting the maxillary teeth), The palatine processes of the maxillae, The palatine, Sphenoid, Vomer, Temporal Occipital bones. Skull: Structure and Function The hard palate (bony palate) is formed by the palatine processes of the maxillae anteriorly and the horizontal plates of the palatine bones posteriorly. Skull: Structure and Function Depressions in the squamous part of the temporal bone, called

OPTOMETRY · SEMESTER 1 Scalp Anatomy Human Anatomy and Physiology START READING NOTES Contents of This Topic OBJECTIVES INTRODUCTION SCALP LAYERS OF SCALP Scalp Anatomy MENINGES DURA MATER Venous blood from the brain drains into venous sinuses between the layers of dura mater ARACHNOID MATER PIA MATER HEAD AND NECK OBJECTIVES Introduction Describe the layers of scalp Identify the bones, joints, cavities and views of the skull Describe the structure (processes, spines, body, rami ) and functions of cervical vertebrae Describe functions and innervation of muscles of the scalp, facial expression, mastication and neck Describe parts band functions of the brain Describe cranial nerves Outline major blood supply and lymphatic drainage of the head and neck Describe surface anatomy of the head and neck INTRODUCTION The head and neck region of the body contains many important structures compressed into a relatively small area The head is formed mainly by the skull with the brain and its covering meninges enclosed in the cranial cavity. The special senses, the eye and the ear, lie within the skull bones or in the cavities bounded by them. The brain gives rise to 12 pairs of cranial nerves, which leave the brain and pass through foramina and fissures in the skull. All the cranial nerves are distributed to structures in the head and neck, except the 10th, which also supplies structures in the chest and abdomen SCALP The scalp consists of skin (normally hair bearing) and subcutaneous tissue that cover the neurocranium from the superior nuchal lines on the occipital bone to the supra-orbital margins of the frontal bone Laterally, the scalp extends over the temporal fascia to the zygomatic arches. LAYERS OF SCALP Skin: thin, except in the occipital region, containing many sweat and sebaceous glands and hair follicles. It has an abundant arterial supply and good venous and lymphatic drainage. Connective tissue: forms the thick, dense, richly vascularized subcutaneous layer that is well supplied with cutaneous nerves. Aponeurosis (epicranial aponeurosis): the broad, strong, tendinous sheet that covers the calvaria and serves as the attachment for muscle bellies converging from the forehead and occiput and from temporal bone on each side Scalp Anatomy Loose areolar tissue: a sponge-like layer including potential spaces that may distend with fluid as a result of injury or infection. This layer allows free movement of the scalp proper (the first three layers—skin, connective tissue, and epicranial aponeurosis) over the underlying calvaria. Pericranium: a dense layer of connective tissue that forms the external periosteum of the neurocranium. MENINGES The central nervous system consists of the brain and spinal cord. The brain and spinal cord are completely covered by three membranes, the meninges lying between the skull and the brain, and between vertebrae and the spinal cord. These are Dura mater Arachnoid mater Pia mater DURA MATER The cerebral dura mater consists of two layers of dense fibrous tissue. The outer layer takes the place of the periosteum on the inner surface of the skull bones, and the inner layer provides a protective covering for the brain. The dura mater forms several structures that separate the cranial cavity into compartments and protect the brain from displacement. These are The falx cerebri separates the hemispheres of the cerebrum The falx cerebelli separates the lobes of the cerebellum The tentorium cerebelli separates the cerebrum from the cerebellum Venous blood from the brain drains into venous sinuses between the layers of dura mater The superior sagittal sinus that runs across the top of the brain is formed by falx cerebri and the tentorium cerebelli forms the straight and transverse sinuses. The epidural space is a potential space that may exist between the dura mater and the skull. If there is hemorrhage in the brain, blood may collect here. The subdural space is a space existing between the dura mater and the middle layer of the meninges, the arachnoid mater ARACHNOID MATER The arachnoid or arachnoid mater is the middle layer of the meninges. In some areas, it projects into the sinuses formed by the dura mater. These projections are the arachnoid granulation or arachnoid villi. . They transfer cerebrospinal fluid from the ventricles back into the bloodstream. The subarachnoid space lies between the arachnoid and pia mater. It is filled with cerebrospinal fluid. All blood vessels entering the brain, as well as cranial nerves pass through this space. PIA MATER This is a fine connective tissue containing many minute blood vessels. It adheres to the brain, completely covering the convolutions and dipping into each fissure. It continues downward covering the spinal cord. Beyond the end of the cord it continues as the filum terminale, pierces the arachnoid tube and goes on, with the dura mater, to fuse with the Periosteum of the coccyx. ← PREVIOUS TOPICNEXT TOPIC →VIEW MODULE NOTESVIEW SEMESTER NOTESALL OPTOMETRY NOTES Need These Notes as PDF? Request a formatted copy for offline study, printing or revision. GET PDF NOTES ON WHATSAPP